Alert archive / Mississippi / Mesoscale Discussions in 2016

Mesoscale Discussion 75

February 2, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Feb 2, 2016, 12:50 PM CST for 4 states. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Feb 2, 2016, 12:50 PM CST (18:50 UTC)
Expired
Feb 2, 2016, 1:45 PM CST
In force
55 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 37 counties

Baldwin County, AL, Butler County, AL, Clarke County, AL, Conecuh County, AL, Covington County, AL, Escambia County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jones County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 58 km from the middle of the area, began a volume at 18:50 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, 6.8 hours before the alert went out and 90 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 12:00Z on 2016-02-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 648 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 12:00Z on 2016-02-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 257 square meters per square second.1939587897Sfc1 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
648 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
447 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
257 m²/s²
0-3 km storm-relative helicity
354 m²/s²
Significant tornado parameter
0.5
Supercell composite
4.5

Open this sounding in Storm Lab

The text

As transmitted.

093 
ACUS11 KWNS 021851
SWOMCD
SPC MCD 021850 
ALZ000-FLZ000-MSZ000-LAZ000-021945-

MESOSCALE DISCUSSION 0075
NWS STORM PREDICTION CENTER NORMAN OK
1250 PM CST TUE FEB 02 2016

AREAS AFFECTED...PORTIONS OF SERN LA...SERN MS...SRN AL...AND THE
FAR WRN FL PANHANDLE

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 

VALID 021850Z - 021945Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE POTENTIAL FOR SEVERE THUNDERSTORMS WILL INCREASE OVER
THE NEXT SEVERAL HOURS...WITH DAMAGING WINDS/ISOLATED TORNADOES THE
MAIN THREATS. TORNADO WATCH ISSUANCE IS LIKELY.

DISCUSSION...SPECIAL 18Z SOUNDING FROM KLIX SHOWS A NEARLY UNCAPPED
SURFACE-BASED PARCEL...AND CONVECTION HAS RECENTLY INCREASED IN
COVERAGE ACROSS PARTS OF SERN LA INTO SRN AL...MOST LIKELY ALONG
MULTIPLE CONFLUENCE LINES AHEAD OF A SFC COLD FRONT NOW APPROACHING
THE MS RIVER. SIMILAR TO THE METEOROLOGICAL REASONING PROVIDED IN
MCD 73 FOR MUCH OF MS...AS LOW-LEVEL MOISTURE CONTINUES TO INCREASE
THROUGH THE AFTERNOON WITH SLY/SELY WINDS...INSTABILITY SHOULD
LIKEWISE INCREASE...WITH MLCAPE OF 500-1000 J/KG BECOMING COMMON
ACROSS THE MCD AREA. BOTH LOW- TO MID-LEVEL WIND SHEAR WILL BECOME
INCREASINGLY SUPPORTIVE OF ROTATING UPDRAFTS THROUGH THE
AFTERNOON...WITH DAMAGING WINDS/ISOLATED TORNADOES THE MAIN THREATS.
TORNADO WATCH ISSUANCE FOR PORTIONS OF THE MCD AREA AS WELL AS
LOCATIONS FURTHER W IN CNTRL/SRN MS AND PARTS OF ERN LA IS LIKELY
WITHIN THE NEXT HOUR.

..GLEASON/GOSS.. 02/02/2016

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

ATTN...WFO...MOB...JAN...LIX...LCH...

LAT...LON   30298822 29718916 29288975 28969074 29279121 29949096
            31399003 31868874 31948790 31928692 31828634 30478653
            30298822

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 2, 1:18 PM CSTTornado WatchSPCBaldwin, Choctaw, Clarke, Mobile, Monroe, Washington and 1 more6 hr
Feb 2, 2:40 PM CSTMesoscale DiscussionSPCAutauga, Bibb, Blount, Chilton, Colbert, Cullman and 27 more95 min
Feb 2, 3:10 PM CSTTornado WatchSPCBibb, Blount, Chilton, Colbert, Cullman, Dallas and 23 more7 hr
Feb 2, 5:18 PM CSTMesoscale DiscussionSPCBaldwin, Choctaw, Clarke, Mobile, Monroe, Washington and 1 more117 min
Feb 2, 5:31 PM CSTMesoscale DiscussionSPCAutauga, Bibb, Blount, Chilton, Colbert, Cullman and 26 more119 min
Feb 2, 10:41 AM CSTMesoscale DiscussionSPCEast Carroll, Franklin, Madison, Tensas2 hr
Feb 2, 12:22 PM CSTTornado WatchSPCAlcorn, Attala, Benton, Bolivar, Calhoun, Carroll and 33 more9 hr
Feb 2, 1:43 PM CSTMesoscale DiscussionSPCChoctaw, Clay, Covington, Jasper, Jefferson Davis, Leake and 9 more2 hr

Nearby

Mesoscale Discussions in Mississippi, 2016Mesoscale Discussions in Louisiana, 2016Mesoscale Discussions in Alabama, 2016Every 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.