Alert archive / Louisiana / Mesoscale Discussions in 2011
Mesoscale Discussion 65
The Storm Prediction Center issued this mesoscale discussion at Feb 1, 2011, 6:46 AM CST for 4 states. It was in force for 119 min.
The area
The outline as issued.
The facts
- Issued
- Feb 1, 2011, 6:46 AM CST (12:46 UTC)
- Expired
- Feb 1, 2011, 8:45 AM CST
- In force
- 119 min
- Issued by
- the Storm Prediction Center
All 69 counties
Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Hempstead County, AR, Jefferson County, AR, Lafayette County, AR, Lincoln County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Union County, AR, Allen Parish, LA, Avoyelles Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Adams County, MS, Bolivar County, MS, Claiborne County, MS, Franklin County, MS, Hinds County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Leflore County, MS, Sharkey County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Yazoo County, MS, Newton County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX
The radar
The Shreveport radar (KSHV), 126 km from the middle of the area, began a volume at 12:49 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
Shreveport, LA (KSHV), launched 12:00Z, 0.8 hours before the alert went out and 118 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.
- Mixed-layer CAPE
- 43 J/kg
- Mixed-layer CIN
- -133 J/kg
- Mixed-layer LCL
- 511 m above ground
- 0-6 km bulk shear
- 81 kt
- 0-1 km storm-relative helicity
- 540 m²/s²
- 0-3 km storm-relative helicity
- 654 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.6
The text
As transmitted, in the capitals the NWS used until 2016.
370
ACUS11 KWNS 011246
SWOMCD
SPC MCD 011246
MSZ000-ARZ000-LAZ000-TXZ000-011445-
MESOSCALE DISCUSSION 0065
NWS STORM PREDICTION CENTER NORMAN OK
0646 AM CST TUE FEB 01 2011
AREAS AFFECTED...FAR E TX...NRN/CNTRL LA...WCNTRL MS...SRN AR
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 011246Z - 011445Z
STRONG PV-ANOMALY WAS MOVING INTO E TX/SRN OK AT DAYBREAK. INTENSE
LARGE-SCALE AND MESOSCALE FORCING ALONG THE ADVANCING COLD FRONT HAS
RESULTED IN AN INTENSIFYING SQUALL LINE OVER FAR E TX. 12Z SHV
SOUNDING SUGGESTS THAT STORMS ARE LIKELY SLIGHTLY ELEVATED WITH
ABOUT AN 800 METER STABLE BOUNDARY LAYER. HOWEVER...RECENT
STRENGTHENING OF STORMS AND MOISTENING OF THE BOUNDARY LAYER
IMMEDIATELY AHEAD OF THE LINE MAY BE SUFFICIENT TO ALLOW DAMAGING
WIND GUSTS TO ACCOMPANY THE STORMS. MEANWHILE...E OF THE LINE...E-W
ORIENTED WARM ADVECTION DERIVED BANDS OF STORMS WERE
DEVELOPING...PRIMARILY OVER SRN AR AND NRN LA. MID-LEVEL LAPSE
RATES AND EFFECTIVE DEEP LAYER SHEAR WERE SUFFICIENT FOR HAIL
PRODUCTION WITH THESE STORMS.
IF STORMS CONTINUE TO THRIVE/INTENSIFY...PARTICULARLY THE SQUALL
LINE...A WW MAY BECOME NECESSARY.
..RACY.. 02/01/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MEG...JAN...LIX...LZK...LCH...SHV...
LAT...LON 33929394 34419223 33739023 32369016 31299090 30669231
30529269 30879448 31909411 33929394SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 31, 10:36 PM CST | Mesoscale Discussion | SPC | Benton, Washington | 5 hr |
| Feb 1, 6:54 AM CST | Mesoscale Discussion | SPC | Boone, Carroll, Madison, Marion, Washington | 5 hr |
| Feb 1, 1:11 PM CST | Mesoscale Discussion | SPC | Benton | 4 hr |
| Feb 1, 8:40 AM CST | Tornado Watch | SPC | Acadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 46 more | 6 hr |
| Feb 1, 12:00 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 24 more | 60 min |
| Feb 1, 1:23 PM CST | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, Jefferson, Lafourche, Livingston and 12 more | 67 min |
| Feb 1, 1:03 PM CST | Tornado Watch | SPC | Clarke, Covington, Forrest, George, Greene, Hancock and 13 more | 7 hr |
| Feb 1, 3:44 PM CST | Mesoscale Discussion | SPC | George, Greene, Hancock, Harrison, Jackson, Perry and 2 more | 61 min |
| Jan 31, 7:55 PM CST | Mesoscale Discussion | SPC | Dallam, Hansford, Hartley, Moore, Oldham, Sherman | 5 hr |
| Jan 31, 9:04 PM CST | Mesoscale Discussion | SPC | Archer, Baylor, Clay, Foard, Haskell, King and 4 more | 6 hr |
| Jan 31, 11:29 PM CST | Mesoscale Discussion | SPC | Brown, Callahan, Coke, Coleman, Comanche, Concho and 26 more | 5 hr |
Nearby
Mesoscale Discussions in Louisiana, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Mississippi, 2011Every mesoscale discussion in 2011
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.