SPC MD 949

MD 0949 CONCERNING SEVERE THUNDERSTORM WATCH 273… FOR PORTIONS SWRN KS…CENTRAL-ERN OK PANHANDLE…ERN TX PANHANDLE…WRN OK.


MESOSCALE DISCUSSION 0949
NWS STORM PREDICTION CENTER NORMAN OK
0658 PM CDT MON JUN 03 2013

AREAS AFFECTED...PORTIONS SWRN KS...CENTRAL-ERN OK PANHANDLE...ERN
TX PANHANDLE...WRN OK.

CONCERNING...SEVERE THUNDERSTORM WATCH 273...

VALID 032358Z - 040200Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 273
CONTINUES.

SUMMARY...CONVECTION HAS INCREASED SUBSTANTIALLY IN
ORGANIZATION...INTENSITY AND COVERAGE DURING PAST HOUR...MAINLY OVER
PORTIONS SWRN KS AND OK PANHANDLE BETWEEN DDC-GUY.  THIS AREA OF
CONVECTION MAY EVOLVE UPSCALE INTO FORWARD-PROPAGATING COMPLEX
MOVING SEWD THEN SWD OVER PORTIONS ERN PANHANDLES AND WRN OK THROUGH
EVENING...WITH DAMAGING WIND AND OCNL HAIL.  MEANWHILE ISOLATED TO
WIDELY SCATTERED DEVELOPMENT REMAINS CONDITIONALLY POSSIBLE ALONG TX
PANHANDLE DRYLINE...WITH LARGE HAIL AND SPOTTY SVR GUSTS POSSIBLE IN
ANY SUSTAINED TSTMS.

DISCUSSION...SFC MESOANALYSIS SHOWS LOW INVOF GLD...NEAR
INTERSECTION OF DRYLINE AND OUTFLOW BOUNDARY FROM NWRN KS CONVECTION
MENTIONED IN MESOSCALE DISCUSSION 947.  LEE TROUGHING REMAINS BACK
IN ERN CO AND INTO WRN TX PANHANDLE.  DRYLINE EXTENDS SSEWD NEAR LBL
THEN SWD PAST PPA TO DONLEY COUNTY TX.  LITTLE ADDITIONAL EWD MOTION
OF DRYLINE IS ANTICIPATED BEFORE EVENING RETROGRESSION ACROSS
PANHANDLES...LOCALLY MODULATED BY OUTFLOW FROM AFOREMENTIONED
CONVECTION.  THAT ACTIVITY PRODUCED HAIL UP TO 1.25 INCHES DIAMETER
IN SEWARD COUNTY KS AT 2250Z.

HOWEVER...PRIMARY SVR CONCERN IS EXPECTED TO TRANSITION TO WIND WITH
TIME...AS AGGREGATED COLD POOL DEVELOPS.  LBL AWOS MEASURED 65-KT
GUST AT 2335Z...WHICH MAY INDICATE BEGINNING OF COLD-POOL DOMINANCE
OF CONVECTIVE PROCESSES.  THIS EVOLUTION SHOULD PRODUCE
STRENGTHENING FORCED ASCENT OF AIR MASS INVOF MOIST AXIS...ANALYZED
AT 2330Z INVOF OK BORDER WITH ERN TX PANHANDLE.  W OF THAT MOIST
AXIS AND ALONG/E OF DRYLINE...STG SFC HEATING HAS CONTRIBUTED TO
NARROW CORRIDOR OF MLCAPE 1000-2000 J/KG...BASED ON MODIFIED MODEL
SOUNDINGS.  SEWD/SWD TURN OF TSTM CLUSTER IS FAVORED DUE TO
COMBINATION OF
1. STRENGTHENING CINH AND WEAKENING BUOYANCY WITH EWD EXTENT ACROSS
NRN OK AND SRN KS...AND
2. NWLY ORIENTATION OF DEEP-SHEAR AND MEAN-WIND VECTORS...WITH
EFFECTIVE SHEAR VALUES GENERALLY IN 40-50 KT RANGE OVER MOST OF
AREA.

..EDWARDS.. 06/03/2013

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

ATTN...WFO...OUN...DDC...LUB...AMA...

LAT...LON   34730099 35930140 36730171 37770150 38159999 37589859
            35989808 34509818 34730099

via SPC Forecast Products http://www.spc.noaa.gov/products/md/md0949.html