Alert archive / Florida / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 42, NWS Mobile, AL

April 4, 2011Okaloosa County, Florida

NWS Mobile, AL issued this severe thunderstorm warning at Apr 4, 2011, 11:30 PM CDT for Okaloosa County, Florida. It was in force for 15 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
Apr 4, 2011, 11:30 PM CDT (04:30 UTC)
Expired
Apr 4, 2011, 11:45 PM CDT
In force
15 min
Issued by
NWS Mobile, AL
Area
Storm-based polygon

County Okaloosa County, FL

The radar

The Eglin Afb radar (KEVX), 57 km from the middle of the area, began a volume at 04:33 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 4, 5:28 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 4.5 hours before the alert went out and 211 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, Tallahassee Rgnl, FL at 00:00Z on 2011-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1916 joules per kilogram.LCLEL10008507005003002001001 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, Tallahassee Rgnl, FL at 00:00Z on 2011-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 189 square meters per square second.193958Sfc1 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
1916 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
521 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
189 m²/s²
0-3 km storm-relative helicity
197 m²/s²
Significant tornado parameter
1.6
Supercell composite
9.6

Open this sounding in Storm Lab

The text

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

654 
WUUS54 KMOB 050430
SVRMOB
FLC091-050445-
/O.NEW.KMOB.SV.W.0042.110405T0430Z-110405T0445Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOBILE AL
1130 PM CDT MON APR 4 2011

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN OKALOOSA COUNTY IN NORTHWEST FLORIDA...
  THIS INCLUDES THE CITIES OF...LAKE LORRAINE...WRIGHT...
  VALPARAISO...OCEAN CITY...NICEVILLE...MARY ESTHER...FORT WALTON
  BEACH...EGLIN AFB...DESTIN...

* UNTIL 1145 PM CDT

* AT 1128 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM 10 MILES WEST OF DE FUNIAK SPRINGS TO 7 MILES SOUTHEAST OF
  FORT WALTON BEACH...AND MOVING SOUTHEAST AT 40 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  VILLA TASSO AROUND 1135 PM CDT...
  OTHERWISE EXTREME SOUTHEASTERN PORTION OF OKALOOSA COUNTY

THIS INCLUDES INTERSTATE 10 BETWEEN MILE MARKERS 58 AND 67.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT UNTIL 100 AM CDT TUESDAY MORNING
FOR SOUTH CENTRAL ALABAMA AND NORTHWEST FLORIDA.

&&

LAT...LON 3040 8673 3043 8672 3097 8639 3047 8638
      3046 8639 3048 8641 3048 8643 3049 8645
      3046 8653 3043 8655 3043 8658 3040 8651
      3042 8645 3042 8640 3039 8638
TIME...MOT...LOC 0429Z 304DEG 30KT 3075 8627 3031 8657

$$
1 follow-up statement
997 
WWUS54 KMOB 050442
SVSMOB

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOBILE AL
1142 PM CDT MON APR 4 2011

FLC091-050451-
/O.EXP.KMOB.SV.W.0042.000000T0000Z-110405T0445Z/
OKALOOSA FL-
1142 PM CDT MON APR 4 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN OKALOOSA COUNTY
WILL EXPIRE AT 1145 PM CDT...

THE LINE OF SEVERE THUNDERSTORMS WILL EXIT EXTREME SOUTHEASTERN 
OKALOOSA COUNTY BY 1145 PM CDT.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 100 AM CDT TUESDAY MORNING 
FOR SOUTH CENTRAL ALABAMA AND NORTHWEST FLORIDA. ONCE THE 
THUNDERSTORM LINE PASSES...THE TORNADO WATCH WILL BE CANCELED.

LAT...LON 3040 8673 3043 8672 3097 8639 3047 8638
      3046 8639 3048 8641 3048 8643 3049 8645
      3046 8653 3043 8655 3043 8658 3040 8651
      3042 8645 3042 8640 3039 8638
TIME...MOT...LOC 0441Z 286DEG 30KT 3070 8620 3026 8650

$$

The office that day

Everything else NWS Mobile, AL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 9:44 PM CDTSevere Thunderstorm WarningMOBEscambia, Okaloosa, Santa Rosa61 min
Apr 4, 10:46 PM CDTSevere Thunderstorm WarningMOBOkaloosa, Santa Rosa44 min
Apr 4, 11:01 PM CDTTornado WarningMOBOkaloosa14 min

Nearby

Severe Thunderstorm Warnings in Florida, 2011Every severe thunderstorm warning in 2011

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.