DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 151730
SWODY2
SPC AC 151728

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT SAT JUN 15 2013

VALID 161200Z - 171200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE GREAT
PLAINS...

...GREAT PLAINS...
AN UPPER-LEVEL RIDGE WILL REMAIN IN PLACE ACROSS THE ROCKIES ON
SUNDAY WITH WEST TO NORTHWEST FLOW LOCATED ACROSS THE GREAT PLAINS.
AT THE SFC...A COLD FRONT IS FORECAST TO MOVE SEWD INTO THE CNTRL
HIGH PLAINS BY SUNDAY AFTERNOON WITH A LEE SFC TROUGH LOCATED TO THE
EAST OF THE FRONT RANGE. THE MODELS DEVELOP THUNDERSTORMS ALONG THE
FRONT IN WRN NEB AND SWD ALONG THE SFC TROUGH IN ERN CO SUNDAY
AFTERNOON. OTHER STORMS SHOULD DEVELOP EWD ACROSS THE WARM SECTOR
FROM CNTRL NEB SWD INTO NRN KS DURING THE AFTERNOON. SEVERAL
CLUSTERS OF THUNDERSTORMS MAY PERSIST INTO THE EARLY EVENING WITH
LINEAR MCS DEVELOPMENT POSSIBLE ACROSS THE CNTRL PLAINS SUNDAY
EVENING.

FORECAST SOUNDINGS ACROSS THE WARM SECTOR EARLY SUNDAY EVENING AT
NORTH PLATTE NEB AND SALINA KS SHOW MLCAPE VALUES IN THE 1500 TO
2500 J/KG RANGE WITH 0-6 KM SHEAR OF 35 TO 45 KT. THIS ENVIRONMENT
SHOULD EASILY SUPPORT SUPERCELL DEVELOPMENT AND LARGE HAIL WILL BE
LIKELY WITH THE MORE ROBUST UPDRAFTS. IF STORMS CAN REMAIN DISCRETE
DURING THE LATE AFTERNOON...THEN A FEW TORNADOES MAY OCCUR.
HOWEVER...THE MODELS SEEM TO SUGGEST THAT THE STORMS WILL DEVELOP
INTO A LINE AND MOVE SWD ACROSS KS POSSIBLY REACHING FAR NRN OK.
THIS SCENARIO WOULD FAVOR WIND DAMAGE BECOMING THE MAIN THREAT
ESPECIALLY AS STORMS MARKEDLY INCREASE DURING THE EARLY EVENING. IF
A LINEAR MCS CAN ORGANIZE AND MOVE SEWD ACROSS THE CNTRL PLAINS AS
IS SUGGESTED BY THE NAM...GFS AND ECMWF...THEN AN ENHANCED WIND
DAMAGE THREAT COULD DEVELOP SUNDAY EVENING FROM SRN NEB SWD ACROSS
WRN AND CNTRL KS.

...MID MS VALLEY/OH VALLEY....
WEST TO NORTHWEST FLOW WILL BE IN PLACE ON SUNDAY ACROSS THE MID MS
VALLEY EXTENDING EWD INTO THE OH VALLEY. AT THE SFC...A SLOW MOVING
COLD FRONT SHOULD BE LOCATED FROM NRN MO/ERN IA EXTENDING EWD ACROSS
NRN IL...NRN IND AND NRN OH. SOUTH OF THE BOUNDARY...SFC DEWPOINTS
SHOULD BE IN THE UPPER 60S F RESULTING IN STRONG DESTABILIZATION
SUNDAY AFTERNOON. THIS COMBINED WITH MODERATE DEEP LAYER SHEAR
ASSOCIATED WITH A BELT OF STRONGER MID-LEVEL FLOW ACROSS THE UPPER
MS VALLEY AND GREAT LAKES REGION...SHOULD BE SUFFICIENT FOR SEVERE
STORMS. HOWEVER...WEAK LARGE-SCALE ASCENT SHOULD KEEP CONVECTIVE
COVERAGE ISOLATED. DUE TO STEEP LOW-LEVEL LAPSE RATES AND
UNIDIRECTIONAL WIND PROFILES...DAMAGING WIND GUSTS WILL BE POSSIBLE
WITH THE STRONGER CELLS LATE SUNDAY AFTERNOON. HAIL WILL ALSO BE
POSSIBLE DUE TO THE STRONG INSTABILITY.

...UPPER MS VALLEY...
WEST OT NORTHWEST FLOW WILL BE IN PLACE ACROSS THE UPPER MS VALLEY
ON SUNDAY AS A SUBTLE SHORTWAVE TROUGH MOVES ESEWD OUT OF SRN CANADA
INTO THE UPPER MS VALLEY. AHEAD OF THIS FEATURE...THE MODELS DEVELOP
MODERATE INSTABILITY ACROSS SRN/CNTRL MN AND WI WHERE SBCAPE VALUES
ARE FORECAST TO BE AROUND 1000 J/KG. THIS COMBINED WITH
UNIDIRECTIONAL WIND PROFILES AND STEEP LOW-LEVEL LAPSE RATES COULD
BE ENOUGH FOR A MARGINAL WIND DAMAGE THREAT LATE SUNDAY AFTERNOON.

...CNTRL AND NRN APPALACHIAN MTNS...
WLY FLOW WILL BE IN PLACE ACROSS THE NERN STATES ON SUNDAY AS A SFC
LOW MOVES EWD ACROSS THE REGION. THUNDERSTORMS ARE FORECAST TO BE
ONGOING AT THE START OF THE PERIOD ALONG A COLD FRONT IN THE OH
VALLEY. THIS ACTIVITY IS FORECAST TO MOVE EWD INTO THE CNTRL AND NRN
APPALACHIAN MTNS SUNDAY AFTERNOON. AFTERNOON FORECAST SOUNDINGS AT
PITTSBURG PA AND CHARLESTON WV SHOW SBCAPE VALUES AROUND 1000 J/KG
WITH 25 TO 30 KT OF 0-6 KM SHEAR. THIS COMBINED WITH STEEP LOW-LEVEL
LAPSE RATES AND UNIDIRECTIONAL WIND PROFILES COULD BE ENOUGH FOR A
MARGINAL WIND DAMAGE THREAT WITH THE STRONGER MULTICELLS.

..BROYLES.. 06/15/2013

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