568
FXUS02 KWBC 091905
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
305 PM EDT MON MAR 9 2026
VALID 12Z THU MAR 12 2026 - 12Z MON MAR 16 2026
..RECORD WARMTH ACROSS THE SOUTHWEST LATE WEEK INTO NEXT WEEK
..HEAVY SNOW/WIND THREATS NORTHWEST/ROCKIES TO THE GREAT LAKES
..PATTERN OVERVIEW
THE UPCOMING MEDIUM RANGE FORECAST PERIOD BEGINS LATER THIS WEEK
WITH A FAIRLY PROGRESSIVE PATTERN ACROSS THE NATION WHICH MAY
PROVE QUITE TRANSITIONAL OVER TIME WITH A GRADUAL LESS AMPLIFIED
TREND LATE WEEK BEFORE RE-AMPLIFYING INTO NEXT WEEK. ON THURSDAY,
TROUGHING OVER THE GREAT LAKES AND NORTHEAST WILL DRIVE A STRONG
COLD FRONT THROUGH THE EASTERN U.S. WITH AN ONGOING ATMOSPHERIC
RIVER BRINGING HEAVY PRECIPITATION THREATS TO THE PACIFIC
NORTHWEST. A CLIPPER SYSTEM ACROSS THE NORTHERN TIER WILL BRING
HIGH WIND THREATS ACROSS THE ROCKIES INTO THE HIGH PLAINS INTO THE
WEEKEND, WITH GUSTY WINDS TO ACCOMPANY A DEEPENING CYCLONE OVER THE
GREAT LAKES AND MIDWEST LATE IN THE WEEK AS WELL. MEANWHILE, UPPER
LEVEL RIDGING WILL BUILD AND HOLD OVER THE SOUTHWEST U.S. BRINGING
WELL ABOVE TO RECORD BREAKING WARMTH ACROSS THE REGION WITH SOME
MODERATE HEATRISK NOTED FOR SOUTHERN CALIFORNIA.
..GUIDANCE/PREDICTABILITY ASSESSMENT
DESPITE TRANSITIONAL UPPER FLOW, GUIDANCE REMAINS WELL CLUSTERED
WITH THE PATTERN EVOLUTION THROUGH THIS FORECAST PERIOD. THERE
REMAINS SOME UNCERTAINTY IN THE DETAILS OF INDIVIDUAL SHORTWAVES
THROUGH THE NORTHERN TIER WHICH IMPACT SENSIBLE WEATHER GRIDS AND
EXACT PLACEMENT OF A DEEPENING LOW PRESSURE SYSTEM, BUT FORECAST
SPREAD HAS DECREASED, BOLSTERING FORECAST CONFIDENCE. MODELS SHOW
GOOD AGREEMENT THAT PATTERN MAY RETURN TO AMPLIFIED BY EARLY NEXT
WEEK, ALBEIT STILL WITH SOME TIMING AND STRENGTH QUESTIONS WITH
MEAN TROUGHING ACROSS THE CENTRAL U.S. WHICH COULD IMPACT THE
STRENGTH OF THE SOUTHWEST RIDGE AS WELL. THE WPC FORECAST TODAY USED
A GFS/ECMWF/UKMET/CANADIAN MODEL BLEND FOR THURSDAY INTO SATURDAY
PERIOD, TRANSITIONING THIS WEEKEND TO A BROADER BLEND ADDING INPUT
FROM COMPATIBLE GEFS/ECMWF/CANADIAN ENSEMBLES AND EC-AIFS MACHINE
LEARNING GUIDANCE TO HELP MITIGATE INDIVIDUAL MODEL VARIANCES.
..WEATHER/HAZARDS HIGHLIGHTS
A STRONG WAVY COLD FRONT INTO THE EAST ON THURSDAY WILL BRING
WIDESPREAD, MODERATE TO LOCALLY HEAVY, RAINFALL TO THE REGION. THIS
FRONT SHOULD BE PROGRESSIVE ENOUGH TO LIMIT THE OVERALL FLOOD
THREAT THOUGH. SOME SNOW OR WINTRY MIX IS POSSIBLE ON THE NORTHERN
EDGE OF THE PRECIPITATION SHIELD ACROSS THE INTERIOR NORTHEAST AND
POSSIBLY INTO PARTS OF THE NORTHERN MID-ATLANTIC. MODEST LAKE
EFFECT SNOWFALL IS ALSO POSSIBLE DOWNWIND OF THE ESPECIALLY THE
LOWER GREAT LAKES. THE NEXT MAIN LOW SLATED TO INTO THE NORTHERN
PLAINS/UPPER MIDWEST/GREAT LAKES THEN NORTHERN NEW ENGLAND WILL
BRING RENEWED PRECIPITATION INCLUDING A SWATH OF HEAVY SNOW AS WELL
AS A THREAT FOR GUSTY WINDS INTO FRIDAY AND SATURDAY.
A COUPLE OF SHORTWAVES SHOULD KEEP THE PACIFIC NORTHWEST QUITE WET
THROUGH MUCH OF THE PERIOD. THE HEAVIEST RAINFALL SHOULD BE
ASSOCIATED WITH AN ATMOSPHERIC RIVER WHICH BEGINS AT THE END OF THE
SHORT RANGE PERIOD AND EXTENDS INTO THE WEEKEND. MARGINAL RISKS
FOR EXCESSIVE RAINFALL ARE HIGHLIGHTED FOR SOUTHWEST WASHINGTON AND
NORTHWEST OREGON BOTH THURSDAY AND FRIDAY. HEAVY SNOWS ARE
POSSIBLE IN THE HIGHER ELEVATIONS OF THE NORTHWEST INLAND INTO THE
ROCKIES. TIGHT PRESSURE GRADIENTS WILL ALSO SUPPORT HIGH TO
DAMAGING WINDS, ESPECIALLY FOR THE NORTHWEST-ROCKIES-HIGH PLAINS
FROM LATER WEEK INTO THE WEEKEND.
FOLLOWING A VERY WARM START TO THE WEEK, THE COLD FRONT THROUGH
THE EAST SHOULD BRING TEMPERATURES BACK TOWARDS NORMAL FOR THE EAST
BY THURSDAY AND FRIDAY. HEAT FROM THE SOUTHWEST TO THE CENTRAL GREAT
BASIN WILL BUILD, WITH WIDESPREAD RECORD BREAKING VALUES POSSIBLE.
MODERATE TO VERY LOCALIZED MAJOR HEATRISK IS FORECAST ACROSS PARTS
OF SOUTHERN CALIFORNIA FROM ROUGHLY SANTA BARBARA TO SAN DIEGO AS
TEMPERATURES SOAR INTO THE 80S, WITH 90S FARTHER INLAND. ABOVE
NORMAL TEMPERATURES WILL OVERSPREAD THE SOUTH AS WELL, WITH SOME
RECORDS POSSIBLE INTO THE SOUTHERN PLAINS. THE NEXT TROUGH INTO THE
NORTH-CENTRAL U.S. EARLY NEXT WEEK WILL BRING WITH IT BELOW NORMAL
TEMPERATURES WITH DAYTIME HIGHS 10 TO 20 DEGREES BELOW NORMAL BY
NEXT MONDAY OVER THE NORTHERN/CENTRAL PLAINS AND INTO THE MIDWEST.
SANTORELLI/SCHICHTEL
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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