Alert archive / Florida / Tornado Watches in 2012
Tornado Watch 186
The Storm Prediction Center issued this tornado watch at Apr 21, 2012, 11:08 PM EDT for 27 counties in Florida. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 21, 2012, 11:08 PM EDT (03:08 UTC)
- Expired
- Apr 22, 2012, 6:03 AM EDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 27 counties
Brevard County, FL, Broward County, FL, Charlotte County, FL, Citrus County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hardee County, FL, Hendry County, FL, Hernando County, FL, Highlands County, FL, Hillsborough County, FL, Indian River County, FL, Lee County, FL, Manatee County, FL, Martin County, FL, Miami-Dade County, FL, Monroe County, FL, Okeechobee County, FL, Osceola County, FL, Palm Beach County, FL, Pasco County, FL, Pinellas County, FL, Polk County, FL, Saint Lucie County, FL, Sarasota County, FL, Sumter County, FL
The radar
The Tampa radar (KTBW), 97 km from the middle of the area, began a volume at 03:08 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 50%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 11:12 PM EDT | Severe Thunderstorm Warning | TBW | Hernando, Hillsborough, Pasco, Pinellas | 48 min |
| Apr 22, 1:58 AM EDT | Severe Thunderstorm Warning | MFL | Glades | 32 min |
| Apr 22, 2:18 AM EDT | Severe Thunderstorm Warning | MFL | Glades | 42 min |
| Apr 22, 2:23 AM EDT | Severe Thunderstorm Warning | TBW | Highlands | 37 min |
| Apr 22, 2:49 AM EDT | Severe Thunderstorm Warning | MLB | Orange, Osceola | 26 min |
| Apr 22, 2:57 AM EDT | Severe Thunderstorm Warning | MFL | Glades | 33 min |
| Apr 22, 3:02 AM EDT | Severe Thunderstorm Warning | TBW | Highlands | 17 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Tampa Bay, FL (KTBW), launched 00:00Z, 3.1 hours before the alert went out and 97 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.
- Mixed-layer CAPE
- 12 J/kg
- Mixed-layer CIN
- -208 J/kg
- Mixed-layer LCL
- 622 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 228 m²/s²
- 0-3 km storm-relative helicity
- 217 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
475
WWUS20 KWNS 220307
SEL6
SPC WW 220307
FLZ000-CWZ000-221100-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 186
NWS STORM PREDICTION CENTER NORMAN OK
1110 PM EDT SAT APR 21 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
CENTRAL AND SOUTHERN FLORIDA PENINSULA
COASTAL WATERS
EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 1110 PM
UNTIL 700 AM EDT.
TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 70 MILES NORTHEAST OF SAINT
PETERSBURG FLORIDA TO 60 MILES SOUTH SOUTHWEST OF MIAMI FLORIDA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU6).
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.
DISCUSSION...SCATTERED THUNDERSTORMS ARE INCREASING OFF THE WEST
COAST OF CENTRAL/SOUTH FL. THESE STORMS ARE ASSOCIATED WITH A
STRONG UPPER TROUGH APPROACHING THE REGION. COOLING TEMPERATURES
ALOFT AND STRENGTHENING WIND FIELDS WILL PROMOTE A RISK OF STRONG TO
SEVERE THUNDERSTORMS OVERNIGHT ACROSS THE WATCH AREA. DAMAGING
WINDS ARE THE MAIN THREAT...BUT A FEW SUPERCELLS CAPABLE OF
TORNADOES ARE POSSIBLE.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 26025.
...HARTSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 10:10 PM EDT | Mesoscale Discussion | SPC | Charlotte, Collier, DeSoto, Glades, Hardee, Hendry and 10 more | 65 min |
| Apr 22, 2:21 AM EDT | Mesoscale Discussion | SPC | Brevard, Broward, Charlotte, Citrus, Collier, DeSoto and 22 more | 54 min |
Nearby
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.