Alert archive / Arkansas / Mesoscale Discussions in 2012
Mesoscale Discussion 84
The Storm Prediction Center issued this mesoscale discussion at Feb 1, 2012, 10:18 AM CST for 4 states. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- Feb 1, 2012, 10:18 AM CST (16:18 UTC)
- Expired
- Feb 1, 2012, 12:15 PM CST
- In force
- 117 min
- Issued by
- the Storm Prediction Center
All 89 counties
Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Conway County, AR, Crawford County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Faulkner County, AR, Franklin County, AR, Garland County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Jefferson County, AR, Johnson County, AR, Lafayette County, AR, Lincoln County, AR, Little River County, AR, Logan County, AR, Lonoke County, AR, Madison County, AR, Miller County, AR, Monroe County, AR, Montgomery County, AR, Nevada County, AR, Newton County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, Union County, AR, Van Buren County, AR, Washington County, AR, White County, AR, Yell County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Union Parish, LA, Webster Parish, LA, Adair County, OK, Choctaw County, OK, LeFlore County, OK, McCurtain County, OK, Pushmataha County, OK, Sequoyah County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Delta County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hopkins County, TX, Hunt County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Rusk County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX
The radar
The Shreveport radar (KSHV), 139 km from the middle of the area, began a volume at 16:17 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, 4.3 hours before the alert went out and 137 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
- 302 J/kg
- Mixed-layer CIN
- -37 J/kg
- Mixed-layer LCL
- 588 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km storm-relative helicity
- 86 m²/s²
- 0-3 km storm-relative helicity
- 73 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
854
ACUS11 KWNS 011618
SWOMCD
SPC MCD 011618
ARZ000-MSZ000-LAZ000-TXZ000-OKZ000-011815-
MESOSCALE DISCUSSION 0084
NWS STORM PREDICTION CENTER NORMAN OK
1018 AM CST WED FEB 01 2012
AREAS AFFECTED...ERN OK...AR...NERN TX...NRN LA
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 011618Z - 011815Z
STORMS ARE EXPECTED TO GRADUALLY INTENSIFY AND INCREASE IN COVERAGE
THIS AFTERNOON. LARGE HAIL WILL BE THE MAIN THREAT. A SLIGHT RISK
WILL BE INTRODUCED FOR MUCH OF AR AND THE ARKLATEX REGION...AND A
WATCH MAY BE NEEDED IN A FEW HOURS.
SURFACE ANALYSIS SHOWS A WEAK LOW NEAR THE METROPLEX...ALONG A
BOUNDARY EXTENDING NEWD INTO WRN AR. VISIBLE IMAGERY ALSO SHOWS
AREAS OF CLEARING WHERE DEWPOINTS ARE SOLIDLY INTO THE MID 50S TO
LOWER 60S F.
VERY COOL AIR IS CURRENTLY OVERSPREADING THE AREA ALOFT...RESULTING
IN STEEP LAPSE RATES. THE 12Z FWD SOUNDING SHOWS VERY STEEP LAPSE
RATES AND LITTLE CAPPING POTENTIAL...SUGGESTING SURFACE TEMPERATURES
IN THE LOWER 70S F WILL TOTALLY REMOVE INHIBITION.
AS ONGOING STORMS APPROACH THE DESTABILIZING INSTABILITY AXIS...THEY
MAY INTENSIFY. OTHER VIGOROUS DEVELOPMENT IS EXPECTED ALONG THE
BOUNDARY LATER THIS AFTERNOON...ALTHOUGH COVERAGE MAY NOT BE
WIDESPREAD. FAVORABLY LONG HODOGRAPHS...AMPLE MOISTURE AND STEEP
LAPSE RATES SHOULD YIELD A LOT OF HAIL...SOME POSSIBLY VERY LARGE.
..JEWELL.. 02/01/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MEG...JAN...LZK...SHV...TSA...FWD...OUN...
LAT...LON 32869621 33369607 34619535 35269507 36179449 36189339
35389164 34809117 33989104 33109127 32209196 31919345
31929487 32059571 32419607 32869621SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 1, 12:37 PM CST | Severe Thunderstorm Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 34 more | 5 hr |
| Feb 1, 1:22 PM CST | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 35 more | 113 min |
| Feb 1, 2:58 PM CST | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 25 more | 2 hr |
| Feb 1, 3:45 PM CST | Severe Thunderstorm Watch | SPC | Ashley, Chicot, Crittenden, Cross, Lee, Phillips and 1 more | 3 hr |
| Feb 1, 1:06 AM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Calcasieu, Cameron, East Feliciana and 5 more | 114 min |
| Feb 1, 1:36 PM CST | Mesoscale Discussion | SPC | Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 12 more | 84 min |
| Feb 1, 5:18 PM CST | Mesoscale Discussion | SPC | Ascension, Livingston, Orleans, Saint Charles, Saint James, Saint John the Baptist and 2 more | 87 min |
Nearby
Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Louisiana, 2012Every mesoscale discussion in 2012
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.