Alert archive / Florida / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 94, NWS Tampa Bay, FL

July 4, 1997Polk County, Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at Jul 4, 1997, 4:54 PM EDT for Polk County, Florida. It was in force for 71 min. 4 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
Jul 4, 1997, 4:54 PM EDT (20:54 UTC)
Expired
Jul 4, 1997, 6:05 PM EDT
In force
71 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 20:54 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
Jul 4, 5:10 PM EDTHail 0.75Lakeland, FLDime sized hail was reported in Bradley along State Road 37.
Jul 4, 5:30 PM EDTHail 0.88Lakeland, FLNickel sized hail was reported in Mulberry along State Road 37.
Jul 4, 5:40 PM EDTHail 1.75Winter Haven, FLGolfball to nickel sized hail was reported in Winter Haven.
Jul 4, 5:45 PM EDTThunderstorm WindWinter Haven, FLThunderstorm winds downed numerous power lines across Winter Haven which left nearly 15,000 residents without electrical power for up to nine hours.

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

Tampa Bay, FL (KTBW), launched 12:00Z, 8.9 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 12:00Z on 1997-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3025 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 1997-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
3025 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
755 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.3

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 Jul 4, 2:54 PM EDT, 2 hours earlier.

Area forecast discussion, Jul 4, 2:54 PM EDT, 2 hours before
AREA FORECAST DISCUSSION...CORRECTED FOR STM MOTION.
NATIONAL WEATHER SERVICE TAMPA BAY-RUSKIN, FL
253 PM EDT FRI JUL 04 1997

...RAISED POPS FOR SCENT AND SW ZONES...
JUST A QUICK UPDATE TO REGROUP SOME ZONES AND RAISE POPS OVR SCENT
AND SW ZONES. 88D SHOWING ACTIVITY PICKING UP RAPIDLY...WITH PULSE
STRNG/SVR STMS OVR SW/SCENT ZONES. EXPECTING HOT SPOT TO BE OVR SCENT
AREA WHERE WCSB AND LAKE BRZ POSSIBLY MEET. STM MOTION HAS BEEN WESTERLY
WITH SFC/LLVL WESTERLY FLO HELPING TO FEED STM DEVELOPMENT.

MORALES

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 3:29 PM EDTSevere Thunderstorm WarningTBWHardee, Manatee61 min
Jul 4, 5:15 PM EDTSevere Thunderstorm WarningTBWHillsborough65 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.