Alert archive / Alabama / Mesoscale Discussions in 2021
Mesoscale Discussion 1008
The Storm Prediction Center issued this mesoscale discussion at Jun 19, 2021, 8:33 AM CDT for 9 counties in Alabama; 7 counties in Florida. It was in force for 57 min.
The area
The outline as issued.
The facts
- Issued
- Jun 19, 2021, 8:33 AM CDT (13:33 UTC)
- Expired
- Jun 19, 2021, 9:30 AM CDT
- In force
- 57 min
- Issued by
- the Storm Prediction Center
- Concerning
- Tornado watch 284
Counties Butler County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Pike County, AL, Bay County, FL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL
The radar
The Eglin Afb radar (KEVX), 29 km from the middle of the area, began a volume at 13:33 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, 1.6 hours before the alert went out and 179 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
- 1367 J/kg
- Mixed-layer CIN
- -13 J/kg
- Mixed-layer LCL
- 747 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 147 m²/s²
- 0-3 km storm-relative helicity
- 315 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.7
The text
As transmitted.
130
ACUS11 KWNS 191333
SWOMCD
SPC MCD 191333
FLZ000-ALZ000-191430-
Mesoscale Discussion 1008
NWS Storm Prediction Center Norman OK
0833 AM CDT Sat Jun 19 2021
Areas affected...southern AL...FL Panhandle
Concerning...Tornado Watch 284...
Valid 191333Z - 191430Z
The severe weather threat for Tornado Watch 284 continues.
SUMMARY...The risk for a tornado or two will probably continue
through the morning and into the afternoon. A tornado watch will be
considered later this morning to the east of tornado watch 284.
DISCUSSION...KMOB radar imagery shows a couple of embedded rotating
updrafts over southern AL and far western part of the FL Panhandle
as of 1330 UTC. The 12 UTC Tallahassee raob showed ample buoyancy
(1400 J/kg MLCAPE). The raob likely sampled to the east of the
moist axis, which was located farther west over the western FL
Panhandle where surface dewpoints are 2-4 deg F higher.
The KEVX VAD data has shown an increase in 3-km AGL flow with speeds
increasing from 40 to 50 kt during the past 2 hours. As a result,
the hodograph has enlarged and around 240 m2/s2 0-1 km SRH is noted.
Given the very moist/strongly sheared low levels, it seems plausible
it will continue to remain favorable for mesocyclogenesis during the
morning. The stronger and more persistent circulations will be
capable of a couple of tornadoes. As the primary band translates
east and north during the morning, the risk for a tornado will
probably spread into parts of southeast AL and potentially the
central part of the FL Panhandle later this morning and into the
afternoon.
..Smith.. 06/19/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TAE...BMX...MOB...
LAT...LON 29978569 30358640 30218776 31428731 32058690 32028606
31598547 30758521 30188525 29918562 29978569SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 19, 1:08 AM CDT | Mesoscale Discussion | SPC | Baldwin, Escambia, Mobile | 3 hr |
| Jun 19, 1:40 AM CDT | Tornado Watch | SPC | Baldwin, Butler, Conecuh, Covington, Crenshaw, Escambia and 3 more | 9 hr |
| Jun 19, 9:33 AM CDT | Tornado Watch | SPC | Barbour, Bullock, Butler, Coffee, Covington, Crenshaw and 10 more | 9 hr |
| Jun 19, 6:22 PM CDT | Mesoscale Discussion | SPC | Barbour, Bullock, Dale, Geneva, Henry, Houston and 2 more | 83 min |
Nearby
Mesoscale Discussions in Alabama, 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.