Alert archive / Florida / Mesoscale Discussions in 2021
Mesoscale Discussion 2052
The Storm Prediction Center issued this mesoscale discussion at Dec 21, 2021, 9:34 AM EST for 10 counties in Florida. It was in force for 26 min.
The area
The outline as issued.
The facts
- Issued
- Dec 21, 2021, 9:34 AM EST (14:34 UTC)
- Expired
- Dec 21, 2021, 10:00 AM EST
- In force
- 26 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 568
Counties Charlotte County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hardee County, FL, Hendry County, FL, Highlands County, FL, Lee County, FL, Manatee County, FL, Sarasota County, FL
The radar
The Tampa radar (KTBW), 135 km from the middle of the area, began a volume at 14:34 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, 2.6 hours before the alert went out and 135 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.
- 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
The text
As transmitted.
129
ACUS11 KWNS 211434
SWOMCD
SPC MCD 211434
FLZ000-211500-
Mesoscale Discussion 2052
NWS Storm Prediction Center Norman OK
0834 AM CST Tue Dec 21 2021
Areas affected...Portions of the central/southern FL Peninsula
Concerning...Tornado Watch 568...
Valid 211434Z - 211500Z
The severe weather threat for Tornado Watch 568 continues.
SUMMARY...Tornado Watch 568 will likely be allowed to expire at the
top of the hour (15Z/10 AM EST).
DISCUSSION...Storms that moved from the eastern Gulf of Mexico over
parts of the western FL Peninsula earlier this morning have since
weakened. Low-level shear remains fairly strong to the south of a
warm front draped across the central FL Peninsula. But, the
thermodynamic environment appears fairly hostile for maintaining
strong to severe storms inland, with generally less than 500 J/kg of
MLCAPE available and poor mid-level lapse rates present per area 12Z
soundings. With a mid-level dry slot beginning to overspread this
region per recent water vapor satellite imagery, it appears unlikely
that additional robust convection will develop this morning.
Accordingly, Tornado Watch 568 will likely be allowed to expire at
the top of the hour (15Z/10 AM EST).
..Gleason.. 12/21/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MFL...MLB...TBW...
LAT...LON 25758158 26478216 27328259 27628252 27638115 27128090
25808085 25758158SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 21, 4:33 AM EST | Mesoscale Discussion | SPC | Charlotte, Collier, DeSoto, Glades, Hardee, Hendry and 3 more | 2 hr |
| Dec 21, 5:22 AM EST | Tornado Watch | SPC | Charlotte, Collier, DeSoto, Glades, Hardee, Hendry and 4 more | 5 hr |
| Dec 21, 8:01 AM EST | Mesoscale Discussion | SPC | Charlotte, Collier, DeSoto, Hardee, Hendry, Lee and 2 more | 89 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.