Alert archive / Florida / Mesoscale Discussions in 2021

Mesoscale Discussion 2051

December 21, 20218 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Dec 21, 2021, 8:01 AM EST for 8 counties in Florida. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Dec 21, 2021, 8:01 AM EST (13:01 UTC)
Expired
Dec 21, 2021, 9:30 AM EST
In force
89 min
Issued by
the Storm Prediction Center
Concerning
Tornado watch 568

Counties Charlotte County, FL, Collier County, FL, DeSoto County, FL, Hardee County, FL, Hendry County, FL, Lee County, FL, Manatee County, FL, Sarasota County, FL

The radar

The Tampa radar (KTBW), 99 km from the middle of the area, began a volume at 13:04 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

Tampa Bay, FL (KTBW), launched 12:00Z, 1.0 hours before the alert went out and 99 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, Tampa Bay, FL at 12:00Z on 2021-12-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 123 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, Tampa Bay, FL at 12:00Z on 2021-12-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 260 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
123 J/kg
Mixed-layer CIN
-150 J/kg
Mixed-layer LCL
533 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
260 m²/s²
0-3 km storm-relative helicity
340 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted.

675 
ACUS11 KWNS 211302
SWOMCD
SPC MCD 211301 
FLZ000-211430-

Mesoscale Discussion 2051
NWS Storm Prediction Center Norman OK
0701 AM CST Tue Dec 21 2021

Areas affected...South FL

Concerning...Tornado Watch 568...

Valid 211301Z - 211430Z

The severe weather threat for Tornado Watch 568 continues.

SUMMARY...Damaging wind gusts are possible with the stronger storm
moving into the SRQ vicinity.

DISCUSSION...Recent surface analysis places the warm front from VNC
eastward across the FL Peninsula to PBI. Am earlier supercell
dissipated at is moved onshore near Fort Myers, with showers now
covering much of the watch area south of the warm front. A stronger
thunderstorm is moving eastward towards SRQ, just north of the warm
front. Primary severe threat with this storm is damaging wind gusts.
Position of this storm north of the warm front suggest the tornado
potential is low, although the veering low-level wind profile
(sampled well by the TBW VAD) suggests the threat is non zero.

..Mosier.. 12/21/2021

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

ATTN...WFO...MFL...TBW...

LAT...LON   27358278 27608259 27578188 27388151 26858120 26178108
            25778161 25968202 26918245 27358278

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 21, 4:33 AM ESTMesoscale DiscussionSPCCharlotte, Collier, DeSoto, Glades, Hardee, Hendry and 3 more2 hr
Dec 21, 5:22 AM ESTTornado WatchSPCCharlotte, Collier, DeSoto, Glades, Hardee, Hendry and 4 more5 hr
Dec 21, 9:34 AM ESTMesoscale DiscussionSPCCharlotte, Collier, DeSoto, Glades, Hardee, Hendry and 4 more26 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.