982
FXUS01 KWBC 012001
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 PM EST FRI DEC 01 2023
VALID 00Z SAT DEC 02 2023 - 00Z MON DEC 04 2023
...PROLONGED WINTER STORM WITH MULTI-DAY ATMOSPHERIC RIVER
ACTIVITY WILL IMPACT THE NORTHWEST WITH SIGNIFICANT MOUNTAIN
SNOWFALL AND HEAVY RAINS...
...UNSETTLED WEATHER FORECAST ACROSS THE EASTERN THIRD OF THE
COUNTRY WITH HEAVY RAIN POTENTIAL ALONG THE GULF COAST AND
SOUTHEAST, WHILE WINTRY WEATHER IS EXPECTED FROM PARTS OF THE
MIDWEST AND GREAT LAKES TO NORTHERN NEW ENGLAND...
METEOROLOGICAL WINTER IS OFF TO A FAST AND ACTIVE START ACROSS
MUCH OF THE PACIFIC NORTHWEST, GREAT BASIN, AND THE ROCKIES AS
PLENTIFUL MOISTURE STREAMS INLAND FROM THE PACIFIC OCEAN OVER AT
LEAST THE NEXT FEW DAYS. AFTER SEEING INITIALLY MORE MODEST
ATMOSPHERIC RIVER ACTIVITY TODAY THROUGH SATURDAY, WITH GENERALLY
MODERATE PRECIPITATION, THE STRONGEST ATMOSPHERIC RIVER RELATED TO
THE SERIES OF COLD FRONTS ADVANCING INLAND OFF THE PACIFIC OCEAN
WILL BE ON SUNDAY. THIS WILL DRIVE LOCALLY SIGNIFICANT IMPACTS
FROM HEAVY MOUNTAIN SNOW AND HEAVY RAINFALL. TOTAL RAINFALL
AMOUNTS THROUGH THIS WEEKEND ARE EXPECTED TO APPROACH 5 TO 10
INCHES ALONG THE COASTAL RANGES OF WESTERN WASHINGTON AND OREGON,
WITH SEVERAL INCHES OF RAIN ALSO EXPECTED FOR PLACES SUCH AS
PORTLAND, OR AND SEATTLE, WA. MEANWHILE, HEAVY SNOWFALL ADDING UP
TO AT LEAST A FEW FEET IS EXPECTED ACROSS THE CASCADES, INCLUDING
MANY MOUNTAIN PASSES. TRAVEL WILL BE DIFFICULT TO HAZARDOUS DUE TO
BOTH HEAVY SNOW AND BLOWING SNOW. SNOW LEVELS ARE EXPECTED TO
INCREASE BY SATURDAY NIGHT AND THROUGHOUT THE DAY ON SUNDAY AS
WARMER AIR ARRIVES, LEADING TO HEAVY RAIN ON TOP OF THE SNOWPACK
THROUGHOUT THE CASCADES. THIS COMBINATION OF HEAVY RAIN AND
SNOWMELT ON SUNDAY WILL LIKELY PRODUCE MINOR TO MODERATE RIVER
FLOODING.
THE HEAVY SNOWFALL THREAT WILL ALSO EXTEND WELL EAST INTO THE
MOUNTAINOUS TERRAIN OF THE GREAT BASIN AND ROCKIES AS PACIFIC
MOISTURE SPILLING OUT OF THE PACIFIC NORTHWEST REACHES THE
WINDWARD SLOPES OF THE INTERMOUNTAIN REGION. THE HIGHER TERRAIN OF
IDAHO, WESTERN MONTANA, NORTHERN UTAH, NORTHWEST WYOMING AND
NORTHWEST COLORADO WILL SEE LOCALLY AS MUCH AS 1 TO 3 FEET OF SNOW
BY EARLY MONDAY. WIDESPREAD WINTER STORM WARNINGS AND WINTER
WEATHER ADVISORIES HAVE BEEN ISSUED FOR MANY AREAS OF THESE AREAS
IN ADDITION TO THE PACIFIC NORTHWEST.
ELSEWHERE ACROSS THE COUNTRY, A STRONG DEEP LAYER AXIS OF MOISTURE
AND WARMER AIR CROSSING THE MID-SOUTH, GULF COAST STATES, AND
LIFTING UP ALONG THE EASTERN SEABOARD WILL FOSTER GENERALLY
UNSETTLED AND MILD WEATHER FOR THESE AREAS FOR THE FIRST WEEKEND
OF DECEMBER. AN INITIAL WEAK STORM SYSTEM IS FORECAST TO PROGRESS
ACROSS THE OHIO VALLEY AND THE LOWER GREAT LAKES REGION TONIGHT
THROUGH MIDDAY SATURDAY AS ANOTHER DEVELOPING SYSTEM RIGHT ON ITS
HEELS ENTERS THE GREAT LAKES ON SUNDAY. OVERALL, LIGHT RAIN IS
EXPECTED ACROSS THE OHIO VALLEY, APPALACHIANS, NORTHEAST, AND
MID-ATLANTIC. HOWEVER, ELEVATED ATMOSPHERIC MOISTURE CONTENT AND
INSTABILITY MAY LEAD TO LOCALLY HEAVY RAINFALL AND THUNDERSTORMS
ALONG PORTIONS OF THE CENTRAL AND EASTERN GULF COAST THROUGH THIS
EVENING AND OVERNIGHT. THIS THREAT OF HEAVY RAINFALL WILL ADVANCE
INTO PARTS OF THE SOUTHEAST ON SATURDAY OUT AHEAD OF A VERY
SLOW-MOVING FRONT, WITH THE FLORIDA PANHANDLE IN PARTICULAR
POTENTIALLY SEEING SUFFICIENT RAINFALL FOR SOME FLOODING CONCERNS.
THE WEATHER PREDICTION CENTER HAS HIGHLIGHTED PORTIONS OF THIS
AREA IN A SLIGHT RISK OF EXCESSIVE RAINFALL FOR SATURDAY AND
SATURDAY NIGHT. FARTHER NORTH, WINTRY WEATHER IS EXPECTED ON THE
NORTHERN PERIPHERY OF THE PRECIPITATION SHIELD AS COLD AIR REMAINS
IN PLACE DUE TO A STRETCHED OUT HIGH PRESSURE SYSTEM EXTENDING
INTO SOUTHEAST CANADA. MOSTLY LIGHT AND LOCALIZED AREAS OF SNOW
MAY IMPACT SOME AREAS THE LOWER MICHIGAN. HEAVIER SNOW IS POSSIBLE
ACROSS NORTHERN NEW ENGLAND BY MONDAY AS A STRONGER STORM SYSTEM
BEGINS TO ORGANIZE NEW COASTAL NEW ENGLAND.
SNELL/ORRISON
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page