Alert archive / Florida / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 252, NWS Jacksonville, FL

August 9, 2017Duval County, Saint Johns County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Aug 9, 2017, 3:45 PM EDT for Duval County, Saint Johns County, Florida. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 9, 2017, 3:45 PM EDT (19:45 UTC)
Expired
Aug 9, 2017, 4:15 PM EDT
In force
30 min
Issued by
NWS Jacksonville, FL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Duval County, FL, Saint Johns County, FL

The radar

The Jacksonville radar (KJAX), 34 km from the middle of the area, began a volume at 19:48 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

Jacksonville, FL (KJAX), launched 12:00Z, 7.8 hours before the alert went out and 36 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, Jacksonville, FL at 12:00Z on 2017-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1920 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jacksonville, FL at 12:00Z on 2017-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 7 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
1920 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
662 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
7 m²/s²
0-3 km storm-relative helicity
26 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

649 
WUUS52 KJAX 091945
SVRJAX
FLC031-109-092015-
/O.NEW.KJAX.SV.W.0252.170809T1945Z-170809T2015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Jacksonville FL
345 PM EDT WED AUG 9 2017

The National Weather Service in Jacksonville has issued a

* Severe Thunderstorm Warning for...
  Northwestern St. Johns County in northeastern Florida...
  Southeastern Duval County in northeastern Florida...

* Until 415 PM EDT

* At 345 PM EDT, severe thunderstorms were located along a line
  extending from near Unf to near Fruit Cove, and are nearly
  stationary.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to roofs, siding, and trees. 

* Locations impacted include...
  Jacksonville, Mandarin, Unf, Fruit Cove, Baymeadows, Bayard,
  Durbin, Craig Field, Switzerland and Riverside.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3034 8148 3003 8144 3001 8164 3032 8169
TIME...MOT...LOC 1945Z 027DEG 3KT 3029 8155 3005 8155 

HAIL...<.75IN
WIND...60MPH
 
$$

ENYEDI
2 follow-up statements
824 
WWUS52 KJAX 092006
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
406 PM EDT WED AUG 9 2017

FLC109-092015-
/O.CAN.KJAX.SV.W.0252.000000T0000Z-170809T2015Z/
St. Johns FL-
406 PM EDT WED AUG 9 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN ST. JOHNS COUNTY
IS CANCELLED...

The storms which prompted the warning have weakened and moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3010 8154 3012 8154 3012 8159 3013 8160
      3013 8166 3032 8169 3034 8148 3010 8146
TIME...MOT...LOC 2005Z 027DEG 3KT 3028 8156 3004 8156 

$$

FLC031-092015-
/O.CON.KJAX.SV.W.0252.000000T0000Z-170809T2015Z/
Duval FL-
406 PM EDT WED AUG 9 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR SOUTHEASTERN DUVAL COUNTY...

At 405 PM EDT, severe thunderstorms were located along a line
extending from near Baymeadows to near Fruit Cove, and are nearly
stationary.
 
HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to roofs, siding, and trees. 

Locations impacted include...
Jacksonville, Mandarin, Unf, Baymeadows, Bayard, Craig Field,
Riverside, San Marco and Nas Jax.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3010 8154 3012 8154 3012 8159 3013 8160
      3013 8166 3032 8169 3034 8148 3010 8146
TIME...MOT...LOC 2005Z 027DEG 3KT 3028 8156 3004 8156 

HAIL...<.75IN
WIND...60MPH
 
$$

ENYEDI
715 
WWUS52 KJAX 092015
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
415 PM EDT WED AUG 9 2017

FLC031-092025-
/O.EXP.KJAX.SV.W.0252.000000T0000Z-170809T2015Z/
Duval FL-
415 PM EDT WED AUG 9 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN DUVAL COUNTY HAS
EXPIRED...
    
The storms which prompted the warning have moved out of the area.
Therefore the warning has been allowed to expire.  However small hail
and gusty winds are still possible with these thunderstorms.

Remember, a Severe Thunderstorm Warning still remains in effect for 
portions of eastern Duval county. 

LAT...LON 3010 8154 3012 8154 3012 8159 3013 8160
      3013 8166 3032 8169 3034 8148 3010 8146
TIME...MOT...LOC 2015Z 027DEG 3KT 3027 8156 3003 8156 

$$

ENYEDI

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 8:09 PM EDTSpecial Weather StatementJAXMarion51 min
Aug 8, 8:12 PM EDTSpecial Weather StatementJAXPutnam48 min
Aug 8, 8:44 PM EDTSpecial Weather StatementJAXPutnam46 min
Aug 8, 8:55 PM EDTSevere Thunderstorm WarningJAXFlagler, Putnam, Saint Johns16 min
Aug 8, 8:58 PM EDTSpecial Marine WarningJAX92 min
Aug 8, 9:05 PM EDTSpecial Weather StatementJAXFlagler40 min
Aug 8, 9:18 PM EDTAreal Flood AdvisoryJAXFlagler, Putnam, Saint Johns3 hr
Aug 8, 9:39 PM EDTSpecial Weather StatementJAXFlagler51 min
Aug 9, 1:45 PM EDTSpecial Weather StatementJAXPutnam30 min
Aug 9, 1:49 PM EDTAreal Flood AdvisoryJAXPutnam86 min
Aug 9, 2:07 PM EDTAreal Flood AdvisoryJAXMarion83 min
Aug 9, 2:13 PM EDTSpecial Weather StatementJAXPutnam32 min
Aug 9, 2:15 PM EDTSpecial Weather StatementJAXLevy30 min
Aug 9, 2:22 PM EDTSpecial Weather StatementJAXClay23 min
Aug 9, 2:36 PM EDTSevere Thunderstorm WarningJAXClay39 min
Aug 9, 2:37 PM EDTSpecial Weather StatementJAXLevy38 min
Aug 9, 2:41 PM EDTSpecial Weather StatementJAXClay34 min
Aug 9, 2:43 PM EDTAreal Flood AdvisoryJAXClay2 hr
Aug 9, 2:45 PM EDTSevere Thunderstorm WarningJAXClay30 min
Aug 9, 2:57 PM EDTSevere Thunderstorm WarningJAXClay, Putnam19 min
Aug 9, 3:00 PM EDTSpecial Weather StatementJAXClay45 min
Aug 9, 3:01 PM EDTSpecial Weather StatementJAXNassau29 min
Aug 9, 3:07 PM EDTSpecial Weather StatementJAXCitrus38 min
Aug 9, 3:13 PM EDTSpecial Weather StatementJAXDuval32 min
Aug 9, 3:23 PM EDTSevere Thunderstorm WarningJAXDuval37 min
Aug 9, 3:25 PM EDTSevere Thunderstorm WarningJAXBradford, Clay22 min
Aug 9, 3:27 PM EDTSpecial Weather StatementJAXSaint Johns48 min
Aug 9, 3:28 PM EDTSpecial Weather StatementJAXAlachua32 min
Aug 9, 3:29 PM EDTAreal Flood AdvisoryJAXClay61 min
Aug 9, 3:35 PM EDTSpecial Weather StatementJAXClay25 min
Aug 9, 3:36 PM EDTSevere Thunderstorm WarningJAXAlachua, Bradford, Columbia, Union28 min
Aug 9, 3:41 PM EDTSpecial Weather StatementJAXAlachua49 min
Aug 9, 3:43 PM EDTSpecial Weather StatementJAXMarion32 min
Aug 9, 3:46 PM EDTSpecial Weather StatementJAXNassau29 min
Aug 9, 3:49 PM EDTSevere Thunderstorm WarningJAXAlachua41 min
Aug 9, 4:00 PM EDTAreal Flood AdvisoryJAXDuval, Saint Johns60 min
Aug 9, 4:01 PM EDTSpecial Weather StatementJAXBradford29 min
Aug 9, 4:05 PM EDTAreal Flood AdvisoryJAXAlachua, Bradford, Union85 min
Aug 9, 4:09 PM EDTSevere Thunderstorm WarningJAXAlachua, Bradford, Union36 min
Aug 9, 4:12 PM EDTSevere Thunderstorm WarningJAXDuval33 min
Aug 9, 4:20 PM EDTSpecial Weather StatementJAXGilchrist25 min
Aug 9, 4:24 PM EDTAreal Flood AdvisoryJAXDuval66 min
Aug 9, 4:24 PM EDTSpecial Weather StatementJAXNassau36 min
Aug 9, 4:28 PM EDTSpecial Weather StatementJAXBaker32 min
Aug 9, 4:30 PM EDTSpecial Weather StatementJAXMarion30 min
Aug 9, 4:35 PM EDTAreal Flood WarningJAXDuval85 min
Aug 9, 4:45 PM EDTAreal Flood AdvisoryJAXGilchrist60 min
Aug 9, 4:48 PM EDTSpecial Weather StatementJAXGilchrist27 min
Aug 9, 4:55 PM EDTAreal Flood AdvisoryJAXDuval, Nassau65 min
Aug 9, 4:59 PM EDTSpecial Weather StatementJAXDuval31 min
Aug 9, 5:04 PM EDTSpecial Weather StatementJAXSuwannee26 min
Aug 9, 5:14 PM EDTAreal Flood WarningJAXAlachua91 min
Aug 9, 5:15 PM EDTSpecial Weather StatementJAXColumbia45 min
Aug 9, 5:22 PM EDTSpecial Weather StatementJAXBaker38 min
Aug 9, 5:32 PM EDTSpecial Weather StatementJAXSuwannee28 min
Aug 9, 5:37 PM EDTSpecial Weather StatementJAXNassau38 min
Aug 9, 6:09 PM EDTSpecial Weather StatementJAXSuwannee36 min
Aug 9, 6:53 PM EDTSpecial Weather StatementJAXSuwannee37 min
Aug 9, 7:34 PM EDTSpecial Weather StatementJAXHamilton26 min

Nearby

Severe Thunderstorm Warnings in Florida, 2017Every severe thunderstorm warning in 2017

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.