Alert archive / Florida / Tornado Watches in 2012
Tornado Watch 590
The Storm Prediction Center issued this tornado watch at Aug 26, 2012, 11:24 PM EDT for 23 counties in Florida. It was in force for 12 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 26, 2012, 11:24 PM EDT (03:24 UTC)
- Expired
- Aug 27, 2012, 11:00 AM EDT
- In force
- 12 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
All 23 counties
Brevard County, FL, Broward County, FL, Charlotte County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hardee County, FL, Hendry 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, Pinellas County, FL, Polk County, FL, Saint Lucie County, FL, Sarasota County, FL
The radar
The Tampa radar (KTBW), 126 km from the middle of the area, began a volume at 03:27 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
- 30%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 10%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 30%
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 27, 12:36 AM EDT | Severe Thunderstorm Warning | MLB | Martin, Okeechobee | 54 min |
| Aug 27, 12:47 AM EDT | Tornado Warning | MLB | Okeechobee | 28 min |
| Aug 27, 1:51 AM EDT | Flash Flood Warning | MFL | Palm Beach | 9 hr |
| Aug 27, 4:13 AM EDT | Severe Thunderstorm Warning | MLB | Brevard, Orange, Osceola | 42 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, 3.4 hours before the alert went out and 126 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
- 275 J/kg
- Mixed-layer CIN
- -34 J/kg
- Mixed-layer LCL
- 782 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 113 m²/s²
- 0-3 km storm-relative helicity
- 163 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.5
The text
As transmitted, in the capitals the NWS used until 2016.
485
WWUS20 KWNS 270331
SEL0
SPC WW 270331
FLZ000-CWZ000-271300-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 590
NWS STORM PREDICTION CENTER NORMAN OK
1125 PM EDT SUN AUG 26 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHERN AND CENTRAL FLORIDA
COASTAL WATERS
EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1125 PM UNTIL
900 AM EDT.
TORNADOES...HAIL TO 0.5 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 85 STATUTE
MILES EITHER SIDE OF A LINE FROM 20 MILES NORTH OF SARASOTA
FLORIDA TO 20 MILES EAST NORTHEAST OF MIAMI FLORIDA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU0).
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...LOW LVL DIRECTIONAL AND SPEED SHEAR HAVE INCREASED
SOMEWHAT OVER THE PAST SEVERAL HOURS ALONG THE SE FL CST. TSTMS ARE
EXPECTED TO CONTINUE FORMING IN LOW LVL CONFLUENCE BAND ARCING NW TO
SE ACROSS THE REGION IN ASSOCIATION WITH T.S. ISSAC. ANOTHER BAND
MAY EVOLVE LATER TNGT/EARLY MON ALONG THE SW FL CST. WITH ISAAC
EXPECTED TO CONTINUE WNW OVERNIGHT FROM ITS CURRENT POSITION OFF THE
SW FL CST...AN AXIS OF INCREASING RICH THETA-E MAY SPREAD NWWD
ACROSS THE SRN THIRD OF THE PENINSULA. COUPLED WITH STRENGTHENING
LOW LVL SHEAR...SETUP MAY FOSTER ISOLD TORNADOES...MAINLY ALONG THE
PREVIOUSLY-MENTIONED CONFLUENCE BANDS.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 15045.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 10:44 PM EDT | Mesoscale Discussion | SPC | Broward, Charlotte, Collier, DeSoto, Glades, Hendry and 4 more | 2 hr |
| Aug 27, 3:44 AM EDT | Mesoscale Discussion | SPC | Broward, Charlotte, Collier, DeSoto, Glades, Hardee and 16 more | 2 hr |
| Aug 27, 7:26 AM EDT | Mesoscale Discussion | SPC | Brevard, Citrus, Dixie, Gilchrist, Hernando, Indian River and 13 more | 3 hr |
| Aug 27, 7:55 AM EDT | Mesoscale Discussion | SPC | Broward, Charlotte, Collier, DeSoto, Glades, Hardee and 16 more | 95 min |
| Aug 27, 11:54 AM EDT | Mesoscale Discussion | SPC | Indian River, Lake, Marion, Orange, Osceola, Saint Lucie and 3 more | 2 hr |
| Aug 27, 2:28 PM EDT | Mesoscale Discussion | SPC | Citrus, DeSoto, Hardee, Hernando, Highlands, Hillsborough and 6 more | 92 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.