Alert archive / Oklahoma / Mesoscale Discussions in 2011

Mesoscale Discussion 2191

September 18, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Sep 18, 2011, 6:48 PM CDT for 4 states. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Sep 18, 2011, 6:48 PM CDT (23:48 UTC)
Expired
Sep 18, 2011, 7:45 PM CDT
In force
57 min
Issued by
the Storm Prediction Center
All 50 counties

Benton County, AR, Carroll County, AR, Conway County, AR, Crawford County, AR, Garland County, AR, Howard County, AR, Little River County, AR, Logan County, AR, Montgomery County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, Washington County, AR, Yell County, AR, Barry County, MO, Christian County, MO, McDonald County, MO, Newton County, MO, Stone County, MO, Adair County, OK, Atoka County, OK, Bryan County, OK, Cherokee County, OK, Choctaw County, OK, Coal County, OK, Craig County, OK, Delaware County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Love County, OK, Marshall County, OK, Mayes County, OK, McCurtain County, OK, McIntosh County, OK, Muskogee County, OK, Okmulgee County, OK, Ottawa County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Sequoyah County, OK, Wagoner County, OK, Lamar County, TX, Red River County, TX

The radar

The Western Arkansas radar (KSRX), 35 km from the middle of the area, began a volume at 23:51 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 12:00Z, 11.8 hours before the alert went out and 210 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 12:00Z on 2011-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2011-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 228 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1001 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
228 m²/s²
0-3 km storm-relative helicity
350 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.

573 
ACUS11 KWNS 182349
SWOMCD
SPC MCD 182348
ARZ000-MOZ000-TXZ000-OKZ000-190045-

MESOSCALE DISCUSSION 2191
NWS STORM PREDICTION CENTER NORMAN OK
0648 PM CDT SUN SEP 18 2011

AREAS AFFECTED...ERN OK...NERN TX...AR

CONCERNING...SEVERE THUNDERSTORM WATCH 852...854...

VALID 182348Z - 190045Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
852...854...CONTINUES.

QUALITY AIR MASS HAS YET TO BE OVERTURNED ACROSS THE ARKLATEX...NWD
INTO CNTRL AR AHEAD OF SLOWLY CONGEALING PRE-FRONTAL CONVECTION.
DEEP LAYER SHEAR IS NOT PARTICULARLY STRONG ACROSS THIS REGION AND
WITH MEAN WIND VECTORS ON THE ORDER OF 20-25KT IT/S NOT APPARENT
THAT FAST MOVING LINE SEGMENTS OR BOWS WILL BE AN ISSUE WITH THIS
ACTIVITY.  FOR THIS REASON IT WOULD SEEM LARGE HAIL IS THE PRIMARY
CONCERN FOR THE NEXT FEW HOURS.

..DARROW.. 09/18/2011

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

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

LAT...LON   36989510 36989294 35339428 35329235 33609382 33629571
            33839554 33839757 36989510

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 18, 2:45 PM CDTMesoscale DiscussionSPCBenton, Crawford, Sebastian, Washington2 hr
Sep 18, 3:30 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more8 hr
Sep 18, 5:41 PM CDTSevere Thunderstorm WatchSPCBoone, Clark, Columbia, Conway, Garland, Hempstead and 19 more7 hr
Sep 17, 10:17 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Cherokee, Cleveland, Coal and 28 more88 min
Sep 18, 3:59 PM CDTMesoscale DiscussionSPCLove31 min
Sep 18, 4:06 PM CDTSevere Thunderstorm WatchSPCAnderson, Bosque, Brown, Callahan, Coke, Coleman and 51 more9 hr
Sep 18, 6:18 PM CDTMesoscale DiscussionSPCBandera, Bexar, Blanco, Comal, Edwards, Hays and 6 more57 min

Nearby

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