Alert archive / Mississippi / Mesoscale Discussions in 2012

Mesoscale Discussion 325

March 22, 2012Mobile County, Alabama; George County, Jackson County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 22, 2012, 6:49 AM CDT for Mobile County, Alabama; George County, Jackson County, Mississippi. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
Mar 22, 2012, 6:49 AM CDT (11:49 UTC)
Expired
Mar 22, 2012, 8:45 AM CDT
In force
116 min
Issued by
the Storm Prediction Center

Counties Mobile County, AL, George County, MS, Jackson County, MS

The radar

The Mobile radar (KMOB), 13 km from the middle of the area, began a volume at 11:52 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 00:00Z, 11.8 hours before the alert went out and 137 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.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 00:00Z on 2012-03-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 131 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 00:00Z on 2012-03-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
131 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
505 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
17 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

936 
ACUS11 KWNS 221150
SWOMCD
SPC MCD 221149
ALZ000-MSZ000-221345-

MESOSCALE DISCUSSION 0325
NWS STORM PREDICTION CENTER NORMAN OK
0649 AM CDT THU MAR 22 2012

AREAS AFFECTED...COASTAL SOUTHEAST MS AND SOUTHWEST AL

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 221149Z - 221345Z

POTENTIAL MAY STILL EXIST FOR THE DEVELOPMENT OF AN ISOLATED SHORT
LIVED TORNADO.  HOWEVER PROBABILITIES APPEAR SUFFICIENTLY LOW...AND
AREA AFFECTED SUFFICIENTLY SMALL...THAT THE NEED FOR A WW IS NOT
CURRENTLY ANTICIPATED.

LATEST RUC MODEL DATA...INCLUDING FORECAST SOUNDINGS...CONTINUE TO
SUGGEST MORE SUBSTANTIVE WEAKENING OF SOUTHERLY LOW-LEVEL WIND
FIELDS AND SHEAR THAN PERHAPS HAS BEEN INDICATED BY VAD WIND
PROFILER DATA FROM MOBILE.  ASSUMING THE VWP DATA IS MORE ACCURATELY
REFLECTIVE OF CURRENT LOW-LEVEL HODOGRAPHS...THE TORNADIC
POTENTIAL...WHILE STILL LOW...MAY NOT BE COMPLETELY NEGLIGIBLE WITH
CONVECTION THAT CONTINUES TO DEVELOP ALONG A VERY SLOWLY EASTWARD
ADVANCING CONVECTIVE OUTFLOW BOUNDARY ALONG THE CENTRAL GULF COAST.
THE AREA OF CONCERN BETWEEN NOW AND 15-16Z APPEARS CONFINED TO A
RELATIVELY SMALL AREA ADJACENT TO COASTAL AREAS EAST OF GULFPORT MS
INTO THE MOBILE BAY AREA.  THIS IS WHERE LOW-LEVEL CONVERGENCE
REMAINS ENHANCED NEAR A WEAK SURFACE LOW...BENEATH STRONGLY DIFLUENT
MID/UPPER FLOW...IN THE PRESENCE OF A MOIST BOUNDARY LAYER WITH WEAK
TO MODERATE CAPE.

..KERR.. 03/22/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MOB...LIX...

LAT...LON   30078863 30748870 31068862 31218835 31028801 30688792
            30388789 30108816 30078863

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 22, 2:28 AM CDTMesoscale DiscussionSPCMobile, Washington2 hr
Mar 22, 9:53 AM CDTMesoscale DiscussionSPCBaldwin, Clarke, Mobile, Washington67 min
Mar 22, 10:55 AM CDTTornado WatchSPCBaldwin, Clarke, Mobile, Monroe, Washington, Wilcox6 hr
Mar 22, 1:00 PM CDTMesoscale DiscussionSPCAutauga, Baldwin, Bibb, Butler, Chilton, Conecuh and 10 more60 min
Mar 22, 3:30 PM CDTMesoscale DiscussionSPCBaldwin, Conecuh, Escambia, Mobile, Monroe, Wilcox60 min
Mar 21, 9:27 PM CDTMesoscale DiscussionSPCClarke, Forrest, George, Greene, Hancock, Harrison and 8 more93 min
Mar 21, 11:49 PM CDTMesoscale DiscussionSPCClarke, George, Greene, Harrison, Jackson, Lauderdale and 2 more56 min
Mar 22, 7:15 AM CDTTornado WatchSPCGeorge, Harrison, Jackson, Stone5 hr

Nearby

Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Alabama, 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.