Alert archive / Mississippi / Mesoscale Discussions in 2012

Mesoscale Discussion 12

January 10, 20127 parishes in Louisiana; 35 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jan 10, 2012, 4:08 PM CST for 7 parishes in Louisiana; 35 counties in Mississippi. It was in force for 82 min.

The area

The outline as issued.

The facts

Issued: Jan 10, 2012, 4:08 PM CST (22:08 UTC)
Expired: Jan 10, 2012, 5:30 PM CST
In force: 82 min
Issued by: the Storm Prediction Center

All 42 counties

East Carroll Parish, LA, Livingston Parish, LA, Madison Parish, LA, Saint Helena Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Washington Parish, LA, Amite County, MS, Attala County, MS, Carroll County, MS, Choctaw County, MS, Claiborne County, MS, Copiah County, MS, Covington County, MS, Franklin County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Warren County, MS, Winston County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 31 km from the middle of the area, began a volume at 22:12 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

Jackson, MS (KJAN), launched 12:00Z, 10.1 hours before the alert went out and 35 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: 14 J/kg
Mixed-layer CIN: -137 J/kg
Mixed-layer LCL: 699 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 133 m²/s²
0-3 km storm-relative helicity: 86 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

250 
ACUS11 KWNS 102208
SWOMCD
SPC MCD 102208 COR
MSZ000-LAZ000-ARZ000-102330-

MESOSCALE DISCUSSION 0012
NWS STORM PREDICTION CENTER NORMAN OK
0408 PM CST TUE JAN 10 2012

AREAS AFFECTED...ERN LA...SCNTRL MS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 102208Z - 102330Z

CORRECTED FOR TYPO IN FIRST LINE BELOW...CHANGE MO TO MS

AN ISOLATED SEVERE THREAT WILL LIKELY DEVELOP ACROSS ERN LA AND
SCNTRL MS THIS AFTERNOON. HAIL AND STRONG WIND GUSTS SHOULD BE THE
PRIMARY THREATS AS THE STORMS GRADUALLY INTENSIFY OVER THE NEXT FEW
HOURS. WW ISSUANCE REMAINS POSSIBLE THIS AFTERNOON ACROSS THE
REGION.

THE LATEST SFC ANALYSIS SHOWS A 1006 MB SFC LOW OVER FAR NE LA WITH
A COLD FRONT EXTENDING SWD ACROSS SE LA WITH A STATIONARY FRONT
LOCATED FROM NRN MS EWD ACROSS NRN AL. TO THE SOUTHEAST OF THE SFC
LOW...THE WARM SECTOR IS CHARACTERIZED BY WEAK INSTABILITY WITH
MESOANALYSIS SHOWING MLCAPE VALUES IN THE 250 TO 500 J/KG ACROSS
MUCH OF MS. IN SPITE OF THE WEAK INSTABILITY...A STRONGLY SHEARED
WIND PROFILE WITH 0-6 KM SHEAR OF 60 TO 70 KT SHOULD BE SUFFICIENT
FOR A FEW ROTATING STORMS THIS AFTERNOON. COLD TEMPS ALOFT /500 MB
TEMPS OF -14C TO -16C/ AND MARGINALLY STEEP MID-LEVEL LAPSE RATES
MAY BE ENOUGH FOR HAIL WITH THE MORE INTENSE CORES. A POTENTIAL FOR
STRONG WIND GUSTS MAY ALSO OCCUR BUT ANY THREAT SHOULD REMAIN VERY
ISOLATED MAINLY DUE TO THE WEAK INSTABILITY.

..BROYLES.. 01/10/2012

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

ATTN...WFO...JAN...LIX...

LAT...LON   31438918 32038885 32718873 33328901 33578976 33279093
            33009137 32409152 31259118 30439075 30309022 30928960
            31438918

Nearby

Mesoscale Discussions in Mississippi, 2012 Mesoscale Discussions in Louisiana, 2012 Every 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.