000
ACUS11 KWNS 192257
SWOMCD
SPC MCD 192257
MTZ000-200030-

MESOSCALE DISCUSSION 1133
NWS STORM PREDICTION CENTER NORMAN OK
0557 PM CDT WED JUN 19 2013

AREAS AFFECTED...WCNTRL AND SCNTRL MT

CONCERNING...SEVERE THUNDERSTORM WATCH 328...

VALID 192257Z - 200030Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 328
CONTINUES.

SUMMARY...THE SEVERE THREAT IS EXPECTED TO INCREASE OVER THE NEXT
FEW HOURS ACROSS WCNTRL AND SCNTRL MT AS THE STORMS EXPAND IN
COVERAGE. LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE WITH THE MORE
INTENSE STORMS. A BRIEF TORNADO ALSO CAN NOT BE RULED OUT.

DISCUSSION...THE LATEST SFC ANALYSIS SHOWS A 993 MB LOW JUST TO THE
SOUTH OF BILLINGS. UPSLOPE FLOW EXISTS TO THE NORTH OF THE LOW
ACROSS THE ERN HALF OF MT WITH A COLD FRONT LOCATED IN WCNTRL MT. TO
THE EAST OF THE COLD FRONT...MLCAPE VALUES ARE ESTIMATED IN THE 1000
TO 2000 J/KG RANGE WITH REGIONAL WSR-88D VWPS SHOWING 40 TO 50 KT OF
DEEP LAYER SHEAR. IN ADDITION...A PLUME OF STEEP MID-LEVEL LAPSE
RATES EXTENDS NWD FROM NW WY INTO WCNTRL MT. THIS ENVIRONMENT SHOULD
SUPPORT SUPERCELLS AND LARGE HAIL WILL BE POSSIBLE IN THE STRONGER
UPDRAFTS. A WIND DAMAGE THREAT SHOULD ALSO EXIST WITH SUPERCELLS AND
MAY INCREASE IF A WEST TO EAST LINE CAN ORGANIZE AS IS SUGGESTED BY
SEVERAL SHORT-TERM MODEL FORECASTS. THE STRONGER SUPERCELLS MAY ALSO
HAVE AN ISOLATED TORNADO THREAT.

..BROYLES/CARBIN.. 06/19/2013

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

ATTN...WFO...BYZ...GGW...TFX...

LAT...LON   45750760 45240865 45350955 46091161 46981249 48101288
            48591134 48140944 46510756 45750760