Alert archive / Oklahoma / Mesoscale Discussions in 2012
Mesoscale Discussion 641
The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2012, 11:28 PM CDT for 4 states. It was in force for 92 min.
The area
The outline as issued.
The facts
- Issued
- Apr 30, 2012, 11:28 PM CDT (04:28 UTC)
- Expired
- May 1, 2012, 1:00 AM CDT
- In force
- 92 min
- Issued by
- the Storm Prediction Center
All 65 counties
Allen County, KS, Bourbon County, KS, Chautauqua County, KS, Cherokee County, KS, Cowley County, KS, Crawford County, KS, Elk County, KS, Greenwood County, KS, Labette County, KS, Montgomery County, KS, Neosho County, KS, Wilson County, KS, Woodson County, KS, Barton County, MO, Jasper County, MO, Newton County, MO, Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Craig County, OK, Creek County, OK, Custer County, OK, Delaware County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Greer County, OK, Hughes County, OK, Jackson County, OK, Kay County, OK, Kingfisher County, OK, Kiowa County, OK, Lincoln County, OK, Logan County, OK, Mayes County, OK, McClain County, OK, Murray County, OK, Noble County, OK, Nowata County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Ottawa County, OK, Pawnee County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Roger Mills County, OK, Rogers County, OK, Seminole County, OK, Stephens County, OK, Tillman County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK, Washita County, OK, Wichita County, TX, Wilbarger County, TX
The radar
The Norman radar (KTLX), 46 km from the middle of the area, began a volume at 04:31 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 00:00Z, 4.5 hours before the alert went out and 58 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.
- Mixed-layer CAPE
- 2178 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 1251 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 47 m²/s²
- 0-3 km storm-relative helicity
- 174 m²/s²
- Significant tornado parameter
- 1.2
- Supercell composite
- 10.1
The text
As transmitted, in the capitals the NWS used until 2016.
229
ACUS11 KWNS 010429
SWOMCD
SPC MCD 010428
ARZ000-MOZ000-OKZ000-KSZ000-TXZ000-010600-
MESOSCALE DISCUSSION 0641
NWS STORM PREDICTION CENTER NORMAN OK
1128 PM CDT MON APR 30 2012
AREAS AFFECTED...PORTIONS OK...SERN KS...SWRN MO...SMALL PART OF NW
TX.
CONCERNING...TORNADO WATCH 212...214...215...
VALID 010428Z - 010600Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH
212...214...215...CONTINUES.
SUPERCELLS EARLIER OVER KS/OK BORDER REGION HAVE EVOLVED INTO
WELL-DEFINED BOW ECHO WITH INTERMITTENT SPIRAL BANDS AND
INTENSE/EMBEDDED BOOKEND VORTEX. THAT VORTEX WAS CENTERED OVER KAY
COUNTY AS OF 4Z. ADDITIONAL VORTICES MAY DEVELOP AND GROW UPSCALE
FARTHER SE ALONG LEADING EDGE OF COLD POOL...IN STORM-RELATIVE
SENSE...AS EARLIER CIRCULATIONS ARE SHED BACK INTO COLD POOL. THESE
MAY POSE TORNADO RISK...WHILE LARGER-SCALE COMPLEX OFFERS ORGANIZED
CHANNEL OF DAMAGING WIND FOR PORTIONS OSAGE/PAWNEE COUNTIES AND
EVENTUALLY AREAS BETWEEN TUL-BVO.
EARLIER FRONT HAS BEEN RENDERED QUASISTATIONARY BY OUTFLOW FROM
TSTMS TO ITS N...AND EXTENDS FROM NRN PORTION OF THIS COMPLEX EWD
OVER EXTREME NERN OK. PRIND BOWING MCS WILL CONTINUE TO FAVOR
BAROCLINIC CORRIDOR AND ADJOINING PARTS OF WARM SECTOR FOR FORWARD
PROPAGATION INTO MOST FAVORABLY MOIST/UNSTABLE AIR MASS WITH
RELATIVELY MAXIMIZED STORM-RELATIVE INFLOW. ISOLATED SVR GUSTS AND
LARGE HAIL ALSO MAY OCCUR WITH CONVECTION OVER EXTREME NERN OK AND
ADJACENT PORTIONS SERN KS/SWRN MO. MODIFIED RAOBS AND FCST
SOUNDINGS DEPICT 1500-2500 J/KG MLCAPE REMAINING FROM
OSAGE/WASHINGTON COUNTIES SWD ACROSS CENTRAL OK. MLCINH INCREASES
AND CAPE DECREASES WITH SWD EXTENT OVER SRN OK BECAUSE OF DRIER DEW
POINTS THAN FARTHER N...WHICH MAY LIMIT POTENTIAL FOR FURTHER
STRENGTHENING OF SECONDARY TSTM COMPLEX OVER SWRN OK. AS OF
415Z...EXPANSIVE GUST FRONT ARCS SWD THEN SWD OFF ERN LIMB OF THAT
COMPLEX THAT IS MOVING THROUGH CHK AREA...AND TSTMS FARTHER SW ARE
BEHIND THAT GUST FRONT. STILL...SWRN/CENTRAL OK CONVECTION MAY
CONTINUE TO POSE RISK OF DAMAGING GUSTS. RESIDUAL POCKET OF
RELATIVELY UNPERTURBED LOW-LEVEL AIR ALSO RESIDES OVER PORTIONS
CENTRAL/NERN OK...WHICH MAY SUPPORT ISOLATED LARGE HAIL/DAMAGING
GUST POTENTIAL WITH CONVECTION BUILDING OVER ROGER MILLS COUNTY.
..EDWARDS.. 05/01/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...SGF...TSA...TOP...ICT...OUN...
LAT...LON 34459964 35679990 36229811 36939821 37419654 38219627
37859443 37009415 36379462 35599576 34179698 34089840
33829841 33889927 34459964SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 7:30 PM CDT | Tornado Watch | SPC | Allen, Barton, Bourbon, Butler, Chase, Chautauqua and 19 more | 7 hr |
| Apr 30, 8:55 PM CDT | Mesoscale Discussion | SPC | Allen, Barber, Bourbon, Butler, Chautauqua, Cherokee and 17 more | 65 min |
| May 1, 1:19 AM CDT | Mesoscale Discussion | SPC | Cherokee, Labette, Montgomery | 56 min |
| May 1, 1:43 AM CDT | Severe Thunderstorm Watch | SPC | Barry, Christian, Greene, Jasper, Lawrence, McDonald and 3 more | 3 hr |
| Apr 30, 9:51 PM CDT | Tornado Watch | SPC | Caddo, Canadian, Carter, Cleveland, Comanche, Cotton and 19 more | 4 hr |
| Apr 30, 9:37 PM CDT | Mesoscale Discussion | SPC | Bandera, Baylor, Brown, Callahan, Coke, Coleman and 33 more | 113 min |
| May 1, 5:43 PM CDT | Mesoscale Discussion | SPC | Brewster, Crane, Crockett, Edwards, Kinney, Maverick and 5 more | 3 hr |
Nearby
Mesoscale Discussions in Oklahoma, 2012Mesoscale Discussions in Kansas, 2012Mesoscale Discussions in Missouri, 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.