Alert archive / Florida / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 212, NWS Tallahassee, FL

August 11, 2020Holmes County, Walton County, Florida

NWS Tallahassee, FL issued this severe thunderstorm warning at Aug 11, 2020, 3:44 PM CDT for Holmes County, Walton County, Florida. It was in force for 61 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 11, 2020, 3:44 PM CDT (20:44 UTC)
Expired
Aug 11, 2020, 4:45 PM CDT
In force
61 min
Issued by
NWS Tallahassee, FL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Holmes County, FL, Walton County, FL

The radar

The Eglin Afb radar (KEVX), 21 km from the middle of the area, began a volume at 20:44 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.

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 8.7 hours before the alert went out and 166 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 2020-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1281 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 2020-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 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
1281 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
910 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
28 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Tallahassee, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 11, 1:15 PM CDT, 2 hours 29 minutes earlier.

Area forecast discussion, Aug 11, 1:15 PM CDT, 2 hours 29 minutes before
Area Forecast Discussion
National Weather Service Tallahassee FL
215 PM EDT Tue Aug 11 2020

.NEAR TERM [Through Wednesday]...

We are still expecting scattered to numerous showers and
thunderstorms this afternoon as the sea breeze boundary moves inland
and a weak upper level vort max slides southward.  Boundary
collisions this afternoon could result in some storms briefly
becoming severe with gusty winds the main threat. The SPC has
outlooked portions of the area in a marginal risk for severe storms.
Convection will gradually weaken this evening after sunset, but some
convection will likely linger well into the evening hours. Overnight
lows will generally be in the low to mid 70s.

For Wednesday, similar conditions are expected with plentiful deep
moisture and weak upper level support. Scattered to numerous showers
and thunderstorms are expected again during the afternoon hours.
Afternoon highs will generally be in the low to mid 90s.

.SHORT TERM [Wednesday Night Through Thursday Night]...

Widespread showers and thunderstorms are expected again on
Thursday as PWs remain near or just over 2 inches. Overall storm
motion will be pretty slow with light steering flow. Forecast
soundings show enough instabililty and an inverted V shape with
DCAPE near 1000 J/kg. This along with the slow storm motion will
keep the primary threats as gusty winds and heavy rainfall. Weak
upper support will help drive more widespread coverage, but
overall placement will probably be driven mostly by the seabreeze
and then subsequent boundary collisions. High temperatures on
Thursday are forecast generally in the upper 80s to low 90s.
Patchy fog will be possible in the early mornings, especially in
areas that receive rainfall.

.LONG TERM [Friday Through Tuesday]...

Scattered to widespread showers and thunderstorms are expected
through the long term period with a little bit better upper level
support Friday into the weekend as a more substantial shortwave
moves slowly across the southeast CONUS. At a minimum, this will
help increase our steering flow and speed up the storm motions,
but could also lead to more widespread convection. By Sunday, a
weak front could sag into our area before stalling, which could
bring a touch drier air into the area and serve as another focus
for showers and storms Sunday into Monday. High temperatures
through the long term are generally in the low to mid 90s each
afternoon.

&&

.AVIATION...
[Through 18Z Wednesday]

Scattered to numerous showers and thunderstorms will produce
occasional restrictions across the area through the late evening
hours. Some brief restrictions due to low clouds and patchy fog
are also possible early Wednesday morning, mainly near VLD.

&&

.MARINE...

Generally benign boating conditions are expected with winds around
10 knots or less and seas near 1 ft. Waterspouts, gusty winds and
locally higher seas will be possible with any showers and
thunderstorms over the next few days.

&&

.FIRE WEATHER...

Humid conditions and high rain chances will keep fire weather
concerns low through the week. Patchy fog will be possible in the
mornings, especially in areas that receive rainfall the previous
day.

&&

.HYDROLOGY...

A wetter pattern is expected this week with widespread rainfall
totals of 1 to 3 inches of rainfall expected over the next 7 days
with locally higher amounts possible. While river flooding is not
expected, some localized areas of minor street flooding are
possible each afternoon.

&&

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur (while following all local, state, and CDC guidelines) by
calling the office or tweeting us @NWSTallahassee.

&&

.PRELIMINARY POINT TEMPS/POPS...

Tallahassee   74  93  74  91  74 /  40  70  40  80  40
Panama City   78  90  78  90  78 /  30  50  40  60  30
Dothan        74  94  74  92  73 /  40  60  40  80  40
Albany        74  95  75  92  74 /  50  60  50  80  40
Valdosta      73  92  74  89  73 /  60  70  50  80  30
Cross City    74  90  74  91  74 /  50  70  40  70  30
Apalachicola  76  89  78  89  77 /  40  50  40  50  30

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&

NEAR TERM...DVD
SHORT TERM...Merrifield
LONG TERM...Merrifield
AVIATION...DVD
MARINE...Merrifield
FIRE WEATHER...Merrifield
HYDROLOGY...Merrifield

In the hours before

Special weather statement, Aug 11, 3:07 PM CDT, 37 minutes before
Special Weather Statement
National Weather Service Tallahassee FL
307 PM CDT Tue Aug 11 2020

ALZ065-068-FLZ007-112045-
Coffee AL-Geneva AL-North Walton FL-
307 PM CDT Tue Aug 11 2020

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN COFFEE...WESTERN GENEVA
AND NORTH CENTRAL WALTON COUNTIES UNTIL 345 PM CDT...

At 306 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 7 miles southeast of Glenwood to 11 miles north
of De Funiak Springs. Movement was west at 15 mph.

Winds in excess of 40 mph will be possible with these storms.

Locations impacted include...
Elba, Samson, Lee, Liberty, Kinston, Pine Level, Cluster Springs,
Perry Store, Gaskin, Curtis, Carl Folsom A/p, Darlington, Ino, Logan
Field Municipal A/P, Glendale, Wise Mill, Basin, Caney Creek,
Earlytown and Hacoda.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3100 8619 3153 8619 3154 8614 3162 8615
      3162 8602 3084 8604 3079 8621 3099 8627
TIME...MOT...LOC 2006Z 067DEG 15KT 3158 8609 3089 8610

42-DVD
Special weather statement, Aug 11, 3:19 PM CDT, 25 minutes before
Special Weather Statement
National Weather Service Tallahassee FL
319 PM CDT Tue Aug 11 2020

ALZ067-112100-
Henry AL-
319 PM CDT Tue Aug 11 2020

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN HENRY COUNTY UNTIL
400 PM CDT...

At 319 PM CDT, Doppler radar was tracking a strong thunderstorm 7
miles south of Abbeville, moving southwest at 5 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Abbeville, Headland, Kinsey, Newville, Haleburg, Tumbleton, Kirkland
Crossroads, Blackwood, Capps, Grandberry Crossroads, Murphy Station,
Headland Municipal A/P, Dancey, Miller and Balkum.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3157 8525 3142 8513 3131 8526 3131 8538
      3136 8542 3151 8542
TIME...MOT...LOC 2019Z 054DEG 6KT 3146 8526

42-DVD
Local storm report, Aug 11, 3:31 PM CDT, 13 minutes before
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Local storm report, Aug 11, 3:33 PM CDT, 11 minutes before
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Local storm report, Aug 11, 3:35 PM CDT, 9 minutes before
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Local storm report, Aug 11, 3:42 PM CDT, 2 minutes before
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The office that day

Everything else NWS Tallahassee, FL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 8:15 AM CDTSpecial Marine WarningTAE60 min
Aug 11, 10:05 AM CDTSpecial Marine WarningTAE40 min
Aug 11, 11:05 AM CDTSpecial Weather StatementTAELiberty40 min
Aug 11, 11:43 AM CDTSpecial Weather StatementTAEGadsden, Liberty62 min
Aug 11, 12:16 PM CDTSpecial Weather StatementTAETaylor44 min
Aug 11, 12:25 PM CDTSpecial Weather StatementTAELeon20 min
Aug 11, 12:36 PM CDTSevere Thunderstorm WarningTAECalhoun, Gadsden, Jackson, Leon, Liberty, Wakulla39 min
Aug 11, 12:46 PM CDTSpecial Weather StatementTAEWakulla44 min
Aug 11, 12:52 PM CDTSpecial Marine WarningTAE83 min
Aug 11, 1:11 PM CDTSpecial Weather StatementTAELeon49 min
Aug 11, 1:20 PM CDTSpecial Weather StatementTAEGulf40 min
Aug 11, 1:30 PM CDTSpecial Marine WarningTAE2 hr
Aug 11, 1:46 PM CDTSpecial Weather StatementTAEJefferson59 min
Aug 11, 1:57 PM CDTSevere Thunderstorm WarningTAEJackson63 min
Aug 11, 2:03 PM CDTSevere Thunderstorm WarningTAEFranklin, Gulf43 min
Aug 11, 2:26 PM CDTSevere Thunderstorm WarningTAEBay, Calhoun, Holmes, Jackson, Washington64 min
Aug 11, 2:50 PM CDTSpecial Weather StatementTAEJefferson, Madison55 min
Aug 11, 3:02 PM CDTSevere Thunderstorm WarningTAEBay, Holmes, Walton, Washington73 min
Aug 11, 3:41 PM CDTSpecial Marine WarningTAE94 min
Aug 10, 8:06 PM CDTSpecial Weather StatementTAEQuitman39 min
Aug 10, 8:20 PM CDTSevere Thunderstorm WarningTAEClay, Quitman, Randolph40 min
Aug 10, 8:42 PM CDTSpecial Weather StatementTAEClay, Quitman, Randolph48 min
Aug 11, 12:02 PM CDTSpecial Weather StatementTAEDecatur43 min
Aug 11, 1:08 PM CDTSpecial Weather StatementTAESeminole52 min
Aug 11, 3:09 PM CDTSevere Thunderstorm WarningTAEGrady, Thomas51 min
Aug 11, 3:34 PM CDTAreal Flood AdvisoryTAEThomas116 min
Aug 11, 4:12 PM CDTSpecial Weather StatementTAEColquitt, Tift48 min
Aug 11, 4:24 PM CDTSpecial Weather StatementTAECalhoun, Clay, Quitman, Randolph51 min
Aug 11, 4:36 PM CDTSpecial Weather StatementTAEBaker, Dougherty, Mitchell39 min
Aug 11, 4:49 PM CDTAreal Flood AdvisoryTAEClay, Quitman, Randolph116 min
Aug 11, 4:53 PM CDTAreal Flood AdvisoryTAEBaker, Dougherty, Mitchell2 hr
Aug 11, 5:06 PM CDTAreal Flood AdvisoryTAECalhoun, Randolph114 min
Aug 11, 5:08 PM CDTSpecial Weather StatementTAEQuitman52 min
Aug 11, 6:17 PM CDTSpecial Weather StatementTAERandolph, Terrell43 min
Aug 11, 1:21 PM CDTSpecial Weather StatementTAEDale39 min
Aug 11, 1:51 PM CDTSevere Thunderstorm WarningTAEDale, Geneva, Houston54 min
Aug 11, 2:40 PM CDTAreal Flood AdvisoryTAEDale, Houston2 hr
Aug 11, 2:44 PM CDTSpecial Weather StatementTAEDale31 min
Aug 11, 3:07 PM CDTSpecial Weather StatementTAECoffee38 min
Aug 11, 3:19 PM CDTSpecial Weather StatementTAEHenry41 min

Nearby

Severe Thunderstorm Warnings in Florida, 2020Every severe thunderstorm warning in 2020

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.