Alert archive / Florida / Tornado Watches in 2012
Tornado Watch 589
The Storm Prediction Center issued this tornado watch at Aug 26, 2012, 8:29 AM EDT for 15 counties in Florida. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 26, 2012, 8:29 AM EDT (12:29 UTC)
- Expired
- Aug 26, 2012, 5:00 PM EDT
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Strongest gust expected
- 65 kt
Counties Broward County, FL, Charlotte County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hendry County, FL, Highlands County, FL, Indian River County, FL, Lee County, FL, Martin County, FL, Miami-Dade County, FL, Monroe County, FL, Okeechobee County, FL, Palm Beach County, FL, Saint Lucie County, FL
The radar
The Miami radar (KAMX), 91 km from the middle of the area, began a volume at 12:33 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
- 50%
- One or more EF2 to EF5 tornadoes
- 30%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 20%
- 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%
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Miami, FL (KMFL), launched 12:00Z, 0.5 hours before the alert went out and 106 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
- 1782 J/kg
- Mixed-layer CIN
- -7 J/kg
- Mixed-layer LCL
- 619 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 204 m²/s²
- 0-3 km storm-relative helicity
- 224 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 6.1
The text
As transmitted, in the capitals the NWS used until 2016.
557
WWUS20 KWNS 261233
SEL9
SPC WW 261233
FLZ000-CWZ000-262100-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 589
NWS STORM PREDICTION CENTER NORMAN OK
830 AM EDT SUN AUG 26 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHERN FLORIDA AND FLORIDA KEYS
COASTAL WATERS
EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 830 AM UNTIL 500
PM EDT.
TORNADOES...THUNDERSTORM WIND GUSTS TO 75 MPH...AND DANGEROUS
LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES SOUTH OF MARATHON
FLORIDA TO 65 MILES NORTHEAST OF FORT MEYERS FLORIDA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU9).
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...SUPERCELL/TORNADO POTENTIAL WILL INCREASE THROUGH AT
LEAST MID-LATE AFTERNOON AS CENTER OF ISAAC MOVES TOWARD LOWER
KEYS...STRENGTHENS FURTHER...AND LOW-LEVEL WIND FIELDS EXPAND PER
LATEST NHC GUIDANCE. MEANWHILE INSTABILITY ALREADY IS FAVORABLE
OVER COASTAL SE FL WITH MLCAPE GREATER THAN 1500 J/KG IN 12Z MFL
RAOB. RICHEST BOUNDARY-LAYER THETAE WILL SPREAD FARTHER WWD ACROSS
SRN FL WITH TIME...AS WILL PROGRESSIVELY MORE FAVORABLE LOW-LEVEL
HODOGRAPHS.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH EXTREME
TURBULENCE AND SURFACE WIND GUSTS TO 65 KNOTS. A FEW CUMULONIMBI
WITH MAXIMUM TOPS TO 550. MEAN STORM MOTION VECTOR 10040.
...EDWARDSSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 7:05 AM EDT | Mesoscale Discussion | SPC | Broward, Charlotte, Collier, Glades, Hendry, Lee and 4 more | 2 hr |
| Aug 26, 12:58 PM EDT | Mesoscale Discussion | SPC | Broward, Collier, Glades, Hendry, Highlands, Lee and 6 more | 2 hr |
| Aug 26, 4:28 PM EDT | Mesoscale Discussion | SPC | Broward, Collier, Glades, Hendry, Martin, Miami-Dade and 2 more | 62 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.