Alert archive / Florida / Tornado Watches in 2016

Tornado Watch 460

September 1, 201641 counties in Florida

The Storm Prediction Center issued this tornado watch at Sep 1, 2016, 2:50 PM EDT for 41 counties in Florida. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Sep 1, 2016, 2:50 PM EDT (18:50 UTC)
Expired
Sep 1, 2016, 11:00 PM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 41 counties

Alachua County, FL, Baker County, FL, Bradford County, FL, Brevard County, FL, Calhoun County, FL, Citrus County, FL, Clay County, FL, Columbia County, FL, Dixie County, FL, Duval County, FL, Flagler County, FL, Franklin County, FL, Gadsden County, FL, Gilchrist County, FL, Gulf County, FL, Hamilton County, FL, Hernando County, FL, Hillsborough County, FL, Jefferson County, FL, Lafayette County, FL, Lake County, FL, Leon County, FL, Levy County, FL, Liberty County, FL, Madison County, FL, Marion County, FL, Nassau County, FL, Orange County, FL, Osceola County, FL, Pasco County, FL, Pinellas County, FL, Polk County, FL, Putnam County, FL, Saint Johns County, FL, Seminole County, FL, Sumter County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Volusia County, FL, Wakulla County, FL

The radar

The Tallahassee radar (KTLH), 148 km from the middle of the area, began a volume at 18:54 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
20%
Ten or more severe wind reports
20%
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
40%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 1, 2:53 PM EDTSevere Thunderstorm WarningMLBLake, Orange37 min
Sep 1, 3:05 PM EDTSevere Thunderstorm WarningMLBLake, Orange25 min
Sep 1, 3:18 PM EDTTornado WarningTBWHernando, Pasco17 min
Sep 1, 3:36 PM EDTSevere Thunderstorm WarningMLBLake, Seminole, Volusia39 min
Sep 1, 3:39 PM EDTTornado WarningMLBVolusia36 min
Sep 1, 4:52 PM EDTSevere Thunderstorm WarningMLBBrevard, Volusia53 min
Sep 1, 5:27 PM EDTTornado WarningTBWHernando, Pasco16 min
Sep 1, 8:01 PM EDTTornado WarningTAETaylor15 min
Sep 1, 8:28 PM EDTTornado WarningMLBLake32 min
Sep 1, 8:34 PM EDTTornado WarningMLBLake, Orange26 min
Sep 1, 8:34 PM EDTTornado WarningTAETaylor26 min
Sep 1, 8:51 PM EDTTornado WarningTAELafayette, Taylor24 min
Sep 1, 8:58 PM EDTTornado WarningTAEDixie32 min
Sep 1, 9:02 PM EDTTornado WarningMLBOrange, Seminole28 min
Sep 1, 9:07 PM EDTTornado WarningTAELafayette23 min
Sep 1, 9:19 PM EDTTornado WarningTAEDixie, Lafayette41 min
Sep 1, 9:58 PM EDTTornado WarningTAELafayette20 min
Sep 1, 10:35 PM EDTTornado WarningTAEDixie, Lafayette, Taylor25 min
Sep 1, 10:45 PM EDTTornado WarningTAELafayette, Taylor30 min
Sep 1, 10:48 PM EDTTornado WarningTAEJefferson, Leon, Taylor, Wakulla27 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, 6.8 hours before the alert went out and 146 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, Tallahassee Rgnl, FL at 12:00Z on 2016-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 365 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, Tallahassee Rgnl, FL at 12:00Z on 2016-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.1939Sfc1 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
365 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
740 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

243 
WWUS20 KWNS 011849
SEL0  
SPC WW 011849
FLZ000-CWZ000-020300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 460
NWS STORM PREDICTION CENTER NORMAN OK
250 PM EDT THU SEP 1 2016

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  NORTHERN AND CENTRAL FLORIDA
  COASTAL WATERS

* EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 250 PM UNTIL
  1100 PM EDT.

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

SUMMARY...WITHIN A MOIST ENVIRONMENT...INCREASINGLY STRONG
LOW/MID-LEVEL WINDS ON THE EASTERN PERIPHERY OF CURRENT TROPICAL
STORM HERMINE WILL CONTRIBUTE TO AN INCREASING POTENTIAL FOR A FEW
TORNADOES AND POSSIBLY ISOLATED THUNDERSTORM-RELATED WIND DAMAGE
THROUGH THIS EVENING.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 90 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES EAST NORTHEAST OF
TALLAHASSEE FLORIDA TO 40 MILES EAST SOUTHEAST OF SAINT
PETERSBURG FLORIDA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE
THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

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.

&&

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 19030.


...GUYER

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 1, 4:09 AM EDTMesoscale DiscussionSPCSarasota3 hr
Sep 1, 11:39 AM EDTMesoscale DiscussionSPCHillsborough, Manatee, Pasco, Pinellas, Sarasota2 hr
Sep 1, 2:12 PM EDTMesoscale DiscussionSPCAlachua, Bradford, Citrus, Clay, Dixie, Franklin and 17 more3 hr
Sep 1, 3:03 PM EDTMesoscale DiscussionSPCCharlotte, DeSoto, Glades, Hendry, Highlands, Martin and 2 more87 min
Sep 1, 6:44 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Citrus, Clay, Columbia and 25 more3 hr

Nearby

Tornado Watches in Florida, 2016Every tornado watch in 2016

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.