Nothing New – Just Another Cold February

February 2015 Central Iowa Climate Review

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Stating the obvious here, but the month of February 2015 was a very cold month as the state of Iowa averaged 14.0°F which was a whopping 10.0°F below normal (See Figures 1 & 2). This resulted in the 10th coldest February out of 143 years of state climate records (See table to the right). The majority of the month, Iowa remained in northwest flow aloft which led to a very persistent cold pattern. In fact, there were only 5 days in which the statewide average temperature was above normal and that occurred from the 6th to the 10th (See Figure 3). The 5th was the first of several very cold air masses to settle into the region as low temperatures bottomed out in the double digits below zero with the coldest temperature of -25°F at Elkader. The coldest temperature of the month, as well as for the winter, was -30°F at Stanley on the 27th and Elkader on the 28th of February. 18 of the 28 days in February, there were stations that recorded temperatures of zero or below zero. In fact, Waterloo was below zero for a total of 105 hours and 7 minutes and only above freezing for 42 hours and 46 minutes during the entire month! Waterloo only had 4 days when the maximum temperature rose above 32°F and recorded 9 days when the average daily temperature was at least 20 degrees colder than normal. The last 3 days of the month, Waterloo was at least 30 degrees colder than its average daily temperature (See Figure 4). Waterloo shattered its record low temperature on the morning of the 27th as it plummeted to -24°F breaking the previous record of -14°F set back in 1897. Mason City also set a new record on the 27th with a low temperature of -18°F breaking the previous record of -12°F set in 1899. Mason City also only had 6 days of the month above normal. Des Moines was below normal for average daily temperatures from the 12th to the end of February and was 9.5°F below normal for the month.

Figure 1: Statewide average temperature for February 2015.
Figure 1: Statewide average temperature for February 2015.

Figure 2: Statewide average temperature departure from normal for February 2015.
Figure 2: Statewide average temperature departure from normal for February 2015.

Figure 3: Statewide average temperature departure from normal for February 6-10, 2015 shows the warmest period during the month.
Figure 3: Statewide average temperature departure from normal for February 6-10, 2015 shows the warmest period during the month.

Figure 4: Statewide average temperature departure from normal for February 2015 shows the coldest period of the month.
Figure 4: Statewide average temperature departure from normal for February 2015 shows the coldest period of the month.

Precipitation

The statewide average precipitation was 1.14 inches which was just barely above the normal 1.05 inches for February (See Figure 5). This is the 62nd wettest February among 143 years of records. Along with the bitter cold month, Iowans endured the 11th snowiest February on record (out of 128 years). The statewide average snowfall was 12.6 inches or 5.8 inches above normal (See Figure 6). However, if we compare February 2015 to other recent years, it still ranks behind 2008 (15.8 inches), 2014 (14.9 inches) and 2010 (14.4 inches). The snowiest February on record, in Iowa, is 1962 with a monthly statewide average of 22.2 inches.

There were two main events (no not wrestling) that brought the majority of the precipitation in February. The first snow event was during the Super Bowl Sunday on the 1st and was a continuation from the snow that began on the January 31. The statewide average snow for the entire event was 8.5 inches and much of the state was covered with 6 to 16 inches of new snow (See Figure 7). The NWS office in Johnston recorded 14.2 inches and the Des Moines Airport received 11.6 inches from the storm. This storm was the largest snow event, in the state of Iowa, since the week of December 23-27, 2009 (See Figure 8). A light snow event affected southern Iowa on the 4th where 3 to 6 inches accumulated along and south of Highway 34 to the Missouri border (See Figure 9). Otherwise, no widespread precipitation affected the state until the 25th when much of the state, except the southwest, received anywhere from 1 to 6 inches. The higher amounts were in north-central to northeast Iowa with Calmar coming in with the highest total of 7.9 inches (See Figure 10). One positive from the month of February was the deep snow pack for much of central to southern Iowa was depleted during the brief warm up between the 6th and 10th. Des Moines had 10 inches of snow depth on the 2nd but carried an inch or a trace from the 9th through the remainder of the month. Northern Iowa, the snow pack was depleted some during the aforementioned warmup but them was replenished with the snow storm on the 25th.

Figure 5: Statewide average precipitation percent of normal for February 2015.
Figure 5: Statewide average precipitation percent of normal for February 2015.

Figure 6: Statewide average snowfall percent of normal for February 2015.
Figure 6: Statewide average snowfall percent of normal for February 2015.

Figure 7: Total snowfall from January 31 to February 1, 2015 snow storm.
Figure 7: Total snowfall from January 31 to February 1, 2015 snow storm.

Figure 8: Total snowfall from December 23-27, 2009.
Figure 8: Total snowfall from December 23-27, 2009.

Figure 9: Total snowfall from February 4, 2015 snow storm across southern Iowa.
Figure 9: Total snowfall from February 4, 2015 snow storm across southern Iowa.

Figure 10: Total snowfall from February 25, 2015.
Figure 7: Total snowfall from February 25, 2015.

Much of the statewide statistics are courtesy of State Climatologist Harry Hillaker and you can find additional statewide information here: http://www.iowaagriculture.gov/climatology/weatherSummaries/2015/pms201502.pdf

Blog Post by Kenny Podrazik – NWS Des Moines

January 2015 Central Iowa Climate Summary

Temperatures

January 2015 was an interesting month with active winter storms and well below normal temperature during the first two weeks of the month, then spring-like conditions during the middle to late part of January before a big winter storm on the 31st. The statewide average temperature for Iowa was 21.3°F or 1.9°F above normal for January (See Figure 1). January 2015 becomes the 51st warmest January on record out of 143 years of records. The first three days of January were just above normal, before cold temperatures settled into the region on the 4th and lasted through the 14th. From the 15th through the end of the month, temperatures were above normal, making it 17 days in a row when the statewide average temperature was above normal.

A large Arctic high pressure dominated the weather pattern and brought the coldest stretch of the month from the 4th through the 8th (See Figure 2). In fact, the high pressure was so strong, that a new record all-time high pressure was set at Des Moines on the 7th with a barometer reading of 31.07” of Mercury. This broke the previous record of 31.06” set back on February 1, 1959 at that station. Low temperatures bottomed out well below zero and resulted in some very cold wind chill values during this time frame. The coldest mornings occurred on January 6 and 7, 2015 when 20 to 35 below zero wind chills were recorded (See Figure 3). Mason City and Clarion recorded -35°F wind chill values on the 7th.  Waterloo recorded low temperatures of -10°F or lower from the 5th to the 9th with the lowest temperature of -18°F on the morning of the 6th. In fact, Waterloo had 10 days in a row with minimum temperatures below 0°F from the 4th to the 13th (See Figure 4). Multiple other stations had similar temperature trends during the aforementioned time frame (See Figure 5).

The second half of the month was well above normal as there were several days with temperatures reaching the 50s and even 60s in a few spots. The warmest temperature of the month was 67°F on the 28th at Shenandoah, Iowa while the coldest temperature was -25°F at Cherokee on the 13th. Des Moines reached at least 50°F on 6 occasions from the 16th to the 28th, with the warmest temperature of the month on the 16th with a high of 57°F. Des Moines’ coldest temperature of the month was -8°F on the 7th. Waterloo’s highest temperature in January was 47°F on the 24th while the station’s coldest temperature was -18°F on the 6th. The warmest two days in January, on average, were the 16th and the 28th (See Figure 6).

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Figure 1: Average Temperature Departure from Mean for January 2015.

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Figure 2: Average Minimum Temperature, Departure from Mean from January 4 to 8, 2015.

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Figure 3: Wind chill values on the morning of January 7, 2015. Image is courtesy IEM.

Figure 4: Waterloo, Iowa temperature trend for January 2015 compared to normal. Notice the complete difference in cold temperatures in the first part of the month versus the warm temperatures in the last half of January.

Figure 4: Waterloo, Iowa temperature trend for January 2015 compared to normal. Notice the complete difference in cold temperatures in the first part of the month versus the warm temperatures in the last half of January.

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Figure 5: Average Temperature Departure from Mean from January 4 to 13, 2015.

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Figure 6: Average Maximum Temperature on January 28, 2015.

Precipitation

The statewide average precipitation totaled 0.56 inches or 0.36 inches below normal, which ranks 33rd driest January among 143 years of records. The statewide average snowfall was 6.3 inches which was 1.4 inches below normal. January 2015 became the 53rd lowest January snowfall total among 128 years of records. It was a fairly active first week of the year across Iowa with two separate blizzards and another light to moderate snow event sandwiched in between the two blizzards. The first storm of the year brought roughly a half inch to nearly 4 inches across central Iowa on the evening of the 3rd to the morning of the 4th, with the higher totals accumulating over northern Iowa. With the light snow and strong wind gusts in excess of 40 mph, visibility was reduced to less than a mile in several locations during the overnight hours from the 3rd to 4th (See Figure 7). A couple days later on the 5th, a clipper system brought a sharp band of snow that set up over northwest to southeast Iowa. Snowfall totals ranged from a trace in southwest Iowa to 4 to 7 inches from Fort Dodge to Ames to Newton (See Figure 8).  By Thursday, January 8, 2015, a very potent clipper brought blizzard conditions to central and northern Iowa as northwest winds gusted over 50 mph.  These strong winds, in conjunction with intermittent snow squalls and the fresh snow that fell on Monday earlier in the week resulted in significant visibility restrictions and even whiteout conditions (See Figure 9).  Travel was nearly impossible and the Iowa DOT even had to pull plows and shut down Interstate 35 Thursday evening (See Figure 10).

After the blizzard on the 8th, temperatures warmed up and allowed for the snow pack to melt during the middle of the month. By the end of the month, a long duration snow storm began on the 31st and finally tapered off on February 1, 2015 dropping a substantial amount snow over the state. Much of the precipitation started out as rain on Saturday the 31st and slowly transitioned to all snow by the evening. The statewide average snowfall from this storm, January 31st to February 1st, was 8.3 inches and was the largest snow average since December 23-27, 2009 snow storm. The totals from this year’s storm ranged from 5 to 15 inches over the state, with the heaviest band setting up along the Interstate 80 corridor from Stuart to Des Moines to as far east as the Quad Cities (See Figure 11).

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Figure 7: Visibility readings on the morning of Sunday January 4, 2015. Significant visibility restrictions resulted from the falling snow and strong winds.

Figure 9: Peak Wind Gusts on January 8, 2015.
Figure 9: Peak Wind Gusts on January 8, 2015.

Figure 10: The Iowa DOT Road Conditions on the evening of January 8, 2015 shows Interstate 35 closed north of Ames, Iowa.
Figure 10: The Iowa DOT Road Conditions on the evening of January 8, 2015 shows Interstate 35 closed north of Ames, Iowa.

Figure 8: Snowfall totals from the snow storm on January 5, 2015 across central Iowa.
Figure 8: Snowfall totals from the snow storm on January 5, 2015 across central Iowa.

Figure 11: Snowfall totals from the long duration snow storm on January 31 to February 1, 2015.
Figure 11: Snowfall totals from the long duration snow storm on January 31 to February 1, 2015.

Statewide statistics courtesy of State Climatologist Harry Hillaker:
http://www.iowaagriculture.gov/climatology/weatherSummaries/2015/pms201501.pdf

Blog Post by Kenny Podrazik – NWS Des Moines

December 2014 Central Iowa Climate Summary

Temperatures

The statewide average temperature was 28.2°F which was 5.3°F above normal. December 2014 becomes the 33rd warmest on record among 142 years of Iowa climate statistics (See Figure 1). The Des Moines CWA average temperature was 27.8°F. Des Moines International Airport averaged 32.5°F or 6.4°F above normal and Waterloo Airport averaged 28.6°F or 6.4°F above normal for monthly temperature average. The warmest stretch during December was from the 12th to the 15th with another well above normal stretch from the 20th through the 26th. Several days during the month, the minimum temperatures remained warmer than the average daily high temperature (See Figure 2). In fact, the week of Christmas, several nights of fog and stratus helped keep the overnight lows much warmer and resulted in minimum temperatures being well above normal (See Figure 3). Waterloo didn’t dip below 0°F until the 30th and 31st but typically during December, Waterloo records 5 days with sub-zero low temperatures. Wind chills dropped to 15 to 25 below zero over much of central Iowa Tuesday night the 30th. Des Moines only recorded 6 days in which the average daily temperature was below normal while Waterloo had 9 days below normal.

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Figure 1: Average Monthly Temperature Departure from Mean for the month of December 2014. The majority of the state was 3 to 4 degrees above normal.

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Figure 2: Average Minimum Temperature Departure from Mean from December 12 to 15, 2014.

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Figure 3: Average Minimum Temperature Departure from Mean from December 20 to 26, 2014.

Precipitation

The statewide average precipitation totaled 1.12 inches which was 0.22 inches below normal. December 2014 ranks as the 70th wettest out of 142 years of records for the state. With temperatures remaining above normal for much of the month, the precipitation generally fell as rain during December with a couple events where rain transitioned to snow. The average snowfall for the state was a mere 1.5 inches for December which is 7.8 inches below normal. This is the 12th lowest December with respect to snowfall among 128 years.

Light to moderate rain covered the state during the stretch from the 14th to the 16th with some light snow that developed over northwest Iowa on the 16th. Another event that began as rain changed to snow by Christmas Eve and dropped a trace to near 4 inches over portions of central to northwest Iowa resulting in a White Christmas for some folks across the state (See Figure 4). Des Moines recorded only 1.9 inches for the month of December which was 7.1 inches below normal. Waterloo only had 0.5 inches of snowfall resulting in 9.4 inches below normal.

Figure 4: Snowfall totals from the December 23-24, 2014 snow event across central to northern Iowa.

Figure 4: Snowfall totals from the December 23-24, 2014 snow event across central to northern Iowa.

Blog Post by Kenny Podrazik – NWS Des Moines

A Cold November 2014

November 2014 Central Iowa Climate Summary

Temperatures
Figure 1: November 2014 Average temperature departure from mean shows that the entire state was well below normal.  Image is courtesy MRCC.

Figure 1: The November 2014 average temperature departure from mean shows the entire state was well below normal during the month. Image is courtesy of MRCC. DMX CWA outlined in white.

November 2014 was a very cold month as the average temperature for the state was 29.1°F or 7.5°F below normal (See Figure 1). November 2014 became the 4th coldest November on record for the state. The average temperature for the Des Moines County Warning Area was fairly similar at 29.2°F. The Des Moines International Airport ended up having a monthly average temperature of 33.6°F which was 5.6°F below normal and became the 15th overall coldest November on record since 1878. Waterloo on the other hand, had an average temperature of 28.4°F for November resulting in the 6th coldest November on record at that station. Records began in Waterloo in 1895. Mason City had its 3rd coldest November ever since records began in 1890 as the average temperature was 25.6°F or 8.0°F below normal. Mason City only had 9 days when the average temperature was above normal and only 2 days when the departure from normal was 10°F or more above normal. Waterloo and Des Moines had similar temperature trends in November (See Figures 2 and 3). For instance, Waterloo recorded 20 days with below normal temperatures, 14 averaged double digits below normal. Des Moines had 13 days in which the average daily temperature was at least 10°F below normal and 9 days with 15°F or more below normal.

Figure 2: November 2014 temperature trend for Des Moines. Image is courtesy of ACIS.

Figure 2: November 2014 temperature trend for Des Moines. Image is courtesy of ACIS.

Figure 3: November 2014 temperature trend for Waterloo. Image is courtesy of ACIS.

Figure 3: November 2014 temperature trend for Waterloo. Image is courtesy of ACIS.

The coldest stretch in November was from the 11th to the 21st when average temperatures ranged 15 to 25 below normal for much of central Iowa (See Figure 4). During this stretch, Des Moines and Mason City set new records for consecutive days with a maximum temperature below freezing (32°F) during the month of the November (See Figures 5-7). Mason City also recorded back-to-back record low temperatures on the 20th and 21st and several other central Iowa locations set new temperature records as well in November (See Table 1). A few locations over northern Iowa dipped below zero on the 16th, 20th and 21st but the coldest day of the month didn’t occur until the 27th or Thanksgiving (See Figure 8). A brief warmup occurred on the 22nd and 23rd before the cold snap occurred on Thanksgiving.

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Figure 4: Average temperature departure from mean from November 11 to November 21, 2014. Image is courtesy MRCC.

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Figure 5: Des Moines set a new record of consecutive days in November when the Maximum temperature remained less than 32°F.

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Figure 6: Mason City set a new record of consecutive days in November when the Maximum temperature remained less than 32°F.

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Figure 7: The normal maximum temperature for November 11 to November 21. The period of average is from 1981 to 2010. Image is courtesy MRCC.

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Figure 8: Average [actual] minimum temperature across central Iowa on Thanksgiving November 27, 2014. Image is courtesy MRCC.

Table 1: New Temperature Records set during November at Mason City, Waterloo, Ottumwa, and Lamoni.

Table 1: New Temperature Records set during November at Mason City, Waterloo, Ottumwa, and Lamoni.

Precipitation

With the bitter cold temperatures during the month of November, the bulk of the precipitation fell as snow. The monthly average precipitation for the Des Moines CWA was 0.49 inches while the statewide average was a little higher at 0.80 inches but was still 1.25 inches below normal. There were a couple light rain events during the first week of November, but any precipitation amounts remained under 0.10 inches.  Otherwise, central Iowa remained dry or well below normal for liquid precipitation.  On the flipside, snowfall was above normal for the month at many locations as there were several light snow events during the last two-thirds of the month. Des Moines reported at least a trace of snow on 14 days and had measurable snow on 4 of those days in November.  Some light freezing rain and freezing drizzle occurred briefly on the 21st over portions east of Interstate 35. The highest and most widespread snow amounts fell on the 15th and 26th (See Figures 9 and 10). In fact, Des Moines set a new daily snowfall record on the 15th with 2.0” breaking the previous record of 1.5” set in 2005. A few locations over northern Iowa received over 6 inches on the 26th and the snow caused some travel issues before the Thanksgiving holiday (See Figures 11 and 12). However, with the brief warm up after Thanksgiving, much of the snow pack melted.

 

Figure 9: Snowfall amounts for November 15 into the early morning on the 16th. Image is courtesy of Iowa Environmental Mesonet.

Figure 10: Snowfall amounts from the morning of November 26, 2014.

Figure 11: Iowa DOT road conditions Snowfall as of 7 am CST on the morning of November 26, 2014. Image is courtesy of Iowa Environmental Mesonet.

Figure 12: Winterset KCCI Webcam at 7 am CST on November 26, 2014.

Blog post by Kenny Podrazik – NWS Des Moines

October 2014 Central Iowa Climate Summary

General Summary

The first half of October was very active with several precipitation events occurring through the 15th which coincided with below normal for temperatures. In contrast, the latter half of the month remained relatively dry and above normal for temperatures (See Figures 1 to 4).

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Figure 1: Accumulated precipitation percent of normal from October 1 to 15, 2014. The southern to eastern portions of the state were well above normal for precipitation during this period. Image courtesy MRCC.

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Figure 2: Accumulated precipitation percent of normal from October 16 to 31, 2014 when the majority of the state remain below normal for precipitation. Image courtesy MRCC.

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Figure 3: Average temperature during the first two weeks of October 2014 were below normal across the entire state of Iowa. Image courtesy MRCC.

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Figure 4: The average temperature across Iowa the last two weeks of October 2014 resulted in being above normal. Image courtesy MRCC.

Temperatures
Figure 5: October 3-5, 2014 average temperature departure from normal.

Figure 5: October 3-5, 2014 average temperature departure from normal.

The average temperature for the state of Iowa was 51.2°F or 0.4°F above normal, while the average temperature for the DMX CWA was 52.3°F for the month of October 2014. October 2014 ranks as the 64th coolest out of 142 Octobers. The majority of the first two weeks remained near or below normal for temperatures. The coldest stretch was from the 3rd to the 5th, with another cold snap from the 9th to the 12th (See Figures 5 & 6). Several places were 10 to 11 degrees below their daily average temperature on the 3rd and 4th with a few areas even receiving a little frost and freezing temperatures on the morning of the 4th.

Figure 6: October 9-12, 2014 average temperature departure from normal.

Figure 6: October 9-12, 2014 average temperature departure from normal.

However, the most widespread hard freeze occurred on the 11th as several locations across northern Iowa dropped into the 20s for low temperatures. The reason the 3rd to 5th stretch was a little cooler than normal, compared to the 9th to the 12th, was the high temperatures during the middle of the month were warmer overall, resulting in a warmer average daily temperature. Halloween resulted in being the coldest day of the month as temperatures fell into the upper teens and lower 20s the final hours of October. The coldest temperature of the month came on the 31st when Spencer dropped to 17°F.

Precipitation

Several cloudy and rainy days affected the first couple of weeks of October. The statewide average precipitation was 3.22 inches resulting in being 0.61 inches above normal. Waterloo reported a trace of snow on October 4th which was the first time snow had occurred at that location on that date since keeping records back to 1895. Otherwise, the bulk of the precipitation accumulated in the southeastern half of the state and much of that occurred on the 14th. A widespread swath of 1 to 2 inches with a few locally higher amounts to over 3 inches accumulated over southern to eastern portions of Iowa on October 14th (See Figure 7). Newton received 2.25” and Knoxville received 3.20” on the 14th. In fact, a new daily precipitation record of 1.78” occurred at Ottumwa on the 14th. This broke the previous record of 1.47” set in 2012. The active weather pattern dried out the last couple of weeks with only a couple days were measurable precipitation occurred. All the precipitation caused a significant increase in flow along major and minor river basins in central Iowa resulting in well above normal flow for October (See Figure 8). It also contributed to a foggy weather pattern late in the month, when a few mornings dense fog developed and caused some significant visibility. The most widespread fog occurred on the 24th of October (See Figure 9).

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Figure 7: Accumulated precipitation on October 14, 2014.

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Figure 8: Many of the river levels across central Iowa during October 2014 were well above their normal flow. Image is courtesy of USGS.

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Figure 9: Visibility across Iowa on the morning of October 24, 2014. Image is courtesy of IEM.

 

 

You can find a more detailed statewide summary by State Climatologist Harry Hillaker: http://www.iowaagriculture.gov/climatology/weatherSummaries/2014/pms201410.pdf
Blog post by Kenny Podrazik – NWS Des Moines

September 2014 Monthly Climate Summary

Temperatures

September 2014 was slightly below normal as the statewide average temperature was 62.0°F resulting in 1.2°F below normal. For the state, it becomes the 43rd coolest Septembers since 1872 when statewide records began.  The Des Moines CWA average temperature was also 62.0°F.  The hottest temperature was 93°F that occurred at Des Moines and Newton on the 4th.  The coldest temperature during September in the Des Moines CWA was 31°F in Webster City, Mason City and Estherville on the morning of the 13th. This was during the coldest stretch in September which was from the 11th to the 16th (See Figure 2) while the coldest day, with respect to average daily temperature, was on the 12th  when much of central Iowa was 15 to 18 degrees below normal (See Figure 3).  In fact, Lamoni, Mason City and Ottumwa all set new record low temperatures on the morning of the 13th (See Table 1). Also, a few areas of frost developed during the aforementioned cold stretch, mainly occurring across northern Iowa (See Figure 4).

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Figure 1: Average temperatures during September 2014. Image Courtesy MRCC.

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Figure 2: Average maximum temperature departure from mean during the stretch from September 11 to 16, 2014. Image Courtesy MRCC.

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Figure 3: Average temperature departure from mean on September 12, 2014. Image Courtesy MRCC.

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Figure 4: Areas across the U.S. that recorded 32°F or less as of September 18, 2014. A few spots across northern Iowa where in this category by mid-September.

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Precipitation

The first couple of weeks in September were cool and wet as several days across the state recorded measurable precipitation in the first half of the month. In fact, the statewide average precipitation for Iowa was 4.37 inches or 0.99 inches above normal and the average precipitation for the Des Moines CWA was 4.07 inches during the month of September (See Figure 5). The highest monthly total, within the DMX CWA, was 7.41 inches in Indianola while the highest in the state was 8.63 inches near Norwalk. The greatest rainfall event came on the 9th where a widespread band of 1 to 4 inches affected central to southern Iowa (See Figure 6). Des Moines, Lamoni, and Ottumwa recorded 3.00”, 3.62”, and 2.20” respectively. Both Des Moines and Ottumwa set new daily rainfall records on the 9th.  The previous record at Des Moines was 1.92” set in 1970 and was the 7th highest one-day rainfall total during the month of September (See Table 2). The previous record at Ottumwa was 2.00” set in 1921. Northern Iowa was closer to normal or even slightly below normal for monthly precipitation at some locations. Estherville, Mason City and Waterloo were all below normal during September.

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Figure 5: Accumulated precipitation departure from mean during the month of September 2014. Image Courtesy MRCC.

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Figure 6: Accumulated precipitation departure from mean during the month of September 2014. Image Courtesy MRCC.

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Blog post by Kenny Podrazik – NWS Des Moines

August 2014 Central Iowa Monthly Climate Summary

Temperature

The statewide average temperature during the month of August was 71.5°F which was normal but still becomes the 60th coolest August among 142 years of records. It was an interesting temperature trend in August as the first half of the month was well below normal, while the last half was above normal (See Figures 1 and 2). Hence, both halves balanced each other out resulting in near normal temperatures for August across central Iowa. In the DMX CWA, the coldest temperature was 47°F at Chariton on the 13th and the hottest temperature was 94°F at Lamoni on the 25th. The hottest period was on the 24th and 25th when much of central Iowa reached the lower 90s for high temperatures (See Figure 3). In fact, Mason City finally reached a maximum temperature of 91°F on the 24th, breaking the consecutive streak of days without reaching 90°F. The number of days was 348 which began on September 10, 2013 and was the 5th longest stretch of its kind at Mason City. Des Moines only reached 90°F 3 times in August but normally has about 7 days that reach 90°F. Typically Waterloo reaches 90°F or greater 6 days during August, but only 3 days topped that mark. One of the colder stretches during the month was on the 12th and 13th when several low temperatures dipped into the 40s and 50s resulting in several degrees below normal (See Figure 4).

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Figure 1: Average Temperature Departure from Mean from August 1 to August 16, 2014. Temperatures were roughly 2 to 4 degrees below normal for central Iowa. The DMX CWA is outlined in white.

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Figure 2: Average Temperature Departure from Mean from August 17to August 31, 2014. Temperatures were roughly 2 to 4 degrees above normal for central Iowa. The DMX CWA is outlined in white.

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Figure 3: Maximum temperatures on August 24-25, 2014 were well into the 80s and into the lower 90s across central Iowa.

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Figure 4: Minimum temperatures on August 12-13, 2014 were 6-9 degrees below normal across central Iowa. The DMX CWA is outlined in white.

Precipitation

The statewide average precipitation was 6.02 inches resulting in being 1.82 inches above normal. As a result, August 2014 becomes the 14th wettest (out of 142) August on record. Several heavy rain events and a couple severe weather events affected central Iowa in August. The most significant heavy rain fell on August the 15th to 16th, 22nd, 23rd, 28th, and on the 31st over portions of western and southern Iowa (See Figures 5 & 6). The 31st was the most widespread severe weather event when a line of thunderstorms produced severe wind damage and a pair of tornadoes. The latter half of the month became the most active with thunderstorms occurring (somewhere over central Iowa) each evening or overnight hours. In fact, the last 12 days of the month, Des Moines recorded measurable precipitation on 10 days and 11 days with at least a trace. The highest amount occurred on the 28th with a whopping total of 3.38 inches at the Des Moines International Airport.  This set a new daily precipitation record as it shattered the 1.74 inches previously set on August 28, 1960. Des Moines came in third all-time highest August precipitation at that location (See Figure 7). Denison (Crawford County) and Greenfield (Adair County) both set new August monthly records (See Table 1).  In fact, much of central Iowa was well above normal for the month of August (See Figures 8 and 9).

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Figure 5: Q3 precipitation estimated for August 22, 2014.

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Figure 6: Q3 precipitation estimated for August 23, 2014 shows much of south central Iowa received another round of significant heavy rain.

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Figure 8: Observed precipitation for the month of August 2014 across central IA.

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Figure 9: August 2014 monthly departure from mean precipitation.

Figure 7: The Des Moines, Iowa accumulated precipitation for the month of August 2014. August came in 3rd highest August since 1878. 1993 and 1977 were the only higher Augusts at Des Moines.

Figure 7: The Des Moines, Iowa accumulated precipitation for the month of August 2014. August came in 3rd highest August since 1878. Only 1993 and 1977 had higher precipitation totals in August at Des Moines.

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Reservoir Summary

August reservoir summary for Lake Red Rock and Saylorville Lake.

August reservoir summary for Lake Red Rock and Saylorville Lake.

August summary of outflow from Lake Red Rock and Saylorville Lake

August summary of outflow from Lake Red Rock and Saylorville Lake

Blog post by Kenny Podrazik – NWS Des Moines

July 2014 Central Iowa Monthly Climate Summary

Temperatures

Figure 1: Average Temperature for the month of July 2014 was 69.0°F for the entire state, while the DMX CWA was 68.8°F

Figure 1: Average Temperature for the month of July 2014 was 69.0°F for the entire state, while the DMX CWA was 68.8°F. The DMX CWA is outlined in white.

For the state of Iowa, the average temperature was 69.0°F which was 4.6°F below normal for the month of July (See Figure 1).  July 2014 is now the 5th coolest July on record for the state among the 142 years of records.* The average temperature for the Des Moines County Warning Area (CWA) was 68.8°F with the coldest spots located over the west-central and far southeast portions of the CWA (See Figure 2).

Figure 2: Average Temperature Departure from Mean for the month of July 2014 was 4°F to 5°F below normal for the month.

Figure 2: Average Temperature Departure from Mean for the month of July 2014 was 4°F to 5°F below normal for the month. The DMX CWA is outlined in white.

There were a few individual days that rose above normal, but no extended heat wave occurred during the month.  The hottest days of the month were on the 12th, 21st, 22nd, and 25th when several locations rose into the lower 90s (See Figure 3).  The hottest temperature of the month, within the Des Moines CWA, was 95°F at Osceola on the 22nd. The highest temperature throughout the entire state was 102°F on the 25th at Sidney in far southwest Iowa. Des Moines reached at least 90°F only 3 times during the month and normally averages 10 days with 90°F or greater during the month of July.  In similar fashion, Waterloo only had 1 day that topped 90°F but normally averages around 8 days with maximum temperatures reaching 90°F or higher in July.  Mason City continued its streak of not reaching 90°F in July as the highest temperature at the station was 89°F.  By the end of the month, this streak extended to 325 days since the last time the station reached 90°F on September 9, 2013.

Figure 3: Average Maximum Temperatures for July 21-22, 2014. These were a couple of the hottest days of the month across central Iowa.

Figure 3: Average Maximum Temperatures for July 21-22, 2014. These were a couple of the hottest days of the month across central Iowa.

On the flip side, there were many more colder than normal days in July.  Table 1 illustrates how often central Iowa was below normal during the month. Ottumwa set a couple of new daily temperature records. The first was a daily low maximum temperature of 65°F on the 2nd which broke the previous record of 67°F set back in 1944. The second record was a record low of 49°F set on the 16th breaking the previous record of 51°F in 1930.  Lamoni also set a new record low temperature of 52°F on the 16th, breaking the previous record of 55°F set in 1961. Another record low maximum of 66°F was set at Waterloo on the 2nd breaking the old record of 67°F from 1941.

Table 1: Automated Surface Observation Stations (ASOS) across central Iowa were well below normal for a good portion of the month of July 2014.

 

Precipitation

Figure 4: the accumulated precipitation percent of mean for the month of July 2014. Much of the state was well below normal, except for the southeast.

Figure 4: the accumulated precipitation percent of mean for the month of July 2014. Much of the state was well below normal, except for the southeast. DMX CWA outlined in white.

Little precipitation fell during the month of July 2014 across central Iowa and there was only one major severe weather event and that occurred on July 6. Other than southeast Iowa, the remainder of the state was well below normal for precipitation (See Figure 4). The majority of the precipitation only fell on a handful of days which includes the 5th, 6th, 12th and the 25th. The Des Moines International Airport recorded 1.99” on the 5th, while several other locations recorded at least an inch of rain on the same day (See Figure 5).  The highest precipitation total during the month, for the state and DMX CWA, was in Montezuma in Poweshiek County with a monthly total of 10.21 inches. The lowest monthly total for the state also occurred in the DMX CWA and that was 0.71 inches at Atlantic in Cass County.

A total of 9 tornadoes occurred on July 6, 2014, 8 dropped down in the DMX CWA. There were two tornadoes rated EF1 and they occurred near the towns of Reinbeck and Dinsdale. The rest were EF0 tornadoes and you can find more information about the event as well as all the tornadoes from 2014 our Tornado Page.

Figure 5: Q3 radar estimated precipitation for July 5, 2014.

Figure 5: Q3 radar estimated precipitation for July 5, 2014. http://nmq.ou.edu/

Reservoir Information

Figure 6: Saylorville Lake Reservoir pool height trend graph during the month of July 2014.

Figure 6: Saylorville Lake Reservoir pool height trend graph during the month of July 2014.

The Saylorville Reservoir pool height rose a about 7 feet during the first week of July to 877.57 feet on the 6th before gradually falling throughout the rest of the month to 851.50 feet on the 31st (See Figure 6). The maximum pool height corresponded to a maximum storage of 446,670 Acre-feet on the 6th while the lowest storage of the month was 171,070 Acre-feet on the 31st. The Des Moines River downstream of Saylorville Lake maximum stage height was 14.29 feet on the 7th and the lowest was 8.45 feet on the 31st. The maximum outflow at the same location was 19,500 CFS on the 2nd to a minimum of 5,600 CFS on the 31st.

Figure 7: The Lake Red Rock Reservoir pool height trend graph during the month of July 2014.

Figure 7: The Lake Red Rock Reservoir pool height trend graph during the month of July 2014.

Lake Red Rock Reservoir pool height rose from 755 feet on the 1st to 766 feet during the middle of the month before dropping back to around 757 feet by the 31st (See Figure 7).  The pool storage nearly reached 1,000,000 Acre-feet when it maxed out at 910,820 Acre-feet on the 11th.  The lowest storage was 483,840 Acre-feet on the 1st. The stage height of the Des Moines River downstream of Lake Red Rock Reservoir ranged from 90.37 feet on the 2nd to 93.69 feet on the 13th.  It remained above 93 feet from the 1th to the 28th and it was only below 91 feet the first two days of the month.  The outflow from Lake Red Rock increased from 13000 CFS on the 1st to around 22,000 CFS by the 12th where it remained steady until the 29th when it dipped down to 18,400 CFS.

*Statewide averages courtesy of State Climatologist Harry Hillaker: http://www.iowaagriculture.gov/climatology/weatherSummaries/2014/pms201407.pdf

 Blog post by Kenny Podrazik – NWS  Des Moines

June 2014 Central Iowa Monthly Climate Summary

Temperature Overview

The statewide monthly average temperature for Iowa in June 2014 was 70.3°F which was 0.6°F above normal. June 2014 ranks 55th warmest June among 141 years of records in the state of Iowa. The average temperature within the NWS Des Moines County Warning Area (DMX CWA) was 70.0°F for June 2014 and the average maximum temperature was 79.8°F and the average minimum temperature was 60.1°F. The DMX CWA is outlined in white in Figures 1-4.  Roughly 3 out the 4 weeks in June remained above normal with a cold stretch occurring from June 7 to 13 (See Figure 1).

The coldest temperature across the DMX CWA was 39°F in Emmetsburg on June 9th while the lowest in the state was 38°F at Battle Creek on the 13th. However, much of the departure from normal only ranged about 1 to 5 degrees above normal during the month. In fact, only one day topped 10 degrees above normal, within the DMX CWA, and that occurred on the 1st (See Figure 2). Since no long duration heat wave developed during June, the majority of stations only reach 90°F a couple of times. Des Moines reached exactly 90°F on the 16th, 18th, and 20th while Waterloo’s hottest temperature was only 88°F on the 1st. Typically, Des Moines averages 4.5 days and Waterloo averages 4.1 days with 90°F or greater maximum temperatures during the month of June. The two stations combined for 4. Other ASOS (Automated Surface Observing System) stations such as Lamoni, Ottumwa, Marshalltown, and Mason City never topped 90°F during the month. By the end of the month, Mason City still had not reached 90°F since September 9, 2013 and this streak continued into July.

June7-13-AVG TempDFM

Figure 1: Average Temperature Departure from Mean from June 7 to June 13, 2014. The map shows much of the state well below normal.

June1-AVG TempDFM

Figure 2: Average Temperature Departure from Mean on June 1, 2014.

Precipitation Overview

The statewide monthly average precipitation for June 2014 was 9.94 inches which was a whopping 4.92 inches above normal (See Figures 3 and 4).  June 2014 became the 3rd wettest June among 141 years of records and the 4th overall wettest month for Iowa (See Table 1).

June 2014 Monthly (Top 4) Precipitation Records for the entire state of Iowa. 2014 comes in at number 4th overall.

Table 1: The Top 4 Monthly Precipitation Records for the entire state of Iowa. June 2014 comes in at number 4th overall for all months.

Daily precipitation records were set at Mason City, Lamoni, and Waterloo during the month (See Table 2). Waterloo, Iowa had its 3rd highest June precipitation with a total of 9.63” for the month, which was just ahead of the 8.79” total in 2008 (See Figure 5).  Most sites across central Iowa reported precipitation for at least two weeks (not consecutively) out of the month of June. For instance, Ottumwa recorded at least a trace of precipitation 19 out of the 30 days in June and 6 days had at least a half inch or more. Des Moines, Waterloo, Lamoni, Estherville, and Marshalltown all had 4 days with 1” or more of precipitation. Ames came in with 5 days with daily totals of 1” or more. All this precipitation led to significant flooding and flash flooding across the DMX CWA during June 2014. The upper Des Moines River and the Cedar River were affected the most as 13 river stations topped flood stage.

A very active severe weather pattern occurred in Iowa during June 2014 with June 3, June 16, and June 30 receiving the most significant and widespread severe weather. On June 16, 9 tornadoes occurred within the DMX CWA, while altogether there were 12 tornadoes in the state. June 29-30, separate systems, but the two-day total for tornadoes was 13 for the state, in which 11 occurred in the DMX CWA. For the entire month, there were 31 tornadoes across the state of Iowa resulting in a total path length of over 107 miles long. The highest rating was EF2 for two tornadoes. The first one occurred on June 3 in Pottawattamie County southeast of Bentley and the second dropped across Tama County northwest of Traer. For more detailed Iowa tornado information, visit our tornado page: http://www.crh.noaa.gov/dmx/?n=iators2014

Tornadoes were not the only severe weather hazards that affected Iowa in June as the aforementioned dates, along with a few other events, produced significant damage from very large hail and damaging winds. On June 3, southwest Iowa was hardest hit with wind-driven hail as it produced significant damage to crops and buildings, where siding was completely shredded off several homes (See Figure 6). June 30 produced similar wind-driven hail that caused major damage across portions of central Iowa and more detailed information the event can be found here: http://www.crh.noaa.gov/dmx/?n=june30event

DailyPrecipRecords-June2014

Figure 3: Statewide Accumulated Precipitation: Percent of Mean for the month of June 2014

Figure 3: Statewide Accumulated Precipitation: Percent of Mean for the month of June 2014

Figure 4: Accumulated precipitation for June 2014.

Figure 4: Accumulated precipitation for June 2014.

Figure 3: Waterloo Accumulated Precipitation for June 2014 as well as June 1947, 1993, and 2008.

Figure 5: Waterloo Accumulated Precipitation for June 2014 as well as June 1947, 1993, and 2008.

Figure 4: Significant wind-driven hail event occurred on June 3, 2014. This image from a resident in Treynor, IA had major damage to the siding and roof.

Figure 6: Significant wind-driven hail event occurred on June 3, 2014. This image from a resident in Treynor, IA had major damage to the siding and roof. Image courtesy of KWWL.

Reservoir Information

The Saylorville Reservoir pool height began at 837.84 feet on the 1st and rose over 30 feet to a height of 868.23 feet by the 30th (See Figure 7). The normal pool height is 836 feet. The pool storage monthly maximum was 333,960 Acre-feet on the 30th while the minimum pool storage was 67,068 Acre-feet on the 13th. The Des Moines River downstream of Saylorville Lake fluctuated throughout the month before cresting at 15.25 feet on the 27th with a flow of 19,500 cubic feet per second or CFS (See Figure 8).

Lake Red Rock Reservoir pool height increased from 743.77 feet on the 1st to 752.30 feet by the 30th. The pool storage doubled in volume within two weeks as it rose from a minimum of 189,420 Acre-feet on the 15th to a monthly maximum of 404,370 Acre-feet on the 30th (See Figure 9). The stage height of the Des Moines River downstream of Lake Red Rock Reservoir increased from a low of 86.73 feet on the 1st to a maximum height of 92.50 feet on the 29th.  The outflow maxed out at 19,000 CFS on the 28th and 29th while the lowest flow was 3,950 CFS on the 16th.

June2014SaylorvillePoolHeight

Figure 7: Stage height trend graph for Saylorville Lake in June 2014.

DSMRiver-Downstream-June-CFS

Figure 8: Output, measured in cubic feet per second, along the Des Moines River downstream of Saylorville Lake Reservoir.

RedRock Pool Storage-June 2014

Figure 9: The storage trend for June 2014 at Lake Red Rock Reservoir.

References:

http://mrcc.isws.illinois.edu/
http://xmacis.rcc-acis.org/
http://www.iowaagriculture.gov/climatology/historicWeatherReports.asp
http://rivergages.mvr.usace.army.mil/WaterControl/new/layout.cfm
http://mesonet.agron.iastate.edu/

Blog post by Kenny Podrazik – NWS Des Moines

May 2014 Central Iowa Temperature and Precipitation Overview

This temperatures and precipitation summary covers the NWS Des Moines County Warning Area (CWA) during the month of May 2014.  The statewide climate statistics mentioned in this blog are courtesy of State Climatologist Harry J. Hillaker.  You can find a more detailed statewide monthly climate summary here: May 2014 Iowa Statewide Climate Summary

Temperature Overview

The statewide average temperature for Iowa was 61.0°F during the month of May 2014 which was normal (See Figure 1). This month ranks as the 66th warmest May on record among 142 years of records.  A roller coaster ride of temperatures affected the first half of the month before temperatures began to level out some after the 20th (See Figures 2 and 3).  For the state, temperatures remained cooler than normal the first 5 days of May where several areas in north-central Iowa dipped into the 30s for low temperatures on the mornings of May 2nd and 3rd. Another cold spell occurred on the 16th and 17th when several locations in central Iowa had light frost or even a brief freeze each morning. The coldest temperature in the Des Moines CWA was 29°F at Mount Ayr and Atlantic on the 16th and at Guthrie Center, Audubon, and Atlantic on the 17th.  However, the coldest temperature in Iowa occurred on the 16th at Spencer with a low of 24°F.  There was a brief warmup on the 7th of May across the CWA when most maximum temperatures reached the upper 80s to the lower 90s. Atlantic recorded the hottest temperature in the Des Moines CWA on May 7th with a high of 94°F. Des Moines and Lamoni reached 90°F for the first time in 2014. Temperatures cooled down considerably during the middle of the month with the coldest stretch occurring from May 13th to May 18th. The average temperatures and average minimum temperatures across the CWA ranged from 10°F to 13°F below normal (See Figures 4 and 5). Several places even dropped below the freezing mark or well into the 30s on the mornings of the 16th and 17th (See Figures 6 and 7). The last third of the month, temperatures rebounded with a long stretch of highs near or slightly above normal (See Figure 8).

Precipitation Review

Although it was an active month for severe weather and rainfall across central Iowa, the statewide average precipitation still was 1.40 inches below normal. The statewide average for the month of the May was 3.16 inches (See Figure 9) and puts May 2014 42nd driest May among 142 years of records. However, there was enough widespread rain across the state to help mitigate the drought conditions, particularly over the south and west (See Figures 10a and 10b). The most significant event during the month of May occurred on the evening of the 11th into the overnight hours on May 12.  Several locations reported over 2 inches of rain (See Figure 11).  Eight tornadoes dropped down on May 11, mainly during the late evening hours over central Iowa just west of the Des Moines Metro. EF2 damage occurred over Lake Panorama in Guthrie County around 10 p.m. CDT May 11 while several locations were affected by damaging winds. A handful over additional severe weather events transpired in May, but were isolated large hail and damaging wind events and not as widespread severe as May 11th.  On May 20th, heavy rain and large hail affected Ames, Iowa where several locations in town had significant flooding issues from 2 to 3 inches in a short time frame (See Figure 12). In fact, the Ames ASOS recorded 3.01 inches for the day which helped push the station to being above normal for the month (See Table 1). However, even though most other stations across central Iowa were above normal for precipitation by the middle of the month, the dry period during latter half led to many stations ending up with below normal precipitation for May 2014 (See Figure 13).

Reservoir Information

The Saylorville Reservoir pool height rose from 836.73 feet on the 1st to 838.10 feet by the 31st. Normal pool height is 836 feet, so the pool height barely rose 2 feet above normal during May 2014. The pool storage monthly maximum was 81,156 Acre-feet on the 16th while the minimum pool storage was 67,416 Acre-feet. The Des Moines River downstream of Saylorville Lake maximum stage height was 7.78 feet on the 17th and the lowest was 3.95 feet on the 9th. The flow at the Des Moines River downstream of Saylorville Lake increased from 1820 CFS on the 1st to 5640 CFS on the 17th before dropping back down to 1410 CFS by the 31st.

 Lake Red Rock Reservoir pool height showed very little changed during the month of May as it ranged around the normal pool height of 742 feet. The pool storage ranged from a minimum of 189,730 Acre-feet on the 2nd to a maximum of 214,750 Acre-feet on the 30th. The stage height of the Des Moines River downstream of Lake Red Rock Reservoir fluctuated from a low of 86.39 feet on the 3rd to a maximum height of 90.98 feet on the 16th.  Similarly, there was a low outflow of 1920 CFS on the 11th to a high outflow of 14,500 CFS on the 16th.

Figure 1: Statewide average temperature departure from normal during May 2014. Image is courtesy of MRCC.

Figure 1: Statewide average temperature departure from normal during May 2014. Image is courtesy of MRCC.

Figure 2: Daily Temperature Trend for Des Moines International Airport for the month of May 2014. The temperature trend during the first half of the month shows sharp contrasts before leveling out by the end of the month.

Figure 2: Daily Temperature Trend for Des Moines International Airport for the month of May 2014. The temperature trend during the first half of the month shows sharp contrasts before leveling out by the end of the month.

Figure 3: Daily Temperature Trend at Waterloo, Iowa during the month of May 2014. The temperature trend during the first half of the month shows sharp contrasts before leveling out by the end of the month.

Figure 3: Daily Temperature Trend at Waterloo, Iowa during the month of May 2014. The temperature trend during the first half of the month shows sharp contrasts before leveling out by the end of the month.

Figure 4: The Average Temperature Departure from Mean from May 13 to May 18, 2014. Much of the DMX CWA (white line) was 10 degrees or more below normal.

Figure 4: The Average Temperature Departure from Mean from May 13 to May 18, 2014. Much of the DMX CWA (white line) was 10 degrees or more below normal.

Figure 5: The Average Minimum Temperature departure from Mean from May 13 to May 18, 2014.

Figure 5: The Average Minimum Temperature departure from Mean from May 13 to May 18, 2014.

Figure 6: Surface temperatures at 7 a.m. CDT on the morning of May 16, 2014 where it shows much of central to western Iowa in the 30s. Image Courtesy of IEM.

Figure 6: Surface temperatures at 7 a.m. CDT on the morning of May 16, 2014 where it shows much of central to western Iowa in the 30s. Image Courtesy of IEM.

Figure 7: Surface temperatures at 7 a.m. CDT on May 17, 2014 where most of the state dropped well into the 30s for minimum temperatures. Image Courtesy of  IEM.

Figure 7: Surface temperatures at 7 a.m. CDT on May 17, 2014 where most of the state dropped well into the 30s for minimum temperatures. Image Courtesy of IEM.

Figure 8: The last 12 days temperatures warmed to above normal when highs rose well into the 80s over the last week of May 2014.

Figure 8: The last 12 days temperatures warmed to above normal when highs rose well into the 80s over the last week of May 2014.

Figure 9: The observed precipitation across Iowa for May 2014. The highest rainfall totals were located over west-central to south-central Iowa.

Figure 9: The observed precipitation across Iowa for May 2014. The highest rainfall totals were located over west-central to south-central Iowa.

Figure 10: The U.S. Drought Monitor shows drought conditions had improved towards the end of May (right image). The greatest chance was over south-central and west-central Iowa where the heaviest rainfall accumulated.

Figure 10a: The U.S. Drought Monitor issued on April 28, 2014 shows significant drought conditions over western and portions of southern Iowa at the beginning of May.

Figure 10: The U.S. Drought Monitor shows drought conditions had improved towards the end of May (right image). The greatest chance was over south-central and west-central Iowa where the heaviest rainfall accumulated.

Figure 10b: The U.S. Drought Monitor issued on June 3, 2014 shows drought conditions had improved towards the end of May. The greatest chance was over south-central and west-central Iowa where the heaviest rainfall accumulated.

Figure 11: NMQ Q3 Estimated 24 hour precipitation accumulation ending at 18z on May 12, 2014. Several locations received 2 to 3 inches over a good portion of the Des Moines CWA.

Figure 11: NMQ Q3 Estimated 24 hour precipitation accumulation ending at 18z on May 12, 2014. Several locations received 2 to 3 inches over a good portion of the Des Moines CWA.

Figure 12: NMQ Q3 Total precipitation estimated 1 to 3 inches over portions of central Iowa on May 20, 2014. Ames recorded just over 3 inches from the heavy rain event. The U.S. Drought Monitor shows drought conditions had improved towards the end of May (right image). The greatest chance was over south-central and west-central Iowa where the heaviest rainfall accumulated.

Figure 12: NMQ Q3 Total precipitation estimated 1 to 3 inches over portions of central Iowa on May 20, 2014. Ames recorded just over 3 inches from the heavy rain event. The U.S. Drought Monitor shows drought conditions had improved towards the end of May (right image). The greatest chance was over south-central and west-central Iowa where the heaviest rainfall accumulated.

Figure 13: Precipitation trend for the month of May at Ottumwa shows the bulk of the rain fell on May 11 before an extended dry period towards the end of the month. The majority of central Iowa reporting stations’ precipitation trend graphs were similar to this one.

Figure 13: Precipitation trend for the month of May at Ottumwa shows the bulk of the rain fell on May 11 before an extended dry period towards the end of the month. The majority of central Iowa reporting stations’ precipitation trend graphs were similar to this one.

Table 1: Total Monthly (May 2014) Precipitation for all the ASOS stations within the Des Moines CWA.

Table 1: Total Monthly (May 2014) Precipitation for all the ASOS stations within the Des Moines CWA.

Blog post by Kenny Podrazik