Alert archive / Florida / Tornado Warnings in 1999
Tornado Warning 20, NWS Tampa Bay, FL
NWS Tampa Bay, FL issued this tornado warning at Aug 12, 1999, 4:25 PM EDT for Hernando County, Florida. It was in force for 35 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
- Aug 12, 1999, 4:25 PM EDT (20:25 UTC)
- Expired
- Aug 12, 1999, 5:00 PM EDT
- In force
- 35 min
- Issued by
- NWS Tampa Bay, FL
- Area
- Whole counties
County Hernando County, FL
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 12, 5:00 PM EDT | Thunderstorm Wind | Istachatta, FL | A Skywarn Spotter reported that thunderstorm winds snapped the tops off two large pine and one oak tree and downed several large ten inch limbs three miles west of Istachatta. |
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, 8.4 hours before the alert went out and 95 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.
- Mixed-layer CAPE
- 2789 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 704 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 15 m²/s²
- 0-3 km storm-relative helicity
- 0 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KTBW 122034 COR TORTBW FLC053-122100- BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING...CORRECTED...CHANGED MOVEMENT NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL 425 PM EDT THU AUG 12 1999 THE NATIONAL WEATHER SERVICE IN RUSKIN HAS ISSUED A * TORNADO WARNING FOR... HERNANDO COUNTY IN WEST CENTRAL FLORIDA * UNTIL 500 PM EDT * AT 425 PM...A DEVELOPING TORNADO WAS INDICATED BY NATIONAL WEATHER SERVICE DOPPLER RADAR EAST OF HWY 41 ABOUT 5 MILES NE OF BROOKSVILLE. LITTLE MOVEMENT OR A SLIGHT DRIFT TO THE SOUTH. THIS IS A DANGEROUS SITUATION. PERSONS IN THE PATH OF THE STORM NEED TO TAKE COVER IN A STURDY BUILDING. MOBILE HOMES AND CARS ARE NOT SAFE.
What forecasters said that day
The local office's own words before this tornado 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 tornado warning went out at Aug 12, 1:30 PM EDT, 2 hours 55 minutes earlier.
Area forecast discussion, Aug 12, 1:30 PM EDT, 2 hours 55 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY-RUSKIN FL 130 PM EDT THU AUG 12 1999 CURRENTLY: STORMS ALONG THE COAST EARLIER TODAY HAVE SENT OUT BOUNDARIES TO THE EAST AND WEST...AND THIS IS WHERE THE NEW CONVECTION IS OCCURRING...I.E. ABOUT 25 MILES INLAND AND ABOUT 25 MILES OUT OVER THE GULF. STILL A FEW STRAGGLERS IN THE IMMEDIATE TAMPA BAY AREA...BUT THE BAY MUDDIES UP THE BOUNDARIES ANYWAY. IN THE NORTHERN COUNTIES A FEW SHOWERS ARE DEVELOPING INLAND. THIS SHOULD CONTINUE THROUGH THE AFTERNOON...MOVING SLOWLY EASTWARD. FORECAST: BASED ON DIURNAL TRENDS THE ACTIVITY OVER THE GULF AND ALONG THE COAST SHOULD DIMINISH BY EARLY EVENING...WITH INLAND SHOWERS AND THUNDERSTORMS HANGING AROUND A BIT LONGER. AS USUAL...THE MODEL SYNOPTIC FIELDS ARE IN REASONABLE AGREEMENT WHILE THE PRECIP FIELDS ARE QUITE DIFFERENT. IT LOOKS LIKE THE NGM VERIFIED ITS AREAL COVERAGE THE BEST SO FAR...SO I WILL USE THIS MODEL...ALTHOUGH I WILL BEEF UP THE CHANCES A BIT BECAUSE THE QPF HAS BEEN RUNNING TOO LOW. I DONT LIKE THE ETA PRECIP FIELD AT ALL... ESPECIALLY IN THE LATER TIME PERIODS. IT BRINGS A LARGE CHUNK OF PRECIP ACROSS OUR INLAND COUNTIES FROM THE NORTHEAST OVERNIGHT FRIDAY NIGHT...AND THIS WOULD BE QUITE UNUSUAL. TEMPS MAY GET QUITE TOASTY OVER THE NORTHERN COUNTIES FRIDAY WHERE I EXPECT THE MOST SUNSHINE. HEAT INDICES APPROACHING 110 WOULD NOT BE SURPRISING IN A FEW SPOTS FROM TAMPA BAY NORTHWARD. ALL MODELS DO SHOW SOME RETURNING MOISTURE BY SATURDAY AS A WEAK SURFACE TROF SETTLES OVER THE WEST COAST OF FLORIDA AND THE EASTERN GULF WATERS...SO I WILL GO ABOUT 10 PERCENT HIGHER POPS FOR MY LAST PERIOD. MARINE: WINDS SHOULD SLACKEN WITH TIME AS THE PRESSURE GRADIENT RELAXES AND WEAK TROF SETTLES IN OVER THE COASTAL WATERS. WILL GRADUALLY STEP DOWN WIND SPEEDS AND SEAS. FRIDAY NIGHT FORECAST IS A BIT TOUGH AS MODELS SHOW WEAK WINDS FROM A VARIETY OF DIRECTIONS. I WILL PLAY FOR A WEAK LANDBREEZE DEVELOPING CREATING OFFSHORE WINDS. THIS WOULD FOLLOW DIURNAL THINKING AS ANY SURFACE TROF SHOULD PLANT ITSELF OVER THE WARMER COASTAL WATERS AT NIGHT RATHER THAN OVER LAND. PRELIM NUMBERS: TPA BB 077/092 077/092 077 77242 FMY TT 078/092 077/093 077 77353 ALSHEIMER
Nearby
Tornado Warnings in Florida, 1999Every tornado warning in 1999Tornadoes 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.