Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS01 KWNS 251948
SWODY1
SPC AC 251947

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0247 PM CDT SAT OCT 25 2014

VALID 252000Z - 261200Z

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS NRN CA AND SWRN
OREGON...

...SUMMARY...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS
NORTHWESTERN CALIFORNIA AND SOUTHWESTERN OREGON FROM MIDDAY THROUGH
THIS AFTERNOON.  A FEW OF THESE MAY BRING THE RISK OF A WEAK/BRIEF
TORNADO.  THUNDERSTORMS WILL ALSO DEVELOP ACROSS NORTHERN PARTS OF
NEW YORK AND NEW ENGLAND.

NO CHANGES ARE REQUIRED TO THE PREVIOUS OUTLOOK.

..JEWELL.. 10/25/2014

.PREV DISCUSSION... /ISSUED 1126 AM CDT SAT OCT 25 2014/

...SW ORE/NW CA AND NRN SACRAMENTO VALLEY THIS AFTERNOON...
A STRONG MIDLEVEL SHORTWAVE TROUGH WILL MOVE INLAND OVER THE PAC NW
AND NRN CA COASTS TODAY.  RADAR IMAGERY HAS CONFIRMED LOW-TOPPED
CONVECTION WITH WEAK ROTATION WITHIN THE DEEP BAROCLINIC ZONE
APPROACHING THE NW CA/SW ORE COAST...WHILE SATELLITE
IMAGERY/LIGHTNING DATA SHOW ADDITIONAL CONVECTION/ISOLATED
THUNDERSTORMS OFFSHORE.  EWD PROGRESSION OF THE TROUGH WILL BRING
COOLER TEMPERATURES ALOFT OVER LAND AND WILL CONTRIBUTE TO
DESTABILIZATION AS FAR E AS THE NRN SACRAMENTO VALLEY THIS
AFTERNOON.  IN TANDEM WITH THE INLAND DESTABILIZATION...VERTICAL
SHEAR PROFILES WILL BE FAVORABLE FOR ROTATING STORMS FOR A FEW HOURS
BEFORE LOW-LEVEL FLOW VEERS AND SHEAR WEAKENS.  SINCE BUOYANCY WILL
REMAIN RATHER WEAK INLAND /SBCAPE OF 100-300 J PER KG/...THE OVERALL
TORNADO RISK WILL REMAIN MARGINAL.

...NRN NY STATE INTO VT/NH THIS AFTERNOON/EVENING...
A STRONG SHORTWAVE TROUGH AND JET STREAK OVER THE UPPER GREAT LAKES
WILL TRANSLATE ESEWD TO THE SAINT LAWRENCE VALLEY THIS
AFTERNOON...ALONG WITH AN ASSOCIATED SURFACE COLD FRONT.  STEEPENING
MIDLEVEL LAPSE RATES WITH THE APPROACH OF THE SHORTWAVE TROUGH...AND
ASCENT WITHIN THE LEFT EXIT REGION OF THE JET STREAK...COULD SUPPORT
ISOLATED LOW-TOPPED THUNDERSTORMS LATER THIS AFTERNOON/EVENING WITH
FRONTAL PASSAGE.




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