Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 295

March 19, 20126 counties in Arkansas; 15 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Mar 19, 2012, 6:32 PM CDT for 6 counties in Arkansas; 15 counties in Oklahoma. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued
Mar 19, 2012, 6:32 PM CDT (23:32 UTC)
Expired
Mar 19, 2012, 7:30 PM CDT
In force
58 min
Issued by
the Storm Prediction Center
All 21 counties

Benton County, AR, Carroll County, AR, Crawford County, AR, Madison County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Atoka County, OK, Bryan County, OK, Cherokee County, OK, Choctaw County, OK, Coal County, OK, Haskell County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, McIntosh County, OK, Muskogee County, OK, Pittsburg County, OK, Pushmataha County, OK, Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 84 km from the middle of the area, began a volume at 23:34 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

Norman, OK (KOUN), launched 12:00Z, 11.5 hours before the alert went out and 193 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, Norman, OK at 12:00Z on 2012-03-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 974 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, Norman, OK at 12:00Z on 2012-03-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 334 square meters per square second.19395878Sfc1 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
974 J/kg
Mixed-layer CIN
-91 J/kg
Mixed-layer LCL
637 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
334 m²/s²
0-3 km storm-relative helicity
407 m²/s²
Significant tornado parameter
1.2
Supercell composite
4.0

Open this sounding in Storm Lab

The text

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

295 
ACUS11 KWNS 192332
SWOMCD
SPC MCD 192332 
ARZ000-OKZ000-200030-

MESOSCALE DISCUSSION 0295
NWS STORM PREDICTION CENTER NORMAN OK
0632 PM CDT MON MAR 19 2012

AREAS AFFECTED...ERN OK THROUGH NWRN AR

CONCERNING...SEVERE THUNDERSTORM WATCH 86...

VALID 192332Z - 200030Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 86
CONTINUES.

BASED ON RECENT CONVECTIVE TRENDS...ERN OK INTO NWRN AR PORTION OF
SEVERE THUNDERSTORM WATCH MAY NEED TO BE UPGRADED TO A TORNADO
WATCH.

SEVERAL DISCRETE CELLS ARE DEVELOPING OVER ERN OK WHERE BOUNDARY
LAYER WARMING HAS CONTRIBUTED TO 1000 J/KG MLCAPE. HODOGRAPHS ARE
VERY LARGE IN THIS REGION ALONG LLJ AXIS AND SUPPORTIVE OF LOW LEVEL
MESOCYCLONES AND TORNADOES WITH ANY SURFACE BASED CONVECTION. GIVEN
THE DISCRETE MODE WITH ACTIVITY DEVELOPING EAST OF THE LINE AND SIZE
OF HODOGRAPHS...STORMS MAY EVENTUALLY EVOLVE INTO SUPERCELLS WITH AN
ATTENDANT TORNADO THREAT.

..DIAL.. 03/19/2012

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

ATTN...WFO...SHV...TSA...OUN...

LAT...LON   34659660 35819527 36459442 36389333 35579385 33979542
            33919674 34659660

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 19, 3:55 PM CDTMesoscale DiscussionSPCBenton, Crawford, Sebastian, Washington95 min
Mar 19, 4:20 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more5 hr
Mar 19, 6:53 PM CDTTornado WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more5 hr
Mar 18, 7:37 PM CDTMesoscale DiscussionSPCBeaver, Beckham, Ellis, Greer, Harmon, Jackson and 2 more53 min
Mar 18, 9:10 PM CDTMesoscale DiscussionSPCBeckham, Ellis, Greer, Harmon, Jackson, Roger Mills and 2 more35 min
Mar 18, 11:37 PM CDTMesoscale DiscussionSPCBeaver, Ellis, Harper53 min
Mar 19, 1:37 AM CDTMesoscale DiscussionSPCBeckham, Greer, Harmon, Jackson, Roger Mills83 min
Mar 19, 1:56 AM CDTSevere Thunderstorm WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Comanche and 19 more4 hr
Mar 19, 3:34 AM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Cleveland, Comanche and 21 more86 min
Mar 19, 10:05 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Cleveland, Coal, Garvin and 15 more115 min
Mar 19, 2:15 PM CDTMesoscale DiscussionSPCBryan, Love, Marshall90 min

Nearby

Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Arkansas, 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.