Alert archive / Florida / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 252, NWS Jacksonville, FL

August 21, 2009Marion County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Aug 21, 2009, 4:11 PM EDT for Marion County, Florida. It was in force for 49 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 21, 2009, 4:11 PM EDT (20:11 UTC)
Expired
Aug 21, 2009, 5:00 PM EDT
In force
49 min
Issued by
NWS Jacksonville, FL
Area
Storm-based polygon

County Marion County, FL

The radar

The Jacksonville radar (KJAX), 158 km from the middle of the area, began a volume at 20:13 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, 8.2 hours before the alert went out and 156 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 2009-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1482 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, Cape Canaveral, FL at 12:00Z on 2009-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
1482 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
902 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
30 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS52 KJAX 212011
SVRJAX
FLC083-212100-
/O.NEW.KJAX.SV.W.0252.090821T2011Z-090821T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE JACKSONVILLE FL
411 PM EDT FRI AUG 21 2009

THE NATIONAL WEATHER SERVICE IN JACKSONVILLE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN MARION COUNTY IN NORTHERN FLORIDA

* UNTIL 500 PM EDT

* AT 412 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 6 MILES
  SOUTH OF WEIRSDALE...OR NEAR LADY LAKE...AND MOVING NORTH AT 20
  MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  WEIRSDALE...LAKE WEIR...OCKLAWAHA...MOSS BLUFF AND SILVER SPRINGS
  SHORES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

REPORT SEVERE WEATHER OR DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY
OR YOUR COUNTY EMERGENCY MANAGEMENT.

&&

LAT...LON 2918 8203 2915 8177 2895 8182 2895 8205
TIME...MOT...LOC 2012Z 189DEG 18KT 2891 8194

$$

HESS
1 follow-up statement
000 
WWUS52 KJAX 212055
SVSJAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
455 PM EDT FRI AUG 21 2009

FLC083-212105-
/O.EXP.KJAX.SV.W.0252.000000T0000Z-090821T2100Z/
MARION FL-
455 PM EDT FRI AUG 21 2009

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN MARION COUNTY WILL
EXPIRE AT 500 PM EDT...

ALTHOUGH THE WARNING IS NO LONGER IN EFFECT...HAIL UP TO ONE HALF
INCH IN DIAMETER...EXCESSIVE CLOUD-TO-GROUND LIGHTNING AND GUSTY
WINDS OF 45 TO 55 MPH CAN BE EXPECTED ALONG WITH POSSIBLE MINOR
DAMAGE.

REPORT SEVERE WEATHER OR DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY
OR YOUR COUNTY EMERGENCY MANAGEMENT.

LAT...LON 2918 8203 2915 8177 2895 8182 2895 8205
TIME...MOT...LOC 2055Z 189DEG 18KT 2912 8190

$$

HESS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 8:05 PM EDTSpecial Weather StatementJAXFlagler25 min
Aug 21, 2:48 AM EDTHigh Surf AdvisoryJAXFlagler, Nassau48 hr
Aug 21, 1:47 PM EDTSpecial Weather StatementJAXUnion28 min
Aug 21, 1:50 PM EDTSpecial Weather StatementJAXAlachua40 min
Aug 21, 3:06 PM EDTSpecial Weather StatementJAXFlagler39 min
Aug 21, 3:08 PM EDTSpecial Weather StatementJAXBaker52 min
Aug 21, 3:35 PM EDTSpecial Weather StatementJAXMarion25 min
Aug 21, 3:45 PM EDTSpecial Marine WarningJAX2 hr
Aug 21, 3:47 PM EDTSpecial Weather StatementJAXNassau43 min
Aug 21, 3:53 PM EDTSpecial Weather StatementJAXPutnam37 min
Aug 21, 3:59 PM EDTSevere Thunderstorm WarningJAXNassau61 min
Aug 21, 4:02 PM EDTSpecial Weather StatementJAXMarion43 min
Aug 21, 4:05 PM EDTSpecial Weather StatementJAXClay40 min
Aug 21, 4:25 PM EDTSpecial Weather StatementJAXDuval, Nassau50 min
Aug 21, 4:27 PM EDTSpecial Weather StatementJAXPutnam48 min
Aug 21, 4:32 PM EDTSevere Thunderstorm WarningJAXClay, Duval, Nassau, Saint Johns58 min
Aug 21, 4:36 PM EDTSevere Thunderstorm WarningJAXClay, Flagler, Putnam, Saint Johns54 min
Aug 21, 4:40 PM EDTSpecial Marine WarningJAX2 hr
Aug 21, 4:56 PM EDTSpecial Weather StatementJAXMarion34 min
Aug 21, 5:30 PM EDTAreal Flood AdvisoryJAXClay, Duval, Putnam, Saint Johns2 hr
Aug 21, 5:30 PM EDTSpecial Weather StatementJAXSaint Johns45 min
Aug 21, 5:37 PM EDTSpecial Weather StatementJAXMarion23 min
Aug 21, 5:44 PM EDTSpecial Weather StatementJAXPutnam31 min
Aug 21, 6:13 PM EDTSpecial Weather StatementJAXPutnam, Saint Johns32 min
Aug 21, 6:34 PM EDTSpecial Weather StatementJAXFlagler26 min
Aug 21, 7:17 PM EDTSpecial Weather StatementJAXPutnam28 min

Nearby

Severe Thunderstorm Warnings in Florida, 2009Every severe thunderstorm warning in 2009

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.