Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 341

April 4, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2011, 5:48 AM CDT for 4 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Apr 4, 2011, 5:48 AM CDT (10:48 UTC)
Expired
Apr 4, 2011, 7:45 AM CDT
In force
117 min
Issued by
the Storm Prediction Center
All 90 counties

Baxter County, AR, Clark County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Garland County, AR, Grant County, AR, Greene County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Little River County, AR, Logan County, AR, Lonoke County, AR, Marion County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Newton County, AR, Perry County, AR, Pike County, AR, Poinsett County, AR, Polk County, AR, Pope County, AR, Prairie County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sevier County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Yell County, AR, Oregon County, MO, Ripley County, MO, Choctaw County, OK, McCurtain County, OK, Anderson County, TX, Bosque County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Collin County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Ellis County, TX, Falls County, TX, Fannin County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Hamilton County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lamar County, TX, Limestone County, TX, Marion County, TX, McLennan County, TX, Morris County, TX, Navarro County, TX, Rains County, TX, Red River County, TX, Rockwall County, TX, Smith County, TX, Somervell County, TX, Tarrant County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Western Arkansas radar (KSRX), 137 km from the middle of the area, began a volume at 10:48 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 00:00Z, 10.8 hours before the alert went out and 180 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, Shreveport, LA at 00:00Z on 2011-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 504 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, Shreveport, LA at 00:00Z on 2011-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.193958Sfc1 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
504 J/kg
Mixed-layer CIN
-318 J/kg
Mixed-layer LCL
1389 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
258 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

160 
ACUS11 KWNS 041048
SWOMCD
SPC MCD 041048 
ARZ000-MOZ000-TXZ000-OKZ000-041245-

MESOSCALE DISCUSSION 0341
NWS STORM PREDICTION CENTER NORMAN OK
0548 AM CDT MON APR 04 2011

AREAS AFFECTED...PORTIONS CENTRAL THROUGH NE TX...EXTREME SERN
OK...AR...SERN AND EXTREME S-CENTRAL MO.

CONCERNING...SEVERE THUNDERSTORM WATCH 87...

VALID 041048Z - 041245Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 87
CONTINUES.

CONVECTION CONTINUES TO INCREASE IN COVERAGE...WITHIN TWO PRIMARY
NODES THAT MAY ENLARGE/MERGE DURING NEXT FEW HOURS...

1. LARGE/PERSISTENT MULTICELLULAR CLUSTER JUST SW OF WW OVER DFW
METROPLEX...WITH CONSISTENTLY COLDEST IR CLOUD TOPS.  ACTIVITY HAS
BEEN RESPONSIBLE FOR A FEW HAIL ESTIMATES UP TO 1.25 INCH DIAMETER
SINCE 851Z...AND BACKBUILDING SWWD.  CLUSTER IS EXPANDING/MOVING
NEWD AND BEGINNING TO AFFECT WRN PORTIONS WW AS OF 1030Z....AND
SHOULD GROW NEWD INTO FAVORABLY MOIST/HIGH-THETAE LOW-LEVEL AIR MASS
THROUGH MIDMORNING.  WHILE INITIALLY RESPONSIBLE FOR MRGL SVR
HAIL...SOME POTENTIAL EXISTS FOR COLD-POOL DEVELOPMENT AND
INCREASING WIND THREAT.

2. CENTRAL/WRN AR...MOVING NEWD TOWARD PORTIONS SRN MO.  EMBEDDED
TSTM YIELDED MRGL SVR HAIL IN CONWAY COUNTY AR AT 954Z.  THIS
ACTIVITY SHOULD MOVE/EXPAND NEWD OUT OF WW DURING NEXT 2-3 HOURS. 
AREAS FARTHER E AND NE INTO MS RIVER LOWLANDS WILL BE MONITORED FOR
POSSIBLE WW.

SFC COLD FRONT WAS ANALYZED AT 1030Z NEAR LINE FROM STL...UNO...30 S
FSM...20 N DFW...BWD...SJT...CONTINUING TO MOVE SWD TO SEWD 30-35
KT.  MODEL FCST SOUNDINGS SUGGEST PRE-STORM ENVIRONMENT AROUND BOTH
CONVECTIVE PLUMES REMAINS CHARACTERIZED BY STG MLCINH...BUT
FAVORABLE ELEVATED INSTABILITY...WITH MUCAPE 2000-3000 J/KG OVER AR
AND 3000-4000 J/KG OVER N TX.  CINH AND SFC GUST POTENTIAL MAY
INCREASE OVER NEXT FEW HOURS...ESPECIALLY ALONG/AHEAD OF SFC COLD
FRONT BEFORE RELATED WEDGE OF CAA-RELATED BOUNDARY-LAYER
STABILIZATION REDUCES DCAPE.

..EDWARDS.. 04/04/2011

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

ATTN...WFO...PAH...MEG...LZK...SGF...SHV...TSA...FWD...OUN...

LAT...LON   31189626 31099788 31989850 34519514 35859352 36699215
            36879099 36639014 35759010 33119393 31189626

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 3, 9:51 PM CDTMesoscale DiscussionSPCBenton, Crawford, Madison, Washington84 min
Apr 4, 1:29 AM CDTMesoscale DiscussionSPCBenton, Carroll91 min
Apr 4, 3:00 AM CDTMesoscale DiscussionSPCClark, Conway, Dallas, Faulkner, Garland, Grant and 20 more3 hr
Apr 4, 3:44 AM CDTSevere Thunderstorm WatchSPCBradley, Calhoun, Clark, Cleburne, Cleveland, Columbia and 37 more7 hr
Apr 4, 7:22 AM CDTTornado WatchSPCArkansas, Bradley, Calhoun, Clark, Clay, Cleburne and 42 more7 hr
Apr 4, 7:44 AM CDTSevere Thunderstorm WatchSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 3 more8 hr
Apr 4, 10:25 AM CDTMesoscale DiscussionSPCAshley, Chicot2 hr
Apr 4, 10:53 AM CDTTornado WatchSPCAshley, Chicot7 hr
Apr 3, 7:26 PM CDTMesoscale DiscussionSPCAdair, Andrew, Buchanan, Caldwell, Carroll, Chariton and 16 more64 min
Apr 3, 7:44 PM CDTMesoscale DiscussionSPCClark, Putnam, Schuyler, Scotland61 min
Apr 3, 8:11 PM CDTSevere Thunderstorm WatchSPCAudrain, Boone, Callaway, Cole, Franklin, Gasconade and 12 more6 hr
Apr 3, 8:15 PM CDTMesoscale DiscussionSPCAdair, Andrew, Barton, Bates, Buchanan, Caldwell and 22 more60 min
Apr 3, 8:33 PM CDTSevere Thunderstorm WatchSPCBarton, Benton, Camden, Cedar, Dade, Hickory and 5 more5 hr
Apr 3, 10:50 PM CDTMesoscale DiscussionSPCChariton, Howard, Knox, Lewis, Macon, Marion and 4 more85 min
Apr 3, 11:02 PM CDTMesoscale DiscussionSPCBarton, Camden, Cedar, Dade, Dallas, Greene and 10 more88 min
Apr 4, 11:20 AM CDTMesoscale DiscussionSPCAngelina, Chambers, Hardin, Harris, Jasper, Jefferson and 11 more115 min

Nearby

Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Missouri, 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.