Alert archive / Florida / Mesoscale Discussions in 2021
Mesoscale Discussion 360
The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2021, 8:58 AM CDT for 15 counties in Florida; 5 counties in Georgia. It was in force for 92 min.
The area
The outline as issued.
The facts
- Issued
- Apr 10, 2021, 8:58 AM CDT (13:58 UTC)
- Expired
- Apr 10, 2021, 10:30 AM CDT
- In force
- 92 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch likely
- Chance of a watch
- 95%
Counties Bay County, FL, Calhoun County, FL, Dixie County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Jackson County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Taylor County, FL, Wakulla County, FL, Washington County, FL, Brooks County, GA, Decatur County, GA, Grady County, GA, Seminole County, GA, Thomas County, GA
The radar
The Tallahassee radar (KTLH), 29 km from the middle of the area, began a volume at 14:02 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
Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 2.0 hours before the alert went out and 31 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
- 13 J/kg
- Mixed-layer CIN
- -541 J/kg
- Mixed-layer LCL
- 1046 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 276 m²/s²
- 0-3 km storm-relative helicity
- 231 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
519
ACUS11 KWNS 101359
SWOMCD
SPC MCD 101358
FLZ000-GAZ000-101530-
Mesoscale Discussion 0360
NWS Storm Prediction Center Norman OK
0858 AM CDT Sat Apr 10 2021
Areas affected...the Florida Panhandle and parts of far southern
Georgia
Concerning...Severe potential...Watch likely
Valid 101358Z - 101530Z
Probability of Watch Issuance...95 percent
SUMMARY...Severe risk continues across the portions of WW 89 that
remain in effect, with some risk evident eastward across the
remainder of the Florida Panhandle. A new WW will likely be issued.
DISCUSSION...Latest radar loop shows the northeastern portion of a
northern Gulf of Mexico band of storms now crossing central portions
of the Florida Peninsula west of Tallahassee. Gusty/damaging wind
risk remains apparent -- per WSR-88D imagery, where outflow in
excess of 50 kt is indicated just off the surface across parts of
Washington and Bay counties.
Very limited heating of the relatively moist airmass just downstream
is supporting mixed-layer CAPE values of 500 to 1000 J/kg. While a
more stable/drier airmass exists into the northern Florida
Peninsula, it appears at this time that a sufficiently unstable
environment downstream into the Big Bend region will support a
continued eastward advance of storms. Locally damaging winds will
remain the primary severe risk, though a QLCS-type tornado or two
will remain possible. With storms expected to move out of the
existing watch within the next hour, a new WW will be issued
shortly.
..Goss/Thompson.. 04/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...JAX...TAE...
LAT...LON 30548604 30998546 30878418 30938356 30608328 29748299
29198324 29498512 29798596 30548604SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 10, 1:52 AM CDT | Mesoscale Discussion | SPC | Escambia, Holmes, Okaloosa, Santa Rosa, Walton, Washington | 113 min |
| Apr 10, 2:30 AM CDT | Tornado Watch | SPC | Bay, Calhoun, Escambia, Gulf, Holmes, Jackson and 4 more | 8 hr |
| Apr 10, 4:06 AM CDT | Mesoscale Discussion | SPC | Escambia, Holmes, Okaloosa, Santa Rosa, Walton, Washington | 114 min |
| Apr 10, 7:10 AM CDT | Mesoscale Discussion | SPC | Bay, Calhoun, Escambia, Franklin, Gadsden, Gulf and 8 more | 2 hr |
| Apr 10, 9:20 AM CDT | Tornado Watch | SPC | Dixie, Franklin, Gadsden, Jefferson, Lafayette, Leon and 4 more | 4 hr |
| Apr 10, 10:49 AM CDT | Mesoscale Discussion | SPC | Jefferson, Lafayette, Leon, Madison, Taylor, Wakulla | 116 min |
| Apr 10, 2:13 PM CDT | Mesoscale Discussion | SPC | Alachua, Baker, Bradford, Citrus, Clay, Columbia and 8 more | 2 hr |
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.