Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 52, NWS Tampa Bay, FL

May 9, 1999Polk County, Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at May 9, 1999, 6:15 PM EDT for Polk County, Florida. It was in force for 30 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: May 9, 1999, 6:15 PM EDT (22:15 UTC)
Expired: May 9, 1999, 6:45 PM EDT
In force: 30 min
Issued by: NWS Tampa Bay, FL
Area: Whole counties

County Polk County, FL

What was reported inside it

Time	Report	Where	Remark
May 9, 6:21 PM EDT	Thunderstorm Wind 55	Lakeland, FL	A 63 mph wind gust was reported by Lakeland Municipal Airport weather observers.

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, 10.3 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 929 J/kg
Mixed-layer CIN: -130 J/kg
Mixed-layer LCL: 1185 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 16 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 May 9, 2:00 PM EDT, 4 hours 15 minutes earlier.

Area forecast discussion, May 9, 2:00 PM EDT, 4 hours 15 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY-RUSKIN FL
200 PM EDT SUN MAY 9 1999

CURRENTLY: WATCH HAS US HOPPING SO DISCUSSION WILL BE BRIEF.
CONVECTION FORMING ON WEST COAST SEABREEZE WITH MOTION BASED AS MUCH
ON PROPOGATION AS IT IS ON ADVECTION WITH LIGHT WINDS HOLDING BACK
STEERING. STORMS SHOULD GRADUALLY MOVE INLAND THROUGH THE AFTERNOON
AND EARLY EVENING. HAIL WILL AGAIN BE THE BIGGEST THREAT.

FORECAST: 3 MODELS GIVE 3 DIFFERENT SOLUTIONS ON EVOLUTION OF UPPER
LOW OVER THE SOUTHEAST DURING THE NEXT 2 DAYS. I HAVE SEEN IN THE
PAST THAT THE AVN MODEL TENDS TO DO BEST WITH THESE TYPES OF CUTOFFS
...SO WOULD LEAN TOWARD THAT SOLUTION. THIS PUTS THE CUTOFF THE
FARTHEST WEST AND RIGHT OVER THE STATE. THE POSITION WILL KEEP
SCATTERED DIURNAL CONVECTION GOING THROUGH THE FORECAST PERIOD AS
COLD TEMPS ALOFT CONTRIBUTE TO CONTINUING INSTABILITY.

TPA 67/88/67/88 1313
FMY 69/90/69/90 1313
LAL 66/90/66/90 2424

ALSHEIMER

The office that day

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

Issued	Product	Office	Counties	Lasted
May 9, 1:05 PM EDT	Severe Thunderstorm Warning	TBW	DeSoto	40 min
May 9, 1:24 PM EDT	Severe Thunderstorm Warning	TBW	Manatee	36 min
May 9, 2:15 PM EDT	Severe Thunderstorm Warning	TBW	Manatee	45 min
May 9, 2:25 PM EDT	Severe Thunderstorm Warning	TBW	Lee	50 min
May 9, 2:45 PM EDT	Severe Thunderstorm Warning	TBW	Highlands	45 min
May 9, 3:15 PM EDT	Severe Thunderstorm Warning	TBW	Lee	45 min
May 9, 4:00 PM EDT	Severe Thunderstorm Warning	TBW	Lee	30 min
May 9, 4:08 PM EDT	Severe Thunderstorm Warning	TBW	Polk	37 min
May 9, 7:08 PM EDT	Severe Thunderstorm Warning	TBW	Polk	47 min
May 9, 7:42 PM EDT	Severe Thunderstorm Warning	TBW	DeSoto	48 min
May 9, 7:55 PM EDT	Severe Thunderstorm Warning	TBW	Polk	35 min

Nearby

Severe Thunderstorm Warnings in Florida, 1999 Every severe thunderstorm 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.