Alert archive / Oklahoma / Mesoscale Discussions in 2011

Mesoscale Discussion 2183

September 17, 20119 counties in Kansas; 15 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Sep 17, 2011, 2:02 PM CDT for 9 counties in Kansas; 15 counties in Oklahoma. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Sep 17, 2011, 2:02 PM CDT (19:02 UTC)
Expired
Sep 17, 2011, 3:30 PM CDT
In force
88 min
Issued by
the Storm Prediction Center
All 24 counties

Barber County, KS, Clark County, KS, Comanche County, KS, Ford County, KS, Harper County, KS, Kingman County, KS, Kiowa County, KS, Pratt County, KS, Sumner County, KS, Alfalfa County, OK, Blaine County, OK, Canadian County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grant County, OK, Harper County, OK, Kay County, OK, Kingfisher County, OK, Major County, OK, Noble County, OK, Woods County, OK, Woodward County, OK

The radar

The Vance AFB radar (KVNX), 76 km from the middle of the area, began a volume at 19:02 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

Lamont, OK (KLMN), launched 12:00Z, 7.0 hours before the alert went out and 133 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 12:00Z on 2011-09-17Temperature 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, Lamont, OK at 12:00Z on 2011-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 307 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
668 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
307 m²/s²
0-3 km storm-relative helicity
327 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

120 
ACUS11 KWNS 171903
SWOMCD
SPC MCD 171902
OKZ000-KSZ000-TXZ000-172030-

MESOSCALE DISCUSSION 2183
NWS STORM PREDICTION CENTER NORMAN OK
0202 PM CDT SAT SEP 17 2011

AREAS AFFECTED...PARTS OF SW/S CNTRL KS AND WRN OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 171902Z - 172030Z

A WATCH LIKELY WILL BE NEEDED LATE THIS AFTERNOON...PERHAPS WITHIN
THE NEXT HOUR OR TWO.

INSOLATION AND A LOW-LEVEL RETURN FLOW OF MOISTURE...CHARACTERIZED
BY MID 60S+ F SURFACE DEW POINTS...ARE CONTRIBUTING TO MODERATE TO
STRONG BOUNDARY LAYER DESTABILIZATION IN THE WARM SECTOR OF A
DEVELOPING SURFACE LOW OVER THE CENTRAL HIGH PLAINS.  ON THE
SOUTHERN FRINGE OF LARGE-SCALE UPPER TROUGHING SHIFTING EAST OF THE
NORTHERN AND CENTRAL ROCKIES...MODELS INDICATE THAT THE LOW WILL
CONTINUE TO DEEPEN WHILE MIGRATING SOUTHEASTWARD THROUGH PORTIONS OF
THE OKLAHOMA AND TEXAS PANHANDLE REGION LATE THIS AFTERNOON.  IT
APPEARS THAT AN AREA OF AT LEAST WEAK MID-LEVEL FORCING FOR ASCENT
WILL OVERSPREAD STRENGTHENING LOW-LEVEL CONVERGENCE AND WARM
ADVECTION ALONG A FRONTAL ZONE NEAR THE KANSAS/OKLAHOMA BORDER AREA
WITHIN THE NEXT COUPLE OF HOURS...WHICH PROBABLY WILL CONTRIBUTE TO
VIGOROUS CONVECTIVE DEVELOPMENT.  THE HIGH RESOLUTION RAPID REFRESH
HAS BEEN CONSISTENT IN INDICATING THIS WILL OCCUR BY THE 20-22Z TIME
FRAME...ROUGHLY IN AN AREA BOUNDED BY GAGE...ENID AND MEDICINE
LODGE.  VERTICAL SHEAR ACROSS THIS REGION IS STILL FAIRLY
MODEST...BUT BACKING LOW-LEVEL FLOW AND STRENGTHENING MID-LEVEL WIND
FIELDS WITH THE PASSAGE OF A 30-40 KT WESTERLY 500 MB JET
STREAK...SHOULD EVENTUALLY CONTRIBUTE TO INCREASINGLY FAVORABLE
SHEAR FOR SUPERCELLS.  THIS WILL BE ACCOMPANIED BY THE RISK FOR
LARGE HAIL...DAMAGING WIND GUSTS...AND PERHAPS A TORNADO OR TWO.

..KERR.. 09/17/2011

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

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

LAT...LON   35729973 36159987 37110032 37520028 37739998 37739905
            37559775 37199722 36789691 35509783 35329897 35729973

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 17, 2:30 PM CDTTornado WatchSPCBarber, Chautauqua, Clark, Comanche, Cowley, Edwards and 14 more9 hr
Sep 17, 4:49 PM CDTMesoscale DiscussionSPCSherman56 min
Sep 17, 5:49 PM CDTMesoscale DiscussionSPCBarber, Harper116 min
Sep 17, 2:38 PM CDTMesoscale DiscussionSPCBeckham, Caddo, Comanche, Cotton, Greer, Harmon and 6 more97 min
Sep 17, 3:16 PM CDTSevere Thunderstorm WatchSPCBeckham, Caddo, Canadian, Comanche, Cotton, Custer and 10 more8 hr

Nearby

Mesoscale Discussions in Oklahoma, 2011Mesoscale Discussions in Kansas, 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.