Alert archive / Alabama / Mesoscale Discussions in 2016

Mesoscale Discussion 264

March 24, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2016, 11:26 AM CDT for 4 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Mar 24, 2016, 11:26 AM CDT (16:26 UTC)
Expired: Mar 24, 2016, 2:00 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 43 counties

Autauga County, AL, Baldwin County, AL, Bibb County, AL, Butler County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Coosa County, AL, Covington County, AL, Crenshaw County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lowndes County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Shelby County, AL, Sumter County, AL, Tuscaloosa County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Jefferson Parish, LA, Lafourche Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 10 km from the middle of the area, began a volume at 16:27 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.

Tornado Watch 54Mar 24, 12:15 PM CDT

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 4.4 hours before the alert went out and 138 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 844 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 511 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 214 m²/s²
0-3 km storm-relative helicity: 350 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 4.4

Open this sounding in Storm Lab

The text

As transmitted.

421 
ACUS11 KWNS 241626
SWOMCD
SPC MCD 241626 
ALZ000-FLZ000-MSZ000-LAZ000-241900-

MESOSCALE DISCUSSION 0264
NWS STORM PREDICTION CENTER NORMAN OK
1126 AM CDT THU MAR 24 2016

AREAS AFFECTED...SERN LA...SRN MS...CNTRL AND SRN AL...WRN FL
PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 241626Z - 241900Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A GRADUAL INCREASE IN SEVERE THREAT IS POSSIBLE THROUGH
AFTERNOON FROM SERN LA INTO CNTRL AL AND THE WRN FL PANHANDLE.
LOCALIZED SEVERE DOWNBURSTS AND/OR A ISOLATED TORNADO ARE POSSIBLE.

DISCUSSION...A GRAVITY WAVE INDUCED LINE OF STORMS CONTINUES TO
EVOLVE AHEAD OF THE MAIN COLD FRONT...FROM NEAR TUSCALOOSA SWWD TO
THE NEW ORLEANS VICINITY. THE STORMS OVER LA AND THE NRN GULF OF
MEXICO ARE MORE ROBUST IN TERMS OF ECHO TOPS DUE TO CLOSER PROXIMITY
TO A MODERATELY UNSTABLE AIR MASS...WHILE CELLS TO THE N CONTINUE TO
LANGUISH ON THE NRN EDGE OF THE LOW-LEVEL THETA-E RETURN. EVEN
SO...SOME OF THE NRN CELLS HAVE SHOWN A PROPENSITY FOR WEAK
ROTATION.

HODOGRAPHS AREA-WIDE ARE FAVORABLE FOR SUPERCELLS CAPABLE OF
PRODUCING TORNADOES...WITH 0-1 SRH OF 200-300 M2/S2 AND A GRADUALLY
MOISTENING AND DESTABILIZING AIR MASS. GIVEN SPOTTY HEATING ACROSS
SRN AL AND WRN FL PANHANDLE...AND A GRADUAL NWD ADVECTION OF MID 60S
F DEWPOINTS...A RISK OF TORNADOES MAY MATERIALIZE THROUGHOUT THE
DAY...WITH A WATCH POSSIBLY NEEDED.

..JEWELL/CORFIDI.. 03/24/2016

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

ATTN...WFO...TAE...BMX...MOB...JAN...LIX...

LAT...LON   29389052 30158973 32428838 33668756 33798680 33458627
            32698596 31628605 30538626 30338663 30198760 29898840
            29638874 29108884 28908934 28998988 29029033 29089057
            29389052

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 24, 12:18 PM CDT	Tornado Watch	SPC	Baldwin, Butler, Coffee, Conecuh, Covington, Crenshaw and 7 more	7 hr
Mar 24, 2:58 PM CDT	Mesoscale Discussion	SPC	Barbour, Coffee, Covington, Crenshaw, Dale, Geneva and 3 more	2 hr
Mar 24, 3:36 PM CDT	Mesoscale Discussion	SPC	Brevard, Broward, Indian River, Martin, Okeechobee, Osceola and 3 more	2 hr
Mar 24, 4:15 PM CDT	Severe Thunderstorm Watch	SPC	Calhoun, Dixie, Franklin, Gadsden, Gulf, Jefferson and 6 more	5 hr
Mar 24, 7:53 AM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Cameron, East Baton Rouge, East Feliciana and 13 more	3 hr

Nearby

Mesoscale Discussions in Alabama, 2016 Mesoscale Discussions in Mississippi, 2016 Mesoscale Discussions in Louisiana, 2016 Every mesoscale discussion in 2016

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.