146
FXUS01 KWBC 040738
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
237 AM EST MON DEC 04 2023
VALID 12Z MON DEC 04 2023 - 12Z WED DEC 06 2023
...EXCESSIVE RAINFALL AND INSTANCES OF FLOODING ARE LIKELY ACROSS
PARTS OF WESTERN WASHINGTON AND OREGON OVER THE NEXT FEW DAYS...
...MODERATE SNOWFALL TO DIMINISH THROUGHOUT NORTHERN NEW ENGLAND
TODAY...
...HEAVY UPSLOPE SNOW POTENTIAL FORECAST ACROSS THE CENTRAL
APPALACHIANS TUESDAY NIGHT INTO WEDNESDAY...
A STRONG ATMOSPHERIC RIVER IS ANTICIPATED TO SOAK THE PACIFIC
NORTHWEST TODAY AND CONTINUE THE HEAVY RAINFALL POTENTIAL THROUGH
MIDWEEK. MAIN IMPACTS ASSOCIATED WITH THIS STORM SYSTEM ARE
EXPECTED TO INCLUDE THE THREAT OF FLOODING CAUSED BY HEAVY
RAINFALL AND SNOWMELT. A BROAD STREAM OF ANOMALOUS ATMOSPHERIC
MOISTURE CONTENT EXTENDING FROM JUST NORTH OF HAWAII IS FORECAST
TO MOVE INLAND INTO WESTERN WASHINGTON AND OREGON BY TONIGHT ALONG
A FRONTAL BOUNDARY, WHICH IS ALSO CONNECTED TO A VERY STRONG LOW
PRESSURE SYSTEM ENTERING THE GULF OF ALASKA. THE SUBTROPICAL
CONNECTION WILL LEAD TO A VERY MILD SYSTEM WITH HIGH SNOW LEVELS.
THIS MEANS MUCH OF THE CASCADES AND COASTAL RANGES WILL EXPERIENCE
HEAVY RAIN AS OPPOSED TO HEAVY SNOW, EXACERBATING THE POTENTIAL
FLOOD THREAT DUE TO INCREASED RUNOFF. FLOOD WATCHES HAVE BEEN
ISSUED FOR MUCH OF WESTERN WASHINGTON AND OREGON, WHERE MOST AREAS
COULD SEE 2-3"+ RAINFALL AMOUNTS BY WEDNESDAY. MODERATE RAINFALL
MAY ALSO EXTEND EAST OF THE CASCADES AND INTO NORTHERN IDAHO.
RESIDENTS ARE ADVISED TO NEVER DRIVE THROUGH FLOODED ROADWAYS AND
HAVE AN ACTION PLAN TO PROTECT PROPERTY IF WITHIN A FLOOD ZONE.
OUTSIDE OF THE NORTHWEST, MOSTLY LIGHT PRECIPITATION IS FORECAST
THROUGHOUT THE REST OF THE COUNTRY BY MIDWEEK. THE ONGOING
SNOWSTORM IMPACTING NORTHERN NEW ENGLAND IS FORECAST TO SLOWLY
SUBSIDE TODAY. A FEW ADDITIONAL INCHES OF SNOWFALL ARE EXPECTED
ACROSS NORTHERN VERMONT AND NEW HAMPSHIRE, AS WELL AS MUCH OF
MAINE, WHICH COULD LEAD TO TREACHEROUS TRAVEL EARLY THIS MORNING.
THE NEXT SYSTEM SPREADING SNOWFALL POTENTIAL INTO PARTS OF THE
U.S. WILL BE AN ALBERTA CLIPPER DIVING FROM THE DAKOTAS TODAY TO
OFF THE NORTH CAROLINA COAST ON WEDNESDAY. STRONG WINDS ARE
EXPECTED AS THE LOW PRESSURE SYSTEM MOVES ACROSS THE NORTHERN
PLAINS TODAY, WHICH HAS PROMPTED HIGH WIND WARNINGS AND WIND
ADVISORIES FOR PARTS OF MONTANA, WYOMING, AND THE DAKOTAS.
SCATTERED SNOW SHOWERS WILL ALSO ACCOMPANY THIS SYSTEM UNTIL
FEEDING THE UPSLOPE SNOW POTENTIAL ACROSS THE CENTRAL APPALACHIANS
BEGINNING TUESDAY NIGHT. SUBFREEZING TEMPERATURES ALONG THE
ALLEGHENY FRONT AND INCREASED MOISTURE DUE TO NORTHWESTERLY FLOW
INTO THE TERRAIN WILL ALLOW FOR POTENTIALLY HEAVY SNOW. WPC
PROBABILITIES FOR AT LEAST 4" OF SNOW REACH TO AROUND 40-60% IN
THE HIGHER TERRAIN OF WEST VIRGINIA ON WEDNESDAY.
SNELL
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page