DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 271713
SWODY2
SPC AC 271712

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1212 PM CDT FRI SEP 27 2013

VALID 281200Z - 291200Z

...NO SVR TSTM AREAS FORECAST...

...SW MO/NW AR/ERN OK/NE TX...
AN UPPER-LEVEL TROUGH WILL MOVE EWD ACROSS THE GREAT PLAINS ON
SATURDAY AS A COLD FRONT ADVANCES SEWD INTO THE SRN PLAINS AND
OZARKS. SFC HEATING AND LOW-LEVEL CONVERGENCE JUST AHEAD OF THE
FRONT SHOULD RESULT IN STORM INITIATION SATURDAY AFTERNOON FROM
CNTRL MO SWWD INTO WCNTRL TX. MODEL FORECASTS SUGGEST THAT MODERATE
INSTABILITY MAY DEVELOP ALONG THIS CORRIDOR BY MID-AFTERNOON. THE
NAM IS THE MOST AGGRESSIVE WITH INSTABILITY SHOWING MLCAPE VALUES
AROUND 1500 J/KG FROM NE TX NNEWD INTO SW MO. THIS COMBINED WITH 30
KT OF 0-6 KM SHEAR MAY BE ENOUGH FOR A MARGINAL SEVERE THREAT.
STRONG GUSTY WINDS WILL BE POSSIBLE IF A LINE OF STRONG
THUNDERSTORMS CAN DEVELOP ACROSS THE REGION. ANY SEVERE THREAT WILL
BE DEPENDENT UPON HOW MUCH INSTABILITY DEVELOPS AHEAD OF THE COLD
FRONT.

...PACIFIC NORTHWEST...
AN UPPER-LEVEL TROUGH WILL MOVE QUICKLY ESEWD ACROSS THE NE PACIFIC
OCEAN APPROACHING THE WEST COAST OF NORTH AMERICA SATURDAY
AFTERNOON. THE EXIT REGION OF A 80 TO 100 KT MID-LEVEL JET WILL
OVERSPREAD THE PACIFIC NORTHWEST BRINGING WITH IT COPIOUS AMOUNTS OF
MID-LEVEL MOISTURE. AS A RESULT...THUNDERSTORMS COULD DEVELOP IN WRN
WA AND NW ORE DURING THE DAY DUE TO THE STRONG LARGE-SCALE ASCENT
ASSOCIATED WITH THE APPROACHING UPPER-LEVEL TROUGH. FORECAST
SOUNDINGS IN WRN WA SATURDAY AFTERNOON SHOW STRONG DEEP LAYER SHEAR
PROFILES AND CURVED HODOGRAPHS SUGGESTING A MARGINAL SEVERE THREAT
WILL BE POSSIBLE WITH CELLS THAT CAN EXHIBIT ROTATION.

..BROYLES.. 09/27/2013

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