Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 7, NWS Tampa Bay, FL

April 11, 20215 counties in Florida

NWS Tampa Bay, FL issued this severe thunderstorm warning at Apr 11, 2021, 11:09 AM EDT for 5 counties in Florida. It was in force for 32 min. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 11, 2021, 11:09 AM EDT (15:09 UTC)
Expired: Apr 11, 2021, 11:41 AM EDT
In force: 32 min
Issued by: NWS Tampa Bay, FL
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

Counties Hernando County, FL, Hillsborough County, FL, Pasco County, FL, Pinellas County, FL, Sumter County, FL

The radar

The Tampa radar (KTBW), 68 km from the middle of the area, began a volume at 15:08 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.

What was reported inside it

Time	Report	Where	Remark
Apr 11, 11:20 AM EDT	TSTM WND GST 43	1 Ese Tarpon Springs, FL	MESONET STATION 0581W 0.8 E TARPON SPRINGS (WEATHERSTEM).
Apr 11, 11:22 AM EDT	TSTM WND DMG	1 Wnw Palm Harbor, FL	ROOF DAMAGE. SHINGLES AND METAL PEELED BACK OR REMOVED.
Apr 11, 11:30 AM EDT	TSTM WND DMG	3 Ne Spring Hill, FL	* 1 FATAL * BROADCAST MEDIA IS CONFIRMING A WEATHER RELATED FATALITY ON EVENGLOW AVE IN SPRING HILL. A TREE FELL ON A CAR AND THE OCCUPANT WAS ELECTROCUTED AS THEY ATTEMPTED TO EXIT THE VEHICLE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

Issued	Product	Office	Lasted
Apr 11, 8:15 AM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 12:00Z, 3.2 hours before the alert went out and 68 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: 1004 J/kg
Mixed-layer CIN: -131 J/kg
Mixed-layer LCL: 1005 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 288 m²/s²
0-3 km storm-relative helicity: 296 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

Open this sounding in Storm Lab

The text

As transmitted.

390 
WUUS52 KTBW 111509
SVRTBW
FLC053-057-101-103-119-111600-
/O.NEW.KTBW.SV.W.0007.210411T1509Z-210411T1600Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tampa Bay Area Ruskin FL
1109 AM EDT Sun Apr 11 2021

The National Weather Service in Ruskin has issued a

* Severe Thunderstorm Warning for...
  Southwestern Sumter County in central Florida...
  Pasco County in west central Florida...
  Hernando County in west central Florida...
  Northwestern Pinellas County in west central Florida...
  Northwestern Hillsborough County in west central Florida...

* Until noon EDT.

* At 1108 AM EDT, severe thunderstorms were located along a line
  extending from 15 miles west of Weeki Wachee Gardens to 8 miles
  west of Beacon Square to 17 miles west of Harbor Bluffs, moving
  east at 35 mph.

  HAZARD...60 mph wind gusts and nickel size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Tampa, Spring Hill, Clearwater, New Port Richey, Zephyrhills,
  Brooksville, Dade City, Hudson, Lutz, Holiday, St. Leo, Weeki
  Wachee, Palm Harbor, New Port Richey East, South Brooksville, North
  Brooksville, Land O Lakes, Hernando County Airport, Wesley Chapel
  South and Timber Pines.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 2799 8284 2823 8276 2866 8268 2865 8227
      2846 8208 2813 8227
TIME...MOT...LOC 1508Z 252DEG 60KT 2858 8287 2824 8289 2799 8309 

HAIL...0.88IN
WIND...60MPH
 
$$

TBW

1 follow-up statement

266 
WWUS52 KTBW 111541
SVSTBW

Severe Weather Statement
National Weather Service Tampa Bay Area Ruskin FL
1141 AM EDT Sun Apr 11 2021

FLC053-057-101-103-119-111550-
/O.CAN.KTBW.SV.W.0007.000000T0000Z-210411T1600Z/
Sumter FL-Pasco FL-Hernando FL-Pinellas FL-Hillsborough FL-
1141 AM EDT Sun Apr 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SUMTER...PASCO...
HERNANDO...NORTHWESTERN PINELLAS AND NORTHWESTERN HILLSBOROUGH
COUNTIES IS CANCELLED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds and
heavy rain are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 400 PM EDT for
central and west central Florida.

LAT...LON 2799 8284 2823 8276 2866 8268 2865 8227
      2846 8208 2813 8227
TIME...MOT...LOC 1539Z 252DEG 60KT 2874 8231 2840 8233 2815 8253 

$$

TBW

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 11, 3:32 AM EDT	Small Craft Advisory	TBW		16 hr
Apr 11, 5:46 AM EDT	Special Weather Statement	TBW	Gilchrist	44 min
Apr 11, 9:13 AM EDT	Special Marine Warning	TBW		92 min
Apr 11, 9:14 AM EDT	Rip Current Statement	TBW	Charlotte, Hillsborough, Lee, Manatee, Pinellas, Sarasota	15 hr
Apr 11, 9:28 AM EDT	Special Weather Statement	TBW	Hernando	47 min
Apr 11, 10:44 AM EDT	Special Marine Warning	TBW		61 min
Apr 11, 11:49 AM EDT	Special Marine Warning	TBW		56 min
Apr 11, 11:56 AM EDT	Special Weather Statement	TBW	Hillsborough, Polk	64 min
Apr 11, 12:23 PM EDT	Special Weather Statement	TBW	Hillsborough, Pinellas	37 min
Apr 11, 1:01 PM EDT	Severe Thunderstorm Warning	TBW	Hardee, Hillsborough, Manatee, Polk	29 min
Apr 11, 1:32 PM EDT	Special Weather Statement	TBW	Hardee, Highlands	43 min
Apr 11, 1:47 PM EDT	Severe Thunderstorm Warning	TBW	Highlands	28 min
Apr 11, 3:13 PM EDT	Special Marine Warning	TBW		62 min
Apr 11, 3:41 PM EDT	Special Weather Statement	TBW	Charlotte, Lee	49 min
Apr 11, 4:08 PM EDT	Severe Thunderstorm Warning	TBW	Lee	17 min

Nearby

Severe Thunderstorm Warnings in Florida, 2021 Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.