Alert archive / Florida / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 35, NWS Tampa Bay, FL

February 20, 1998Hillsborough County, Manatee County, Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at Feb 20, 1998, 2:10 AM EST for Hillsborough County, Manatee County, Florida. It was in force for 30 min. 2 reports 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
Feb 20, 1998, 2:10 AM EST (07:10 UTC)
Expired
Feb 20, 1998, 2:40 AM EST
In force
30 min
Issued by
NWS Tampa Bay, FL
Area
Whole counties

Counties Hillsborough County, FL, Manatee County, FL

The radar

The Tampa radar (KTBW), 5 km from the middle of the area, began a volume at 07:10 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
Feb 20, 2:20 AM ESTThunderstorm WindRuskin, FLThunderstorm winds downed numerous trees and power lines across the southern portion of Hillsborough County.
Feb 20, 2:25 AM ESTThunderstorm WindBradenton, FLThunderstorm winds destroyed a carport in Bradenton.

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 watch it was issued in

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

IssuedProductOfficeLasted
Feb 19, 9:00 PM ESTTornado WatchSPC6 hr

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 00:00Z, 7.2 hours before the alert went out and 5 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 00:00Z on 1998-02-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 762 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 00:00Z on 1998-02-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 267 square meters per square second.1939587897Sfc1 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
762 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
786 m above ground
0-6 km bulk shear
78 kt
0-1 km storm-relative helicity
267 m²/s²
0-3 km storm-relative helicity
289 m²/s²
Significant tornado parameter
1.6
Supercell composite
7.5

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 Feb 19, 7:15 PM EST, 6 hours 55 minutes earlier.

Area forecast discussion, Feb 19, 7:15 PM EST, 6 hours 55 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY-RUSKIN, FL
715 PM EST THU FEB 19 1998

CONVECTION OVR CNTRL/NRN FA ASSOCIATED WITH MESOSCALE/SYNOPTIC SCALE
BNDRYS COMBINED WITH UPR JET AND UPR DIVERGENCE. ADDITIONAL ACTIVITY
OFFSHORE IN ADVANCE OF SFC FNT. NHC PLOTS SFC BNDRY ACRS SRN FL WHICH
MAY TRIGGER ACTIVITY OVR THE SRN FA. EXPECT SHOWERS AND THUNDERSTORMS
TO CONTINUE OVR THE FA OVERNIGHT AS THE FNT APPROACHES THE FA AND THE
UPR DYNAMICS REMAIN SOMEWHAT. CONVECTION WL END NW TO SE AFTER FROPA
FRI. CURRENT FCST REASONABLE.

11

In the hours before

Special weather statement, Feb 19, 11:11 PM EST, 2 hours 59 minutes before
FLZ043-048-049-200440-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1111 PM EST THU FEB 19 1998

...THE TORNADO WATCH FOR THE COUNTIES OF HERNANDO...PASCO AND
   SUMTER HAS BEEN CANCELLED...

...THE TORNADO WATCH REMAINS FOR THE COUNTIES OF PINELLAS...
   HILLSBOROUGH... MANATEE... SARASOTA... CHARLOTTE... POLK...
   HIGHLANDS... DESOTO ... AND HARDEE...

AT 1110 PM EST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THAT STRONG TO SEVERE THUNDERSTORMS HAVE MOVED OUT OF THE FOREGOING
COUNTIES. HOWEVER...RESIDENTS SHOULD REMAIN ALERT FOR ADDITIONAL
SHOWERS AND THUNDERSTORMS TONIGHT.

COLLINS

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 19, 8:22 PM ESTTornado WarningTBWHillsborough, Pasco48 min
Feb 19, 9:44 PM ESTSevere Thunderstorm WarningTBWPinellas51 min
Feb 19, 9:53 PM ESTSevere Thunderstorm WarningTBWHillsborough, Manatee47 min
Feb 19, 10:48 PM ESTSevere Thunderstorm WarningTBWManatee47 min
Feb 19, 10:54 PM ESTSevere Thunderstorm WarningTBWPolk46 min
Feb 20, 12:14 AM ESTSevere Thunderstorm WarningTBWHillsborough66 min
Feb 20, 1:25 AM ESTFlash Flood WarningTBWHillsborough, Pinellas4 hr
Feb 20, 2:20 AM ESTTornado WarningTBWHillsborough30 min

Nearby

Severe Thunderstorm Warnings in Florida, 1998Every severe thunderstorm warning in 1998

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.