667
FXUS01 KWBC 290804
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
404 AM EDT FRI AUG 29 2008
VALID 12Z FRI AUG 29 2008 - 00Z SUN AUG 31 2008
THE UPPER-LEVEL PATTERN ACROSS THE UNITED STATES WILL CONSIST OF
AN ACTIVE NORTHERN STREAM WITH NUMEROUS DISTURBANCES MOVING ACROSS
THE NORTHERN TIER STATES. MEANWHILE...FARTHER SOUTH...AN EAST-WEST
ORIENTED RIDGE AXIS WILL REMAIN IN PLACE THROUGH THE EARLY PART OF
THE WEEKEND. THIS RIDGE OVER THE DEEP SOUTH IS EXPECTED TO PLAY A
MAJOR ROLE IN HOW TROPICAL CYCLONES...WHICH ARE CURRENTLY WELL
OFFSHORE...WILL IMPACT THE COUNTRY NEXT WEEK.
WHAT WAS FORMERLY TROPICAL STORM FAY HAS FINALLY DISSIPATED AND
DOES NOT SHOW ANY DISCERNIBLE REFLECTION AT THE SURFACE. A CLUSTER
OF SHOWERS AND THUNDERSTORMS WHICH HAD EARLIER AFFECTED THE
MID-ATLANTIC STATES HAS GRADUALLY MOVED OFFSHORE.
HOWEVER...SCATTERED THUNDERSTORMS CANNOT BE RULED OUT AS DAYTIME
HEATING ON FRIDAY MAY REINVIGORATE ANOTHER ROUND OF STORMS ACROSS
AN AREA STRETCHING FROM UPSTATE NEW YORK SOUTHWARD THROUGH THE
MID-ATLANTIC STATES AND INTO THE CAROLINAS. BY THE FOLLOWING
DAY...ANOTHER THREAT FOR SHOWERS AND THUNDERSTORMS LOOMS AS A WEAK
SURFACE COLD FRONT SLOWLY MOVES ACROSS THE OHIO RIVER VALLEY.
TEMPERATURES SHOULD INITIALLY RESIDE BELOW CLIMATOLOGY ON FRIDAY
UNDERNEATH AN EXTENSIVE CLOUD DECK WITH MID TO UPPER 70S BEING
COMMONPLACE. BY SATURDAY...WARM ADVECTION OCCURRING IN ADVANCE OF
THE FRONTAL BOUNDARY SHOULD RAISE TEMPERATURES ENOUGH TO PUNCH
INTO THE LOW TO MID 80S.
ACROSS THE PACIFIC NORTHWEST...AN UPPER-LEVEL TROUGH WILL CONTINUE
TO CONTROL THE DAILY WEATHER PATTERN THROUGH THE WEEKEND. IN
RESPONSE TO THE UPPER-LEVEL LOW CENTER...A COLD FRONT WILL QUICKLY
SURGE INLAND BY THE AFTERNOON HOURS ON FRIDAY. THIS WILL ENHANCE
THE ONSHORE COMPONENT OF THE SURFACE WINDS WHICH WILL HELP SPAWN
AN AREA OF LIGHT TO MODERATE RAINFALL ALONG THE COASTLINE AND
ACROSS THE COASTAL MOUNTAIN RANGES OF WASHINGTON. AS THE WEATHER
SYSTEM MOVES FARTHER INLAND INTO THE INTERMOUNTAIN WEST...WINDS
WILL BEGIN TO PICK UP IN INTENSITY AS THE SURFACE LOW PRESSURE
OVER SASKATCHEWAN GRADUALLY DEEPENS. AT THIS POINT...MUCH OF THE
PRECIPITATION SHIELD SHOULD HAVE DIMINISHED IN SPATIAL EXTENT AS
MOISTURE WILL BE LACKING ACROSS THE REGION.
ELSEWHERE...AN ACTIVE SOUTHWESTERN U.S. MONSOON WILL KEEP THE
WEATHER UNSETTLED ACROSS MUCH OF THE DESERT SOUTHWEST EASTWARD
INTO THE LONE STAR STATE. WITH PLENTY OF MOISTURE IN PLACE FROM
THE MONSOONAL FLOW PATTERN...DAYTIME SURFACE HEATING WILL FIRE
SHOWERS AND THUNDERSTORMS ACROSS THE REGION...ESPECIALLY ALONG THE
HIGH TERRAIN WHERE OROGRAPHIC FORCING WILL ENHANCE THE CONVECTION.
AS SUFFICIENT CLOUD COVER WILL BLANKET THE REGION...HIGH
TEMPERATURES SHOULD REMAIN BELOW THE TRIPLE DIGIT MARK. ALTHOUGH
THIS WILL NOT BE THE CASE ACROSS THE MAJOR DESERTS OF SOUTHERN
CALIFORNIA AND CENTRAL ARIZONA WHERE TEMPERATURES SHOULD APPROACH
105 TO 110 DEGREES ON FRIDAY AND SATURDAY.
RUBIN-OSTER
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