137
FXUS02 KWBC 212000
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 PM EST SAT FEB 21 2026
VALID 12Z TUE FEB 24 2026 - 12Z SAT FEB 28 2026
..OVERVIEW
AN ATMOSPHERIC RIVER IN CONNECTION WITH A WAVY AND SLOW-MOVING
PACIFIC FRONT WILL LEAD TO HEAVY RAIN IN NORTHERN/CENTRAL
CALIFORNIA TUESDAY, WINDING DOWN TUESDAY NIGHT INTO WEDNESDAY.
UNSETTLED WEATHER IS LIKELY ACROSS THE INTERMOUNTAIN WEST TUESDAY
AND WEDNESDAY. A CLIPPER SYSTEM SHOULD GENERALLY BRING MODEST
SNOWFALL ACROSS THE NORTHERN TIER THROUGH MIDWEEK. FROM MIDWEEK
ONWARD, ANOTHER CLIPPER EJECTING OUT OF THE NORTHERN ROCKIES COULD
LEAD TO UNCERTAIN DOWNSTREAM AMPLIFICATION WITH WINTRY
PRECIPITATION IMPLICATIONS ACROSS THE NORTHEAST ALONG WITH POST-
FRONTAL ARCTIC AIR INTRUSION INTO THE NORTHERN PLAINS.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODEL GUIDANCE CONTINUES THE GRADUAL NORTHWARD TREND ON THE AXIS OF
THE ATMOSPHERIC RIVER DIRECTED TOWARD NORTHERN CALIFORNIA AS THE
MEDIUM RANGE PERIOD BEGINS NEXT TUESDAY. MEANWHILE, MODELS HAVE
SPED UP THE CLIPPER SYSTEM ACROSS THE GREAT LAKES ON WEDNESDAY.
THEREAFTER, UNCERTAINTY BECOMES MORE APPARENT FROM THE CENTRAL U.S.
TO THE NORTHEAST THROUGH LATE NEXT WEEK, DUE TO POTENTIAL
AMPLIFICATION OF A LOW PRESSURE WAVE, WITH DOWNSTREAM WINTRY
WEATHER IMPLICATIONS ACROSS THE NORTHEAST, FOLLOWED BY ARCTIC AIR
INTRUSION INTO THE NORTHERN PLAINS. THE BROAD QPF MAXIMUM ACROSS
THE EAST-CENTRAL U.S. THURSDAY TO FRIDAY APPEARS TO REFLECT THE
UNCERTAINTY OF THE WAVE INTERACTIONS. ATTEMPTS WERE MADE TO NARROW
DOWN THE QPF AXIS THERE BASED ON THE ENSEMBLE MEAN POSITION OF THE
FRONT WHERE A LOW PRESSURE WAVE APPEARS TO FORM OVER THE SOUTHERN
MID-ATLANTIC LATE NEXT WEEK. IN ADDITION, A WAVE EJECTING OUT OF
THE NORTHERN ROCKIES WAS MOST DEVELOPED IN THE GFS BUT LESS
DEVELOPED IN THE CMC, AND BASICALLY FRONTAL IN THE 00Z ECMWF.
HOWEVER, THE LATEST 06Z AND 12Z ECMWF HAVE SHOWN A MUCH BETTER
DEVELOPED WAVE IN AGREEMENT WITH THE GFS SOLUTION, WHICH WILL HAVE
WINTRY PRECIPITATION IMPLICATIONS ACROSS THE NORTHEAST THROUGH
FRIDAY. THIS SCENARIO IS SUPPORTED BY THE AI MODELS. THE WPC
FORECASTS FOR DAY 6 TO 7 WERE MAINLY BASED ON THE CONSENSUS OF THE
00Z EC MEAN, 06Z GEFS, AND THE 00Z CMC MEAN WHICH ONLY INDICATES
MODEST WAVE AMPLIFICATION THROUGH THE NORTHEAST THROUGH FRIDAY. BY
NEXT WEEKEND, THERE APPEARS TO BE A GOOD AGREEMENT ON AN OUTBREAK
OF ARCTIC AIR INTO THE NORTHERN U.S.
THUS THE WPC FORECAST WAS BASED ON A GENERAL MODEL BLEND EARLY IN
THE PERIOD, WITH INCREASING PROPORTIONS FROM THE ENSEMBLE MEANS
TOWARD THE END OF THE FORECAST PERIOD.
..WEATHER/HAZARDS HIGHLIGHTS
AN ATMOSPHERIC RIVER WILL BE ONGOING ACROSS NORTHERN/CENTRAL
CALIFORNIA ON TUESDAY, BRINGING ANOMALOUSLY HIGH MOISTURE IN THE
FORM OF PRECIPITABLE WATER VALUES OVER THE 95TH PERCENTILE. A
MARGINAL RISK REMAINS IN PLACE THERE FOR THE DAY 4/TUESDAY ERO FOR
FLOODING CONCERNS. SOME AREAS IN THE SIERRA NEVADA VICINITY THAT
JUST RECEIVED MULTIPLE FEET OF SNOW COULD SEE RAIN WITH THIS WARMER
SYSTEM. PRECIPITATION, INCLUDING HIGHER ELEVATION SNOW, IS LIKELY
FARTHER INLAND ACROSS MUCH OF THE INTERMOUNTAIN WEST AND ROCKIES ON
TUESDAY AND WEDNESDAY. BY LATER WEEK, THE PACIFIC NORTHWEST AND
THE NORTHERN ROCKIES SHOULD SEE INCREASING PRECIPITATION CHANCES
WITH THE ARRIVAL OF THE NEXT PACIFIC SYSTEM. DOWNSTREAM, THE MEAN
WESTERLY FLOW WILL LEAD TO HIGH WINDS CONCERNS ACROSS THE ROCKIES
AND HIGH PLAINS THROUGH MUCH OF NEXT WEEK, WITH FIRE WEATHER A
POTENTIAL THREAT.
FARTHER EAST, A COUPLE OF CLIPPER SYSTEMS ARE FORECAST TO IMPACT
THE CENTRAL AND NORTHERN U.S. TUESDAY AND WEDNESDAY. LIGHT TO
PERHAPS LOCALLY MODERATE SNOWFALL IS FORECAST ACROSS THE GREAT
LAKES REGION, WHILE LIGHTER SNOW IS FORECAST FARTHER WEST ACROSS
THE NORTHERN PLAINS. LIGHT RAIN IS ALSO POSSIBLE FOR THE CENTRAL
PLAINS/MID-MISSISSIPPI VALLEY. ENERGIES ALOFT COMBINING WITH A
SURFACE FRONTAL SYSTEM WILL ALLOW FOR INCREASING PRECIPITATION
POTENTIAL FROM THE MID-SOUTH THROUGH THE OHIO VALLEY TO INTERIOR
NORTHEAST ON WEDNESDAY, AND SPREADING INTO MUCH OF THE EASTERN
SEABOARD ON THURSDAY. A STRONGER FRONTAL WAVE WILL LEAD TO AN
INCREASING CHANCE OF STRONG TO SEVERE THUNDERSTORMS ACROSS THE
MID-SOUTH TO THE TN VALLEYS ON THURSDAY, POSSIBLY INTO THE EAST
COAST THURSDAY NIGHT OR EARLY FRIDAY. WINTRY PRECIPITATION COULD
IMPACT PORTIONS OF THE NORTHEAST IF THE WAVE AMPLIFIES.
COLDER THAN AVERAGE TEMPERATURES BY 10 TO 20 DEGREES ARE LIKELY
ACROSS THE EASTERN U.S. INTO TUESDAY UNDER A CHILLY SURFACE HIGH
PRESSURE SYSTEM. TEMPERATURES SHOULD MODERATE AFTER A COOL
WEDNESDAY MORNING IN FLORIDA. MEANWHILE MUCH WARMER THAN AVERAGE
TEMPERATURES WILL BE INCREASING IN COVERAGE AND MAGNITUDE
UNDERNEATH AN UPPER RIDGE BEHIND THIS SYSTEM. THE SOUTHWEST INTO
THE PLAINS CAN EXPECT TEMPERATURES OF 15 TO 25 DEGREES ABOVE
AVERAGE, LEADING TO HIGHS IN THE 80S IN TEXAS AT TIMES AND OVER 90F
IN PARTS OF THE DESERT SOUTHWEST. FRIDAY INTO SATURDAY COULD SEE
A RATHER ROBUST INTRUSION OF ARCTIC AIR INTO THE NORTHERN U.S.
KONG/TATE
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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