Alert archive / Florida / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 12, NWS Tampa Bay, FL

March 21, 2003Hillsborough County, Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at Mar 21, 2003, 10:20 AM EST for Hillsborough County, Florida. It was in force for 40 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
Mar 21, 2003, 10:20 AM EST (15:20 UTC)
Expired
Mar 21, 2003, 11:00 AM EST
In force
40 min
Issued by
NWS Tampa Bay, FL
Area
Counties, with a storm outline in the text

County Hillsborough County, FL

The radar

The Tampa radar (KTBW), 23 km from the middle of the area, began a volume at 15:21 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 12:00Z, 3.3 hours before the alert went out and 23 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, Tampa Bay, FL at 12:00Z on 2003-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1275 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, Tampa Bay, FL at 12:00Z on 2003-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 120 square meters per square second.19395878Sfc1 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
1275 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
506 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
120 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
0.8
Supercell composite
4.1

Open this sounding in Storm Lab

The text

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

000 
WUUS52 KTBW 211520
SVRTBW
FLC057-211600-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1020 AM EST FRI MAR 21 2003

THE NATIONAL WEATHER SERVICE IN RUSKIN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL HILLSBOROUGH COUNTY IN FLORIDA.

* UNTIL 1100 AM EST

* AT 1020 AM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM WITH DAMAGING WINDS...9 MILES SOUTH OF TAMPA...
  MOVING NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL AFFECT...
  GIBSONTON BY 1020 AM EST.
  PALM RIVER CLAIR MEL BY 1030 AM EST.
  EAST LAKE ORIENT PARK BY 1035 AM EST.
  BRANDON BY 1040 AM EST.
  MANGO BY 1045 AM EST.
  SEFFNER BY 1050 AM EST.

MOVE INSIDE A STURDY BUILDING. DAMAGING WIND...LARGE HAIL...
TORRENTIAL RAIN...AND DEADLY LIGHTNING ARE EXPECTED. STAY INSIDE AWAY
FROM WINDOWS UNTIL THE STORM HAS PASSED.

&&

LAT...LON 2789 8257 2776 8243 2792 8215 2810 8230

$$

57

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 Tampa Bay, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Mar 21, 9:04 AM EST, 1 hour 16 minutes earlier.

Area forecast discussion, Mar 21, 9:04 AM EST, 1 hour 16 minutes before
WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
904 AM EST FRI MAR 21 2003

FRONT THROUGH NORTHERN COUNTIES ALREADY WILL PROMPT SOME ADDITIONAL
CHANGES TO THE ZONES THIS MORNING. POPS LOOK ISOLATED AT BEST THIS
AFTERNOON FOR THE NORTHERN COUNTIES...AND WILL LOWER POPS
APPROPRIATELY THERE. I WILL ALSO VEER THE WIND DIRECTION AS FRONT
WILL BE PASSED.

ELSEWHERE...MOISTURE AND INSTABILITY POOLING WILL CONTINUE ALONG
THE FRONT THROUGH THE DAY WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS...SLOWLY DIMINISHING IN COVERAGE AS THE DAY WEARS ON...
ESPECIALLY NEAR THE COAST WHERE CONVERGENCE SHOULD WEAKEN.

MARINE: WILL SHIFT WINDS AROUND FOR THE NORTHERN LEG THIS AFTERNOON
TO A WESTERLY DIRECTION...WHICH IS REALLY MORE OF AN AVERAGE OF THE
VARIABLE NORTHWEST TO SOUTHWEST IT SHOULD BE.

.TBW...NONE.

ALSHEIMER
Hazardous weather outlook, Mar 21, 5:00 AM EST, 5 hours 20 minutes before
FLZ039-042-043-048>052-055>057-060>062-065-211530-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
500 AM EST FRI MAR 21 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL AND SOUTHWEST
FLORIDA.

.DAY ONE...TODAY:

...ISOLATED STRONG THUNDERSTORMS POSSIBLE TODAY...

A WEAK COLD FRONT WILL APPROACH THE AREA SLOWLY FROM THE NORTH
TODAY...WHICH COMBINED WITH SOME UPPER LEVEL ENERGY...WILL ALLOW FOR
SCATTERED SHOWERS AND THUNDERSTORMS. SHOWERS AND THUNDERSTORMS
WILL MOVE TOWARD THE NORTHEAST AT 20 TO 25 MPH. ATMOSPHERIC
CONDITIONS ARE FAVORABLE FOR SOME STORMS TO BECOME STRONG...
ESPECIALLY OVER INTERIOR LOCATIONS THIS AFTERNOON. ANY STORMS THAT
DO BECOME STRONG COULD PRODUCE GUSTY WINDS OF 30 TO 40 MPH...BRIEF
HEAVY DOWNPOURS...AND FREQUENT CLOUD TO GROUND LIGHTNING.

FOR MARINE INTERESTS...CONDITIONS WILL BE FAVORABLE THROUGH THIS
MORNING FOR ISOLATED WATERSPOUTS...ESPECIALLY WITHIN 10 MILES OF THE
COAST. BE PREPARED TO SEEK SAFE HARBOR IF THREATENING WEATHER
APPROACHES.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY:

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED.

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT
HTTP://WWW.SRH.NOAA.GOV/TBW

MORALES

In the hours before

Special weather statement, Mar 21, 9:28 AM EST, 52 minutes before
FLZ050-211515-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
928 AM EST FRI MAR 21 2003

...STRONG THUNDERSTORMS WILL AFFECT SOUTHERN PINELLAS COUNTY...

A LINE OF THUNDERSTORMS...MOVING NORTHEAST AT 30 MPH...WILL AFFECT
PINELLAS PARK...SEMINOLE AND SAINT PETERSBURG...UNTIL 1015 AM EST.
GUSTY WINDS UP TO 50 MPH MAY CAUSE LOOSE OBJECTS TO BLOW AROUND.
SOME DAMAGE TO TREE LIMBS AND WIRES IS POSSIBLE.

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 21, 9:20 AM ESTSpecial Marine WarningTBW55 min
Mar 21, 10:19 AM ESTSpecial Marine WarningTBW26 min

Nearby

Severe Thunderstorm Warnings in Florida, 2003Every severe thunderstorm warning in 2003

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.