Alert archive / Louisiana / Mesoscale Discussions in 2003

Mesoscale Discussion 992

May 15, 200316 parishes in Louisiana; Adams County, Mississippi; 6 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 15, 2003, 2:27 AM CDT for 16 parishes in Louisiana; Adams County, Mississippi; 6 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 15, 2003, 2:27 AM CDT (07:27 UTC)
Expired: May 15, 2003, 4:30 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 23 counties

Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Webster Parish, LA, Winn Parish, LA, Adams County, MS, Gregg County, TX, Harrison County, TX, Marion County, TX, Panola County, TX, Rusk County, TX, Shelby County, TX

The radar

The Shreveport radar (KSHV), 47 km from the middle of the area, began a volume at 07:31 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

Shreveport, LA (KSHV), launched 00:00Z, 7.5 hours before the alert went out and 41 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: 2404 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 1182 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 114 m²/s²
0-3 km storm-relative helicity: 250 m²/s²
Significant tornado parameter: 2.2
Supercell composite: 10.6

Open this sounding in Storm Lab

The text

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

438 
ACUS11 KWNS 150727
SWOMCD
SPC MCD 150727 
LAZ000-MSZ000-TXZ000-150930-

MESOSCALE DISCUSSION 0992
NWS STORM PREDICTION CENTER NORMAN OK
0227 AM CDT THU MAY 15 2003

AREAS AFFECTED...NE TX...NRN LA

CONCERNING...SEVERE THUNDERSTORM WATCH 376...

VALID 150727Z - 150930Z

CURRENT TRENDS SUGGEST WW MAY BE CANCELLED PRIOR TO 10Z.

WHILE VERY STRONG INSTABILITY ABOVE SURFACE INVERSION IS EVIDENT IN
THE 15/00Z FORT WORTH SOUNDING AND MODEL FORECAST SOUNDINGS...MUCH
COOLER LOW-LEVEL ENVIRONMENT ALONG FRONTAL ZONE ACROSS NORTHERN
LOUISIANA APPEARS TO BE LIMITING MOST UNSTABLE CAPE TO AROUND 1000
J/KG.  BRIEF ENHANCEMENT OF ACTIVITY WITHIN LAST HOUR OR TWO MAY
HAVE BEEN IN RESPONSE TO FORCING/SHEAR ASSOCIATED WITH MID-LEVEL JET
STREAK...WHICH MODELS SUGGEST WILL CONTINUE TO PROPAGATE EAST
SOUTHEAST OF THE LOWER MISSISSIPPI VALLEY BY DAYBREAK.	THUS...
WHILE MARGINALLY SEVERE HAIL WILL REMAIN POSSIBLE WITH ISOLATED
STRONGER CELLS ALONG FRONTAL ZONE...OVERALL SEVERE THREAT APPEARS TO
BE DIMINISHING.

..KERR.. 05/15/2003

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

ATTN...WFO...JAN...LIX...LCH...SHV...

33069496 33009406 32579245 31939139 31369133 31379306
32029479

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 14, 9:20 PM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Caldwell, Claiborne, East Carroll and 12 more	115 min
May 14, 11:35 PM CDT	Severe Thunderstorm Watch	SPC	Bienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 19 more	5 hr
May 15, 11:48 AM CDT	Mesoscale Discussion	SPC	Attala, Carroll, Chickasaw, Choctaw, Clarke, Clay and 15 more	117 min
May 14, 7:36 PM CDT	Mesoscale Discussion	SPC	Bowie, Red River	114 min
May 14, 11:20 PM CDT	Mesoscale Discussion	SPC	Bell, Bosque, Coryell, Ellis, Falls, Freestone and 5 more	115 min
May 14, 11:45 PM CDT	Severe Thunderstorm Watch	SPC	Anderson, Bosque, Collin, Dallas, Delta, Denton and 16 more	5 hr
May 15, 2:10 AM CDT	Mesoscale Discussion	SPC	Anderson, Collin, Dallas, Denton, Ellis, Henderson and 13 more	2 hr
May 15, 1:31 PM CDT	Mesoscale Discussion	SPC	Armstrong, Briscoe, Carson, Castro, Dallam, Deaf Smith and 10 more	119 min
May 15, 1:55 PM CDT	Tornado Watch	SPC	Armstrong, Carson, Collingsworth, Dallam, Deaf Smith, Donley and 13 more	6 hr
May 15, 3:41 PM CDT	Mesoscale Discussion	SPC	Armstrong, Baylor, Briscoe, Carson, Castro, Childress and 30 more	94 min
May 15, 4:05 PM CDT	Tornado Watch	SPC	Borden, Briscoe, Castro, Childress, Cottle, Crosby and 20 more	6 hr
May 15, 5:15 PM CDT	Mesoscale Discussion	SPC	Frio, Kinney, Maverick, Uvalde, Zavala	2 hr
May 15, 5:49 PM CDT	Mesoscale Discussion	SPC	Baylor, Coke, Cottle, Fisher, Foard, Hardeman and 17 more	116 min
May 15, 6:25 PM CDT	Tornado Watch	SPC	Archer, Baylor, Borden, Briscoe, Brown, Callahan and 45 more	6 hr
May 15, 6:47 PM CDT	Mesoscale Discussion	SPC	Childress, Collingsworth, Donley, Gray, Hall, Hansford and 6 more	58 min
May 15, 6:50 PM CDT	Tornado Watch	SPC	Armstrong, Carson, Collingsworth, Dallam, Donley, Gray and 12 more	5 hr

Nearby

Mesoscale Discussions in Louisiana, 2003 Mesoscale Discussions in Texas, 2003 Mesoscale Discussions in Mississippi, 2003 Every mesoscale discussion in 2003

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.