Alert archive / Oklahoma / Mesoscale Discussions in 2009

Mesoscale Discussion 1021

June 10, 200917 counties in Oklahoma; 7 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 10, 2009, 10:44 AM CDT for 17 counties in Oklahoma; 7 counties in Texas. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Jun 10, 2009, 10:44 AM CDT (15:44 UTC)
Expired
Jun 10, 2009, 12:15 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
All 24 counties

Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kiowa County, OK, Roger Mills County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Collingsworth County, TX, Donley County, TX, Foard County, TX, Hardeman County, TX, Wheeler County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 70 km from the middle of the area, began a volume at 15:44 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, 3.7 hours before the alert went out and 170 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 2009-06-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 528 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 2009-06-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 153 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
528 J/kg
Mixed-layer CIN
-315 J/kg
Mixed-layer LCL
1998 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
153 m²/s²
0-3 km storm-relative helicity
200 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.

000 
ACUS11 KWNS 101545
SWOMCD
SPC MCD 101544 
OKZ000-TXZ000-101715-

MESOSCALE DISCUSSION 1021
NWS STORM PREDICTION CENTER NORMAN OK
1044 AM CDT WED JUN 10 2009

AREAS AFFECTED...PORTIONS OF NWRN TX AND THE ERN TX PNHDL INTO CNTRL
OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 101544Z - 101715Z

SEVERE STORM THREAT CURRENTLY OVER W TX IS EXPECTED TO SPREAD NEWD
ACROSS DISCUSSION AREA TODAY.  CONVECTIVE TRENDS ARE BEING MONITORED
FOR A POSSIBLE WW ISSUANCE.

A CLUSTER OF ELEVATED TSTMS FROM PVW TO SW OF CDS AS OF 1530Z IS
MOVING/DEVELOPING NEWD AT 30-40 KT WITH EXTRAPOLATION TAKING IT N OF
WW 363 BETWEEN 1600-1630Z.  THIS ACTIVITY IS LIKELY ASSOCIATED WITH
A LEAD SHORT WAVE TROUGH LIFTING NEWD THROUGH SWRN TX AND ERN NM
WHICH IS EVIDENT IN WATER VAPOR IMAGERY AND NOTED INCREASE IN
MIDLEVEL WIND FIELDS AT TUCUMCARI NM.  COMPARISON OF 12Z ELP AND MAF
SOUNDING DATA INDICATE THAT CONSIDERABLE TROPOSPHERIC COOLING IS
ASSOCIATED WITH THIS IMPULSE WHICH SHOULD GRADUALLY ERODE STRONGER
CAP OBSERVED FROM FWD THROUGH OUN.

LATEST TRENDS IN SURFACE OBSERVATIONAL DATA INDICATE DEEPENING
SURFACE LOW ALONG COLD FRONT OVER W-CNTRL OK WHICH IS CONTRIBUTING
TO LOW-LEVEL MOISTENING ACROSS NWRN TX INTO SWRN OK.  WHILE
INCREASING CLOUDINESS MAY TEND TO LIMIT DIABATIC HEATING...THIS
MOISTENING COUPLED WITH THE DYNAMIC COOLING ASSOCIATED WITH THE
MIDLEVEL IMPULSE SHOULD CONTINUE TO SUPPORT AIR MASS DESTABILIZATION
ACROSS AREA WITH MLCAPE OF 1500-3000 J/KG POSSIBLE BY AFTERNOON. 
THIS INSTABILITY IN CONJUNCTION WITH THE STRENGTHENING WIND FIELDS
SHOULD MAINTAIN ONGOING TSTM COMPLEX WITH ACTIVITY BECOMING
PROGRESSIVELY SURFACE-BASED ALONG AND E/SE OF SURFACE BOUNDARY. 
LARGE HAIL AND DAMAGING WIND GUSTS WILL BE THE PRIMARY THREATS WITH
THE MOST INTENSE STORMS.

..MEAD.. 06/10/2009

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

ATTN...WFO...OUN...AMA...

LAT...LON   34830112 35590063 35989982 36129920 36089829 35769773
            35379755 34709767 34159811 33759869 33649955 33819992
            34799994 34830112

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 9, 9:15 PM CDTMesoscale DiscussionSPCCraig, Delaware, Mayes, Ottawa60 min
Jun 9, 9:46 PM CDTSevere Thunderstorm WatchSPCDelaware, Ottawa7 hr
Jun 9, 11:30 PM CDTMesoscale DiscussionSPCDelaware60 min
Jun 10, 2:26 AM CDTMesoscale DiscussionSPCDelaware, Ottawa64 min
Jun 10, 11:09 AM CDTSevere Thunderstorm WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Comanche and 20 more7 hr
Jun 10, 12:30 PM CDTMesoscale DiscussionSPCCraig, Nowata, Ottawa, Washington90 min
Jun 10, 1:35 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Comanche and 15 more85 min
Jun 10, 2:13 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Cleveland, Coal, Garvin and 10 more10 hr
Jun 10, 3:46 PM CDTSevere Thunderstorm WatchSPCAdair, Cherokee, Choctaw, Craig, Creek, Delaware and 19 more6 hr
Jun 10, 5:38 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Jefferson and 5 more67 min
Jun 10, 6:17 PM CDTMesoscale DiscussionSPCMcCurtain58 min
Jun 10, 6:37 PM CDTSevere Thunderstorm WatchSPCMcCurtain8 hr
Jun 10, 7:56 AM CDTMesoscale DiscussionSPCAndrews, Borden, Cochran, Crane, Crosby, Dawson and 19 more64 min
Jun 10, 8:38 AM CDTSevere Thunderstorm WatchSPCAndrews, Borden, Briscoe, Childress, Cochran, Cottle and 18 more6 hr
Jun 10, 11:46 AM CDTMesoscale DiscussionSPCAndrews, Borden, Briscoe, Childress, Cochran, Cottle and 18 more89 min

Nearby

Mesoscale Discussions in Oklahoma, 2009Mesoscale Discussions in Texas, 2009Every mesoscale discussion in 2009

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.