Alert archive / Florida / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 306, NWS Jacksonville, FL

August 26, 2015Nassau County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Aug 26, 2015, 5:29 PM EDT for Nassau County, Florida. It was in force for 31 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 26, 2015, 5:29 PM EDT (21:29 UTC)
Expired
Aug 26, 2015, 6:00 PM EDT
In force
31 min
Issued by
NWS Jacksonville, FL
Area
Storm-based polygon

County Nassau County, FL

The radar

The Jacksonville radar (KJAX), 16 km from the middle of the area, began a volume at 21:33 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 9.5 hours before the alert went out and 268 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Cape Canaveral, FL at 12:00Z on 2015-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 751 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Cape Canaveral, FL at 12:00Z on 2015-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
751 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
1157 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
7 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Jacksonville, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 26, 2:55 PM EDT, 2 hours 34 minutes earlier.

Area forecast discussion, Aug 26, 2:55 PM EDT, 2 hours 34 minutes before
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Hazardous weather outlook, Aug 26, 4:10 AM EDT, 13 hours 19 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSONVILLE FL
410 AM EDT WED AUG 26 2015

AMZ450-452-454-470-472-474-FLZ020>025-030>033-035>038-040-124-125-
GAZ132>136-149>154-162>166-271100-
COASTAL WATERS FROM ALTAMAHA SOUND
TO FERNANDINA BEACH FL OUT 20 NM-COASTAL WATERS FROM FERNANDINA
BEACH TO ST. AUGUSTINE FL OUT 20 NM-COASTAL WATERS FROM ST.
AUGUSTINE TO FLAGLER BEACH FL OUT 20 NM-WATERS FROM ALTAMAHA SOUND
GA TO FERNANDINA BEACH FL FROM 20 TO 60 NM-WATERS FROM FERNANDINA
BEACH TO ST. AUGUSTINE FL FROM 20 TO 60 NM-WATERS FROM ST. AUGUSTINE
TO FLAGLER BEACH FL FROM 20 TO 60 NM-HAMILTON-SUWANNEE-COLUMBIA-
BAKER-INLAND NASSAU-INLAND DUVAL-UNION-BRADFORD-CLAY-ST. JOHNS-
GILCHRIST-ALACHUA-PUTNAM-FLAGLER-MARION-COASTAL NASSAU-COASTAL DUVAL-
COFFEE-JEFF DAVIS-BACON-APPLING-WAYNE-ATKINSON-WARE-PIERCE-BRANTLEY-
INLAND GLYNN-COASTAL GLYNN-ECHOLS-CLINCH-CHARLTON-INLAND CAMDEN-
COASTAL CAMDEN-
410 AM EDT WED AUG 26 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST FLORIDA...
SOUTHEAST GEORGIA AND THE ADJACENT COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT...

ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE
EXPECTED ACROSS COASTAL SOUTHEAST GEORGIA AND NORTHEAST FLORIDA.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

SCATTERED TO NUMEROUS AFTERNOON AND EVENING THUNDERSTORMS ARE
POSSIBLE EACH DAY ACROSS NORTHEAST FLORIDA AND SOUTHEAST GEORGIA.
LOCALLY HEAVY RAINFALL WILL BE POSSIBLE WITH THESE STORMS.

THE FORECAST TRACK AND STRENGTH OF TROPICAL STORM ERIKA IS STILL
UNCERTAIN INTO EARLY NEXT WEEK. SWELLS ARE EXPECTED TO INCREASE IN
THE COASTAL WATERS INCREASING THE RIP CURRENT RISK LATE THIS WEEKEND
INTO NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE
IN JACKSONVILLE WEBSITE ON THE INTERNET AT WEATHER.GOV/JAX.

In the hours before

Special weather statement, Aug 26, 4:26 PM EDT, 1 hour 3 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
426 PM EDT WED AUG 26 2015

FLZ025-125-262115-
COASTAL DUVAL FL-INLAND DUVAL FL-
426 PM EDT WED AUG 26 2015

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL DUVAL COUNTY UNTIL 515 PM
EDT...

AT 426 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM OVER
JACKSONVILLE...MOVING NORTHEAST AT 10 MPH.

EXCESSIVE CLOUD-TO-GROUND LIGHTNING CAN BE EXPECTED. POSTPONE OUTDOOR
ACTIVITIES PROMPTLY. GO QUICKLY INSIDE A COMPLETELY ENCLOSED
BUILDING. UNPLUG ELECTRONIC DEVICES AND APPLIANCES AS THEY ARE
SUSCEPTIBLE TO POWER SURGES AND MAY BE DAMAGED BY NEARBY LIGHTNING
STRIKES.

LOCATIONS IMPACTED INCLUDE...
JACKSONVILLE...ARLINGTON...ORTEGA...FORT CAROLINE...RIVERSIDE...SAN
MARCO AND TALLYRAND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...
REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY
EMERGENCY MANAGEMENT.

LAT...LON 3022 8174 3027 8178 3048 8154 3037 8147
TIME...MOT...LOC 2026Z 240DEG 7KT 3033 8165

PETERSON
Local storm report, Aug 26, 4:40 PM EDT, 49 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
440 PM EDT WED AUG 26 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0423 PM     TSTM WND GST     ST. AUGUSTINE           29.89N 81.31W
08/26/2015  M44 MPH          ST. JOHNS          FL   ASOS

&&

AWALKER
Special weather statement, Aug 26, 4:54 PM EDT, 35 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
454 PM EDT WED AUG 26 2015

FLZ124-GAZ166-262145-
COASTAL NASSAU FL-COASTAL CAMDEN GA-
454 PM EDT WED AUG 26 2015

...SIGNIFICANT WEATHER ADVISORY FOR  UNTIL 545 PM EDT...

AT 454 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
KINGS BAY BASE...MOVING EAST AT 5 MPH.

EXCESSIVE CLOUD-TO-GROUND LIGHTNING CAN BE EXPECTED. POSTPONE OUTDOOR
ACTIVITIES PROMPTLY. GO QUICKLY INSIDE A COMPLETELY ENCLOSED
BUILDING. UNPLUG ELECTRONIC DEVICES AND APPLIANCES AS THEY ARE
SUSCEPTIBLE TO POWER SURGES AND MAY BE DAMAGED BY NEARBY LIGHTNING
STRIKES.

LOCATIONS IMPACTED INCLUDE...
FERNANDINA BEACH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...
REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY
EMERGENCY MANAGEMENT.

LAT...LON 3069 8146 3072 8147 3070 8149 3069 8147
      3068 8150 3072 8149 3073 8147 3074 8150
      3079 8150 3076 8149 3076 8148 3080 8148
      3081 8145 3075 8146 3070 8143
TIME...MOT...LOC 2054Z 252DEG 6KT 3075 8146

PETERSON
Special weather statement, Aug 26, 4:59 PM EDT, 30 minutes before
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Special weather statement, Aug 26, 5:18 PM EDT, 11 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
518 PM EDT WED AUG 26 2015

FLZ033-125-262200-
COASTAL DUVAL FL-ST. JOHNS FL-
518 PM EDT WED AUG 26 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN DUVAL AND
NORTHWESTERN ST. JOHNS COUNTIES UNTIL 600 PM EDT...

AT 518 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
BAYARD...OR NEAR UNF...MOVING EAST AT 5 MPH.

EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY WINDS OF 45 TO 55 MPH
CAN BE EXPECTED ALONG WITH POSSIBLE MINOR DAMAGE.

LOCATIONS IMPACTED INCLUDE...
JACKSONVILLE...PONTE VEDRA BEACH...FRUIT COVE...BAYARD...DURBIN...
SWITZERLAND AND PALM VALLEY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...
REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY
EMERGENCY MANAGEMENT.

LAT...LON 2995 8151 3004 8169 3009 8168 3013 8162
      3012 8157 3012 8154 3010 8154 3011 8151
      3014 8154 3018 8156 3020 8156 3021 8157
      3024 8155 3025 8138 3024 8138
TIME...MOT...LOC 2118Z 262DEG 6KT 3019 8151

PETERSON
Local storm report, Aug 26, 5:26 PM EDT, 3 minutes before
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The office that day

Everything else NWS Jacksonville, FL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 25, 9:16 PM EDTSpecial Weather StatementJAXNassau44 min
Aug 25, 9:55 PM EDTAreal Flood AdvisoryJAXDuval, Nassau2 hr
Aug 25, 10:02 PM EDTSpecial Weather StatementJAXDuval43 min
Aug 25, 10:14 PM EDTSpecial Marine WarningJAX91 min
Aug 25, 10:54 PM EDTSpecial Weather StatementJAXClay51 min
Aug 25, 11:01 PM EDTSpecial Marine WarningJAX59 min
Aug 26, 12:08 AM EDTSpecial Marine WarningJAX67 min
Aug 26, 3:18 PM EDTSpecial Weather StatementJAXSaint Johns42 min
Aug 26, 4:26 PM EDTSpecial Weather StatementJAXDuval49 min
Aug 26, 4:59 PM EDTSpecial Weather StatementJAXNassau46 min
Aug 26, 5:03 PM EDTSevere Thunderstorm WarningJAXNassau27 min
Aug 26, 5:08 PM EDTSpecial Marine WarningJAX112 min
Aug 26, 5:18 PM EDTSpecial Weather StatementJAXSaint Johns42 min
Aug 26, 5:35 PM EDTAreal Flood AdvisoryJAXNassau85 min
Aug 26, 5:41 PM EDTAreal Flood AdvisoryJAXDuval, Saint Johns94 min
Aug 26, 6:01 PM EDTSpecial Weather StatementJAXSaint Johns44 min
Aug 26, 6:04 PM EDTSpecial Weather StatementJAXFlagler41 min
Aug 26, 6:21 PM EDTAreal Flood AdvisoryJAXSaint Johns84 min
Aug 26, 6:41 PM EDTAreal Flood AdvisoryJAXSaint Johns94 min
Aug 26, 6:48 PM EDTSpecial Weather StatementJAXSaint Johns42 min
Aug 26, 6:52 PM EDTSpecial Marine WarningJAX113 min
Aug 26, 6:57 PM EDTSevere Thunderstorm WarningJAXSaint Johns33 min
Aug 26, 7:01 PM EDTSpecial Weather StatementJAXDuval44 min
Aug 26, 7:43 PM EDTSpecial Weather StatementJAXBradford47 min
Aug 25, 10:58 PM EDTSpecial Weather StatementJAXCharlton47 min
Aug 25, 11:09 PM EDTSpecial Weather StatementJAXCamden36 min
Aug 25, 11:16 PM EDTAreal Flood AdvisoryJAXCamden89 min
Aug 25, 11:35 PM EDTAreal Flood AdvisoryJAXCharlton85 min
Aug 25, 11:49 PM EDTSpecial Weather StatementJAXCamden26 min
Aug 25, 11:58 PM EDTAreal Flood WarningJAXCamden2 hr
Aug 25, 11:59 PM EDTSpecial Weather StatementJAXCamden31 min
Aug 26, 12:10 AM EDTSpecial Weather StatementJAXCamden35 min
Aug 26, 3:24 PM EDTSpecial Weather StatementJAXCamden51 min
Aug 26, 4:54 PM EDTSpecial Weather StatementJAXCamden51 min

Nearby

Severe Thunderstorm Warnings in Florida, 2015Every severe thunderstorm warning in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.