Alert archive / Florida / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 53, NWS Tampa Bay, FL

June 17, 2009Hillsborough County, Pasco County, Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at Jun 17, 2009, 6:30 PM EDT for Hillsborough County, Pasco County, Florida. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 17, 2009, 6:30 PM EDT (22:30 UTC)
Expired
Jun 17, 2009, 7:00 PM EDT
In force
30 min
Issued by
NWS Tampa Bay, FL
Area
Storm-based polygon

Counties Hillsborough County, FL, Pasco County, FL

The radar

The Tampa radar (KTBW), 45 km from the middle of the area, began a volume at 22:32 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

Jacksonville, FL (KJAX), launched 12:00Z, 10.5 hours before the alert went out and 274 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, Jacksonville, FL at 12:00Z on 2009-06-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3004 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, Jacksonville, FL at 12:00Z on 2009-06-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
3004 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
605 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

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 Jun 17, 1:17 PM EDT, 5 hours 13 minutes earlier.

Area forecast discussion, Jun 17, 1:17 PM EDT, 5 hours 13 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
117 PM EDT WED JUN 17 2009

.SYNOPSIS...AREA IS ON THE EAST SIDE OF A HIGH CENTER OVER THE
NORTHERN GULF COAST...WITH A WEAK PRESSURE GRADIENT ACROSS THE
PENINSULA. LIKEWISE...ALOFT HAVE RIDGING TO OUR WEST...WITH OUR
REGION MOVING INTO SOME DRIER AIR.

&&

.SHORT TERM (TONIGHT-FRIDAY)...THE AIR IS NOT TOO DRY FOR STORM
DEVELOPMENT...AND EXPECT ISOLATED TO SCATTERED STORMS THROUGH THIS
EVENING. PATTERN DOESNT CHANGE MUCH THURSDAY OR FRIDAY...THOUGH THE
UPPER RIDGE WILL MOVE INTO POSITION OVER THE DEEP SOUTH. THIS
PATTERN SHIFT SHOULD MEAN SOME MORE DRY MID LEVEL AIR AND
SINKING...ESPECIALLY OVER THE NORTHERN CWA...CLOSER TO THE HIGH
CENTER. STILL SHOULD BE ENOUGH MOISTURE FOR ISOLATED TO SCATTERED
STORMS EACH DAY AS TEMPERATURES CONTINUE ABOVE NORMAL.

.LONG TERM (FRIDAY NIGHT-WEDNESDAY)...STRONG UPPER RIDGE OVER THE
LOWER MISSISSIPPI VALLEY/NORTHERN GULF REGION WILL HOLD FIRM THROUGH
SATURDAY THEN WILL WEAKEN SOME AND RETROGRADE WEST SUNDAY THROUGH
EARLY NEXT WEEK AS A LONG WAVE TROUGH DEVELOPS OVER THE EASTERN
SEABOARD. SURFACE RIDGE AXIS INITIALLY ACROSS THE CENTRAL PENINSULA
WILL SINK SOUTH IN RESPONSE TO THE DEVELOPING UPPER TROUGH WITH THE
AXIS SETTING UP SHOP ACROSS THE SOUTHERN PENINSULA AND FLORIDA
STRAITS THROUGH THE PERIOD. ISOLATED TO SCATTERED SHOWERS AND STORMS
(POPS 20-30% RANGE) ARE EXPECTED ALONG THE SEA BREEZE CIRCULATIONS
DURING SATURDAY AND SUNDAY WITH A WESTERLY STEERING FLOW FAVORING
BEST COVERAGE OF SHOWERS/STORMS OVER INLAND SECTIONS DURING THE
AFTERNOON AND EARLY EVENING HOURS.

DURING MONDAY THROUGH WEDNESDAY THE AFOREMENTIONED DEVELOPING UPPER
TROUGH COMBINED WITH AMPLE MOISTURE...WEAK VORT LOBES MOVING
SOUTHEAST ACROSS THE REGION WITHIN THE DEVELOPING CYCLONIC NORTHWEST
FLOW ALOFT...THE SEA BREEZE CIRCULATIONS AND A BACK-DOOR TYPE FRONT
SAGGING SOUTH WILL ALL LEAD TO INCREASING RAIN CHANCES OVER THE
FORECAST AREA. ENSEMBLE POPS LOOK A BIT LOW GIVEN THE ABOVE
MENTIONED FEATURES...SO WILL DEPICT POPS IN THE 40-60% RANGE COAST
TO INLAND LOCATIONS DURING THIS TIME FRAME. ONSHORE FLOW WILL
CONTINUE TO FAVOR SHOWERS/STORMS ALONG THE COAST DURING THE LATE
NIGHT AND EARLY MORNING HOURS WITH THE CONVECTION SHIFTING TOWARD
INLAND LOCATIONS EACH AFTERNOON. ABOVE NORMAL TEMPERATURES ARE
EXPECTED THROUGH THE WEEKEND BEFORE RETURNING TO NEAR NORMAL LEVELS
EARLY NEXT WEEK AS THE RAIN CHANCES INCREASE.

ON A SIDE NOTE THE LATEST GFS SHOWS DRIER AIR BEING DRAWN SOUTH INTO
THE REGION DURING TUESDAY/WEDNESDAY AS THE EAST COAST TROUGH
AMPLIFIES WITH SOME SORT OF WEAK SURFACE LOW DEVELOPMENT OFF THE
SOUTHWEST FLORIDA COAST ALONG THE TAIL END OF THE BACK-DOOR FRONT.
00Z/06Z GFS AND 00Z ECMWF RUNS DID NOT SHOW THIS DRIER AIR OR LOW
DEVELOPMENT...SO FOR THE TIME BEING WILL ERR ON THE SIDE OF CAUTION
WITH RESPECT TO THIS SOLUTION AND KEEP ABOVE NORMAL POPS IN PLACE
AND WAIT TO SEE WHAT FUTURE MODEL RUNS SHOW OVER THE NEXT FEW DAYS.

&&

.AVIATION...SCATTERED SHOWERS AND THUNDERSTORMS MAY PRODUCE BRIEF
TEMPO MVFR/IFR CEILINGS AND VISIBILITIES AT THE TERMINAL SITES
THROUGH 18/03Z THIS EVENING...THEN VFR CONDITIONS ARE EXPECTED
OVERNIGHT. ADDITIONAL BRIEF MVFR/IFR CIGS/VSBYS WILL AGAIN BE
POSSIBLE LATE MORNING THROUGH THE AFTERNOON ON THURSDAY AS SHOWERS
AND THUNDERSTORMS REDEVELOP ACROSS THE REGION.

&&

.MARINE...EXPECT ISOLATED STORMS LATER THIS AFTERNOON AND EVENING
NEAR THE COAST AND THEN AGAIN TOMORROW LATE AFTERNOON. OTHERWISE
WEATHER IS FAIRLY TRANQUIL FOR BOATING.

&&

.FIRE WEATHER...NO CONCERNS.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  77  93  77  92 /  30  30  20  20
FMY  75  94  74  94 /  30  40  20  30
GIF  75  95  75  95 /  30  40  20  30
SRQ  75  92  74  91 /  30  20  20  20
BKV  70  93  70  94 /  20  30  20  20
SPG  80  93  80  92 /  20  30  20  20

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&

SHORT TERM/MARINE/FIRE WEATHER...55/SHARP
LONG TERM/AVIATION...57/MCMICHAEL
Hazardous weather outlook, Jun 17, 5:04 AM EDT, 13 hours 26 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
504 AM EDT WED JUN 17 2009

FLZ039-042-043-048>052-055>057-060>062-065-172115-
LEVY-CITRUS-SUMTER-HERNANDO-PASCO-PINELLAS-HILLSBOROUGH-POLK-
MANATEE-HARDEE-HIGHLANDS-SARASOTA-DE SOTO-CHARLOTTE-LEE-
504 AM EDT WED JUN 17 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL AND SOUTHWEST
FLORIDA.

.DAY ONE...TODAY AND TONIGHT.

...THUNDERSTORM IMPACT...
SHOWERS AND THUNDERSTORMS WILL BEGIN IN THE LATE MORNING OR EARLY
AFTERNOON AND THEN CONTINUE THROUGH THE EVENING...SCATTERED ACROSS
INLAND AREAS BUT ISOLATED ALONG IMMEDIATE COASTAL LOCATIONS. THE
MAIN THREATS WILL BE FREQUENT LIGHTNING...GUSTY WINDS AND HEAVY
BUT BRIEF RAINFALL.

...EXCESSIVE HEAT IMPACT...
TEMPERATURES WILL RISE QUICKLY INTO THE MID 90S BY MID AFTERNOON
WITH HEAT INDICES OF 100 TO 105 IN SCATTERED LOCATIONS AWAY FROM
THE GULF. DRINK PLENTY OF WATER...BEFORE YOU GET THIRSTY. WEAR
LIGHTWEIGHT AND LIGHT COLORED CLOTHING. RESERVE STRENUOUS EXERCISE
FOR EARLY MORNING OR EVENING HOURS. STAY NEAR AIR CONDITIONED
LOCATIONS IF POSSIBLE.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

...THUNDERSTORM IMPACT...
ISOLATED TO SCATTERED THUNDERSTORMS...IN THE AFTERNOONS AND EARLY
EARLY EVENINGS...WILL CONTINUE THROUGH MONDAY AND THEN INCREASE TO
SCATTERED TO NUMEROUS TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

09/RKR

In the hours before

Special weather statement, Jun 17, 4:42 PM EDT, 1 hour 48 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
442 PM EDT WED JUN 17 2009

FLZ039-172115-
LEVY-
442 PM EDT WED JUN 17 2009

...STRONG THUNDERSTORMS WILL AFFECT SOUTHERN LEVY COUNTY...

NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATES A THUNDERSTORM...
MOVING WEST AT 5 MPH...WILL AFFECT LEBANON...UNTIL 515 PM EDT.

GUSTY WINDS UP TO 40 MPH WILL OCCUR. FREQUENT LIGHTNING IS EXPECTED.
TO BE SAFE GO INDOORS IMMEDIATELY IF CAUGHT OUTSIDE...FIND A LOW
SPOT...AND STAY AWAY FROM TALL OBJECTS. THIS STORM WILL PRODUCE PEA
SIZE HAIL. TORRENTIAL RAINS WILL REDUCE VISIBILITY TO NEAR ZERO AND
WILL CAUSE PONDING OF WATER ON ROADWAYS.

LAT...LON 2904 8273 2918 8279 2927 8267 2915 8254
TIME...MOT...LOC 2042Z 073DEG 3KT 2917 8267
Special weather statement, Jun 17, 4:53 PM EDT, 1 hour 37 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
453 PM EDT WED JUN 17 2009

FLZ049-051-172145-
HILLSBOROUGH-PASCO-
453 PM EDT WED JUN 17 2009

...STRONG THUNDERSTORMS WILL AFFECT SOUTHERN PASCO AND NORTHERN
HILLSBOROUGH COUNTIES...

NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATES A THUNDERSTORM...
MOVING SOUTHWEST AT 5 MPH...WILL AFFECT LUTZ AND CARROLLWOOD...UNTIL
545 PM EDT.

GUSTY WINDS UP TO 40 MPH WILL OCCUR. FREQUENT LIGHTNING IS EXPECTED.
TO BE SAFE GO INDOORS IMMEDIATELY IF CAUGHT OUTSIDE...FIND A LOW
SPOT...AND STAY AWAY FROM TALL OBJECTS. THIS STORM WILL PRODUCE PEA
SIZE HAIL. TORRENTIAL RAINS WILL REDUCE VISIBILITY TO NEAR ZERO AND
WILL CAUSE PONDING OF WATER ON ROADWAYS.

LAT...LON 2800 8245 2808 8256 2820 8245 2815 8233
TIME...MOT...LOC 2054Z 037DEG 5KT 2814 8244
Local storm report, Jun 17, 5:18 PM EDT, 1 hour 12 minutes before
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Local storm report, Jun 17, 5:20 PM EDT, 1 hour 10 minutes before
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Local storm report, Jun 17, 5:37 PM EDT, 53 minutes before
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Local storm report, Jun 17, 6:27 PM EDT, 3 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jun 16, 8:20 PM EDTSpecial Weather StatementTBWDeSoto, Hardee, Highlands, Polk, Sumter70 min
Jun 16, 9:27 PM EDTSpecial Weather StatementTBWDeSoto, Hardee, Highlands, Polk48 min
Jun 16, 11:14 PM EDTSpecial Weather StatementTBWCharlotte, Lee61 min
Jun 16, 11:17 PM EDTSpecial Marine WarningTBW43 min
Jun 17, 3:28 PM EDTSpecial Weather StatementTBWHernando32 min
Jun 17, 4:21 PM EDTSpecial Weather StatementTBWHernando24 min
Jun 17, 4:42 PM EDTSpecial Weather StatementTBWLevy33 min
Jun 17, 4:53 PM EDTSpecial Weather StatementTBWHillsborough52 min
Jun 17, 5:13 PM EDTSevere Thunderstorm WarningTBWHillsborough47 min
Jun 17, 5:27 PM EDTSevere Thunderstorm WarningTBWLevy33 min
Jun 17, 5:38 PM EDTSpecial Marine WarningTBW52 min
Jun 17, 5:56 PM EDTSevere Thunderstorm WarningTBWHillsborough34 min
Jun 17, 6:49 PM EDTSpecial Marine WarningTBW41 min
Jun 17, 6:56 PM EDTSevere Thunderstorm WarningTBWDeSoto, Hardee18 min
Jun 17, 7:23 PM EDTSevere Thunderstorm WarningTBWHernando, Pasco37 min

Nearby

Severe Thunderstorm Warnings in Florida, 2009Every severe thunderstorm warning in 2009

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.