Alert archive / Oklahoma / Mesoscale Discussions in 2012

Mesoscale Discussion 618

April 29, 201214 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2012, 1:37 AM CDT for 14 counties in Oklahoma. It was in force for 23 min.

The area

The outline as issued.

The facts

Issued
Apr 29, 2012, 1:37 AM CDT (06:37 UTC)
Expired
Apr 29, 2012, 2:00 AM CDT
In force
23 min
Issued by
the Storm Prediction Center

Counties Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Custer County, OK, Dewey County, OK, Garfield County, OK, Grant County, OK, Kay County, OK, Kingfisher County, OK, Logan County, OK, Major County, OK, Noble County, OK, Payne County, OK, Roger Mills County, OK

The radar

The Vance AFB radar (KVNX), 55 km from the middle of the area, began a volume at 06:37 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

Lamont, OK (KLMN), launched 00:00Z, 6.6 hours before the alert went out and 71 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, Lamont, OK at 00:00Z on 2012-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 167 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, Lamont, OK at 00:00Z on 2012-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
167 J/kg
Mixed-layer CIN
-203 J/kg
Mixed-layer LCL
868 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
228 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

916 
ACUS11 KWNS 290637
SWOMCD
SPC MCD 290637 
OKZ000-KSZ000-TXZ000-290700-

MESOSCALE DISCUSSION 0618
NWS STORM PREDICTION CENTER NORMAN OK
0137 AM CDT SUN APR 29 2012

AREAS AFFECTED...PARTS OF NRN AND WRN OK

CONCERNING...SEVERE THUNDERSTORM WATCH 200...

VALID 290637Z - 290700Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 200
CONTINUES.

WHILE ISOLATED HAIL POTENTIAL CONTINUES WITH A FEW
REMAINING/ELEVATED SUPERCELLS...WW WILL BE ALLOWED TO EXPIRE AT
29/07Z.

LATEST RADAR LOOP SHOWS CONTINUED/GRADUAL DECREASE IN STORM
ORGANIZATION/INTENSITY ACROSS THE WRN AND NRN OK PORTIONS OF WW 200.
 WITH AMPLE CAPE/SHEAR LINGERING ACROSS MAINLY N CENTRAL OK...A FEW
ADDITIONAL LARGE HAIL EVENTS REMAIN POSSIBLE OVER THE NEXT COUPLE OF
HOURS.  HOWEVER...DECREASING/ISOLATED NATURE OF THE THREAT DOES NOT
WARRANT NEW WW ISSUANCE.

..GOSS.. 04/29/2012

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

ATTN...WFO...TSA...ICT...OUN...AMA...

LAT...LON   36979674 36109686 35629823 35149949 35270001 35940000
            37079798 37139704 36979674

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 28, 10:36 PM CDTTornado WatchSPCCaddo, Canadian, Cleveland, Comanche, Cotton, Garvin and 11 more3 hr
Apr 28, 10:54 PM CDTMesoscale DiscussionSPCCaddo, Canadian, Cleveland, Comanche, Cotton, Grady and 4 more2 hr
Apr 28, 11:52 PM CDTSevere Thunderstorm WatchSPCAdair, Cherokee, Craig, Creek, Delaware, McIntosh and 13 more5 hr
Apr 29, 1:53 AM CDTMesoscale DiscussionSPCAdair, Cherokee, Craig, Creek, Delaware, Kay and 12 more2 hr
Apr 29, 3:13 AM CDTMesoscale DiscussionSPCBeckham, Custer, Dewey, Roger Mills92 min
Apr 29, 2:22 PM CDTMesoscale DiscussionSPCCimarron113 min
Apr 29, 5:10 PM CDTSevere Thunderstorm WatchSPCBeaver, Cimarron, Harper, Texas8 hr
Apr 29, 5:51 PM CDTMesoscale DiscussionSPCAlfalfa, Canadian, Craig, Creek, Garfield, Grant and 17 more2 hr

Nearby

Mesoscale Discussions in Oklahoma, 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.