Alert archive / Alabama / Mesoscale Discussions in 2012
Mesoscale Discussion 128
The Storm Prediction Center issued this mesoscale discussion at Feb 18, 2012, 2:02 PM CST for 9 counties in Alabama; 7 counties in Florida; George County, Harrison County, Jackson County, Mississippi. It was in force for 58 min.
The area
The outline as issued.
The facts
- Issued
- Feb 18, 2012, 2:02 PM CST (20:02 UTC)
- Expired
- Feb 18, 2012, 3:00 PM CST
- In force
- 58 min
- Issued by
- the Storm Prediction Center
Counties Baldwin County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Houston County, AL, Mobile County, AL, Escambia County, FL, Holmes County, FL, Jackson County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, George County, MS, Harrison County, MS, Jackson County, MS
The radar
The Mobile radar (KMOB), 106 km from the middle of the area, began a volume at 20:05 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
Slidell Radar S, LA (KSIL), launched 12:00Z, 8.0 hours before the alert went out and 251 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
- 449 m above ground
- 0-6 km bulk shear
- 57 kt
- 0-1 km storm-relative helicity
- 160 m²/s²
- 0-3 km storm-relative helicity
- 177 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
810
ACUS11 KWNS 182002
SWOMCD
SPC MCD 182002
GAZ000-FLZ000-ALZ000-MSZ000-LAZ000-182100-
MESOSCALE DISCUSSION 0128
NWS STORM PREDICTION CENTER NORMAN OK
0202 PM CST SAT FEB 18 2012
AREAS AFFECTED...SRN AL...WRN FL PANHANDLE
CONCERNING...TORNADO WATCH 29...
VALID 182002Z - 182100Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 29 CONTINUES.
SW-NE ORIENTED LINE SEGMENT ACROSS SRN MS HAS RECENTLY ACCELERATED
TO AROUND 50 KT FORWARD MOTION. SHOULD THE LINE MAINTAIN ITS CURRENT
INTENSITY...EXTRAPOLATION WOULD TRACK IT ACROSS SWRN AL AND THE WRN
FL PANHANDLE WITHIN WW 29 THROUGH ABOUT 22-23Z. ANY THREAT FOR
ISOLATED DAMAGING WINDS AND BRIEF TORNADOES SHOULD REMAIN TIED TO
THIS FEATURE. DISCRETE TSTM DEVELOPMENT AHEAD OF THE LINE APPEARS
UNLIKELY OWING TO ABUNDANT STRATIFORM/CLOUD SHIELD...PROGRESSIVELY
MINIMAL SURFACE-BASED INSTABILITY AND COMPARATIVELY WEAKER FORCING
FOR ASCENT. HOWEVER...PER COORDINATION WITH WFO TAE...A WW IS BEING
CONSIDERED FOR ISSUANCE E OF WW 29 BY 21Z.
..GRAMS.. 02/18/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...TAE...MOB...LIX...
LAT...LON 29988812 30138932 30688892 31178829 31468741 31578579
31448495 30898496 29918578 30088675 29988812SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 18, 11:21 AM CST | Mesoscale Discussion | SPC | Baldwin, Escambia, Mobile | 54 min |
| Feb 18, 11:49 AM CST | Tornado Watch | SPC | Baldwin, Covington, Escambia, Mobile | 5 hr |
| Feb 18, 1:03 PM CST | Mesoscale Discussion | SPC | Baldwin, Escambia, Mobile | 57 min |
| Feb 18, 2:58 PM CST | Tornado Watch | SPC | Coffee, Dale, Geneva, Henry, Houston | 5 hr |
| Feb 18, 3:41 PM CST | Mesoscale Discussion | SPC | Baldwin, Coffee, Conecuh, Covington, Crenshaw, Dale and 4 more | 64 min |
| Feb 18, 4:29 PM CST | Mesoscale Discussion | SPC | Baldwin, Covington, Escambia, Mobile | 31 min |
| Feb 18, 4:48 PM CST | Tornado Watch | SPC | Baldwin, Covington, Escambia, Mobile | 4 hr |
| Feb 18, 9:31 AM CST | Mesoscale Discussion | SPC | Hancock, Harrison, Pearl River | 59 min |
| Feb 18, 9:55 AM CST | Tornado Watch | SPC | Hancock, Harrison, Jackson, Pearl River | 7 hr |
| Feb 18, 2:21 PM CST | Mesoscale Discussion | SPC | Harrison, Jackson | 24 min |
Nearby
Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in Florida, 2012Mesoscale Discussions in Mississippi, 2012Every mesoscale discussion in 2012
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.