National Weather Service United States Department of Commerce

Stormy Weather in the Northwest; Fire Weather Threat Redeveloping in Southern California this Weekend

An active fall storm pattern in the Pacific Northwest is bringing heavy rain and high elevation snow to the region which will persist through this weekend. Strong winds associated with this system will bring a renewed period of critical fire weather to southern California later this weekend into next week. Read More >

Day 1 Convective Outlook issued at 0001 UTC 15 September 2007
SPC AC 150001
   
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0701 PM CDT FRI SEP 14 2007
   
VALID 150100Z - 151200Z
   
...THERE IS A SLGT RISK OF SVR TSTMS ...
   
...CAROLINAS...
   
WIDESPREAD CONVECTION HAS EVOLVED WITHIN VERY MOIST PLUME ALONG
FAVORED ZONE OF LOW LEVEL CONFLUENCE FROM NRN SC INTO CNTRL NC. 
MANY OF THESE STORMS HAVE EXHIBITED ROTATION AT TIMES...A FEW OF
WHICH HAVE PRODUCED ISOLATED TORNADOES.  IT APPEARS LOW LEVEL SHEAR
ALONG THIS BAROCLINIC ZONE IS PARTLY RESPONSIBLE FOR BRIEF TORNADO
ACTIVITY.  WITH TIME NUMEROUS STORM MERGERS AND DIURNAL COOLING WILL
HAVE AN ADVERSE AFFECT REGARDING SUPERCELL STORM MODE...LIKELY
LEADING TO MORE MULTICELL-TYPE CLUSTERING WHICH SHOULD THEN RESULT
IN MAINLY GUSTY WINDS.  FOR THE NEXT FEW HOURS THOUGH...MORE
DISCRETE SUPERCELL STRUCTURES COULD PRODUCE ISOLATED TORNADOES.
   
...UPSTATE NY...
   
LARGE SCALE ASCENT IS NOW ACTING ON NRN EDGE OF MOIST WARM SECTOR
FROM WEST OF BGM TO ERN EDGE OF LAKE ERIE...WELL AHEAD OF COLD
FRONT.  GREATEST RISK OF STRONG THUNDERSTORMS WILL OCCUR ALONG THIS
NARROW AXIS OF INSTABILITY WHERE SHEAR PROFILES ARE CERTAINLY MORE
THAN ADEQUATE FOR SUSTAINING ORGANIZED UPDRAFTS.  AS COLD FRONT
INTERACTS WITH THIS ZONE OF INSTABILITY IT APPEARS ADDITIONAL
THUNDERSTORMS WILL DEVELOP.  ISOLATED DAMAGING WINDS AND SOME HAIL
COULD ACCOMPANY THE STRONGEST STORMS THROUGH EARLY EVENING.
   
..DARROW.. 09/15/2007
 
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z