Alert archive / Mississippi / Mesoscale Discussions in 2016

Mesoscale Discussion 101

February 15, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Feb 15, 2016, 11:50 AM CST for 4 states. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
Feb 15, 2016, 11:50 AM CST (17:50 UTC)
Expired
Feb 15, 2016, 1:45 PM CST
In force
115 min
Issued by
the Storm Prediction Center
All 72 counties

Autauga County, AL, Baldwin County, AL, Barbour County, AL, Bullock County, AL, Butler County, AL, Choctaw County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Geneva County, AL, Greene County, AL, Hale County, AL, Lowndes County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Sumter County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Livingston Parish, LA, Saint Helena Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, Amite 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, Jackson County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Newton 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

The radar

The Mobile radar (KMOB), 72 km from the middle of the area, began a volume at 17:51 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, 5.8 hours before the alert went out and 186 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 2016-02-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 569 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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 2016-02-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 257 square meters per square second.1939587897117Sfc1 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
569 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
649 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
257 m²/s²
0-3 km storm-relative helicity
320 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.4

Open this sounding in Storm Lab

The text

As transmitted.

072 
ACUS11 KWNS 151750
SWOMCD
SPC MCD 151750 
FLZ000-ALZ000-MSZ000-LAZ000-151945-

MESOSCALE DISCUSSION 0101
NWS STORM PREDICTION CENTER NORMAN OK
1150 AM CST MON FEB 15 2016

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

CONCERNING...TORNADO WATCH 14...

VALID 151750Z - 151945Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 14 CONTINUES.

SUMMARY...AN ISOLATED TORNADO THREAT ALONG WITH A POTENTIAL FOR WIND
DAMAGE WILL SPREAD EWD FROM SCNTRL MS INTO SRN AND CNTRL AL AND THE
WRN FL PANHANDLE THIS AFTERNOON. WW ISSUANCE WILL LIKELY BE NEEDED
TO THE EAST OF WW 14.

DISCUSSION...LATEST SFC ANALYSIS SHOWS A 1007 MB LOW NEAR JACKSON MS
JUST AHEAD OF A COLD FRONT. A SFC TROUGH EXTENDS SSWWD FROM THE SFC
LOW INTO SRN LA WITH STRONG TO SEVERE THUNDERSTORMS ONGOING ALONG
THE SFC TROUGH. A THERMAL BOUNDARY EXTENDS TO THE EAST OF THE SFC
LOW INTO CNTRL AL. SFC DEWPOINTS ALONG AND SOUTH OF THIS BOUNDARY
ARE IN THE UPPER 50S TO LOWER 60S F AND MLCAPE IS ESTIMATED BY
MESOSCALE ANALYSIS IN THE 500 TO 1000 J/KG RANGE. IN
ADDITION...STRONGLY ROTATING THUNDERSTORMS ARE ONGOING ALONG A
CONFLUENCE ZONE EXTENDING NEWD ACROSS FAR SRN MS INTO SRN AL. THE
AXIS OF A 40 TO 50 KT LOW-LEVEL JET IS ANALYZED ALONG THIS CORRIDOR.
THE MOBILE WSR-88D VWP IS SAMPLING THE LOW-LEVEL JET WELL WITH A
LOOPED HODOGRAPH AND 0-3 KM STORM RELATIVE HELICITY OF 475 TO 500
M2/S2. AS INSTABILITY CONTINUES TO SLOWLY INCREASE EARLY THIS
AFTERNOON...THE STRONG LOW-LEVEL SHEAR WILL BE FAVORABLE FOR
SUPERCELLS AND POSSIBLY A COUPLE TORNADOES. TORNADIC STORMS MAY BE
MOST FAVORABLE ALONG THE CONFLUENCE ZONE IN SRN MS AND SRN AL AND
ALSO ALONG THE THERMAL BOUNDARY ACROSS SCNTRL AL. SUPERCELLS AND
SHORT LINE SEGMENTS WILL ALSO HAVE A POTENTIAL FOR WIND DAMAGE THIS
AFTERNOON.

..BROYLES.. 02/15/2016

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

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

LAT...LON   30388629 30448864 30248966 30299084 30669137 31329129
            31989078 32678976 32908746 32748620 32258550 31678526
            30618551 30388629

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 15, 12:02 PM CSTTornado WatchSPCAutauga, Baldwin, Barbour, Bullock, Butler, Choctaw and 27 more9 hr
Feb 15, 1:51 PM CSTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bibb, Bullock, Butler and 28 more114 min
Feb 15, 4:24 PM CSTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 11 more2 hr
Feb 15, 5:27 AM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 11 more3 hr
Feb 15, 7:41 AM CSTMesoscale DiscussionSPCAllen, Avoyelles, Beauregard, Calcasieu, Catahoula, Concordia and 8 more3 hr
Feb 15, 9:30 AM CSTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 27 more8 hr

Nearby

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