A cold front stalled over northern Florida with a prefrontal trough ahead of the front sliding down the peninsula, along with a line of thunderstorms. One of these storms produced damaging wind gusts.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS TBW wrote it up.
A cold front stalled over northern Florida with a prefrontal trough ahead of the front sliding down the peninsula, along with a line of thunderstorms. One of these storms produced damaging wind gusts.
The local office's own words before the first event, 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 the first event at Aug 20, 1:02 PM EST, 3 hours 3 minutes earlier.
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
202 PM EDT MON AUG 20 2012
...FLOOD WATCH IN EFFECT FOR HERNANDO...CITRUS...LEVY AND SUMTER
COUNTIES...
.SYNOPSIS...
EARLY THIS AFTERNOON - ALOFT...A LOW EAST OF JAMES BAY TROUGHED
SOUTH ACROSS THE EASTERN HALF OF THE U.S. TO THE NORTHERN GULF.
A RIDGE OVER THE OPEN ATLANTIC REACHED OVER CUBA TO THE NORTHWEST
CARIBBEAN. AT THE SURFACE...HIGH PRESSURE SPRAWLED ACROSS THE
NORTHERN AND CENTRAL PLAINS AS A STALLED FRONTAL BOUNDARY OVER
THE SOUTHERN PLAINS EXTENDED ACROSS THE GULF COAST AND SE U.S. TO
A LOW PRESSURE AREA OFFSHORE THE MID-ATLANTIC STATES. ATLANTIC
HIGH PRESSURE BETWEEN LATITUDE 25 AND 30 NORTH RIDGED THROUGH THE
FL STRAITS TO NEAR THE YUCATAN.
&&
.SHORT TERM (TONIGHT - WEDNESDAY)...
THE UPPER LOW MEANDERS EAST ACROSS CENTRAL QUEBEC AS THE LONG
WAVE TROUGH SHIFTS SOUTH OVER THE GULF AND THEN EAST IN RESPONSE
TO SHORT WAVE TROUGHS ROTATING AROUND THE MAIN TROUGH THROUGH
TUE. BY WED THE TROUGH BEGINS TO LIFT BACK TO THE NORTH SOME. THE
FRONTAL BOUNDARY GRADUALLY SAGS SOUTH AS IT DISSIPATES BUT LEAVES
RESIDUAL MOISTURE ACROSS MOST OF THE AREA...WITH MODEL PWAT VALUES
IN THE 1.9 TO 2.2 INCH RANGE. THE SURFACE RIDGE FROM THE ATLANTIC
ACROSS SOUTHERN FL TONIGHT SLOWLY TREKS NORTH AS THE TROUGH LIFTS
NORTH AND THE BOUNDARY WASHES OUT...WITH ITS AXIS REACHING CENTRAL
OR NORTH-CENTRAL BY WED.
AS NOTED ABOVE THESE FEATURES KEEP VERY DEEP MOISTURE FOCUSED
ACROSS NORTH AND PARTS OF CENTRAL FL WITH DEEP MOISTURE FOR THE
REST OF THE CWA. THE FORECAST WILL REFLECT THIS WITH THE HIGHEST
POPS...LIKELY...IN NORTH AND TENDING DOWN GOING SOUTH ON TUE.
FOR WED AS THE BOUNDARY BEGINS TO DISSIPATE AND THE UPPER TROUGH
ALONG WITH THE SURFACE RIDGE BOTH MOVE NORTH POPS WILL LOWER BUT
STILL STAY IN THE MID TO HIGH END SCATTERED RANGE. THE EXPECTED
HEAVY RAIN IN THE NORTH...THE POSSIBILITY OF TRAINING STORMS...AND
ALREADY SATURATED GROUND COULD LEAD TO A FLOODING RISK FOR
HERNANDO COUNTY NORTHWARD...WITH A FLOOD WATCH IN PLACE THROUGH
TUE EVENING.
.LONG TERM (WEDNESDAY NIGHT - MONDAY)...
BASE OF MID LEVEL TROUGH OVER THE EASTERN U.S. AND ATTENDANT
STATIONARY FRONT WILL PERSIST ACROSS THE NORTHERN GULF REGION
THROUGH THURSDAY. EMBEDDED SHORT WAVES MOVING THROUGH THE BASE
OF THE TROUGH COMBINED WITH AMPLE MOISTURE AND A DIVERGENT FLOW
ALOFT WILL CONTINUE TO SUPPORT A GOOD DEAL OF SHOWERS AND STORMS
WITH SOME LOCALLY HEAVY RAINFALL ACROSS WEST CENTRAL AND SOUTHWEST
FLORIDA WITH POPS IN THE 40 PERCENT RANGE. ON FRIDAY THE MID LEVEL
TROUGH AND FRONTAL BOUNDARY TO THE NORTH WILL WEAKEN SOME AS SURFACE
AND MID LEVEL RIDGING BUILDS BACK ACROSS THE NORTH CENTRAL PENINSULA
WITH AN EASTERLY FLOW DEVELOPING ACROSS THE FORECAST AREA WITH A
MORE TYPICAL SUMMERTIME REGIME EXPECTED WITH SCATTERED SHOWERS AND
STORMS ALONG THE SEA BREEZE DURING THE AFTERNOON WITH RAIN CHANCES
REMAINING IN THE SCATTERED RANGE.
DURING THE UPCOMING WEEKEND ALL EYES WILL BECOME FOCUSED ON THE
TROPICS. THE LATEST AND PREVIOUS RUNS OF THE GFS SHOWS A POTENTIAL
TROPICAL CYCLONE MOVING WEST ACROSS THE EASTERN CARIBBEAN ON
SATURDAY...THEN LIFTING NORTH INTO THE EASTERN GULF OF MEXICO ON
SUNDAY. THE ECMWF ON THE OTHER HAND KEEPS THIS SYSTEM MUCH FURTHER
TO THE SOUTH TRACKING IT WEST ACROSS THE CARIBBEAN AND TOWARD THE
YUCATAN PENINSULA. GIVEN THE DIFFERENCES IN THE MODELS WILL ERR ON
THE SIDE OF CAUTION AND KEEP SCATTERED RANGE POPS (30 TO 40 PERCENT)
IN PLACE THROUGH THE WEEKEND FOR NOW AND WAIT TO SEE IF BETTER
CONTINUITY DEVELOPS AMONG THE MODELS OVER THE COMING DAYS.
TEMPERATURES WILL RUN CLOSE TO NORMAL WITH DAYTIME HIGHS CLIMBING
INTO THE UPPER 80S TO AROUND 90 ALONG THE COAST AND LOWER 90S INLAND
WITH OVERNIGHT LOWS IN THE 70S.
&&
.AVIATION...
VFR CONDITIONS AT ALL TERMINALS THIS AFTERNOON WITH LCL VFR CIGS
035-040 MAINLY VCNTY LAL. OTHERWISE SCT CLDS 030-040 AND SCT LCL
BKN 250. SCATTERED TSTMS WILL DEVELOP THROUGH THE AFTERNOON WITH
LCL MVFR CIGS AND IFR VSBYS WITH THE BEST CHANCE OF THUNDERSTORMS
FROM TPA-SRQ AND EAST TO LAL.
&&
.MARINE...
ATLANTIC HIGH PRESSURE RIDGING ACROSS SOUTH FL WILL GRADUALLY MOVE
TO CENTRAL FL BY WED AS A FRONTAL BOUNDARY DISSIPATES ACROSS
NORTHERN FL. THE RIDGE CONTINUES MOVING NORTH...REACHING NORTH FL
FOR THE WEEKEND.
WINDS 5-10 KT THROUGH THE WORK WEEK AS THE RIDGE MOVES BY WITH
SOUTH AND SW WINDS...WITH AFTERNOON SEA BREEZES...BECOME NE AND
EAST. WINDS WILL PICK UP SOME FOR THE WEEKEND BUT ARE EXPECTED TO BE
NO MORE THAN 15 KT. SHOWERS AND THUNDERSTORMS...ESPECIALLY OVER
THE NORTHERN WATERS...CAN BE EXPECTED THROUGH THE NEXT FEW DAYS.
&&
.FIRE WEATHER...
AMPLE MOISTURE CONTINUES WITH NO CONCERNS THROUGH THE FORECAST
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 77 88 77 87 / 30 60 30 50
FMY 77 92 76 91 / 30 40 30 40
GIF 75 90 74 91 / 30 60 30 50
SRQ 77 88 76 88 / 30 50 30 50
BKV 73 87 72 89 / 40 60 30 50
SPG 79 87 79 85 / 30 60 30 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH TUESDAY EVENING FOR CITRUS-HERNANDO-
LEVY-SUMTER.
GULF WATERS...NONE.
&&
SYNOPSIS/SHORT TERM/MARINE/FIRE WEATHER...09/RUDE
LONG TERM...57/MCMICHAEL
AVIATION...13/OGLESBYHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL 129 PM EDT MON AUG 20 2012 FLZ039-042-043-048>052-055>057-060>062-065-210530- LEVY-CITRUS-SUMTER-HERNANDO-PASCO-PINELLAS-HILLSBOROUGH-POLK- MANATEE-HARDEE-HIGHLANDS-SARASOTA-DESOTO-CHARLOTTE-LEE- 129 PM EDT MON AUG 20 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL AND SOUTHWEST FLORIDA. .DAY ONE...THIS AFTERNOON AND TONIGHT. ...THUNDERSTORM IMPACT... A TROUGH OF LOW PRESSURE OVER NORTH FLORIDA COMBINED WITH DAYTIME HEATING AND DEEP TROPICAL MOISTURE WILL ALLOW WIDESPREAD SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE NATURE COAST THIS AFTERNOON. A FEW STORMS MAY BE SEVERE WITH DAMAGING WINDS AND POSSIBLY A BRIEF TORNADO...MAINLY NORTH OF BROOKSVILLE. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE REMAINDER OF WEST CENTRAL FLORIDA WITH AN ISOLATED SEVERE THUNDERSTORM POSSIBLE WITH DAMAGING WINDS..WITH THE GREATEST THREAT OVER THE INTERIOR PENINSULA. ...FLOOD IMPACT... THE QUASI STATIONARY TROUGH OVER NORTH FLORIDA WILL BE THE FOCUS FOR NUMEROUS SHOWERS AND THUNDERSTORMS FOR THE NEXT COUPLE OF DAYS. DEEP TROPICAL MOISTURE OVER THE AREA WILL CREATE IDEAL CONDITIONS FOR VERY HEAVY RAIN. SLOW MOVING BANDS OF THUNDERSTORMS MAY ALLOW FOR TRAINING TO DEVELOP WHICH COULD PRODUCE LOCALLY EXCESSIVE RAINFALL WHICH MAY CAUSE FLOODING OF ROADS AND LOW LYING AREAS. RAINFALL TOTALS OF 3 TO 6 INCHES IS POSSIBLE THROUGH TUESDAY WITH LOCALLY HIGHER AMOUNTS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. ...THUNDERSTORM IMPACT... TROUGH OF LOW PRESSURE OVER NORTH FLORIDA WILL CONTINUE TO PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE NATURE COAST ON TUESDAY. A FEW STORMS MAY BE STRONG WITH DAMAGING WINDS. THE MAIN THREAT WILL BE LOCALLY HEAVY RAIN. ...FLOOD IMPACT... POTENTIAL FOR FLOODING OF STREETS AND LOW LYING AREAS WILL CONTINUE ACROSS THE NATURE COAST INTO TUESDAY AS DEEP TROPICAL MOISTURE WILL REMAIN OVER THE AREA WITH LOCALLY HEAVY RAIN. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD MONITOR THE WEATHER AND SELF ACTIVATE IF NEEDED. OGLESBY
The Tampa radar (KTBW), 45 km away, was scanning. The volume nearest the first event began at 21:06 UTC.
2 thunderstorm wind. Local standard time, as filed.
Broadcast media reported an aluminum awning was torn off a building at the intersection of South Evergreen Avenue and Bellair Road.
Thunderstorm wind gusts knocked down an elongated temporary tent being setup as a tunnel for the Republican National Convention. Wind gusts in the area were reported as high as 45 MPH.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2012Every state in 2012This day in weather historyWarnings in Florida, August 2012
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 408901, 410467.