Alert archive / Florida / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 144, NWS Tampa Bay, FL

September 4, 2001Polk County, Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at Sep 4, 2001, 6:37 PM EDT for Polk County, Florida. It was in force for 38 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
Sep 4, 2001, 6:37 PM EDT (22:37 UTC)
Expired
Sep 4, 2001, 7:15 PM EDT
In force
38 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 22:37 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
Sep 4, 6:45 PM EDTThunderstorm WindDavenport, FLThe Davenport fire department reported that several large three to six foot long branches were downed between Davenport and Loughman along U.S. Highway 92 in extreme northeast Polk county.

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, 10.6 hours before the alert went out and 131 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 2001-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2418 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 2001-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 square meters per square second.1939Sfc1 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
2418 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
681 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
-4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 Sep 4, 1:30 PM EDT, 5 hours 7 minutes earlier.

Area forecast discussion, Sep 4, 1:30 PM EDT, 5 hours 7 minutes before
WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
130 PM EDT TUE SEP 4 2001

CURRENTLY...SCT SHOWERS AND TSTMS FIRING AS EXPECTED ALONG THE WEST
COAST SEA BREEZE. TSTMS AROUND THE TAMPA BAY AREA MUCH EARLIER THAN
YESTERDAY. VISIBLE SAT LOOP SHOWING S-N ALLIGNED CLOUD STREETS...
WHICH CLEARLY INDICATES A SOUTHERLY STEERING FLOW. A SLIGHT
ANTICYCLONIC CURVATURE IN THE CLOUD STREETS OVER THE CENT FA UNDER
THE SFC RIDGE AXIS.

--FCST DISC--
MODELS VERY SIMILAR WITH SHOWING LITTLE TO NO CHANGE IN LARGE SCALE
PATTERN THROUGH 60 HRS. UPPER SHEAR AXIS AND WEAK SFC TROF WILL
REMAIN WELL NORTH OF THE AREA OVER S GA...WHILE IL-DEFINED SFC
RIDGE AXIS SITS GENERALLY OVER THE N 1/2 OF THE FA. WEAK SSE
SYNOPTIC LOW LEVEL FLOW WILL PERSIST...WITH AFTN WEST COAST SEA
BREEZES. WITH WEAK SOUTHERLY STEERING FLOW...EXPECT STORMS TO FIRST
FORM ALONG THE SEA BREEZE...AND THEN FORM ALONG CONFLUENT BOUNDARIES
WELL INLAND. BY LATER IN THE AFTN/EVENING...THE WEST COAST SEA
BREEZE AND OUTFLOW BOUNDARIES WILL INTERACT...ESPECIALLY FROM ABT
SRQ N...WHERE WEST COAST SEA BREEZE EXPECTED TO PUSH FARTHER INLAND.
NEAR CLIMO 40-50% POPS SEEM APPROPRIATE FOR NOW...SAME AS CURRENT
FCST.

--EXTENDED--
NEW AVN AND OLD MRF INDICATE ESE FLOW TO PERSIST THROUGH EARLY NEXT
WEEK. LITTLE/NO CHANGE EXPECTED TO CURRENT EXTENDED. WILL ALSO NEED
TO KEEP A CLOSE EYE ON FUTURE TRACK OF ERIN.

--MARINE--
RELATIVELY LIGHT WINDS WITH NO HIGHLIGHTS TO CONTINUE THROUGH THE
PERIOD. NO SIGNIFICANT CHGS EXPECTED.

PRELIM S:
TPA 077/090 076/090 3545
FMY 075/091 075/091 4555=

.TBW...NONE.
MORALES

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.