Alert archive / Florida / Mesoscale Discussions in 2021

Mesoscale Discussion 90

February 15, 20216 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Feb 15, 2021, 1:38 PM CST for 6 counties in Florida. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Feb 15, 2021, 1:38 PM CST (19:38 UTC)
Expired
Feb 15, 2021, 3:15 PM CST
In force
97 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 7

Counties Bay County, FL, Calhoun County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Liberty County, FL

The radar

The Eglin Afb radar (KEVX), 82 km from the middle of the area, began a volume at 19:42 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, 7.6 hours before the alert went out and 98 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 2021-02-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2021-02-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 252 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
468 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
252 m²/s²
0-3 km storm-relative helicity
303 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

549 
ACUS11 KWNS 151939
SWOMCD
SPC MCD 151938 
FLZ000-GAZ000-152115-

Mesoscale Discussion 0090
NWS Storm Prediction Center Norman OK
0138 PM CST Mon Feb 15 2021

Areas affected...central portions of the Florida Panhandle

Concerning...Tornado Watch 7...

Valid 151938Z - 152115Z

The severe weather threat for Tornado Watch 7 continues.

SUMMARY...Tornado threat is increasing over portions of the central
Florida Panhandle, within WW 007.

DISCUSSION...Latest surface analysis indicates dewpoints increasing
across coastal counties across portions of the Florida Panhandle, as
winds veer to a more southerly direction ahead of the line of storms
now advancing eastward across Walton County. While convection has
remained generally elevated inland up to this point, the increasing
boundary-layer moisture suggests that risk for surface-based
convection is also increasing.  Therefore, tornado risk is likewise
becoming greater with time, particularly across the Bay, Calhoun,
Liberty, and Gulf County areas over the next 1-2 hours.  Some
potential for a strong tornado exists, given favorably
veering/increasing flow with height observed by the latest KTLH
WSR-88D VWP.

..Goss.. 02/15/2021

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

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

LAT...LON   29888612 30448615 30678538 30728457 30328428 29898444
            29538490 29588535 29888612

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 15, 11:24 AM CSTMesoscale DiscussionSPCBay, Calhoun, Escambia, Franklin, Gadsden, Gulf and 12 more66 min
Feb 15, 11:55 AM CSTTornado WatchSPCBay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 8 more5 hr
Feb 15, 1:47 PM CSTMesoscale DiscussionSPCAlachua, Baker, Bradford, Citrus, Clay, Columbia and 17 more118 min
Feb 15, 2:02 PM CSTTornado WatchSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 13 more7 hr
Feb 15, 3:08 PM CSTMesoscale DiscussionSPCAlachua, Baker, Bradford, Calhoun, Clay, Columbia and 18 more2 hr
Feb 15, 5:32 PM CSTMesoscale DiscussionSPCBrevard, Indian River, Osceola, Seminole118 min

Nearby

Mesoscale Discussions in Florida, 2021Every mesoscale discussion in 2021

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.