879
FXUS02 KWBC 031938
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
238 PM EST MON NOV 3 2025
VALID 12Z THU NOV 06 2025 - 12Z MON NOV 10 2025
..OVERVIEW
THE UPPER LEVEL WEATHER PATTERN WILL INITIALLY BE QUITE ZONAL WITH
SEVERAL DISTURBANCES MOVING WEST TO EAST ACROSS THE COUNTRY ON
THURSDAY AND FRIDAY. THE PATTERN IS EXPECTED TO AMPLIFY THIS
WEEKEND AS A DEEP UPPER LOW/TROUGH APPROACHES THE WEST COAST WHILE
STRONG RIDGING DEVELOPS OVER THE INTERMOUNTAIN WEST AND STRONG
TROUGHING DEVELOPS OVER THE EAST. THIS PATTERN WILL DRIVE A SERIES
OF PROGRESSIVE FRONTAL SYSTEMS ACROSS THE NATION LATER THIS WEEK,
WITH PERSISTENT PRECIPITATION CHANCES FOR THE NORTHERN TIER AND
PERIODS OF PRECIPITATION FOR THE OHIO AND TENNESSEE VALLEYS AS
WELL. SOME WINTRY WEATHER IS EXPECTED IN THE HIGH ELEVATIONS IN THE
WEST AND ACROSS NORTHERN NEW ENGLAND. AS THE PATTERN AMPLIFIES, AN
ARCTIC COLD FRONT SHOULD SINK SOUTH ACROSS THE CENTRAL AND EASTERN
U.S., USHERING IN COLDER TEMPERATURES.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST MODEL GUIDANCE TODAY CONTINUES TO SHOW GOOD AGREEMENT
ON THE OVERALL LARGE SCALE PATTERN THROUGH THE ENTIRE PERIOD,
THOUGH WITH TYPICAL UNCERTAINTIES IN THE DETAILS AND TIMING OF
INDIVIDUAL SYSTEMS WHICH HAS SOME NOTICEABLE INFLUENCE ON SENSIBLE
WEATHER, ESPECIALLY QPF. FOR THE EARLY PART OF THE PERIOD, WITH
MORE ZONAL FLOW, THE MOST UNCERTAIN PART OF THE FORECAST IS THE
TIMING OF A SHORTWAVE AS IT CROSSES FROM THE CENTRAL U.S. ON FRIDAY
INTO THE EAST ON SATURDAY. THE CMC WAS SLIGHTLY SHARPER/DEEPER
WITH THE WAVE WHICH TRANSLATED TO A MORE SOUTHERLY AND OCCLUDED
SURFACE LOW TRACK COMPARED TO THE BETTER CONSENSUS. OUT WEST, THERE
IS SOME TIMING UNCERTAINTIES WITH A DEEP TROUGH AS IT APPROACHES
THE WEST COAST NEXT MONDAY, AND UNCERTAINTY IN THE DETAILS AND
EVOLUTION OF A POSSIBLE CUTOFF UPPER LOW OFF THE CALIFORNIA COAST,
WITH NORTHERN STREAM ENERGY MOVING INTO THE NORTHWEST. THIS MAINLY
IMPACTED QPF WITH MUCH OF THE DETERMINISTIC GUIDANCE SHOWING LITTLE
TO NO PRECIPITATION INTO THE WEST BY THE END OF THE PERIOD WITH
THIS SYSTEM, BUT THE ENSEMBLE MEANS (WHICH SHOW MORE OF AN
ELONGATED TROUGH AS COMPARED TO SPLIT FLOW) SHOWING PRECIP
APPROACHING THE COAST QUICKER. THIS INFLUENCED NBM QPF AND SO QPF
AMOUNTS HAD TO BE TEMPERED SOMEWHAT IN THE GRIDS.
THE WPC FORECAST TODAY WAS BASED ON GENERAL DETERMINISTIC MODEL
AGREEMENT THE FIRST HALF OF THE PERIOD, WITH INCREASING ENSEMBLE
MEAN WEIGHTING THE LATTER HALF OF THE PERIOD. THIS MAINTAINED GOOD
AGREEMENT WITH THE PREVIOUS WPC FORECAST AS WELL.
..WEATHER/HAZARDS HIGHLIGHTS
THE FIRST FRONTAL SYSTEM WILL TRACK ACROSS THE NORTHERN TIER
THURSDAY INTO FRIDAY WHILE THE NEXT SYSTEM MOVES ONSHORE IN THE
PACIFIC NORTHWEST. THE LEADING SYSTEM WILL BRING PRECIPITATION
CHANCES FROM THE UPPER MIDWEST/GREAT LAKES TO THE NORTHEAST AND
DOWN INTO THE OHIO AND TENNESSEE VALLEYS. LOCALLY HEAVY RAINFALL
MAY BE POSSIBLE IN THE WARM SECTOR OF THE SYSTEM OVER THE OHIO AND
TENNESSEE VALLEYS, BUT THE FRONT SHOULD BE PROGRESSIVE ENOUGH TO
LIMIT MUCH OF ANY FLASH FLOOD THREAT. WINTRY WEATHER WILL BE
POSSIBLE ON THE NORTHERN SIDE OF THE SYSTEM ACROSS NORTHERN NEW
ENGLAND.
IN THE NORTHWEST, ANOMALOUS PACIFIC MOISTURE WILL MOVE ONSHORE
WITH THE SECOND SYSTEM ON THURSDAY, RESULTING IN WIDESPREAD
PRECIPITATION CHANCES WITH MODERATE TO LOCALLY HEAVY RAIN AND
MOUNTAIN SNOW ACROSS WESTERN WASHINGTON AND OREGON AND NORTHWESTERN
CALIFORNIA. PRECIPITATION RATES WILL LIKELY BE HIGH ENOUGH TO POSE
A RISK OF ISOLATED INSTANCES OF FLASH FLOODING, ESPECIALLY NEAR
STEEP TERRAIN AND BURN SCAR AREAS, AND THERE IS A MARGINAL RISK OF
EXCESSIVE RAINFALL IN EFFECT FOR THURSDAY. PRECIPITATION CHANCES
WILL CONTINUE ACROSS THE NORTHWEST THROUGH THE END OF THE WEEK, BUT
PRECIPITATION INTENSITIES ARE FORECAST TO DECREASE.
AS THE SECOND FRONTAL SYSTEM PUSHES EAST LATE THIS WEEK INTO THE
WEEKEND, PRECIPITATION CHANCES WILL EXPAND INTO THE NORTH-CENTRAL
U.S. AND ONCE AGAIN TO THE GREAT LAKES, NORTHEAST, AND OHIO AND
TENNESSEE VALLEYS. WHILE MOISTURE FROM THE SECOND SYSTEM ENTERS THE
NORTH-CENTRAL U.S. FRIDAY INTO SATURDAY, AN ARCTIC COLD FRONT WILL
DIP SOUTH INTO THE REGION AS WELL, CREATING CHANCES OF WINTRY
WEATHER ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST. ANOTHER SHOT
OF WINTRY WEATHER WILL ALSO BE POSSIBLE ACROSS THE NORTHEAST ON
SATURDAY AND SUNDAY AS THE LOW PRESSURE CENTER TRACKS ACROSS THE
REGION. THE ARCTIC FRONT WILL CONTINUE TO PUSH SOUTH ACROSS THE
CENTRAL AND EASTERN U.S. THIS WEEKEND INTO EARLY NEXT WEEK,
USHERING IN COLDER AND DRIER AIR. MEANWHILE, THE NEXT SYSTEM WILL
APPROACH THE WEST COAST AND SLOW, CREATING COASTAL PRECIPITATION
CHANCES ON SATURDAY AND SUNDAY, THOUGH WITH UNCERTAIN TIMING AND
INLAND EXTENT.
FOR MUCH OF THE SOUTHERN AND CENTRAL U.S., WEAK UPPER LEVEL
RIDGING WILL KEEP THE FORECAST DRY WITH ABOVE AVERAGE TEMPERATURES
THROUGH THE END OF THE WEEK. HIGH TEMPERATURES ARE FORECAST TO RUN
10-20 DEGREES ABOVE AVERAGE. AS THE PATTERN AMPLIFIES OVER THE
WEEKEND AND EARLY NEXT WEEK, UPPER LEVEL RIDGING AND ABOVE NORMAL
TEMPERATURES WILL BUILD OVER THE INTERMOUNTAIN WEST WHILE UPPER
LEVEL TROUGHING AND BELOW NORMAL TEMPERATURES DEVELOP IN THE EAST.
SANTORELLI/DOLAN
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,
QUANTITATIVE PRECIPITATION FORECAST (QPF), EXCESSIVE RAINFALL
OUTLOOK (ERO), WINTER WEATHER OUTLOOK (WWO) PROBABILITIES, HEAT
INDICES, AND KEY MESSAGES CAN BE ACCESSED FROM:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=ERO
HTTPS://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW
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