A warm and moist environment was in place with high pressure ridging across the area. Scattered afternoon thunderstorms developed along sea breeze and outflow boundaries producing strong 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 warm and moist environment was in place with high pressure ridging across the area. Scattered afternoon thunderstorms developed along sea breeze and outflow boundaries producing strong 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 21, 11:55 AM EST, 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL 1255 PM EDT FRI AUG 21 2009 .SHORT TERM (TONIGHT-SUNDAY0...DEEP SUMMER TROF FROM THE GREAT LAKES DOWN INTO THE GULF OF MEXICO FOR THE WEEKEND. ATTENDANT VORT MAX TO PUSH ASSOCIATED SURFACE FRONT THROUGH THE DEEP SOUTH INTO THE N FL PENINSULA SATURDAY. THE VORT MAX CURRENTLY GENERATING THE LARGE AREA OF CONVECTION OVER THE N CENTRAL GULF AHEAD OF THE FRONT THIS AFTERNOON TO SWING INTO THE AREA SATURDAY COMBINING WITH DIURNAL HEATING TO PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS FROM THE BAY AREA NWARD THROUGH THE NATURE COAST AND HAVE RAISED POPS ALL AREAS. FURTHER S 40-50 POPS SHOULD HOLD FURTHEST AWAY FROM THESE DYNAMICS. WESTERLY FLOW SHOULD FAVOR MORNING THROUGH EARLY AFTERNOON STORMS NEAR THE COAST TRANSITIONING TO INLAND AREAS LATER IN THE AFTERNOON. FRONT STALLS AND WASHES OUT OVER THE AREA SUNDAY WHILE ANOTHER SHEARED VORT LOBE WRAPS AROUND THE BASE OF THE UPPER TROF IN THE REGION. THIS IS SLIGHTLY DIFFERENT THAN PREVIOUS MODELS RUNS...AS THEY HAD THE FRONT CLEARING THE AREA BEFORE...BUT THIS BEING AUGUST EXPECT THE FRONT TO STALL. SO HAVE INCREASED POPS TO SCATTERED ALL AREAS WITH HIGHER END FROM THE BAY AREA NWARD. TEMPS TO HOLD AROUND NORMAL ALL AREAS THROUGH THE WEEKEND. .LONG TERM (SUNDAY NIGHT-FRIDAY)...THE UPPER TROUGH WILL BE LIFTING OUT AS RIDGING BUILDS OVER THE STATE THROUGH MONDAY. UPPER RIDGING WILL THEN BE IN PLACE OVER THE AREA THROUGH FRIDAY. AT THE SFC...HIGH PRESSURE WILL BE TRANSITIONING FROM ACROSS SOUTH FL TO NORTH OF THE AREA SUNDAY NIGHT THROUGH MONDAY. THIS WILL TRANSITION WESTERLY FLOW TO EASTERLY FLOW BY MONDAY AND TRANSITION CONVECTION TIMING BACK TO LATE AFTERNOON/EVENING HOURS ALONG SEA BREEZE AND OUTFLOW BOUNDARIES. HIGH PRESSURE WILL THEN REMAIN CENTERED NORTH OF THE AREA THROUGH THURSDAY AND THEN WEAKEN ACROSS THE AREA FRIDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL WITH RIDGING IN PLACE. && .AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE NEXT 24 HOURS. SCATTERED THUNDERSTORMS THIS AFTERNOON WILL POSSIBLY CAUSE BRIEF MVFR CONDITIONS MAINLY 20-24Z. && .MARINE...COLD FRONT TO SLOWLY SINK INTO THE N GULF TONIGHT AND SATURDAY WITH LIGHT TO MODERATE WESTERLY FLOW OVER THE NE GULF WATERS SATURDAY WITH SEAS 2-3 FT AND SCATTERED TO NUMEROUS THUNDERSTORMS. WINDS/SEAS AND RAIN CHANCES TO DECREASE SUNDAY AS FRONT WASHES OUT IN THE AREA. HIGH PRESSURE TO BUILD BACK INTO THE REGION NEXT WEEK FOR A RETURN TO LIGHT EASTERLY FLOW AND AFTERNOON SEABREEZES AND STORMS. && .FIRE WEATHER...ABUNDANT LOW LEVEL MOISTURE CONTINUES. && .PRELIMINARY POINT TEMPS/POPS... TPA 92 77 89 76 / 40 20 60 30 FMY 93 76 91 75 / 30 20 40 30 GIF 93 75 90 75 / 50 20 60 30 SRQ 91 76 89 76 / 30 20 50 30 BKV 93 72 88 72 / 40 20 70 30 SPG 91 79 88 79 / 30 20 60 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && SHORT TERM/MARINE/FIRE WEATHER...25/DAVIS LONG TERM/AVIATION...24/COLSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL 540 AM EDT FRI AUG 21 2009 FLZ039-042-043-048>052-055>057-060>062-065-211600- LEVY-CITRUS-SUMTER-HERNANDO-PASCO-PINELLAS-HILLSBOROUGH-POLK- MANATEE-HARDEE-HIGHLANDS-SARASOTA-DE SOTO-CHARLOTTE-LEE- 540 AM EDT FRI AUG 21 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL AND SOUTHWEST FLORIDA. .DAY ONE...TODAY AND TONIGHT. ...THUNDERSTORM IMPACT... ABUNDANT MOISTURE WILL COMBINE WITH DAYTIME HEATING AND THE SEA BREEZES TO CAUSE SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON AND EVENING. A FEW OF THESE STORMS COULD BECOME STRONG AND PRODUCE LOCALLY HEAVY RAINFALL...GUSTY WINDS UP TO 40 MPH AND FREQUENT CLOUD TO GROUND LIGHTNING. REMEMBER...IF YOU CAN HEAR THUNDER THEN YOU ARE CLOSE ENOUGH TO THE STORM TO BE STRUCK BY LIGHTNING. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY. ...THUNDERSTORM IMPACT... A WEAKENING COOL FRONT WILL MOVE INTO THE DEEP SOUTH OVER THE WEEKEND HELPING TO SUPPRESS THE RIDGE AXIS TO ACROSS SOUTH FLORIDA. THIS WILL CAUSE A WEST TO SOUTHWEST FLOW TO SETUP ACROSS THE REGION SHIFTING THE TIMING OF THE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO LATE NIGHT INTO THE MIDDAY HOURS NEAR THE COAST AND OVER INLAND AREAS DURING THE AFTERNOON AND EVENING. EARLY NEXT WEEK HIGH PRESSURE WILL BUILD BACK IN FROM THE EAST SHIFTING THE FLOW BACK TO AN EASTERLY DIRECTION AND CAUSING THE TIMING TO CHANGE BACK TO THE AFTERNOON AND EVENING HOURS ACROSS THE ENTIRE AREA. ...WATERSPOUT IMPACT... THE WEST TO SOUTHWEST FLOW OVER THE WEEKEND WILL CAUSE THE THREAT OF WATERSPOUTS TO INCREASE ACROSS THE COASTAL WATERS. MARINERS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND BE PREPARED TO MOVE TO SAFE HARBOR QUICKLY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY. PRC
The Tampa radar (KTBW), 36 km away, was scanning. The volume nearest the first event began at 17:19 UTC.
1 thunderstorm wind, 1 lightning. Local standard time, as filed.
The ASOS station at the St. Petersburg-Clearwater International Airport measured a wind gust of 54 knots. This wind gust flipped over a Cessna 172 aircraft.
Lightning struck a house on Langley Place causing an attic fire. Quick response kept damage amounts minimal.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2009Every state in 2009This day in weather historyWarnings in Florida, August 2009
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: 191807, 192281.