Alert archive / Florida / Tornado Watches in 2007

Tornado Watch 148

April 15, 200724 counties in Florida

The Storm Prediction Center issued this tornado watch at Apr 15, 2007, 9:45 AM EDT for 24 counties in Florida. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 15, 2007, 9:45 AM EDT (13:45 UTC)
Expired
Apr 15, 2007, 5:00 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 24 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, Indian River County, FL, Lake County, FL, Lee County, FL, Martin County, FL, Miami-Dade County, FL, Monroe County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Palm Beach County, FL, Polk County, FL, Saint Lucie County, FL, Sarasota County, FL, Seminole County, FL, Volusia County, FL

The radar

The Tampa radar (KTBW), 88 km from the middle of the area, began a volume at 13:46 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
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 15, 10:45 AM EDTSevere Thunderstorm WarningTBWPolk45 min
Apr 15, 1:10 PM EDTSevere Thunderstorm WarningMLBBrevard35 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 12:00Z, 1.8 hours before the alert went out and 88 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-pSkew-T log-p diagram, Tampa Bay, FL at 12:00Z on 2007-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1470 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tampa Bay, FL at 12:00Z on 2007-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 331 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
1470 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
579 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
331 m²/s²
0-3 km storm-relative helicity
310 m²/s²
Significant tornado parameter
2.9
Supercell composite
12.0

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 151344
SEL8  
SPC WW 151344
FLZ000-CWZ000-152100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 148
NWS STORM PREDICTION CENTER NORMAN OK
945 AM EDT SUN APR 15 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       CENTRAL AND SOUTHERN FLORIDA
       COASTAL WATERS

EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 945 AM UNTIL 500
PM EDT.

TORNADOES...HAIL TO 1.5 INCHES 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 40 MILES NORTH NORTHWEST OF
ORLANDO FLORIDA TO 50 MILES SOUTHWEST OF MIAMI FLORIDA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU8).

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.

OTHER WATCH INFORMATION...CONTINUE...WW 146...WW 147...

DISCUSSION...LINE OF STRONG/SEVERE THUNDERSTORMS WILL CONTINUE
TRACKING EASTWARD ACROSS THE PENINSULA TODAY.  MORNING SOUNDINGS AND
MODEL GUIDANCE INDICATE A CONTINUED RISK OF EMBEDDED SUPERCELLS AND
BOWS WITHIN THE LINE...POSING A RISK OF DAMAGING WINDS AND ISOLATED
TORNADOES.  PARTS OF SOUTH FL WILL SEE CONSIDERABLE HEATING
TODAY...WHICH MAY OFFSET WEAKER LARGE SCALE FORCING AND MAINTAIN
THREAT THIS AFTERNOON.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 26035.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 14, 8:09 PM EDTMesoscale DiscussionSPCBay, Calhoun, Escambia, Franklin, Gadsden, Gulf and 12 more2 hr
Apr 14, 11:45 PM EDTTornado WatchSPCCalhoun, Franklin, Gadsden, Gulf, Jackson, Jefferson and 4 more6 hr
Apr 15, 2:27 AM EDTMesoscale DiscussionSPCAlachua, Citrus, Dixie, Franklin, Gilchrist, Hernando and 4 more2 hr
Apr 15, 9:31 AM EDTMesoscale DiscussionSPCBrevard, Broward, Charlotte, Collier, DeSoto, Flagler and 22 more59 min
Apr 15, 1:03 PM EDTMesoscale DiscussionSPCBroward, Collier, Glades, Hendry, Highlands, Indian River and 7 more117 min
Apr 15, 3:42 PM EDTMesoscale DiscussionSPCBroward, Miami-Dade, Monroe, Palm Beach93 min

Nearby

Tornado Watches in Florida, 2007Every tornado watch in 2007

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.