Alert archive / Florida / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 18, NWS Tampa Bay, FL

March 31, 2001Hillsborough County, Pasco County, Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at Mar 31, 2001, 1:46 PM EST for Hillsborough County, Pasco County, Florida. It was in force for 29 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Mar 31, 2001, 1:46 PM EST (18:46 UTC)
Expired
Mar 31, 2001, 2:15 PM EST
In force
29 min
Issued by
NWS Tampa Bay, FL
Area
Whole counties

Counties Hillsborough County, FL, Pasco County, FL

The radar

The Tampa radar (KTBW), 45 km from the middle of the area, began a volume at 18:50 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

TimeReportWhereRemark
Mar 31, 2:00 PM ESTHail 0.75Thonotosassa, FLDime sized hail was reported by a park ranger at the Hillsborough River State Park along U.S. Highway 301.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 6.8 hours before the alert went out and 190 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 2001-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1036 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, Cape Canaveral, FL at 12:00Z on 2001-03-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.1939587897117Sfc1 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
1036 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
575 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

957 
WUUS52 KTBW 311846
SVRTBW
FLC057-101-311915-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
146 PM EST SAT MAR 31 2001

THE NATIONAL WEATHER SERVICE IN RUSKIN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN HILLSBOROUGH COUNTY IN FLORIDA.
  SOUTHEASTERN PASCO COUNTY IN FLORIDA.

* UNTIL 215 PM EST.

* AT 146 PM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM WITH LARGE HAIL...5 MILES NORTH OF TEMPLE
  TERRACE...MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL AFFECT...
  THONOTOSASSA.
  HILLSBOROUGH RIVER STATE PARK.
  ZEPHYRHILLS.

SEVERE THUNDERSTORMS CONTAIN WIND GUSTS OF 60 MPH OR HIGHER...AND
HAIL THE SIZE OF DIMES OR LARGER. MOVE TO A PLACE OF SAFETY.

$$

LAT...LON 2819 8248 2802 8243 2807 8208 2828 8214

NNNN

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 31, 12:30 PM EST, 1 hour 16 minutes earlier.

Area forecast discussion, Mar 31, 12:30 PM EST, 1 hour 16 minutes before
WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1230 PM EST SAT MAR 31 2001

UPDATE: SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR THE SOUTHERN
HALF OF THE AREA. AMENDED ZONES TO REFLECT THIS. WILL LEAVE IT OUT
OF THE MARINE FORECAST AS BIGGEST THREAT IS INLAND FROM THE COAST.

.TBW...FLOOD WATCH TODAY FLZ050>052-055>057-060>061-062.
    ...FIRE WX WATCH SUNDAY FLZ039-042>043-052-056>057-061...AND
       INTERIOR FLZ048>049.

ALSHEIMER

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 31, 2:02 PM ESTSevere Thunderstorm WarningTBWPinellas28 min
Mar 31, 2:22 PM ESTSevere Thunderstorm WarningTBWHillsborough38 min
Mar 31, 2:27 PM ESTSevere Thunderstorm WarningTBWPolk33 min
Mar 31, 3:01 PM ESTSevere Thunderstorm WarningTBWHillsborough, Polk29 min
Mar 31, 3:31 PM ESTSevere Thunderstorm WarningTBWPolk44 min
Mar 31, 4:15 PM ESTSevere Thunderstorm WarningTBWPolk25 min
Mar 31, 5:18 PM ESTSevere Thunderstorm WarningTBWManatee, Sarasota57 min
Mar 31, 6:27 PM ESTSevere Thunderstorm WarningTBWSarasota48 min

Nearby

Severe Thunderstorm Warnings in Florida, 2001Every severe thunderstorm warning in 2001

Sources

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