Alert archive / Florida / Mesoscale Discussions in 2021
Mesoscale Discussion 92
The Storm Prediction Center issued this mesoscale discussion at Feb 15, 2021, 2:47 PM EST for 23 counties in Florida; Camden County, Charlton County, Echols County, Georgia. It was in force for 118 min.
The area
The outline as issued.
The facts
- Issued
- Feb 15, 2021, 2:47 PM EST (19:47 UTC)
- Expired
- Feb 15, 2021, 4:45 PM EST
- In force
- 118 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...tornado watch likely
- Chance of a watch
- 80%
All 26 counties
Alachua County, FL, Baker County, FL, Bradford County, FL, Citrus County, FL, Clay County, FL, Columbia County, FL, Dixie County, FL, Duval County, FL, Flagler County, FL, Gilchrist County, FL, Hamilton County, FL, Lafayette County, FL, Levy County, FL, Madison County, FL, Marion County, FL, Nassau County, FL, Putnam County, FL, Saint Johns County, FL, Sumter County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Volusia County, FL, Camden County, GA, Charlton County, GA, Echols County, GA
The radar
The Jacksonville radar (KJAX), 120 km from the middle of the area, began a volume at 19:48 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Jacksonville, FL (KJAX), launched 12:00Z, 7.8 hours before the alert went out and 122 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 408 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 83 m²/s²
- 0-3 km storm-relative helicity
- 135 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted.
240
ACUS11 KWNS 151948
SWOMCD
SPC MCD 151947
FLZ000-GAZ000-152145-
Mesoscale Discussion 0092
NWS Storm Prediction Center Norman OK
0147 PM CST Mon Feb 15 2021
Areas affected...northern portions of the Florida Peninsula
Concerning...Severe potential...Tornado Watch likely
Valid 151947Z - 152145Z
Probability of Watch Issuance...80 percent
SUMMARY...Risk for locally damaging winds, and a tornado or two, is
increasing across northern Florida. A tornado watch may be needed
within the next hour.
DISCUSSION...Latest radar loop shows isolated storms increasing
across portion of northern Florida, with on cell over Putnam County
exhibiting updraft rotation. While lesser than areas farther west,
a weakly veering wind field with height is in place, which
strengthens to around 40 kt at mid levels. Despite the somewhat
lesser wind field, instability is much more substantial across this
region, with low 70s dewpoints supporting 1000 to 1500 J/kg
surface-based CAPE. As such, the increasing risk will likely
require tornado watch issuance within the hour.
..Goss/Grams.. 02/15/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MLB...TBW...JAX...TAE...
LAT...LON 29498383 30758355 30978166 29898071 29078109 28648217
28688278 29498383SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 15, 12:24 PM EST | Mesoscale Discussion | SPC | Bay, Calhoun, Escambia, Franklin, Gadsden, Gulf and 12 more | 66 min |
| Feb 15, 12:55 PM EST | Tornado Watch | SPC | Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 8 more | 5 hr |
| Feb 15, 2:38 PM EST | Mesoscale Discussion | SPC | Bay, Calhoun, Franklin, Gadsden, Gulf, Liberty | 97 min |
| Feb 15, 3:02 PM EST | Tornado Watch | SPC | Alachua, Baker, Bradford, Clay, Columbia, Dixie and 13 more | 7 hr |
| Feb 15, 4:08 PM EST | Mesoscale Discussion | SPC | Alachua, Baker, Bradford, Calhoun, Clay, Columbia and 18 more | 2 hr |
| Feb 15, 6:32 PM EST | Mesoscale Discussion | SPC | Brevard, Indian River, Osceola, Seminole | 118 min |
Nearby
Mesoscale Discussions in Florida, 2021Mesoscale Discussions in Georgia, 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.