Alert archive / Florida / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 32, NWS Tampa Bay, FL

April 25, 1997Polk County, Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at Apr 25, 1997, 8:05 PM EDT for Polk County, Florida. It was in force for 55 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 25, 1997, 8:05 PM EDT (00:05 UTC)
Expired
Apr 25, 1997, 9:00 PM EDT
In force
55 min
Issued by
NWS Tampa Bay, FL
Area
Whole counties

County Polk County, FL

The radar

The Tampa radar (KTBW), 74 km from the middle of the area, began a volume at 00:08 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 nearest sounding before it

Tampa Bay, FL (KTBW), launched 00:00Z, 0.1 hours before the alert went out and 74 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 1997-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2124 joules per kilogram.LCLEL10008507005003002001001 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 1997-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 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
2124 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
975 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
188 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.0

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 Apr 25, 4:00 PM EDT, 4 hours 5 minutes earlier.

Area forecast discussion, Apr 25, 4:00 PM EDT, 4 hours 5 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY-RUSKIN, FL
300 PM EST FRI APR 25 1997

CLOUDS DEVELOPED OVER MOST OF THE FORECAST AREA (FA) TODAY POSSIBLY
DUE TO OVERRUNNING OR MOISTURE TRAPPED IN A FRONTAL INVERSION.  RADAR
CURRENTLY SHOWING ISOLATED THUNDERSTORM EAST OF NAPLES...AND A FEW
SHOWERS IN LEE COUNTY.  EXPECT THESE...AND ANY OTHER ISOLATED TO
WIDELY SCATTERED SHOWERS OR THUNDERSTORMS THAT FORM THIS
AFTERNOON...TO DIE OFF AFTER SUNSET.
MODELS...PARTICULARLY NGM...PAINTING WET SCENARIO OVER SOUTHEAST
GULF...FLORIDA STRAITS...SOUTH FLORIDA OVERNIGHT AND SATURDAY PROBABLY
DUE TO UPPER IMPULSE OR COLD POOL ALOFT OVER AN OLD FRONTAL BOUNDARY.
HOWEVER...AS HEIGHTS ALOFT START TO BUILD OVER US AHEAD OF CLOSED LOW
TO THE WEST...FEEL THAT THE MODELS ARE OVERPLAYING RAIN AMOUNTS.
SO...VARIABLE CLOUDINESS WITH 20 TO 30 PERCENT CHANCES FOR SHOWERS
THROUGH TOMORROW SEEM LIKE THE WAY TO GO FOR THE SOUTHERN HALF OF THE
FA.  GENERALLY FAIR WEATHER EXPECTED NORTHERN HALF.  PRESSURE GRADIENT
STARTS TO TIGHTEN TONIGHT AND TOMORROW AS HIGH MOVES INTO THE MID
ATLANTIC AND LOW PRESSURE INTENSIFIES OVER TEXAS.  BREEZY CONDITIONS
EXPECTED SATURDAY.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 25, 8:04 PM EDTSevere Thunderstorm WarningTBWPolk56 min
Apr 26, 5:01 AM EDTTornado WarningTBWHillsborough, Pinellas44 min
Apr 26, 6:50 AM EDTSevere Thunderstorm WarningTBWPinellas40 min
Apr 26, 7:23 AM EDTTornado WarningTBWPinellas67 min
Apr 26, 7:42 AM EDTSevere Thunderstorm WarningTBWHillsborough63 min
Apr 26, 7:49 AM EDTTornado WarningTBWHillsborough56 min
Apr 26, 8:35 AM EDTSevere Thunderstorm WarningTBWHillsborough, Pasco55 min
Apr 26, 8:59 AM EDTSevere Thunderstorm WarningTBWManatee61 min
Apr 26, 10:00 AM EDTSevere Thunderstorm WarningTBWManatee60 min
Apr 26, 10:21 AM EDTFlash Flood WarningTBWHillsborough, Manatee4 hr
Apr 26, 10:21 AM EDTFlash Flood WarningTBWPinellas4 hr
Apr 26, 10:21 AM EDTTornado WarningTBWManatee54 min
Apr 26, 10:24 AM EDTSevere Thunderstorm WarningTBWSarasota66 min
Apr 26, 11:20 AM EDTTornado WarningTBWPolk55 min
Apr 26, 11:30 AM EDTSevere Thunderstorm WarningTBWSarasota60 min
Apr 26, 11:37 AM EDTSevere Thunderstorm WarningTBWHardee, Polk68 min
Apr 26, 12:11 PM EDTSevere Thunderstorm WarningTBWHighlands64 min
Apr 26, 12:25 PM EDTSevere Thunderstorm WarningTBWDeSoto65 min

Nearby

Severe Thunderstorm Warnings in Florida, 1997Every severe thunderstorm warning in 1997

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.