Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 407

April 11, 201123 counties in Arkansas; 20 counties in Missouri; 8 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2011, 2:04 AM CDT for 23 counties in Arkansas; 20 counties in Missouri; 8 counties in Oklahoma. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Apr 11, 2011, 2:04 AM CDT (07:04 UTC)
Expired
Apr 11, 2011, 3:00 AM CDT
In force
56 min
Issued by
the Storm Prediction Center
All 51 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Conway County, AR, Crawford County, AR, Franklin County, AR, Fulton County, AR, Izard County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Pope County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, Washington County, AR, Yell County, AR, Barry County, MO, Carter County, MO, Christian County, MO, Dent County, MO, Douglas County, MO, Greene County, MO, Howell County, MO, Iron County, MO, Laclede County, MO, Oregon County, MO, Ozark County, MO, Phelps County, MO, Pulaski County, MO, Reynolds County, MO, Shannon County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Webster County, MO, Wright County, MO, Adair County, OK, Cherokee County, OK, Coal County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, Pittsburg County, OK, Sequoyah County, OK

The radar

The Springfield radar (KSGF), 127 km from the middle of the area, began a volume at 07:04 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

Springfield, MO (KSGF), launched 00:00Z, 7.1 hours before the alert went out and 110 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, Springfield, MO at 00:00Z on 2011-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 601 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, Springfield, MO at 00:00Z on 2011-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 234 square meters per square second.1939587897117Sfc1 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
601 J/kg
Mixed-layer CIN
-95 J/kg
Mixed-layer LCL
1468 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
234 m²/s²
0-3 km storm-relative helicity
188 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.1

Open this sounding in Storm Lab

The text

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

166 
ACUS11 KWNS 110705
SWOMCD
SPC MCD 110704
MOZ000-ARZ000-OKZ000-110800-

MESOSCALE DISCUSSION 0407
NWS STORM PREDICTION CENTER NORMAN OK
0204 AM CDT MON APR 11 2011

AREAS AFFECTED...SRN MO...NRN AR...SE OK

CONCERNING...TORNADO WATCH 124...

VALID 110704Z - 110800Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 124 CONTINUES.

...ISOLD DMGG WINDS...POSSIBLE INCREASE IN AR SEVERE RISKS BY
DAYBREAK...

PRE-FRONTAL TSTMS HAVE BEEN STRUGGLING...PRESUMABLY AS THEY MOVE
INTO A REGION WHERE INFLOW TRAJECTORIES EXHIBIT INCREASING
INHIBITION.  REGION IS ALSO BETWEEN THE DEPARTING MID/UPPER-LEVEL
JETSTREAK OVER THE UPPER MIDWEST AND A MODEST PV-ANOMALY BEGINNING
TO TURN NEWD IN CNTRL TX.  TSTMS ARE APPROACHING ERN FRINGE OF THE
TORNADO WATCH AND ENTIRE WATCH EXPIRES AT 08Z.  INDICATIONS ARE THAT
A NEW WW WILL NOT BE REQUIRED...AT LEAST RIGHT AWAY.  AS THE
AFOREMENTIONED PV-ANOMALY CONTINUES NEWD TOWARD THE
ARKLATEX...STRONG-SEVERE STORMS MAY MOVE/DEVELOP ENE FROM NCNTRL TX
TOWARD CNTRL/NRN AR BY DAYBREAK.  AT THAT TIME...A NEW WW MAY BE
REQUIRED FOR CNTRL/NRN AR.

..RACY.. 04/11/2011

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

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA...OUN...

LAT...LON   34309674 37329355 37919221 37819117 37669063 36979056
            36399118 35549214 34769320 34619488 34309674

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 10, 7:28 PM CDTTornado WatchSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 7 more8 hr
Apr 10, 8:52 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Madison, Washington53 min
Apr 11, 1:49 AM CDTTornado WatchSPCHempstead, Howard, Lafayette, Little River, Miller, Nevada and 1 more4 hr
Apr 11, 4:19 AM CDTMesoscale DiscussionSPCCalhoun, Clark, Cleburne, Cleveland, Columbia, Conway and 28 more56 min
Apr 11, 9:46 AM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 10 more29 min
Apr 11, 10:31 AM CDTTornado WatchSPCArkansas, Bradley, Cleveland, Crittenden, Desha, Drew and 6 more6 hr
Apr 11, 12:37 PM CDTMesoscale DiscussionSPCArkansas, Bradley, Cleveland, Crittenden, Desha, Drew and 6 more53 min

Nearby

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