Alert archive / Florida / Tornado Watches in 2015

Tornado Watch 4

February 25, 201513 counties in Florida; 5 counties in Georgia

The Storm Prediction Center issued this tornado watch at Feb 25, 2015, 5:39 PM CST for 13 counties in Florida; 5 counties in Georgia. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Feb 25, 2015, 5:39 PM CST (23:39 UTC)
Expired: Feb 26, 2015, 1:00 AM CST
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 0.5 in
Strongest gust expected: 60 kt

Counties Bay County, FL, Calhoun County, FL, Dixie County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Taylor County, FL, Wakulla County, FL, Brooks County, GA, Decatur County, GA, Grady County, GA, Lowndes County, GA, Thomas County, GA

The radar

The Tallahassee radar (KTLH), 33 km from the middle of the area, began a volume at 23:39 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: 30%
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: 60%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Feb 25, 6:22 PM CST	Tornado Warning	TAE	Franklin, Gulf, Liberty	23 min
Feb 25, 7:10 PM CST	Severe Thunderstorm Warning	TAE	Leon, Wakulla	35 min
Feb 25, 7:30 PM CST	Severe Thunderstorm Warning	TAE	Jefferson, Leon, Taylor, Wakulla	30 min
Feb 25, 7:50 PM CST	Severe Thunderstorm Warning	TAE	Franklin, Jefferson, Taylor, Wakulla	40 min
Feb 25, 7:57 PM CST	Severe Thunderstorm Warning	TAE	Jefferson, Madison, Taylor	48 min
Feb 25, 8:20 PM CST	Severe Thunderstorm Warning	TAE	Brooks, Lowndes	40 min
Feb 25, 8:44 PM CST	Severe Thunderstorm Warning	TAE	Lafayette, Madison, Taylor	61 min
Feb 25, 9:39 PM CST	Severe Thunderstorm Warning	TAE	Lafayette, Madison, Taylor	66 min
Feb 25, 10:42 PM CST	Severe Thunderstorm Warning	TAE	Dixie, Lafayette, Madison, Taylor	63 min
Feb 25, 11:35 PM CST	Severe Thunderstorm Warning	TAE	Dixie, Lafayette	55 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 11.7 hours before the alert went out and 35 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 735 m above ground
0-6 km bulk shear: 66 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 166 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

354 
WWUS20 KWNS 252335
SEL4  
SPC WW 252335
FLZ000-GAZ000-CWZ000-260500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 4
NWS STORM PREDICTION CENTER NORMAN OK
635 PM EST WED FEB 25 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  CENTRAL AND EASTERN FLORIDA PANHANDLE
  SOUTHWEST GEORGIA
  COASTAL WATERS

* EFFECTIVE THIS WEDNESDAY NIGHT FROM 635 PM UNTIL MIDNIGHT EST.

* PRIMARY THREATS INCLUDE...
  A COUPLE TORNADOES POSSIBLE
  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES EAST SOUTHEAST OF
APALACHICOLA FLORIDA TO 35 MILES WEST NORTHWEST OF VALDOSTA
GEORGIA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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...THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND
INTENSITY THIS EVENING AHEAD OF A SURFACE LOW AND COLD FRONT
TRACKING ACROSS THE AREA. STRONG VERTICAL SHEAR WILL BE FAVORABLE
FOR SUPERCELLS AND BOWING STRUCTURES CAPABLE OF A COUPLE OF
TORNADOES AND/OR LOCALLY DAMAGING WIND GUSTS.

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
400. MEAN STORM MOTION VECTOR 24035.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 25, 3:43 PM CST	Mesoscale Discussion	SPC	Bay, Calhoun, Gadsden, Gulf, Leon, Liberty and 1 more	2 hr
Feb 25, 3:10 PM CST	Mesoscale Discussion	SPC	Bartow, Catoosa, Chattooga, Cherokee, Cobb, Dade and 21 more	4 hr

Nearby

Tornado Watches in Florida, 2015 Tornado Watches in Georgia, 2015 Every tornado watch in 2015

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.