Alert archive / Florida / Mesoscale Discussions in 2021
Mesoscale Discussion 359
The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2021, 7:10 AM CDT for Dale County, Geneva County, Houston County, Alabama; 14 counties in Florida; 6 counties in Georgia. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 10, 2021, 7:10 AM CDT (12:10 UTC)
- Expired
- Apr 10, 2021, 9:15 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 89
All 23 counties
Dale County, AL, Geneva County, AL, Houston County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Franklin County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Leon County, FL, Liberty County, FL, Okaloosa County, FL, Wakulla County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Decatur County, GA, Early County, GA, Grady County, GA, Miller County, GA, Seminole County, GA
The radar
The Eglin Afb radar (KEVX), 20 km from the middle of the area, began a volume at 12:09 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, 0.2 hours before the alert went out and 175 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.
065
ACUS11 KWNS 101210
SWOMCD
SPC MCD 101210
FLZ000-GAZ000-ALZ000-101415-
Mesoscale Discussion 0359
NWS Storm Prediction Center Norman OK
0710 AM CDT Sat Apr 10 2021
Areas affected...Florida Panhandle...Far Southeast Alabama...Far
Southwest Georgia
Concerning...Tornado Watch 89...
Valid 101210Z - 101415Z
The severe weather threat for Tornado Watch 89 continues.
SUMMARY...A severe threat may continue for a few more hours across
the eastern Gulf Coast. A tornado threat, along with the possibility
of wind damage and hail may occur with the stronger thunderstorms. A
small watch or local extension may be needed to the east of WW 89.
DISCUSSION...The latest radar imagery shows a linear MCS from
southern Alabama extending west-southwestward into southern
Louisiana. A corridor of maximized low-level moisture is located
just ahead of the line across the western Florida Panhandle. Surface
dewpoints are in the upper 60s F with MLCAPE estimated by the RAP
near 1500 J/kg. This combined with 0-6 km shear near 50 kt, evident
on regional WSR-88D VWPs should support severe thunderstorms for a
few more hours this morning. Wind damage will be possible along the
leading edge of the faster-moving bowing line segments. A tornado
will also be possible with cells that rotate within the ongoing
quasi-linear convective system. However, instability weakens with
eastward extent. The line of strong storms will eventually move into
much weaker instability. For this reason, any severe threat may
become more isolated with time. A local extension or small watch
would be sufficient for any lingering severe threat.
..Broyles.. 04/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TAE...MOB...
LAT...LON 31508562 30928632 30668705 30518764 30148782 29908759
29928619 29508519 29778412 31388420 31508562SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 9, 7:20 PM CDT | Mesoscale Discussion | SPC | Colbert, Lauderdale | 115 min |
| Apr 9, 9:15 PM CDT | Severe Thunderstorm Watch | SPC | Bibb, Colbert, Cullman, Dallas, Fayette, Franklin and 14 more | 7 hr |
| Apr 9, 10:25 PM CDT | Severe Thunderstorm Watch | SPC | Choctaw, Clarke, Washington, Wilcox | 6 hr |
| Apr 10, 1:52 AM CDT | Mesoscale Discussion | SPC | Baldwin, Butler, Clarke, Coffee, Conecuh, Covington and 8 more | 113 min |
| Apr 10, 2:30 AM CDT | Tornado Watch | SPC | Baldwin, Butler, Coffee, Conecuh, Covington, Crenshaw and 7 more | 8 hr |
| Apr 10, 4:06 AM CDT | Mesoscale Discussion | SPC | Baldwin, Butler, Clarke, Coffee, Conecuh, Covington and 8 more | 114 min |
| Apr 10, 8:58 AM CDT | Mesoscale Discussion | SPC | Bay, Calhoun, Dixie, Franklin, Gadsden, Gulf and 9 more | 92 min |
| 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, 2021Mesoscale Discussions in Alabama, 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.