Alert archive / Mississippi / Mesoscale Discussions in 2016

Mesoscale Discussion 36

January 21, 2016East Feliciana Parish, Saint Helena Parish, Louisiana; 8 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jan 21, 2016, 4:57 PM CST for East Feliciana Parish, Saint Helena Parish, Louisiana; 8 counties in Mississippi. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Jan 21, 2016, 4:57 PM CST (22:57 UTC)
Expired: Jan 21, 2016, 6:00 PM CST
In force: 63 min
Issued by: the Storm Prediction Center

Counties East Feliciana Parish, LA, Saint Helena Parish, LA, Amite County, MS, Jefferson Davis County, MS, Lawrence County, MS, Lincoln County, MS, Pike County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 99 km from the middle of the area, began a volume at 22:58 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 7Jan 21, 6:30 PM CST

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 11.0 hours before the alert went out and 101 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 551 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 173 m²/s²
0-3 km storm-relative helicity: 154 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

112 
ACUS11 KWNS 212258
SWOMCD
SPC MCD 212257 
MSZ000-LAZ000-220000-

MESOSCALE DISCUSSION 0036
NWS STORM PREDICTION CENTER NORMAN OK
0457 PM CST THU JAN 21 2016

AREAS AFFECTED...A PORTION OF SERN LA NEWD INTO SWRN AND S-CNTRL MS

CONCERNING...TORNADO WATCH 6...

VALID 212257Z - 220000Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 6 CONTINUES.

SUMMARY...GREATEST TORNADO RISK OVER THE NEXT 2 HOURS APPEARS TO BE
FOCUSED FROM NEAR AND NORTH OF BATON ROUGE TO NEAR AND IMMEDIATELY
SOUTHEAST OF JACKSON.

DISCUSSION...22Z SUBJECTIVE SURFACE MESOANALYSIS PLACES A TRIPLE
POINT 1008MB LOW 30 MI NNW MCB WITH A STATIONARY FRONTAL ZONE DRAPED
NW TO SE AND AN EFFECTIVE/MARITIME FRONT EXTENDING FROM THE MOUTH OF
THE MS RIVER NWWD INTO SERN LA AND NNEWD INTO S-CNTRL MS.  A NARROW
WEDGE OF RICHER AND PARTIALLY MODIFIED MOISTURE WITH DEWPOINTS IN
THE LOWER 60S IS LOCATED WITHIN THIS CORRIDOR.  VAD WIND TRENDS OVER
THE PAST 2-4 HOURS AT KDGX SHOW SWLY WINDS INCREASING BY 10 KT IN
THE 2-5KM LAYER--RESULTING IN A MODEST INCREASE IN HODOGRAPH SIZE
/150-200 M2 PER S2 0-1 KM SRH/.  AS STORMS CURRENTLY OVER SERN LA
MATURE AND DEVELOP NEWD WITHIN THE WARM SECTOR AHEAD OF THE
CONVECTIVE LINE...THE POTENTIAL FOR MESOCYCLONE
DEVELOPMENT/INTENSIFICATION WILL PROBABLY INCREASE.  A SUPERCELL
TORNADO RISK WILL ACCOMPANY THE STRONGER STORMS AND A DMGG WIND
THREAT WILL ALSO EXIST BOTH WITH THE SUPERCELLS AND WITH AREAS WHERE
THE CONVECTIVE LINE SURGES/BOWS.

..SMITH.. 01/21/2016

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

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

LAT...LON   30799135 31679055 32258986 32238948 31928937 30509067
            30799135

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 21, 4:40 AM CST	Mesoscale Discussion	SPC	Allen, Beauregard, Bienville, Caddo, De Soto, Grant and 8 more	95 min
Jan 21, 10:59 AM CST	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Evangeline and 7 more	2 hr
Jan 21, 11:48 AM CST	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 12 more	5 hr
Jan 21, 1:44 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 29 more	2 hr
Jan 21, 2:14 PM CST	Tornado Watch	SPC	Ascension, Assumption, Catahoula, Concordia, East Baton Rouge, East Feliciana and 23 more	6 hr
Jan 21, 11:03 AM CST	Mesoscale Discussion	SPC	Attala, Hinds, Leake, Madison, Warren, Yazoo	87 min
Jan 21, 5:29 PM CST	Mesoscale Discussion	SPC	Clarke, George, Greene, Harrison, Jackson, Lauderdale and 3 more	2 hr

Nearby

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.