Alert archive / Florida / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 39, NWS Jacksonville, FL

April 21, 2012Duval County, Nassau County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Apr 21, 2012, 6:26 PM EDT for Duval County, Nassau County, Florida. It was in force for 49 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 21, 2012, 6:26 PM EDT (22:26 UTC)
Expired: Apr 21, 2012, 7:15 PM EDT
In force: 49 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon

Counties Duval County, FL, Nassau County, FL

The radar

The Jacksonville radar (KJAX), 17 km from the middle of the area, began a volume at 22:25 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.

What was reported inside it

Time	Report	Where	Remark
Apr 21, 6:55 PM EDT	TSTM WND DMG	3 Sw Downtown Jacksonvi, FL	WJXT TV REPORTED SEVERAL LARGE TREES DOWN DAMAGING HOMES AND CARS AND CAUSING POWER OUTAGES IN AVONDALE. FIREFIGHTERS HAD TO CUT WOMAN OUT OF A CAR AFTER A LARGE WATER OAK TREE FELL ON HER CAR ON ST. JOHNS AVENUE AND DONALD ST.
Apr 21, 7:19 PM EDT	TSTM WND GST 44	Jacksonville Intl Arpt, FL	THE JAX ASOS REPORTED A THUNDERSTORM WIND GUST OF 44 MPH.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 10.4 hours before the alert went out and 18 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 716 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 745 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 53 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.

667 
WUUS52 KJAX 212226
SVRJAX
FLC031-089-212315-
/O.NEW.KJAX.SV.W.0039.120421T2226Z-120421T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE JACKSONVILLE FL
626 PM EDT SAT APR 21 2012

THE NATIONAL WEATHER SERVICE IN JACKSONVILLE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN DUVAL COUNTY IN NORTHEAST FLORIDA
  CENTRAL NASSAU COUNTY IN NORTHEAST FLORIDA

* UNTIL 715 PM EDT

* AT 626 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
  LOCATED 9 MILES SOUTHWEST OF NORMANDY...OR 12 MILES NORTHWEST OF
  LAKESIDE...AND MOVING NORTH AT 25 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  BRYCEVILLE...JACKSONVILLE INTERNATIONAL AIRPORT...RATLIFF AND
  CALLAHAN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3064 8201 3066 8171 3021 8169 3019 8199
TIME...MOT...LOC 2226Z 170DEG 22KT 3029 8190

$$

STRUBLE

2 follow-up statements

546 
WWUS52 KJAX 212245
SVSJAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
645 PM EDT SAT APR 21 2012

FLC031-089-212315-
/O.CON.KJAX.SV.W.0039.000000T0000Z-120421T2315Z/
DUVAL FL-NASSAU FL-
645 PM EDT SAT APR 21 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR CENTRAL NASSAU AND WESTERN DUVAL COUNTIES...

AT 645 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
TRACK A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...
AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 6
MILES SOUTHEAST OF BRYCEVILLE...OR 13 MILES WEST OF DOWNTOWN
JACKSONVILLE...MOVING NORTH AT 25 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
BRYCEVILLE...JACKSONVILLE INTERNATIONAL AIRPORT...RATLIFF AND
CALLAHAN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF
YOUR HOME OR BUSINESS. THIS STORM HAS THE POTENTIAL TO CAUSE SERIOUS
INJURY AND SIGNIFICANT DAMAGE TO PROPERTY.

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

&&

LAT...LON 3064 8201 3066 8171 3021 8169 3019 8199
TIME...MOT...LOC 2245Z 185DEG 21KT 3035 8187

$$

STRUBLE

538 
WWUS52 KJAX 212257
SVSJAX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
657 PM EDT SAT APR 21 2012

FLC031-089-212315-
/O.CON.KJAX.SV.W.0039.000000T0000Z-120421T2315Z/
DUVAL FL-NASSAU FL-
657 PM EDT SAT APR 21 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR CENTRAL NASSAU AND WESTERN DUVAL COUNTIES...

AT 658 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
TRACK A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...
AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 7
MILES SOUTHWEST OF RATLIFF...OR 11 MILES SOUTHWEST OF JACKSONVILLE
INTERNATIONAL AIRPORT...MOVING NORTH AT 25 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
JACKSONVILLE INTERNATIONAL AIRPORT...RATLIFF AND CALLAHAN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF
YOUR HOME OR BUSINESS. THIS STORM HAS THE POTENTIAL TO CAUSE SERIOUS
INJURY AND SIGNIFICANT DAMAGE TO PROPERTY.

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

&&

LAT...LON 3021 8188 3064 8201 3066 8171 3021 8169
TIME...MOT...LOC 2258Z 185DEG 21KT 3043 8186

$$

STRUBLE

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 21, 2:02 PM EDT	Special Weather Statement	JAX	Suwannee	28 min
Apr 21, 2:21 PM EDT	Small Craft Advisory for Winds	JAX		15 hr
Apr 21, 3:03 PM EDT	Special Weather Statement	JAX	Suwannee	42 min
Apr 21, 3:53 PM EDT	Special Weather Statement	JAX	Union	52 min
Apr 21, 4:49 PM EDT	Special Weather Statement	JAX	Marion	41 min
Apr 21, 4:52 PM EDT	Special Weather Statement	JAX	Baker	53 min
Apr 21, 5:49 PM EDT	Special Weather Statement	JAX	Baker	41 min
Apr 21, 6:20 PM EDT	Special Weather Statement	JAX	Duval	40 min
Apr 21, 6:26 PM EDT	Special Weather Statement	JAX	Clay	34 min
Apr 21, 6:34 PM EDT	Severe Thunderstorm Warning	JAX	Clay, Duval, Saint Johns	41 min
Apr 21, 6:38 PM EDT	Areal Flood Advisory	JAX	Clay, Duval, Saint Johns	82 min
Apr 21, 6:52 PM EDT	Severe Thunderstorm Warning	JAX	Duval, Nassau	53 min

Nearby

Severe Thunderstorm Warnings in Florida, 2012 Every severe thunderstorm warning in 2012

Sources

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