El Niño and its Effect on Florida

In the central and eastern Pacific, there is a lot of year-to-year variability. Some years are much warmer and wetter (El Niño), and some years are much cooler and drier (La Niña). We are in the midst of an El Niño phase of the ENSO (El Niño/Southern Oscillation) cycle. There is currently a strong El Niño present across the equatorial Pacific Ocean.  El Niño isn’t a storm that will hit a specific area at a specific time. Instead, the warmer tropical Pacific waters cause changes to the global atmospheric circulation, resulting in a wide range of changes to global weather. Think of how a big construction project across town can change the flow of traffic near your house, with people being re-routed, side roads taking more traffic, and normal exits and on-ramps closed. Different neighborhoods will be affected most at different times of the day. You would feel the effects of the construction project through its changes to normal patterns, but you wouldn’t expect the construction project to hit your house. For more information on regional effects around the United States, please watch this video.

Sea surface temperatures (SST) have been at least 1.5°C above-average across much of the central and east-central equatorial Pacific since May.  Peak is still expected during late fall / early winter, potentially near or exceeding 2°C.

SST

Based on current observations and dynamical model forecasts, El Niño is expected to strengthen and last through Northern Hemisphere winter 2015-16. A strong El Niño event is most likely this winter. El Niño should gradually weaken through the spring.

ENSO

El Niño has global impacts: some negative, some positive. Even for Florida and the Southeast U.S., some El Niño influences are beneficial; some not so beneficial.

  • El Niño has significantly reduced Atlantic hurricane activity this 2015 season.
  • El Niño is expected to bring above average precipitation to Florida during Fall-Winter-Spring…reduced risk of wildfires…higher risk of flooding.
  • Increased storminess across the southern U.S. increases the threat of severe weather in Florida this winter.

The overall El Niño impact for the Southeast U.S. this winter calls for cooler and wetter conditions this winter, not because of numerous arctic outbreaks, but because of the stronger influence of the subtropical jet stream. Storm tracks will then be farther south producing more clouds, rain, and potentially more severe weather.

TempOutlook

PrecipOutlook

Winter Precipitation

Florida winter rainfall distributions are explained below. The plots are box and whisker diagrams where the maximum and minimum amounts are the top and bottom of the diagrams, and the box describes the middle 33% of the cases. In all four Florida locations, the rainfall distribution is higher in the El Niño years.

PrecipDistribution

JetStream

LargeScale

There is a noticeable correlation between stronger and more frequent storms, particularly across the central part of the peninsula of Florida.

LaNinaVsElNino

Distilling the data further, there is also a direct correlation with more frequent severe weather and tornadic activity across Southeast Georgia and Northeast Florida associated with Strong El Niños.  During El Niño, there are strong systems that migrate across the Gulf of Mexico while there is ample moisture being pushed into Southeast Georgia and Northeast Florida with greater instability ahead of frontal systems that move into the region.

HailTornado

NEFLSEGA

The graphic below shows the seven recent Years of La Niña and Neutral Conditions across the region, and the associated, and more limited tornadic activity with it across SE Georgia and NE Florida.

ColdSeasonENSONeutralThe graphic below shows the seven strongest El Niño years and the tornadic activity associated with those particular combined El Niño seasons. Generally tornadoes that do develop during the strong El Niño season, tend to be longer in duration and stronger.  This is due to the ample pooling of moisture, stronger jet, and more frequent storms moving across the Gulf of Mexico with a more persistent southern jet stream.

ColdSeasonElNino

PublicAwareness

Preparation

Partnerships

PublicWeatherOutlook

Neptune Beach Severe Weather Event 22 July 2015

During the afternoon of Wednesday, July 22nd, 2015, a severe thunderstorm swept over the eastern portion of Duval County which caused damage in the City of Neptune Beach and very southern portions of Atlantic Beach. In particular, the damage path began near Neptune Beach Elementary School and extended east-northeast in a narrow path ending near East Coast Drive and 1st Street in Atlantic Beach (Figure 1). The damage began around 3:50 p.m. and continued until approximately 4:15 p.m.

Figure1_neptune

National Weather Service Doppler Radar (Figure 2), located at Jacksonville International Airport (JIA), indicated a distinct downburst signature at that time with the brighter green colored winds moving toward the radar (located at JIA) and the bright red winds moving away from the radar. The damage pattern observed was consistent with a downburst with much of the damage being confined to trees and weaker and/or weakened infrastructure.

Figure2_neptune

Many of the downed light poles, signs, and fences exhibited signs of corrosion at their bases (Figures 3, and 4, Credit Mr. Miller Norton, Duval County Emergency Management).

Figure3_neptune

Figure4_neptune

The large signs brought down such as the McDonalds sign and the Aqua East Surf Shop sign were signs with large surface areas and were located at an altitude where they would be expected to feel stronger winds, making them more prone to wind damage at lower wind speeds (Figures 5, and 6, Credit Mr. Miller Norton, Duval County Emergency Management).

Figure5_neptune

Figure6_neptune

Overall, wind speeds were estimated to have been in the 75 to 90 mph range. These magnitudes are consistent with winds from a category 1 hurricane. Also of note were several structures in the damage area which were under construction, and other structures had scaffolding alongside of them. These types of structure would be vulnerable in a tornado event, yet none had apparent damage from yesterday’s strong winds.

Storm Survey for Southside Jacksonville (Duval County) EF-1 Tornado – April 25, 2015

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…NWS DAMAGE SURVEY RESULT FOR 4/25/15 SOUTHSIDE TORNADO IN DUVAL COUNTY…

NWS METEOROLOGISTS HAVE CONFIRMED A TORNADO DEVELOPED AND MOVED ASHORE IN THE SOUTHSIDE AREA OF DUVAL COUNTY JUST SOUTH OF RIVER
OAKS PARK AROUND 552 PM ON APRIL 25TH.

A SEVERE THUNDERSTORM PUSHED ESE THROUGH THE JAX METRO AREA AT ABOUT 50 MPH AND INTENSIFIED AS IT MOVED OVER THE ST. JOHNS RIVER. RADAR IMAGERY INDICATES A BRIEF TIGHT ROTATION DEVELOPED ON THE NORTH END OF A DEVELOPING DOWNBURST.

THE TORNADO MOVED ASHORE AND PUSHED JUST SOUTH OF HENDRICKS ELEMENTARY SNAPPING TREES AND POWERLINES. SEVERAL STRUCTURES WERE IMPACTED BY FALLING TREES AND LIMBS. INITIAL DAMAGE WAS TIGHTLY CLUSTERED WITH A PATH OF APPROXIMATELY 200 YARDS. AS THE TORNADO CROSSED PHILLIPS HIGHWAY SEVERAL BUSINESSES SUSTAINED ROOF DAMAGE. TRAILERS IN THE PINE OAKS MOBILE HOME PARK WERE DAMAGED AS WELL.

THE TORNADO BEGAN TO TURN MORE TO THE SOUTHEAST AS IT PASSED I-95 AND WIDENED TO 350 YARDS AS IT NEARED ENGLEWOOD HIGH SCHOOL.  AT ABOUT 5:58 PM THE TORNADO BEGAN TO WEAKEN AND DISSIPATE. A WIDE
SWATH OF STRAIGHT LINE WINDS CONTINUED TO CAUSE DAMAGE FURTHER TO THE SOUTH AND EAST OF THE PATH UNTIL SHORTLY AFTER 6 PM. THE PATH WIDTH VARIED FROM 200-350 YARDS ALONG A 3.45 MILE PATH. THE TORNADO
LASTED 5 OR 6 MINUTES WITH THE MAXIMUM WIND SPEEDS REACHING 104 MPH.

RATING:               EF-1
ESTIMATED PEAK WINDS: 104 MPH
PATH LENGTH/STATUTE:  3.45 MILES
PATH WIDTH/MAXIMUM:   350 YARDS
FATALITIES:           0
INJURIES:             0

START DATE:           APRIL 25 2015
START TIME:           552 PM EDT
START LOCATION:       4 MILES SOUTHWEST OF ARLINGTON
START LAT/LON:        30.2910/-81.6565

END DATE:             APRIL 25 2015
END TIME:             558 PM EDT
END LOCATION:         5 MILES SOUTH OF ARLINGTON
END LAT/LON:          30.2688/-81.6058

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Possible FunnelShingles in Fence San JoseSan Marco Treecasocardamagetree_down_blocking_AC_Skinner_pkwyGrant&Emerson Tree Down

Storm Survey for Palm Cay (Marion County) EF-1 Tornado – April 20, 2015

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NWS METEOROLOGISTS HAVE CONFIRMED A TORNADO ACROSS SOUTHWESTERN MARION COUNTY ON THE AFTERNOON OF MONDAY APRIL 20 2015. THE NATIONAL WEATHER SERVICE JACKSONVILLE WOULD LIKE TO EXPRESS APPRECIATION TO MARION COUNTY EMERGENCY  MANAGEMENT FOR ASSISTING OUR TEAM DURING THE SURVEY.

THE TORNADO TOUCHED DOWN SHORTLY AFTER 330 PM EDT MONDAY JUST EAST OF STATE ROAD 200 AT THE OAK RUN COUNTRY CLUB. SPOTTY EF-0 DAMAGE WAS NOTED THROUGHOUT THE OAK RUN COUNTRY CLUB NEIGHBORHOOD. THE TORNADO CONTINUED ON AN EAST TO EAST-NORTHEAST PATH INTO THE PALM CAY SUBDIVISION, REACHING ITS MAXIMUM INTENSITY OF EF-1.  SPOTTY EF-0 DAMAGE WAS NOTED JUST SOUTH OF SOUTHWEST 103RD STREET ROAD AT THE CONCLUSION OF THE TORNADO
PATH, WHICH WAS APPROXIMATELY 2 MILES IN LENGTH. THE DURATION OF THIS TORNADO WAS LIKELY LESS THAN 5 MINUTES.  MARION COUNTY EMERGENCY MANAGEMENT REPORTS THAT 55 HOMES WERE DAMAGED, WITH 10 OF THOSE HOMES DEEMED UNINHABITABLE.

RATING: EF-1
ESTIMATED PEAK WINDS: 85-90 MPH
PATH LENGTH/STATUTE: 2.0 MILES
PATH WIDTH/MAXIMUM: 350 YARDS
FATALITIES: 0
INJURIES: 0

START DATE: APRIL 20 2015
START TIME: 331 PM EDT
START LOCATION: 11.8 MILES SOUTHWEST OF OCALA
START LAT/LON: 29.06087/-82.27132

END DATE: APRIL 20 2015
END TIME: 335 PM EDT
END LOCATION: 10.2 MILES SOUTHWEST OF OCALA
END LAT/LON: 29.06900/-82.24051

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We thank Marion County Emergency Management and WCJB-TV in Gainesville for providing the following photos of the damage caused by this EF-1 tornado:

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marion-storm-8-042115 marion-storm-7-042115 marion-storm-6-042115  marion-storm-5-042115 marion-storm-4-042115 marion-storm-3-042115 marion-storm-2-042115 marion-storm-1-042115 marion-roof-storms-042015 marion-roof-house-storm-042015

The National Weather Service in Jacksonville issued a severe thunderstorm warning for Marion County at 3:31 PM.  As you can see from available base reflectivity and storm relative velocity data from the JAX Doppler Radar near the Jacksonville International Airport at that time,  the lowest available elevation for that radar to sample data in southwestern Marion County is at nearly 10,300 feet above ground level (agl).  Most tornadoes that form from rotating wall clouds exhibit strong rotation in the Storm Relative Velocity data (image to the right on the slide below) below 10,000 feet. The velocity data below displayed broad mid-altitude rotation (right image) embedded within a strong reflectivity core (left image).

marion_base

The radar that is able to sample the lowest elevations in southwest Marion County is located in Ruskin, FL (Tampa Bay region).  However, even this radar is unable to sample data below about 8,500 feet.  This Storm Relative Velocity data image from a few minutes before the tornado (image below) depicts broad rotation and converging winds at 8,500 feet, with green returns indicating winds blowing towards the TBW Doppler Radar site located to the south-southwest, while red returns indicate winds blowing away from the TBW radar.  Futhermore, the National Weather Service in Ruskin was dealing with severe weather impacting their area of responsibility and thus chose a scanning pattern that focused closer in on their local area, providing limited velocity data for much of Marion County. This is evident by the purple data region, which is known as range folding.  This tornado essentially formed within a range folded, or “no available velocity data” region, rendering use of the Ruskin Doppler Radar data suspect for issuing warnings despite being slightly closer in geographic range to southwest Marion County.

TBW_SRV_042015_1926z

This scenario underscores several facts:

1) Marion County and much of north central Florida is not adequately sampled amongst JAX, TBW, and MLB (Melbourne, FL) Doppler Radars in situations where tornado formation is considered, given that much of the precursor low level rotation prior to a tornado touchdown occurs at elevations below which these Doppler Radars are able to scan.

2) Storm Spotters are vital in these severe weather situations when locations are too far removed from Doppler Radar data for reliable detection of low level rotation.  A severe thunderstorm watch was issued for much of north and north central Florida by the Storm Prediction Center at 11 am EDT on April 20 (http://www.spc.noaa.gov/products/watch/ww0086.html) , meaning that available Storm Spotters were activated to provide vital ground truth.  National Weather Service offices throughout the nation provide basic and advanced storm spotter training sessions in-person and sometimes virtually.

3) This tornado formed, touched down, traveled about 2 miles on the ground, and then lifted back into the clouds within the span of about 5 minutes.  Even with perfect available velocity data, it is difficult for meteorologists manning a Doppler Radar to issue a tornado warning with lead time for such a short-lived event. Even at its shortest scanning mode, National Weather Service Doppler Radars take approximately 4 minutes to complete a full data scan.  This is why it is so important for the public and first responders to be aware of the potential for severe weather during the watch phase, particularly in a state like Florida where short-lived tornadoes are the norm rather than the larger, longer lived twisters that are found in the Midwest.

…NWS DAMAGE SURVEY RESULT FOR 4/19/15 COFFEE COUNTY TORNADO EVENT…

NWS METEOROLOGISTS HAVE CONFIRMED A TORNADO ACROSS CENTRAL COFFEE COUNTY GEORGIA FROM THE AFTERNOON OF SUNDAY APRIL 19 2015. NWS JACKSONVILLE FLORIDA WOULD LIKE TO EXPRESS APPRECIATION TO COFFEE COUNTY EMA DIRECTOR FOR ASSISTING OUR TEAM DURING THE SURVEY WHERE HE WAS INSTRUMENTAL IN OUR RURAL COMMUTE ACROSS SATURATED DIRT ROADS OF THE COUNTY AND HELPING US IDENTIFY AND PIN POINT DAMAGE ALONG THE TORNADO PATH LIST BELOW. ALSO…THANK YOU TO THE COFFEE COUNTY GEORGIA POLICE SCANNER FACEBOOK PAGE FOR SOME OF THE PHOTOS FROM THE TORNADO.

THE TORNADO WAS SPAWNED AND MIGRATED OVER WEST CENTRAL COFFEE  COUNTY IN THE RURAL OUTSKIRTS WEST OF THE CITY OF DOUGLAS GEORGIA BY A SHORT-LIVED SUPERCELL THUNDERSTORM. THERE WAS DAMAGE TO HOUSE SIDING, SHALLOW ROOTED PINES WERE PUSH OVER, LARGE BRANCHES WERE BROKEN OFF TREES, MINOR ROOF DAMAGE, AND LOSS OF WOOD AND METAL PANELS ON SMALL FARM OUTBUILDINGS.

RATING:                                             EF-0
ESTIMATED PEAK WINDS:  75-85 MPH
PATH LENGTH/STATUTE:     4.0 MILES
PATH WIDTH/MAXIMUM:   60 YARDS
FATALITIES:                                     0
INJURIES:                                         0

START DATE:                     APRIL 19 2015
START TIME:                     201 PM EDT
START LOCATION:       6 MILES SSE OF AMBROSE
START LAT/LON:           31.514679/-82.960982

END DATE:                       APRIL 19 2015
END TIME:                       205 PM EDT
END LOCATION:         5 MILES SSW OF BROXTON
END LAT/LON:              31.547234/-82.906651

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…Tornado Watch through 8 pm for SE Ga and portions of NE FL…

…Strong to Severe Storms and a Few Tornadoes Possible through this mid-evening…

Synopsis & Timing

Broken bands of showers and thunderstorms will continue to impact SE Georgia and the Suwannee River Valley of NE Florida this afternoon with a more consolidated line of showers and thunderstorms just east of the aforementioned region that will continue to track east across the region this late afternoon and early evening.  There is markedly less activity across our SE Florida zones at this time. Even outside of thunderstorm activity, showers can produce wind gusts of 30-40 mph at times.  Some storms are exhibiting rotation over Southeast Georgia and it is important to remain vigilant with a weather eye to the sky through the remaining afternoon hours and this evening.

Remember, a watch means that severe storms or tornadoes are possible in and near the watch area, and to stay alert for possible warnings as storms near your location.

tornadowatch19APR2015_200

Northeast Florida and Southeast Georgia Impacts:

Tornadoes:   At this time, the threat for isolated tornadoes appears to be increasing with the low level jet strengthening and the approach of the consolidated squall line.  Brief tornadoes could quickly come to fruition along or ahead of the squall line/convective line this late afternoon through mid- evening. Please utilize media, internet, smart phone and tabular apps and NOAA weather radio to keep abreast of the latest warnings from the National Weather Service.

Winds:  While the main threat from any thunderstorms that form will be strong winds in the neighborhood of 40-50 mph, the potential exists for a few stronger storms capable of higher wind speeds of 50 to 70 mph. Damaging straight line winds in excess of 58 MPH will be possible and are more likely along and ahead of the squall line this evening as storms track eastward.

Hail:  The threat for severe hail will be limited with some of the stronger storms having hail near the size of quarters.

Rainfall: Rainfall amounts of 1″ to 2″ will be possible with isolated higher pockets of 3” likely with rain efficient thunderstorms, especially along and west of a line from Jesup, Georgia to Lake City, FL.

Please call us directly with any specific questions and/or concerns for your local area.

Best regards,

Scott Cordero

 

Additional Information Resources:

NWS Jacksonville Webpage:  weather.gov/jax

NWS Jacksoville Facebook:  facebook.com/US.NationalWeatherService.Jacksonville.gov

NWS Jacksonville Twitter:   twitter.com/NWSJacksonville

AHPS River Forecasts:  water.weather.gov/ahps2/index.php?wfo=jax

 

 

Bacon County, Georgia January 4 EF-1 Tornado

…STORM SURVEY FOR THE BACON COUNTY GEORGIA EF-1 TORNADO…

RATING:                 EF-1
PATH LENGTH /STATUTE/:  6.2 MILES (10 KM)
PATH WIDTH /MAXIMUM/:   30-50 YARDS
FATALITIES:             0
INJURIES:               2 (1 CRITICAL)

START DATE:             JAN 4 2015
START TIME:             103 PM EST
START LOCATION:         3 MILES ESE OF ALMA / BACON / GA
LAT/LON:                31.5345 / -82.4286
END LOCATION:           3 MILES NE OF NEW LACY / BACON / GA
END_LAT/LON:            31.5719 / -82.3597

tornado path

SURVEY SUMMARY: THE NATIONAL WEATHER SERVICE IN JACKSONVILLE
CONDUCTED A STORM SURVEY ON JANUARY 5TH IN BACON COUNTY GEORGIA. OUR
WARNING COORDINATION METEOROLOGIST CONDUCTED THE SURVEY…WITH ALMA-BACON
COUNTY EMERGENCY MANAGEMENT…DETERMINING THAT THE TORNADO TOUCHED DOWN
APPROXIMATELY 3 MILES EAST-SOUTHEAST OF ALMA NEAR RADIO STATION ROAD
AROUND 103 PM EST JANUARY 4, 2015. HIGH END EF-1 DAMAGE WAS NOTED AND
CONFINED ALONG THE TORNADO PATH EAST OF JOHNSON LAKE ROAD ALONG GEORGIA
STATE ROAD 32. IN THIS PATH OF THE TORNADO THERE WERE TWO MOBILE
HOMES THAT HAD ENHANCED DAMAGE INCLUDING A DOUBLEWIDE TRAILOR WHERE THE
WALLS WERE SEPARATED…FRAME BENT AND FLIPPED ON ITS SIDE. THERE WERE
ALSO LARGE TREES SNAPPED ALONG THE PATH. EF-0 DAMAGE WAS NOTED ALONG
MOST OF THE PATH AS THE TORNADO WENT FROM RADIO STATION ROAD TO MCCARTY
LANE TO FLOWER ROAD…WITH THE TORNADO STRENGTHENING TO EF-1 INTENSITY
AS THE STORM APPROACHED GEORGIA STATE ROAD 32. THE TORNADO CONTINUED TO
MOVE NORTHEAST AND WEAKENED AS IT CROSSED TEN MILE CREEK INTO MALLARD
ROAD AND TERMINATED ITS TRACK BY BOBWHITE ROAD. THE MAXIMUM WIDTH OF
THE TORNADO WAS ESTIMATED TO BE 30 TO 50 YARDS NEAR GEORGIA STATE ROAD
32. BACON COUNTY EMERGENCY MANAGEMENT REPORTED THAT 2 MOBILE HOMES WERE
DESTROYED WITH TWO INJURIES…ONE WAS CRITICAL IN THE VICINITY OF WHEN
THE TORNADO WAS THE STRONGEST AS AN EF-1…WITH WINDS OF 100 TO 110
MPH. THE ONE CRITICAL INJURY WAS FEMALE AND HAD TO BE LIFE-FLIGHTED TO
SAVANNAH.

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Below is a home video of a possible tornado that moved through Bacon County east of Alma. This video was sent by WSAV in Savannah via one of their TV viewers.

Bacon County falls “in between” Doppler Radar sites at Moody Air Force Base near Valdosta, GA, Jacksonville, FL, and Robins Air Force Base near Warner Robins, GA.  The closest radar data to this event was from Moody Air Force Base, with the lowest available scan sampling data from more than 4,000 feet above the ground in Bacon County.  Storm relative velocity scans from the Moody Air Force Base Doppler Radar revealed at least two short-lived and broad rotational signatures in Bacon County at the time of the tornado. Much of the rotation within this broken squall line of showers and thunderstorms moving through Bacon County was likely occurring below 4000 feet.

VAX_Radar

NWS Storm Survey Team to Investigate Storm Damage in Bacon County GA This Morning

A LINE OF SEVERE THUNDERSTORMS MOVED ACROSS BACON COUNTY GEORGIA EARLY SUNDAY AFTERNOON...PRODUCING DAMAGING THUNDERSTORM WIND GUSTS JUST EAST OF ALMA IN THE VICINITY OF THE TOWN OF ROCKINGHAM ALONG GEORGIA HIGHWAY 32. REPORTS FROM BACON COUNTY EMERGENCY MANAGEMENT INDICATED THAT 2 MOBILE HOMES WERE DESTROYED...INJURING TWO PEOPLE...ONE CRITICALLY. OTHER HOMES IN THE AREA WERE REPORTEDLY DAMAGED. THE NATIONAL WEATHER SERVICE IN JACKSONVILLE IS SENDING A DAMAGE SURVEY TEAM TO BACON COUNTY ON THIS MORNING TO DETERMINE IF THIS SIGNIFICANT DAMAGE WAS THE RESULT OF A TORNADO OR FROM STRAIGHT LINE WINDS FROM A SEVERE THUNDERSTORM.

Below are two zoomed-in damage photos of the affected mobile homes via WALB in Albany, GA, along with a Facebook photo sent into Action News in Jacksonville from a viewer.  Bacon County Emergency Manager reported that these 2 mobile homes were destroyed, injuring 2 people.  One of the injured was critical and one was life-flighted to Savannah. Additional homes were reportedly damaged. 

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mobilehomemapdamage

Below is a home video of a possible tornado that moved through Bacon County east of Alma. This video was sent by WSAV is Savannah via one of their TV viewers. 

An addition update will be sent to via this blog, our webpage, Facebook and Twitter once the survey is completed by this afternoon.