026
FXUS66 KPQR 012226
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
225 PM PST SUN MAR 1 2026
SYNOPSIS
A LOW PRESSURE SYSTEM MOVING INTO NORTHERN CALIFORNIA
WILL MAINTAIN RAIN SHOWERS ACROSS SOUTHERN PARTS OF THE FORECAST
AREA THROUGH TONIGHT, WITH SNOW CONFINED TO THE HIGHEST CASCADE
PEAKS. SEASONABLY WARM AND DRY CONDITIONS EXPECTED ON MONDAY AS HIGH
PRESSURE MOVES OVER THE REGION. THE NEXT FRONTAL SYSTEM ARRIVING
LATER TUESDAY WILL BRING MORE WIDESPREAD VALLEY RAIN AND CASCADE
SNOW THROUGH WEDNESDAY, FOLLOWED BY SHOWERS LATER WED AFTERNOON.
ANOMALOUSLY STRONG HIGH PRESSURE LIKELY DEVELOPS OVER THE NE PACIFIC
LATER THIS WEEK, THOUGH THE POSITION OF THIS RIDGE WILL DETERMINE IF
STORMS RIDING OVER THE RIDGE WILL BE ABLE TO IMPACT OUR REGION. THIS
UNCERTAINTY MAINTAINS CHANCES FOR PRECIPITATION THROUGH THE END OF
THE WEEK INTO NEXT WEEKEND.
DISCUSSION...NOW THROUGH SATURDAY
SATELLITE AND RADAR IMAGERY
THIS AFTERNOON REVEALS A LOW PRESSURE SYSTEM OFF THE NORTHERN
CALIFORNIA COAST SPREADING CLOUDS AND LIGHT RAIN SHOWERS NORTHWARD
INTO PARTS OF NW OREGON. THE MAJORITY OF RAIN SHOWERS ACROSS THE
FORECAST AREA ARE EXPECTED TO CONTINUE ACROSS MUCH OF LANE COUNTY
THROUGH THIS EVENING, WHILE THE NORTHERN PERIPHERY OF THE RAIN
LIKELY EXTENDS AS FAR NORTH AS LINN, BENTON, AND LINCOLN COUNTIES.
THERE IS AROUND A 30-40% (OR LESS) CHANCE OF A FEW SPRINKLES FROM
SALEM NORTHWARD, WITH MOST OF SW WASHINGTON EXPECTED TO REMAIN DRY
THROUGH TONIGHT. HIGHEST RAINFALL AMOUNTS ARE EXPECTED OVER THE
CENTRAL OREGON CASCADES AND FOOTHILLS ACROSS LINN AND LANE COUNTIES
DUE TO OROGRAPHIC ENHANCEMENTS AS THE UPPER LOW PUSHES INLAND OVER
NORTHERN CALIFORNIA TONIGHT. MEAN 24-HOUR QPF AMOUNTS RANGE FROM
0.50 TO 1.0 INCH, ALTHOUGH NBM PROBS SUGGEST THERE IS AROUND A 15-
35% CHANCE FOR RAINFALL TOTALS TO EXCEED 1 INCH. THIS COULD OCCUR
WITH ANY HEAVIER SHOWERS THAT DEVELOP. SNOWFALL IS NOT EXPECTED AT
CASCADE PASSES AS SNOW LEVELS SITTING AT AROUND 7000 FT ARE NOT
EXPECTED TO FALL BELOW 6000 FT TONIGHT.
WEAK, TRANSIENT RIDGING MOVES ACROSS THE PACIFIC NW ON MONDAY
RETURNING MOST OF THE AREA TO DRIER CONDITIONS. SLIGHTLY ABOVE
AVERAGE TEMPERATURES CONTINUE, ALTHOUGH SKIES ARE LIKELY TO REMAIN
MOSTLY CLOUDY TO PARTLY SUNNY. A FEW LIGHT SHOWERS WILL BE POSSIBLE
(15-30% CHANCE) AT THE COAST AND OVER HIGHER TERRAIN ON MONDAY. BY
TUESDAY, THE UPPER RIDGE SHIFTS EAST OF THE CASCADES AS MOIST
SOUTHWEST FLOW DEVELOPS ACROSS THE REGION. PRECIPITATION CHANCES
WILL INCREASE THROUGH THE DAY FROM WEST TO EAST, BUT ANY RAIN THAT
DOES FALL LIKELY REMAINS LIGHT THROUGH TUESDAY AFTERNOON.
MORE SUBSTANTIAL RAINS ARRIVES LATER TUESDAY NIGHT INTO WEDNESDAY AS
AN UPPER LEVEL TROUGH PUSHES A COLD FRONT ACROSS THE REGION. CHANCES
FOR EXCEEDING 1 INCH OF PRECIPITATION THROUGH WEDNESDAY NIGHT ARE
HIGHEST ACROSS THE TERRAIN (65-95%), WHILE THERE IS AROUND A 30-60%
CHANCE ALONG THE COAST, AND 5-25% CHANCE THROUGH THE INLAND VALLEYS.
NO WIND IMPACTS EXPECTED, THOUGH COULD SEE SOUTHERLY WINDS GUSTING
UP TO 30-35 MPH AT THE COAST AND UP TO 25 MPH INLAND AS THE FRONT
PUSHES INLAND LATE TUE NIGHT/EARLY WED MORNING. BY WEDNESDAY
AFTERNOON, COOLER AIR ALOFT ASSOCIATED WITH THE UPPER TROUGH MAY
ALLOW FOR SOME DEEPER SHOWERS TO DEVELOP, BUT CHANCES FOR
THUNDERSTORMS REMAINS CAPPED AT AROUND 10-15%.
SNOW LEVELS ARE ALSO EXPECTED TO DROP TO AROUND 4000 FT ON
WEDNESDAY, BRINGING POTENTIAL FOR ADVISORY LEVEL SNOWFALL TO THE
CASCADE PASSES. CHANCES FOR 6+ INCHES OF SNOWFALL IN 24-HOURS AT THE
SANTIAM AND WILLAMETTE PASSES IS AROUND 50%, WITH HIGHEST SNOWFALL
RATES LIKELY OCCURRING WEDNESDAY MORNING. THOSE PLANNING TO TRAVEL
THROUGH THE CASCADES MID-WEEK SHOULD CHECK ROAD CONDITIONS BEFORE
LEAVING AND CARRY AN EMERGENCY SUPPLY KIT.
THURSDAY TO SATURDAY, THERE REMAINS SOME UNCERTAINTY WITH THE UPPER
LEVEL PATTERN OVER THE REGION, BUT THE MAJORITY OF ENSEMBLE MEMBERS
SUGGEST ANOMALOUS, BROAD UPPER LEVEL RIDGING OFFSHORE OVER THE
NORTHEAST PACIFIC. THE OFFSHORE PLACEMENT OF THIS RIDGE IS NOT
FAVORABLE FOR A RETURN TO DRY AND SUNNY WEATHER. MOST ENSEMBLE
GUIDANCE SUGGESTS THAT MOISTURE WILL RIDE THE NORTHERN OR EASTERN
PERIPHERY OF THE RIDGE AND TRACK TOWARDS THE PACIFIC NORTHWEST,
MAINTAINING CHANCES FOR PRECIPITATION THROUGH THE END OF THE WEEK.
THOUGH MEAN QPF AMOUNTS REMAIN RELATIVELY LIGHT, THERE ARE A FEW
SCENARIOS WHERE MORE SUBSTANTIAL PRECIPITATION OCCURS, BUT CHANCES
FOR THOSE IS CURRENTLY AROUND 10-20%, HIGHEST TO THE NORTH. DH/10
AVIATION
HIGH LEVEL CLOUDS CONTINUE TO INCREASE FROM THE SOUTH
AS UPPER LEVEL LOW PRESSURE SHIFTS INLAND OVER NORTHERN CALIFORNIA
AND SOUTHERN OREGON. SCATTERED SHOWERS INCREASE FROM SOUTH TO
NORTH THROUGH THE DAY BUT ACTIVITY SHOULD REMAIN SOUTH OF
KSLE/KONP. CIGS ARE EXPECTED TO GRADUALLY LOWER THROUGH THE DAY
FROM SOUTH TO NORTH AS WELL. CHANCES FOR MVFR CIGS IN THE SOUTHERN
AND CENTRAL WILLAMETTE VALLEY INCREASE TO 40-60% AFTER 00Z MONDAY
AND WITH POTENTIAL IN THE NORTHERN WILLAMETTE VALLEY INCREASING
AFTER 06Z MONDAY TO 30-60%. LIGHT OFFSHORE WINDS ALONG THE COAST
AND VARIABLE INLAND LESS THAN 5 KT.
KPDX AND APPROACHES...PREDOMINATELY VFR CONDITIONS THROUGH THE
TAF PERIOD WITH A 10-40% CHANCE FOR MVFR OR LOWER CIGS AT ANY
GIVEN HOUR AFTER 12Z MON AS THE SYSTEM FROM THE SOUTH SPREADS
LOWER CIGS NORTHWARD. 10-15% CHANCE FOR RAIN AFTER 00Z MON.
VARIABLE WINDS AROUND 5 KT OR LESS. -19
MARINE
BENIGN CONDITIONS EXPECTED THROUGH MONDAY NIGHT. SURFACE
HIGH PRESSURE OFFSHORE AND A WEAK THERMAL TROUGH ALONG THE COAST
WILL MAINTAIN NORTHEASTERLY WINDS 5-10 KT ACROSS THE WATERS TODAY.
SEAS FALL TO 3-4 FT AT 9-10 SEC TONIGHT INTO MONDAY. WINDS TURN
MORE SOUTHERLY ON MONDAY AHEAD OF THE NEXT SYSTEM, BUT REMAIN
LIGHT. THE NEXT FRONTAL SYSTEM ARRIVES ON TUESDAY, LIKELY
RETURNING SMALL CRAFT CONDITIONS. THERE IS A 60-80% CHANCE FOR
FREQUENT AND WIDESPREAD SOUTHERLY WIND GUSTS OF 22 KT OR GREATER
ACROSS THE WATERS ON TUESDAY. SEAS WILL ALSO GRADUALLY BUILD ON
WEDNESDAY AND THURSDAY AS A WESTERLY SWELL MOVES IN. CHANCES FOR
SEAS EXCEEDING 10 FT ARE 30-50% DURING THIS TIME, WITH THE HIGHEST
CHANCES BEYOND 10-20 NM OFFSHORE. -19/10
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page