Alert archive / Florida / Flash Flood Warnings in 1999

Flash Flood Warning 3, NWS Tampa Bay, FL

September 21, 1999Lee County, Florida

NWS Tampa Bay, FL issued this flash flood warning at Sep 21, 1999, 5:15 AM EDT for Lee County, Florida. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 21, 1999, 5:15 AM EDT (09:15 UTC)
Expired
Sep 21, 1999, 11:00 AM EDT
In force
6 hr
Issued by
NWS Tampa Bay, FL
Area
Whole counties

County Lee County, FL

The radar

The Tampa radar (KTBW), 132 km from the middle of the area, began a volume at 09:19 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, 9.3 hours before the alert went out and 132 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 1999-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 123 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 1999-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 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
123 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
689 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KTBW 210918
FFWTBW
FLC071-211500-

BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
515 AM EDT TUE SEP 21 1999

THE NATIONAL WEATHER SERVICE IN RUSKIN HAS RE-ISSUED A

* FLOOD WARNING FOR...
  SOUTHERN LEE COUNTY IN SOUTHWESTERN FLORIDA

* UNTIL 1100 AM EDT

* AT 5 AM...DOPPLER RADAR INDICATED THE HEAVIEST RAINFALL ASSOCIATED
WITH TROPICAL STORM HARVEY WAS CONFINED TO SOUTHWESTERN FLORIDA...
MAINLY FROM EXTREME SOUTHERN LEE COUNTY...SOUTHWARD INTO COLLIER
COUNTY. FLOODING IS EXPECTED TO CONTINUE IN AREAS FROM SAN
CARLOS PARK SOUTHWARD INTO BONITA SPRINGS...WHERE ONE TO TWO INCHES
OF ADDITIONAL RAINFALL IS POSSIBLE THROUGH 11 AM. IN ADDITION...
WATER FROM THE VERY HEAVY RAINFALL OVER WESTERN HENDRY AND
NORTHWESTERN COLLIER COUNTIES MAY FLOW SLOWLY WESTWARD TOWARD
SOUTHERN LEE COUNTY THROUGH THE REST OF THIS MORNING...WHICH MAY
WORSEN ANY FLOODING ALREADY ONGOING.

MOST FLOODING DEATHS OCCUR IN AUTOMOBILES. NEVER ATTEMPT TO DRIVE
THROUGH WATER WHICH COVERS THE ROADS. PERSONS LIVING IN FLOOD PRONE
AREAS NEED TO TAKE ACTION TO PROTECT PROPERTY AND MOVE TO HIGHER
GROUND. STAY AWAY FROM STORM DRAINS AND DRAINAGE DITCHES.

MORALES

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Sep 21, 2:30 AM EDT, 2 hours 45 minutes earlier.

Area forecast discussion, Sep 21, 2:30 AM EDT, 2 hours 45 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY-RUSKIN, FL
230 AM EDT TUE SEP 21 1999

ITS TIME TO START THINKING ABOUT POST HARVEY.  HARVEY WILL RAPIDLY
MOVE OFF TO THE NORTHEAST...DRAGGING COOLER DRIER AIR SOUTHWARD. THE
SURFACE RIDGE BUILDS ACROSS NORTH OF THE STATE BY THURSDAY VEERING
WINDS AROUND TO NORTHEAST.  THE TROUGH ALOFT HANGS BACK ACROSS THE
EASTERN GULF LEADING ME TO BELIEVE THAT THE WEATHER WILL NOT BE
COMPLETELY DRY...BUT MOISTURE AT THAT TIME SEEMS TO BE CONFINED TO
THE SOUTHERN THIRD OF THE STATE.

I WILL START BACKING OFF CONDITIONS A BIT FOR TODAY AS WINDS AND
SEAS SUBSIDE.  THE FRONT WILL PUSH THROUGH TONIGHT AND WINDS
WEDNESDAY WILL BE FROM THE NORTH NORTHWEST.  WITH WATER TEMPERATURES
IN THE 80S WE MAY SEE SOME STRATO CU MOVING ONSHORE...SO I WILL NOT
COMPLETELY CLEAR OUT COASTAL COUNTIES EVEN AFTER HARVEY HAS
COMPLETELY CLEARED THE AREA.

I AM WILL NOT STRAY TO FAR FROM A BLEND BETWEEN FWC AND FAN
GUIDANCE...EXCEPT FOR MAYBE UP THE POPS AND WINDS A BIT FOR
TODAY.

PRELIMINARY NUMBERS

TPA TB 083/073 086/070 732
FMY TB 083/075 087/072 743

SOBIEN

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 11:18 PM EDTFlash Flood WarningTBWLee6 hr

Nearby

Flash Flood Warnings in Florida, 1999Every flash flood warning in 1999

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.