Alert archive / Florida / Tornado Watches in 2017

Tornado Watch 261

May 24, 201736 counties in Florida; 6 counties in Georgia

The Storm Prediction Center issued this tornado watch at May 24, 2017, 6:56 AM EDT for 36 counties in Florida; 6 counties in Georgia. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
May 24, 2017, 6:56 AM EDT (10:56 UTC)
Expired
May 24, 2017, 3:00 PM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 42 counties

Alachua County, FL, Baker County, FL, Bay County, FL, Bradford 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, Jackson 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, Pasco County, FL, Putnam County, FL, Saint Johns County, FL, Sumter County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Volusia County, FL, Wakulla County, FL, Brooks County, GA, Decatur County, GA, Grady County, GA, Lowndes County, GA, Seminole County, GA, Thomas County, GA

The radar

The Tallahassee radar (KTLH), 74 km from the middle of the area, began a volume at 10:56 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
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 24, 9:23 AM EDTSevere Thunderstorm WarningJAXPutnam37 min
May 24, 9:28 AM EDTSevere Thunderstorm WarningTAEFranklin, Jefferson, Wakulla26 min
May 24, 9:29 AM EDTTornado WarningJAXPutnam31 min
May 24, 9:47 AM EDTTornado WarningJAXSaint Johns28 min
May 24, 9:53 AM EDTSevere Thunderstorm WarningTAEJefferson, Madison24 min
May 24, 10:07 AM EDTTornado WarningJAXSaint Johns23 min
May 24, 10:36 AM EDTSevere Thunderstorm WarningTAELafayette, Taylor39 min
May 24, 10:47 AM EDTSevere Thunderstorm WarningJAXBaker, Columbia, Hamilton, Suwannee43 min
May 24, 11:37 AM EDTSevere Thunderstorm WarningJAXClay, Duval, Saint Johns38 min
May 24, 11:51 AM EDTSevere Thunderstorm WarningTBWLevy39 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 00:00Z, 10.9 hours before the alert went out and 71 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 00:00Z on 2017-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 238 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tallahassee Rgnl, FL at 00:00Z on 2017-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 125 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
238 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
1160 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
125 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted.

506 
WWUS20 KWNS 241054
SEL1  
SPC WW 241054
FLZ000-GAZ000-CWZ000-241900-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 261
NWS Storm Prediction Center Norman OK
655 AM EDT Wed May 24 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  North Florida
  Southern Georgia
  Coastal Waters

* Effective this Wednesday morning and afternoon from 655 AM
  until 300 PM EDT.

* Primary threats include...
  A few tornadoes possible
  Scattered damaging wind gusts to 70 mph possible
  Isolated large hail events to 1.5 inches in diameter possible

SUMMARY...Severe thunderstorms capable of a few tornadoes along with
damaging winds are expected to gradually increase through the
morning. This includes an early-day risk across the north-central
peninsula near a remnant boundary, while other storms will move in
from the Gulf of Mexico and Florida Panhandle and intensify within a
very moist and increasingly unstable environment.

The tornado watch area is approximately along and 55 statute miles
north and south of a line from 35 miles south southwest of Marianna
FL to 25 miles north northeast of Daytona Beach FL. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU1).

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 1.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 24030.

...Guyer

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 3:45 AM EDTMesoscale DiscussionSPCAlachua, Bradford, Clay, Duval, Gilchrist, Levy and 3 more2 hr
May 24, 6:30 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Brevard, Citrus, Clay and 33 more2 hr
May 24, 10:26 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bay, Bradford, Calhoun, Citrus and 32 more94 min
May 24, 11:03 AM EDTTornado WatchSPCBaker, Columbia, Duval, Hamilton, Nassau, Suwannee10 hr
May 24, 12:54 PM EDTMesoscale DiscussionSPCAlachua, Bradford, Brevard, Broward, Charlotte, Citrus and 30 more2 hr
May 24, 2:10 PM EDTMesoscale DiscussionSPCBaker, Columbia, Duval, Hamilton, Madison, Nassau and 1 more95 min
May 24, 2:49 PM EDTSevere Thunderstorm WatchSPCBrevard, Broward, Charlotte, Clay, Collier, DeSoto and 23 more7 hr
May 24, 5:25 PM EDTMesoscale DiscussionSPCBaker, Columbia, Duval, Hamilton, Madison, Nassau and 2 more65 min
May 23, 8:12 PM EDTMesoscale DiscussionSPCBartow, Carroll, Cherokee, Clayton, Cobb, Coweta and 15 more93 min
May 23, 8:46 PM EDTMesoscale DiscussionSPCAppling, Bacon, Brantley, Bryan, Bulloch, Candler and 12 more89 min
May 24, 7:41 AM EDTMesoscale DiscussionSPCBartow, Catoosa, Chattooga, Dade, Fannin, Floyd and 8 more3 hr
May 24, 8:29 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 83 more3 hr
May 24, 10:04 AM EDTTornado WatchSPCBanks, Barrow, Bartow, Carroll, Catoosa, Chattooga and 50 more11 hr
May 24, 3:02 PM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Carroll, Cherokee, Clarke and 43 more88 min

Nearby

Tornado Watches in Florida, 2017Tornado Watches in Georgia, 2017Every tornado watch in 2017

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.