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FXUS01 KWBC 072054
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
454 PM EDT TUE OCT 07 2008
VALID 00Z WED OCT 08 2008 - 12Z THU OCT 09 2008
THE WEATHER PATTERN WILL BE ACTIVE EAST OF THE MISSISSIPPI RIVER
AS AN UPPER-LEVEL TROUGH MOVES THROUGH THE MISSISSIPPI VALLEY THIS
EVENING. A STEADY FLOW OF MOISTURE IN ADVANCE OF THE FRONTAL
BOUNDARY HAS ALLOWED NUMEROUS SHOWERS AND THUNDERSTORM TO FIRE
ACROSS THE LOWER AND MIDDLE MISSISSIPPI VALLEYS TODAY. WHILE THIS
FRONT WILL NOT CAUSE A DISCERNIBLE CHANGE IN TEMPERATURE...IT WILL
BRING WET CONDITIONS TO MANY REGIONS OF THE CENTRAL GULF
COAST...TENNESSEE VALLEY...AND OHIO VALLEY ON WEDNESDAY.
HOWEVER...THE BEST CHANCE FOR HEAVIER PRECIPITATION WILL BE ALONG
THE GULF COAST AS A BULK OF THE ENERGY ALOFT WITH MOVE EASTWARD
WITH THE SOUTHERN BRANCH OF THE JET STREAM.
ACROSS THE NORTHWESTERN TIER...A SERIES OF WAVES OF ENERGY WILL
MOVE THROUGH SOUTHWESTERN CANADA THROUGHOUT THE DAY AND EVENTUALLY
DIP DOWN INTO THE NORTHERN PLAINS BY WEDNESDAY AFTERNOON. WHILE A
BULK OF THE DISTURBED WEATHER WILL REMAIN ACROSS BRITISH COLUMBIA
AND ALBERTA...SOME PRECIPITATION SHOULD FALL ACROSS THE FAVORED
TERRAIN OF THE PACIFIC NORTHWEST. ACROSS THE HIGHEST
ELEVATIONS...COOL ENOUGH TEMPERATURES WILL BE SUPPORTIVE OF A
DUSTING OF SNOW. THE WEATHER ACROSS THE PACIFIC NORTHWEST ALONG
WITH MUCH OF THE UPPER AND CENTRAL INTERMOUNTAIN WEST WILL BE COOL
AND MOSTLY CLOUDY AS A LARGE UPPER-LEVEL TROUGH REMAINS OVERHEAD.
AS THE PREVIOUSLY MENTIONED DISTURBANCES MOVE TOWARD MANITOBA AND
THE UPPER MIDWEST...A MORE SIGNIFICANT SURGE OF COLD AIR WILL DIVE
SOUTHEASTWARD FROM THE GULF OF ALASKA AND SLAM INTO THE U.S.
COASTLINE. IN ADVANCE OF THIS PACIFIC SYSTEM...WINDS WILL
SIGNIFICANTLY PICK UP ALONG THE PACIFIC NORTHWEST COAST REACHING
GUSTS UP TO 30 TO 35 MPH BY MIDDAY THURSDAY. IN ADDITION...THE
ENHANCED ONSHORE FLOW WILL HELP SPAWN NUMEROUS SHOWERS ACROSS
WESTERN WASHINGTON.
A RIDGE OVER THE DESERT SOUTHWEST WILL HOLD STRONG ANOTHER COUPLE
OF DAYS BEFORE BREAKING DOWN AS THE STRENGTHENING TROUGH OVER THE
EASTERN PACIFIC MOVES INTO THE REGION. THE AREA OF HIGH PRESSURE
WILL PROMOTE DAYTIME TEMPERATURES APPROACHING THE CENTURY MARK
WITH WIDESPREAD 90S ACROSS THE VALLEYS AND DESERTS. BY THE END OF
THE WORK WEEK...A CHANGE IN THE WEATHER PATTERN WILL BRING A CLOSE
TO THE ABUNDANT WARMTH.
OVER THE NORTHEASTERN U.S...A DOME OF SURFACE HIGH PRESSURE
EXITING THE EASTERN SEABOARD WILL BRING ONE MORE COLD NIGHT TO THE
REGION. UNDERNEATH THIS RIDGE...CLEARING SKIES ACCOMPANIED BY CALM
WINDS WILL PROMOTE EXTENSIVE COOLING TUESDAY NIGHT WHICH HAS
CAUSED NUMEROUS FREEZING WARNINGS AND FROST ADVISORIES TO BE PUT
INTO EFFECT. TEMPERATURES OVERNIGHT WILL APPROACH THE LOW TO MID
30S WHILE THE METROPOLITAN CITIES SHOULD REMAIN ABOVE 40 DEGREES.
RUBIN-OSTER
GRAPHICS AVAILABLE AT WWW.HPC.NCEP.NOAA.GOV
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