Alert archive / Alabama / Mesoscale Discussions in 2021
Mesoscale Discussion 218
The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2021, 1:52 AM CDT for 8 counties in Alabama; 4 counties in Florida; 7 counties in Georgia. It was in force for 83 min.
The area
The outline as issued.
The facts
- Issued
- Mar 18, 2021, 1:52 AM CDT (06:52 UTC)
- Expired
- Mar 18, 2021, 3:15 AM CDT
- In force
- 83 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 36...38
Counties Barbour County, AL, Coffee County, AL, Covington County, AL, Dale County, AL, Geneva County, AL, Henry County, AL, Pike County, AL, Russell County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Chattahoochee County, GA, Clay County, GA, Marion County, GA, Quitman County, GA, Randolph County, GA, Stewart County, GA, Webster County, GA
The radar
The Ft Rucker radar (KEOX), 47 km from the middle of the area, began a volume at 06:54 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
Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 6.9 hours before the alert went out and 186 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
- 1019 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 126 m²/s²
- 0-3 km storm-relative helicity
- 171 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
003
ACUS11 KWNS 180653
SWOMCD
SPC MCD 180652
GAZ000-ALZ000-FLZ000-180815-
Mesoscale Discussion 0218
NWS Storm Prediction Center Norman OK
0152 AM CDT Thu Mar 18 2021
Areas affected...Portions of the FL Panhandle...southeastern
AL...and western GA
Concerning...Tornado Watch 36...38...
Valid 180652Z - 180815Z
The severe weather threat for Tornado Watch 36, 38 continues.
SUMMARY...An isolated severe threat continues early this morning,
including the potential for a tornado.
DISCUSSION...Convection has weakened across western GA over the past
couple of hours, as it has generally outpaced the low-level moisture
return and moved into an increasingly more stable environment.
Farther south, strong storms are ongoing across parts of the FL
Panhandle into southeastern AL. A wind gust of 48 kt (55 mph) was
recently reported at KPRN in south-central AL. VWPs from KEOX and
KEVX ahead of the broken line show decent veering/strengthening of
the wind profile with height through mid levels. With 250+ m2/s2 of
effective SRH present across the warm sector, a tornado remains a
possibility with any storm that can remain surface based.
Strong/gusty outflow winds may also occur with the more linear
convection in the western FL Panhandle and south-central AL. The
overall severe threat will probably remain fairly isolated through
the early morning hours, as the best large-scale forcing for ascent
associated with an upper trough/low over the lower/mid MS Valley
remains displaced to the north of the central Gulf Coast.
..Gleason.. 03/18/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FFC...TAE...BMX...MOB...
LAT...LON 30268766 30868723 31968593 32478495 32418441 32088434
31678475 30858580 30388654 30268766SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 17, 7:07 PM CDT | Tornado Watch | SPC | Colbert, Cullman, Franklin, Lauderdale, Lawrence, Limestone and 3 more | 3 hr |
| Mar 17, 9:16 PM CDT | Mesoscale Discussion | SPC | Cullman, DeKalb, Jackson, Limestone, Madison, Marshall and 1 more | 89 min |
| Mar 17, 10:15 PM CDT | Mesoscale Discussion | SPC | Baldwin, Barbour, Bullock, Calhoun, Chambers, Cherokee and 18 more | 90 min |
| Mar 17, 11:02 PM CDT | Tornado Watch | SPC | Coffee, Covington, Dale, Geneva, Henry, Houston | 9 hr |
| Mar 18, 4:28 AM CDT | Mesoscale Discussion | SPC | Coffee, Dale, Geneva, Henry, Houston | 92 min |
| Mar 18, 6:32 AM CDT | Mesoscale Discussion | SPC | Bay, Calhoun, Franklin, Gadsden, Gulf, Jackson and 6 more | 58 min |
| Mar 18, 6:53 AM CDT | Tornado Watch | SPC | Dixie, Franklin, Gadsden, Gulf, Jefferson, Lafayette and 5 more | 5 hr |
| Mar 18, 10:05 AM CDT | Mesoscale Discussion | SPC | Columbia, Dixie, Hamilton, Jefferson, Lafayette, Madison and 2 more | 115 min |
| Mar 18, 10:42 AM CDT | Tornado Watch | SPC | Alachua, Baker, Bradford, Clay, Columbia, Duval and 7 more | 6 hr |
| Mar 18, 9:34 AM CDT | Mesoscale Discussion | SPC | Banks, Barrow, Clarke, Elbert, Franklin, Habersham and 5 more | 2 hr |
| Mar 18, 1:08 PM CDT | Tornado Watch | SPC | Elbert, Lincoln | 4 hr |
| Mar 18, 2:10 PM CDT | Mesoscale Discussion | SPC | Elbert | 3 hr |
Nearby
Mesoscale Discussions in Alabama, 2021Mesoscale Discussions in Georgia, 2021Mesoscale 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.