Mesoscale Discussion 1532

Issued

Aug 16, 2021, 10:20 AM EDT (14:20 UTC)

Expired

Aug 16, 2021, 12:15 PM EDT

In force

115 min

Issued by

the Storm Prediction Center

Concerning

Tornado watch 441

Counties Franklin County, FL, Wakulla County, FL

The Tallahassee radar (KTLH), 76 km from the middle of the area, began a volume at 14:25 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.

997 
ACUS11 KWNS 161421
SWOMCD
SPC MCD 161420 
FLZ000-161615-

Mesoscale Discussion 1532
NWS Storm Prediction Center Norman OK
0920 AM CDT Mon Aug 16 2021

Areas affected...Western Shore of Apalachee Bay

Concerning...Tornado Watch 441...

Valid 161420Z - 161615Z

The severe weather threat for Tornado Watch 441 continues.

SUMMARY...The waterspout/tornado potential over the next 1-2 hours
will be highest across the western Apalachee Bay shore in the
Florida Panhandle.

DISCUSSION...Latest radar and IR satellite trends show convection
being focused along a confluent rain band associated with tropical
storm Fred off the west coast of the FL peninsula and into Apalachee
Bay. Easterly winds are advecting higher theta-e air (characterized
by dewpoints in the mid to upper 70s) from the FL peninsula into the
rain band, which is supporting transient convection. This trend
should continue in the near term, and 150-200 m2/s2 SRH in the
lowest 1-2 km (as sampled by the KTLH VWP) is allowing for periods
of weak rotation with some of these storms. Although the
thermodynamic environment becomes less favorable with northern and
westward extent across the FL panhandle, storms propagating along
the rain band and onto the western shore of Apalachee bay will pose
the risk for brief waterspouts/tornadoes. Given the slow motion of
the tropical storm, this band will likely remain focused south of
the Tallahassee, FL - primarily across the Franklin county area -
over the next 1-2 hours. The tornado threat is still expected to
gradually shift northward through the rest of the day.

..Moore.. 08/16/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...TAE...

LAT...LON   29488509 29648528 29888501 30018469 30108447 30088419
            29908420 29808431 29708445 29598474 29488509

Mesoscale Discussions in Florida, 2021Every mesoscale discussion in 2021

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.