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FXUS01 KWBC 242100
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
459 PM EDT SUN AUG 24 2008
VALID 00Z MON AUG 25 2008 - 12Z TUE AUG 26 2008
THE RECENTLY DOWNGRADED TROPICAL DEPRESSION FAY WILL CONTINUE TO
AFFECT THE CENTRAL GULF STATES ANOTHER COUPLE OF DAYS. AS THE
SYSTEM WILL INITIALLY REMAIN QUASI-STATIONARY THROUGH MONDAY
NIGHT...MOISTURE WILL STREAM NORTHWARD ON THE EASTERN SIDE OF FAY
HELPING SPAWN MODERATE TO HEAVY RAINFALL OVER THE CENTRAL GULF AND
EXTENDING INTO THE LOWER TENNESSEE VALLEY. WHILE THE HIGH WIND
THREAT WILL BECOME OF LESS CONCERN AS FAY GRADUALLY WEAKENS OVER
LAND...FLOODING REMAINS POSSIBLE ACROSS THE CENTRAL GULF STATES AS
THE RAIN BANDS HAVE NOT MOVED SIGNIFICANTLY. TEMPERATURES ACROSS
THE REGION WILL REMAIN CLOSE TO THE 80 DEGREE MARK WITH HIGH
HUMIDITY AS EXTENSIVE CLOUD COVER AND PERSISTENT RAINS WILL LIMIT
SURFACE HEATING.
FARTHER NORTH...A HIGHLY AMPLIFIED UPPER-LEVEL PATTERN WILL RESULT
IN A LARGE AMOUNT OF VARIABILITY IN THE SENSIBLE WEATHER.
BEGINNING WITH THE INITIAL TROUGH...AN UPPER AIR DISTURBANCE WHICH
WENT THROUGH CENTRAL CANADA CONTINUES TO MOVE FARTHER AWAY FROM
THE UNITED STATES. ITS ASSOCIATED FRONTAL BOUNDARY...WHICH WILL
MOVE THROUGH THE NORTHEAST AND MID-ATLANTIC STATES MIDDAY ON
MONDAY...WILL PROVIDE A FOCUS FOR SCATTERED SHOWER AND
THUNDERSTORM ACTIVITY. WHILE AMOUNTS WILL REMAIN ON THE LIGHT
SIDE...THE MORE NOTICEABLE DIFFERENCE WILL BE IN THE TEMPERATURES
AND HUMIDITY LEVELS. INITIALLY...THESE PARAMETERS WILL NOT
SIGNIFICANTLY CHANGE WITH THE FRONTAL PASSAGE. HOWEVER...AS THE
RIDGE OF HIGH PRESSURE BUILDS BEHIND THE BOUNDARY...COOLER AND
DRIER AIR WILL FILL IN DROPPING DAYTIME TEMPERATURES INTO THE
UPPER 70S TO LOWER 80S.
THE SECOND TROUGH WHICH IS CURRENTLY IMPACTING THE PACIFIC
NORTHWEST WILL BRING ANOTHER SHOT OF COLD AIR TO THE COUNTRY.
COASTAL REGIONS OF WASHINGTON AND OREGON CAN EXPECT HIGH
TEMPERATURES IN THE 60S AS THE COOL...PACIFIC AIR MASS MOVES
ONSHORE. LIKEWISE...TEMPERATURES WILL BEGIN TO PLUMMET FARTHER
INLAND AS THE BOUNDARY MOVES INTO THE UPPER INTERMOUNTAIN WEST
MONDAY MORNING. IN ADDITION TO THE CHANGE IN
TEMPERATURES...MODERATE RAIN SHOWERS WILL IMPACT THE COASTLINE
ALONG WITH THE COASTAL MOUNTAIN RANGES. HOWEVER...AS THE SYSTEM
MOVES INLAND...RAINFALL AMOUNTS ACROSS THE INTERMOUNTAIN WEST WILL
DIMINISH AS THE ONSHORE FLOW WEAKENS.
IN ADVANCE OF THE THE PACIFIC SYSTEM...A STRENGTHENING RIDGE OF
HIGH PRESSURE WILL BRING TEMPERATURES TO NEAR TRIPLE DIGITS ACROSS
MUCH OF THE NORTHERN ROCKIES AND NORTHERN HIGH PLAINS ON
MONDAY...BY THE FOLLOWING DAY...THE PACIFIC SYSTEM WILL HAVE MOVED
INTO THE ROCKIES DROPPING TEMPERATURES CLOSER TO CLIMATOLOGY. IN
ADDITION...AS THE SURFACE LOW PRESSURE DEEPENS...CONDITIONS WILL
BECOME BREEZY WITH SUSTAINED WINDS EXPECTED ANYWHERE BETWEEN 15 TO
25 MPH WITH OCCASIONAL STRONGER GUSTS.
RUBIN-OSTER
GRAPHICS AVAILABLE AT WWW.HPC.NCEP.NOAA.GOV
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