Alert archive / Arkansas / Mesoscale Discussions in 2012

Mesoscale Discussion 87

February 1, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Feb 1, 2012, 2:58 PM CST for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Feb 1, 2012, 2:58 PM CST (20:58 UTC)
Expired
Feb 1, 2012, 5:00 PM CST
In force
2 hr
Issued by
the Storm Prediction Center
All 60 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, Crittenden County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Hot Spring County, AR, Jefferson County, AR, Lafayette County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Nevada County, AR, Ouachita County, AR, Phillips County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, Union County, AR, White County, AR, Woodruff County, AR, Bienville Parish, LA, Bossier Parish, LA, Claiborne Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Benton County, MS, Bolivar County, MS, Carroll County, MS, Coahoma County, MS, DeSoto County, MS, Grenada County, MS, Humphreys County, MS, Lafayette County, MS, Leflore County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Tunica County, MS, Washington County, MS, Yalobusha County, MS, Fayette County, TN, Shelby County, TN, Tipton County, TN

The radar

The Little Rock radar (KLZK), 127 km from the middle of the area, began a volume at 20:58 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.

The nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 9.0 hours before the alert went out and 175 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, Little Rock, AR at 12:00Z on 2012-02-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 34 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Little Rock, AR at 12:00Z on 2012-02-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -28 square meters per square second.1939587897Sfc1 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
34 J/kg
Mixed-layer CIN
-85 J/kg
Mixed-layer LCL
838 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
-28 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

379 
ACUS11 KWNS 012059
SWOMCD
SPC MCD 012058
MSZ000-TNZ000-ARZ000-LAZ000-012300-

MESOSCALE DISCUSSION 0087
NWS STORM PREDICTION CENTER NORMAN OK
0258 PM CST WED FEB 01 2012

AREAS AFFECTED...AR...NRN LA...WRN TN AND NWRN MS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 012058Z - 012300Z

SEVERE STORMS WITH HAIL CONTINUE OVER CNTRL AR...EXTENDING SWD INTO
NRN LA. THE LEADING EDGE OF THE AR STORMS ARE APPROXIMATELY TWO
HOURS AWAY FROM THE MS RIVER AS OF 21Z....BUT A NEW WATCH MAY BE
REQUIRED LATER TODAY E OF THE CURRENT WATCH.

SURFACE ANALYSIS SHOWS TEMPERATURES INTO THE MID 70S OVER SRN AR AND
NRN LA WHERE HEATING CONTINUES. WITH DEWPOINTS FROM 58 TO 62
F...THIS SHOULD PROVE FAVORABLE FOR A CONTINUED THREAT OF SEVERE
STORMS PRODUCING LARGE HAIL. DEEP LAYER FLOW AND PROGRESSIVE NATURE
OF THE UPPER TROUGH MAY ALLOW SEVERE STORMS TO PERSIST INTO WRN TN
AND NWRN MS....WITH STORMS MOVING IN AN ENE DIRECTION AT
APPROXIMATELY 30 KT.

..JEWELL.. 02/01/2012

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

ATTN...WFO...MEG...JAN...LZK...SHV...

LAT...LON   32149378 33629363 34549315 35289178 35588957 35118918
            34278918 33468971 32809109 32149378

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 1, 10:18 AM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 43 more117 min
Feb 1, 12:37 PM CSTSevere Thunderstorm WatchSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 34 more5 hr
Feb 1, 1:22 PM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 35 more113 min
Feb 1, 3:45 PM CSTSevere Thunderstorm WatchSPCAshley, Chicot, Crittenden, Cross, Lee, Phillips and 1 more3 hr
Feb 1, 1:06 AM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Calcasieu, Cameron, East Feliciana and 5 more114 min
Feb 1, 1:36 PM CSTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 12 more84 min
Feb 1, 5:18 PM CSTMesoscale DiscussionSPCAscension, Livingston, Orleans, Saint Charles, Saint James, Saint John the Baptist and 2 more87 min
Feb 1, 4:49 PM CSTMesoscale DiscussionSPCAttala, Benton, Calhoun, Carroll, Chickasaw, Choctaw and 17 more56 min
Feb 1, 4:59 PM CSTSevere Thunderstorm WatchSPCAlcorn, Attala, Benton, Calhoun, Carroll, Chickasaw and 21 more4 hr

Nearby

Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Mississippi, 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.