Alert archive / Louisiana / Mesoscale Discussions in 2014

Mesoscale Discussion 13

January 10, 2014Choctaw County, Washington County, Alabama; 33 parishes in Louisiana; 32 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jan 10, 2014, 11:41 PM CST for Choctaw County, Washington County, Alabama; 33 parishes in Louisiana; 32 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jan 10, 2014, 11:41 PM CST (05:41 UTC)
Expired
Jan 11, 2014, 1:45 AM CST
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 67 counties

Choctaw County, AL, Washington County, AL, Acadia Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Hinds County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS, Wilkinson County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 5.7 hours before the alert went out and 71 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 2014-01-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 65 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 2014-01-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 270 square meters per square second.19395878Sfc1 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
65 J/kg
Mixed-layer CIN
-103 J/kg
Mixed-layer LCL
502 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
270 m²/s²
0-3 km storm-relative helicity
327 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

824 
ACUS11 KWNS 110542
SWOMCD
SPC MCD 110541 
ALZ000-MSZ000-LAZ000-110745-

MESOSCALE DISCUSSION 0013
NWS STORM PREDICTION CENTER NORMAN OK
1141 PM CST FRI JAN 10 2014

AREAS AFFECTED...LA INTO SRN MS AND FAR SWRN AL LATE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 110541Z - 110745Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...SCATTERED STORMS WILL PERSIST TONIGHT AND COULD INTENSIFY
A BIT...BUT THE SEVERE THREAT APPEARS TO BE TOO LOW FOR A WATCH.

DISCUSSION...A ZONE OF LOW-LEVEL THETA-E ADVECTION ASSOCIATED WITH A
STRONG SWLY LOW LEVEL JET WILL PERSIST AHEAD OF THE UPPER TROUGH
THROUGH THE EARLY MORNING HOURS AS COOLING ALOFT OVERSPREADS
MOISTENING LOW LEVELS. MID 60S F BOUNDARY LAYER DEWPOINTS CONTINUE
TO MOVE SLOWLY NWD ACROSS SRN LA AND INTO SRN MS...WHERE GPS
PRECIPITABLE WATER VALUES WERE APPROACHING 1.60 INCHES. 

CONVECTION ALLOWING MODELS SHOW AN EVENTUAL CONSOLIDATION OF
STRONGER ECHOES ALONG THE DEVELOPING COLD FRONT MAINLY IN THE 9-12 Z
PERIOD ACROSS SERN LA...SRN MS AND INTO SRN AL BY EARLY MORNING.
CONDITIONALLY...SHEAR PROFILES WILL FAVOR THE DEVELOPMENT OF
ROTATION WITHIN ANY STRONGER UPDRAFTS THAT CAN DEVELOP...WITH A
MARGINAL WIND OR TORNADO THREAT WHERE EFFECTIVE BOUNDARY LAYER
PARCELS REMAIN UNSTABLE. HOWEVER...MOST OF THE FORCING FOR ASCENT
WILL BE WHERE INSTABILITY IS WEAKEST. CONDITIONS WILL BE CLOSELY
MONITORED TONIGHT FOR ANY DEVELOPING THREAT SHOULD A MORE ORGANIZED
BAND OF STORMS MATERIALIZE.

..JEWELL/HART.. 01/11/2014

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

ATTN...WFO...BMX...MOB...JAN...LIX...LCH...SHV...

LAT...LON   29258979 29069002 28999042 28989094 29189122 29419166
            29499216 29559272 29689295 30009293 31809183 32219108
            32469018 32528991 32478952 32318869 32038796 31858789
            31698791 31328808 29488952 29258979

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 11, 3:18 AM CSTMesoscale DiscussionSPCAutauga, Baldwin, Butler, Choctaw, Clarke, Conecuh and 13 more117 min
Jan 11, 7:03 AM CSTMesoscale DiscussionSPCBarbour, Bullock, Butler, Chambers, Coffee, Conecuh and 12 more27 min
Jan 11, 7:07 AM CSTTornado WatchSPCBarbour, Bullock, Chambers, Lee, Macon, Montgomery and 2 more7 hr
Jan 11, 10:04 AM CSTSevere Thunderstorm WatchSPCDale, Geneva, Henry, Houston6 hr
Jan 11, 12:53 PM CSTMesoscale DiscussionSPCHenry, Houston97 min

Nearby

Mesoscale Discussions in Louisiana, 2014Mesoscale Discussions in Mississippi, 2014Mesoscale Discussions in Alabama, 2014Every mesoscale discussion in 2014

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.