787
FXUS02 KWBC 191922
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
322 PM EDT SUN OCT 19 2025
VALID 12Z WED OCT 22 2025 - 12Z SUN OCT 26 2025
..GENERAL OVERVIEW
A CLOSED LOW POSITIONED NORTH OF THE GREAT LAKES WILL SUSTAIN AN
OCCLUDED SURFACE LOW WITH A COLD FRONT THAT WILL EXIT THE COAST ON
WEDNESDAY, WITH A RETURN TO COOLER CONDITIONS AS CANADIAN HIGH
PRESSURE SETTLES INTO THE REGION. FURTHER WEST, A CLOSED UPPER LOW
INITIALLY OFF THE COAST OF CALIFORNIA WILL ADVANCE INLAND ACROSS
THE SOUTHERN ROCKIES AND EVOLVES INTO AN UPPER TROUGH IN THE
SOUTHERN STREAM TO SUPPORT A SURFACE LOW OVER THE CENTRAL PLAINS
WITH INCREASING SHOWERS AND THUNDERSTORMS. A STRONGER STORM SYSTEM
IS LIKELY TO APPROACH THE PACIFIC NORTHWEST THURSDAY INTO FRIDAY
WITH A POTENTIAL ATMOSPHERIC RIVER AHEAD OF A STRONG COLD FRONT,
BRINGING WIDESPREAD RAIN AND MOUNTAIN SNOW TO CLOSE OUT THE WORK
WEEK.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST SUITE OF GUIDANCE HAVE A GOOD HANDLE ON THE LARGE SCALE
PATTERNS AND THEIR EVOLUTION. IT WAS NOTED THAT THE CMC WAS
PERSISTENTLY ON THE LEADING EDGE OF WITH THE CLUSTER WITH THE
FEATURE CROSSING THE PLAINS AND DEEPER/SLOWER WITH THE LOW/TROUGH
NORTH OF THE GREAT LAKES/NORTHEAST. WHEREAS, THE ECMWF/EC MEAN
MIGRATED TO THE BACK EDGE/SLOWING FROM THE REST OF THE SOLUTIONS.
A MULTI- DETERMINISTIC MODEL BLEND WAS USED AS A STARTING POINT AND
GRADUALLY INCREASED THE ENSEMBLE MEANS TO 40% BY NEXT WEEKEND.
..WEATHER/HAZARDS HIGHLIGHTS
THE WEST COAST WILL BE HEADING INTO A MORE ACTIVE, WET PATTERN
AS AN AMPLIFYING TROUGH AND STRONG COLD FRONT ADVECTS COPIOUS
PACIFIC MOISTURE TOWARDS THE COAST. WESTERN WASHINGTON AND OREGON
WILL HAVE AN INCREASE IN PRECIPITATION THURSDAY NIGHT (DAY
5/THURSDAY MARGINAL RISK AREA) BEFORE SPREADING TO NORTHERN
CALIFORNIA INTO FRIDAY, WITH A FEW INCHES OF RAINFALL POSSIBLE FOR
THE COASTAL MOUNTAIN RANGES WITH A POTENTIAL ATMOSPHERIC RIVER
AFFECTING THE REGION.
CONVECTION WILL DEVELOP AND INCREASE IN COVERAGE ACROSS THE SOUTH-
CENTRAL U.S. LATER INT HE WEEK AS A SURFACE LOW DEVELOPS. THERE
CONTINUES TO BE A SIGNAL FOR SOME LOCALLY HEAVY RAINFALL ACROSS THE
SOUTHERN PLAINS TO THE LOWER MISSISSIPPI VALLEY. THE DAY 5 MARGINAL
RISK AREA WAS MAINTAINED FOR KANSAS TO NORTHWESTERN ARKANSAS. SOME
STRONG TO SEVERE THUNDERSTORMS WILL ALSO BE POSSIBLE IN THIS SAME
GENERAL AREA AS INSTABILITY INCREASES.
HIGH TEMPERATURES ACROSS THE SOUTH-CENTRAL U.S. ARE FORECAST TO
REMAIN ABOVE AVERAGE FOR MID TO LATE WEEK, ESPECIALLY FOR TEXAS
WHERE HIGHS INTO THE 90S MAY TIE/BREAK A FEW DAILY HIGH TEMPERATURE
RECORDS. THERE MAY BE SOME PERIODS OF BELOW AVERAGE TEMPERATURES
FOR THE MIDWEST/NORTHEAST FOLLOWING COLD FRONTAL PASSAGES, THOUGH
HIGHS IN GENERAL LOOK TO REMAIN NEAR AVERAGE THROUGH MUCH OF NEXT
WEEK. THE NORTHERN-TIER FROM THE ROCKIES EAST TO THE PLAINS/UPPER
MIDWEST WILL SEE INCREASINGLY ABOVE AVERAGE HIGHS LATE NEXT WEEK
AND INTO THE WEEKEND AS AN UPPER-RIDGE BUILDS OVERHEAD. THE PACIFIC
SYSTEM WILL BRING COOLER, WELL BELOW AVERAGE TEMPERATURES TO
PORTIONS OF THE WEST COAST BY EARLY NEXT WEEKEND.
CAMPBELL/HAMRICK
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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