Alert archive / Florida / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 16, NWS Tampa Bay, FL

March 31, 2011Hillsborough County, Manatee County, Pinellas County, Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at Mar 31, 2011, 11:22 AM EDT for Hillsborough County, Manatee County, Pinellas County, Florida. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Mar 31, 2011, 11:22 AM EDT (15:22 UTC)
Expired: Mar 31, 2011, 12:00 PM EDT
In force: 38 min
Issued by: NWS Tampa Bay, FL
Area: Storm-based polygon

Counties Hillsborough County, FL, Manatee County, FL, Pinellas County, FL

The radar

The Tampa radar (KTBW), 26 km from the middle of the area, began a volume at 15:24 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Mar 31, 6:00 AM EDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 12:00Z, 3.4 hours before the alert went out and 26 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: 728 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 787 m above ground
0-6 km bulk shear: 69 kt
0-1 km storm-relative helicity: 543 m²/s²
0-3 km storm-relative helicity: 606 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 8.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

693 
WUUS52 KTBW 311522
SVRTBW
FLC057-081-103-311600-
/O.NEW.KTBW.SV.W.0016.110331T1522Z-110331T1600Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1122 AM EDT THU MAR 31 2011

THE NATIONAL WEATHER SERVICE IN RUSKIN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN HILLSBOROUGH COUNTY IN FLORIDA.
  NORTHWESTERN MANATEE COUNTY IN FLORIDA.
  SOUTHEASTERN PINELLAS COUNTY IN FLORIDA.

* UNTIL NOON EDT

* AT 1120 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS IN
  EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR SAINT PETERSBURG
  BEACH...AND MOVING SOUTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SAINT PETERSBURG BEACH.
  GULFPORT.
  PALMETTO.
  ELLENTON.
  PARRISH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF
YOUR HOME OR BUSINESS. THIS STORM HAS THE POTENTIAL TO CAUSE SERIOUS
INJURY AND SIGNIFICANT DAMAGE TO PROPERTY.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 100 PM EDT THURSDAY AFTERNOON
FOR SOUTHWESTERN FLORIDA.

&&

LAT...LON 2774 8261 2768 8266 2761 8258 2771 8250
      2767 8234 2740 8256 2754 8274 2753 8268
      2758 8274 2759 8277 2760 8277 2754 8265
      2760 8261 2764 8265 2761 8274 2767 8273
      2776 8277 2777 8277
TIME...MOT...LOC 1522Z 298DEG 27KT 2770 8275

$$

JOHNSON

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 Mar 31, 9:58 AM EDT, 1 hour 24 minutes earlier.

Area forecast discussion, Mar 31, 9:58 AM EDT, 1 hour 24 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
958 AM EDT THU MAR 31 2011

.UPDATE...BUSY MORNING ACROSS WEST CENTRAL FLORIDA WITH INTENSE
AREA OF THUNDERSTORMS SPAWNING MULTIPLE TORNADOES. THE GRIDS WILL
ONLY BE UPDATED FOR MAJOR CHANGES SUCH AS ANY CHANGES TO OUR
WATCHES.

EXPECT THIS LINE OF SHOWERS AND STORMS TO CONTINUE THROUGH AT
LEAST MID AFTERNOON BEFORE A COLD FRONT PUSHES THE ACTIVITY OUT TO
THE EAST.

&&

.AVIATION...
STRONG TO SEVERE CONVECTION REMAINING NORTH OF THE TERMINAL SITES
EARLY THIS MORNING WITH A SOUTHWARD PROGRESSION NOTED IN RADAR
DATA. EXPECT AN INCREASE IN MVFR/IFR CONDITIONS AT PIE-TPA-SRQ
LATER THIS MORNING INTO EARLY THIS AFTERNOON. SRQ AND FMY-RSW WILL
SEE AN INCREASE IN CONVECTIVE ACTIVITY MID-LATER AFTERNOON AS THE
FRONTAL SYSTEM PUSHES SOUTH AND EAST...OTHERWISE VFR CONDITIONS
EXPECTED OVER SOUTHERN TERMINALS THROUGH THE EARLY AFTERNOON.

&&

.MARINE...HAZARDOUS WEATHER CONDITIONS EXIST OVER THE COASTAL
WATERS TODAY. NUMEROUS SHOWERS AND STORMS...SOME SEVERE...WILL
CONTINUE THROUGH MUCH OF THE DAY. THE ACTIVITY HAS BEEN PRIMARILY
NORTH OF TARPON SPRINGS BUT WILL SOON MOVE SOUTHEAST ACROSS THE
REMAINDER OF THE WATERS.

&&

.TBW WATCHES/WARNINGS/ADVISORIES...

FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING
     FOR ENGLEWOOD TO TARPON SPRINGS OUT 20 NM-ENGLEWOOD TO TARPON
     SPRINGS OUT 20 TO 60 NM-TAMPA BAY WATERS-TARPON SPRINGS TO
     SUWANNEE RIVER OUT 20 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT
     20 TO 60 NM.

&&

UPDATE/MARINE...JILLSON
AVIATION...LAMARRE

Hazardous weather outlook, Mar 31, 5:52 AM EDT, 5 hours 30 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL
552 AM EDT THU MAR 31 2011

FLZ039-042-043-048>052-055>057-060>062-065-312200-
LEVY-CITRUS-SUMTER-HERNANDO-PASCO-PINELLAS-HILLSBOROUGH-POLK-
MANATEE-HARDEE-HIGHLANDS-SARASOTA-DE SOTO-CHARLOTTE-LEE-
552 AM EDT THU MAR 31 2011

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

.DAY ONE...TODAY AND TONIGHT.

...THUNDERSTORM IMPACT...
A COLD FRONT WILL MOVE ACROSS THE AREA LATER TODAY BRINGING
SHOWERS AND THUNDERSTORMS. SOME OF THESE STORMS COULD BE STRONG
TO SEVERE AND PRODUCE DAMAGING WINDS AND AN ISOLATED TORNADO.
OTHERWISE STORMS WILL CONTAIN DEADLY LIGHTNING AND LOCALLY HEAVY
RAINFALL RESULTING IN MINOR FLOODING OF LOW LYING AND POOR
DRAINAGE AREAS.

...RIP CURRENT IMPACT...
MODERATE SOUTH TO SOUTHWEST WINDS TODAY WILL ALLOW FOR A MODERATE
RISK OF RIP CURRENTS AT AREA BEACHES. A RIP CURRENT IS A
10 TO 30 YARD WIDE CHANNEL OF WATER THAT CAN PULL EVEN A STRONG
SWIMMER INTO DEEPER WATER.

TO AVOID GETTING CAUGHT IN A RIP CURRENT...SWIM AT GUARDED
BEACHES AND HEED THE ADVICE OF THE BEACH PATROL. AT UNGUARDED
BEACHES AND NEAR PIERS...JETTIES...AND INLETS...DO NOT GO INTO THE
SURF MUCH ABOVE YOUR KNEES.

IF CAUGHT IN THE SEAWARD PULL OF A RIP CURRENT...DO NOT ATTEMPT
TO MOVE DIRECTLY TOWARD SHORE. INSTEAD...MOVE SIDEWAYS ACROSS THE
RIP CURRENT UNTIL THE PULL EASES. ANOTHER METHOD OF ESCAPE IS TO
LET THE RIP CURRENT PULL YOU SEAWARD 50 TO 100 YARDS...WHERE THE
FORCE WEAKENS. THEN...SWIM TOWARD THE BEACH AT AN ANGLE AWAY FROM
THE CURRENT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS SHOULD MONITOR THE WEATHER.
FORMAL ACTIVATION MAY BE NEEDED.

CARLISLE

In the hours before

Local storm report, Mar 31, 10:29 AM EDT, 53 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1029 AM EDT THU MAR 31 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0900 AM     TSTM WND DMG     HILLSBOROUGH RIVER STAT 28.10N 82.28W
03/31/2011                   HILLSBOROUGH       FL   EMERGENCY MNGR

            SEVERAL TREES DAMAGED IN PARK. REPORTED AS NO BIG DEAL.

&&

NOAH

Special weather statement, Mar 31, 10:37 AM EDT, 45 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1037 AM EDT THU MAR 31 2011

FLZ042-043-048-311515-
SUMTER-HERNANDO-CITRUS-
1037 AM EDT THU MAR 31 2011

...A SIGNIFICANT WEATHER ADVISORY HAS BEEN ISSUED FOR CITRUS...
NORTHWESTERN HERNANDO AND NORTHERN SUMTER COUNTIES FOR STRONG
THUNDERSTORMS WITH STRONG WIND GUSTS VALID UNTIL 1115 AM EDT...

AT 1033 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATES
STRONG THUNDERSTORMS LOCATED NEAR INVERNESS...MOVING EAST AT 50 MPH
WILL AFFECT INVERNESS...LAKE PANASOFFKEE AND WILDWOOD.

THIS INCLUDES INTERSTATE 75 BETWEEN EXITS 321 AND 329.

GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED WHICH CAN CAUSE UNSECURED
OBJECTS TO BLOW AROUND...SNAP TREE LIMBS AND CAUSE POWER OUTAGES.
FREQUENT TO CONTINUOUS LIGHTNING IS EXPECTED. TO BE SAFE GO INDOORS
IMMEDIATELY. IF CAUGHT OUTSIDE...FIND A LOW SPOT...AND STAY AWAY FROM
TALL OBJECTS. TORRENTIAL RAINS WILL REDUCE VISIBILITY TO NEAR ZERO
AND WILL CAUSE PONDING OF WATER ON ROADWAYS.

&&

LAT...LON 2902 8237 2896 8231 2896 8194 2875 8195
      2865 8265 2870 8265 2871 8267 2874 8268
      2875 8265 2876 8268 2886 8271 2889 8266
      2890 8269 2896 8273
TIME...MOT...LOC 1437Z 258DEG 45KT 2882 8225

JOHNSON

Local storm report, Mar 31, 11:08 AM EDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1108 AM EDT THU MAR 31 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0900 AM     TSTM WND GST     INDIAN ROCKS BEACH      27.90N 82.84W
03/31/2011  E70 MPH          PINELLAS           FL   MESONET

            RECORDED FROM A HOME WEATHER STATION.

&&

NOAH

Local storm report, Mar 31, 11:09 AM EDT, 13 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1109 AM EDT THU MAR 31 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1105 AM     TSTM WND GST     INDIAN ROCKS BEACH      27.90N 82.84W
03/31/2011  E70.00 MPH       PINELLAS           FL   MESONET

            RECORDED FROM A HOME WEATHER STATION. CORRECTED TIME.

&&

NOAH

Local storm report, Mar 31, 11:20 AM EDT, 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1120 AM EDT THU MAR 31 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1116 AM     HEAVY RAIN       FLORAL CITY             28.74N 82.29W
03/31/2011  E0.00 INCH       CITRUS             FL   EMERGENCY MNGR

            HEAVY RAIN HAS CLOSED TWO ROADS IN FLORAL CITY.

1116 AM     HEAVY RAIN       HERNANDO                28.91N 82.37W
03/31/2011  E0.00 INCH       CITRUS             FL   EMERGENCY MNGR

            ONE ROAD CLOSED IN HERNANDO.

1116 AM     HEAVY RAIN       CRYSTAL RIVER           28.90N 82.60W
03/31/2011  E0.00 INCH       CITRUS             FL   EMERGENCY MNGR

            LOCALIZED FLOODING.

&&

NOAH

Local storm report, Mar 31, 11:22 AM EDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
1122 AM EDT THU MAR 31 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1118 AM     TSTM WND DMG     MADEIRA BEACH           27.80N 82.79W
03/31/2011                   PINELLAS           FL   TRAINED SPOTTER

            ROOF DAMAGE AND SIGNS BLOWING ACROSS ROAD.

&&

NOAH

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 30, 8:57 PM EDT	Special Marine Warning	TBW		63 min
Mar 31, 1:06 AM EDT	Special Marine Warning	TBW		54 min
Mar 31, 4:50 AM EDT	Small Craft Advisory	TBW		17 hr
Mar 31, 5:47 AM EDT	Special Marine Warning	TBW		58 min
Mar 31, 6:10 AM EDT	Tornado Warning	TBW	Hernando, Pasco	50 min
Mar 31, 6:23 AM EDT	Severe Thunderstorm Warning	TBW	Hillsborough, Pasco, Pinellas	52 min
Mar 31, 6:43 AM EDT	Special Marine Warning	TBW		62 min
Mar 31, 7:15 AM EDT	Special Weather Statement	TBW	Polk	45 min
Mar 31, 7:30 AM EDT	Severe Thunderstorm Warning	TBW	Polk	45 min
Mar 31, 7:49 AM EDT	Special Marine Warning	TBW		26 min
Mar 31, 7:53 AM EDT	Severe Thunderstorm Warning	TBW	Hillsborough, Pasco, Pinellas	52 min
Mar 31, 8:24 AM EDT	Tornado Warning	TBW	Hillsborough, Pasco, Pinellas	51 min
Mar 31, 8:38 AM EDT	Special Weather Statement	TBW	Levy	52 min
Mar 31, 8:47 AM EDT	Special Marine Warning	TBW		58 min
Mar 31, 8:57 AM EDT	Tornado Warning	TBW	Hillsborough, Pasco, Polk	33 min
Mar 31, 9:13 AM EDT	Special Marine Warning	TBW		92 min
Mar 31, 9:14 AM EDT	Special Weather Statement	TBW	Citrus, Hernando	46 min
Mar 31, 9:26 AM EDT	Special Marine Warning	TBW		94 min
Mar 31, 9:29 AM EDT	Tornado Warning	TBW	Polk	19 min
Mar 31, 9:36 AM EDT	Special Weather Statement	TBW	Hernando, Sumter	39 min
Mar 31, 9:37 AM EDT	Areal Flood Advisory	TBW	Citrus, Hernando, Pasco, Polk, Sumter	113 min
Mar 31, 9:39 AM EDT	Special Weather Statement	TBW	Levy	51 min
Mar 31, 9:44 AM EDT	Tornado Warning	TBW	Citrus, Hernando, Sumter	31 min
Mar 31, 10:09 AM EDT	Special Marine Warning	TBW		51 min
Mar 31, 10:14 AM EDT	Severe Thunderstorm Warning	TBW	Hernando, Sumter	31 min
Mar 31, 10:29 AM EDT	Tornado Warning	TBW	Pinellas	61 min
Mar 31, 10:37 AM EDT	Special Weather Statement	TBW	Citrus	38 min
Mar 31, 10:52 AM EDT	Special Marine Warning	TBW		23 min
Mar 31, 11:09 AM EDT	Special Marine Warning	TBW		66 min
Mar 31, 11:14 AM EDT	Tornado Warning	TBW	Hillsborough, Pinellas	46 min
Mar 31, 11:35 AM EDT	Severe Thunderstorm Warning	TBW	Hillsborough, Polk	40 min
Mar 31, 11:47 AM EDT	Areal Flood Advisory	TBW	Hillsborough, Pinellas	88 min
Mar 31, 11:51 AM EDT	Tornado Warning	TBW	Hillsborough, Polk	39 min
Mar 31, 11:57 AM EDT	Severe Thunderstorm Warning	TBW	Hillsborough, Polk	33 min
Mar 31, 12:01 PM EDT	Special Marine Warning	TBW		59 min
Mar 31, 12:01 PM EDT	Severe Thunderstorm Warning	TBW	Manatee	44 min
Mar 31, 12:10 PM EDT	Special Weather Statement	TBW	Pinellas	50 min
Mar 31, 12:13 PM EDT	Tornado Warning	TBW	Polk	32 min
Mar 31, 12:16 PM EDT	Flash Flood Warning	TBW	Polk	59 min
Mar 31, 12:23 PM EDT	Severe Thunderstorm Warning	TBW	Polk	22 min
Mar 31, 12:25 PM EDT	Severe Thunderstorm Warning	TBW	Hillsborough, Manatee, Pinellas	35 min
Mar 31, 12:27 PM EDT	Special Marine Warning	TBW		63 min
Mar 31, 12:53 PM EDT	Special Weather Statement	TBW	Polk	52 min
Mar 31, 1:02 PM EDT	Special Marine Warning	TBW		118 min
Mar 31, 1:25 PM EDT	Areal Flood Advisory	TBW	Hillsborough, Manatee, Pinellas, Polk	2 hr
Mar 31, 1:29 PM EDT	Severe Thunderstorm Warning	TBW	Hillsborough, Manatee	31 min
Mar 31, 1:34 PM EDT	Special Weather Statement	TBW	Hillsborough, Pinellas	41 min
Mar 31, 2:01 PM EDT	Special Weather Statement	TBW	Manatee	44 min
Mar 31, 2:29 PM EDT	Special Weather Statement	TBW	Manatee, Sarasota	46 min
Mar 31, 2:33 PM EDT	Special Marine Warning	TBW		57 min
Mar 31, 3:13 PM EDT	Special Weather Statement	TBW	Hernando, Sumter	47 min
Mar 31, 3:16 PM EDT	Special Weather Statement	TBW	Pinellas	44 min
Mar 31, 3:18 PM EDT	Special Marine Warning	TBW		12 min
Mar 31, 3:21 PM EDT	River Flood Warning	TBW	Pasco	7 days
Mar 31, 3:21 PM EDT	River Flood Warning	TBW	Hillsborough	3 days
Mar 31, 3:35 PM EDT	Special Marine Warning	TBW		115 min
Mar 31, 4:27 PM EDT	Special Weather Statement	TBW	Manatee, Polk	63 min
Mar 31, 4:39 PM EDT	Severe Thunderstorm Warning	TBW	Hardee, Hillsborough, Manatee, Sarasota	36 min
Mar 31, 4:51 PM EDT	Severe Thunderstorm Warning	TBW	Manatee, Sarasota	24 min
Mar 31, 5:18 PM EDT	Special Marine Warning	TBW		57 min
Mar 31, 5:22 PM EDT	Special Weather Statement	TBW	DeSoto, Hardee, Highlands, Sarasota	53 min
Mar 31, 6:03 PM EDT	Severe Thunderstorm Warning	TBW	Hillsborough, Pasco, Pinellas	29 min
Mar 31, 6:14 PM EDT	Special Marine Warning	TBW		61 min
Mar 31, 7:47 PM EDT	Special Marine Warning	TBW		58 min
Mar 31, 7:55 PM EDT	Special Weather Statement	TBW	Charlotte	50 min

Nearby

Severe Thunderstorm Warnings in Florida, 2011 Every severe thunderstorm warning in 2011

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.