480
FXUS66 KPQR 152128
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
228 PM PDT THU MAY 15 2025
SYNOPSIS
A PROGRESSIVE WEATHER PATTERN WILL BRING PERIODS OF
LIGHT RAIN THROUGH THE WEEKEND, AND POSSIBLY INTO EARLY NEXT
WEEK. EXPECT TEMPERATURES TO REMAIN SLIGHTLY BELOW AVERAGE
DURING THIS PERIOD. LIGHT, STEADY RAIN EXPECTED AS A WEAK FRONT
MOVES ACROSS THE AREA TODAY. RAIN SHOWERS INCREASE LATE FRIDAY NIGHT
THROUGH SATURDAY, ALONG WITH A 10-20% CHANCE OF THUNDERSTORMS SAT
AFTERNOON. LINGERING SHOWERS INTO SUNDAY, THOUGH MOST AREAS LIKELY
DRIER. TEMPERATURES TRENDING WARMER TOWARD THE END OF NEXT WEEK.
DISCUSSION...TONIGHT THROUGH THURSDAY
RADAR IMAGERY SHOWS LIGHT
RAIN SPREADING ACROSS THE AREA THIS AFTERNOON AS A WEAK FRONT PUSHES
ONSHORE. EXPECT THE COOL, CLOUDY AND DAMP CONDITIONS TO PERSIST
THROUGH THIS EVENING. ONSHORE FLOW WILL MAINTAIN LIGHT SCATTERED
RAIN SHOWERS OVERNIGHT INTO FRIDAY, WITH THE HIGHEST CHANCES OF RAIN
PERSISTING ALONG THE NORTHERN COAST AND COAST RANGE THROUGH FRIDAY.
TOTAL RAINFALL AMOUNTS ARE GENERALLY EXPECTED AROUND A TENTH OF AN
INCH OR LESS, EXCEPT 0.20-0.40 INCH NORTH OF ASTORIA, INCLUDING THE
WILLAPA HILLS. HIGH TEMPERATURES WARM INTO THE MID-60S INLAND, UPPER
50S ALONG THE COAST, ON FRIDAY, POTENTIALLY WARMER ACROSS SOUTHERN
PORTIONS OF THE AREA (E.G. LANE COUNTY) WHERE MORE SUNSHINE IS
POSSIBLE AS CLOUDS SCATTER OUT.
THE ACTIVE PATTERN CONTINUES LATE FRIDAY INTO SATURDAY AS AN UPPER
LEVEL JET OVER THE NORTH PACIFIC MOVES TOWARDS THE OREGON COAST. AN
INITIAL SHORTWAVE TROUGH SLIDES ACROSS WESTERN OREGON EARLY SATURDAY
MORNING, INITIATING WIDESPREAD RAIN SHOWERS. NORTHWEST FLOW ALOFT IS
MAINTAINED AS THE STRONGER SYSTEM DROPS SOUTHWARD ALONG THE BRITISH
COLUMBIA COAST, DIGGING INTO THE PACIFIC NORTHWEST. THIS WILL ALSO
BRING A SLIGHT CHANCE (10-20%) OF THUNDERSTORMS TO THE AREA FOR
SATURDAY AFTERNOON/EVENING. PERSISTENT SHOWERS WILL LIKELY PRODUCE A
BIT MORE SUBSTANTIAL RAINFALL AMOUNTS, INCLUDING A 30-50% CHANCE OF
EXCEEDING 0.25 INCH THROUGH SATURDAY NIGHT ACROSS MUCH OF THE
FORECAST AREA. SHOWERS WILL LIKELY PERSIST ALONG THE HIGHER TERRAIN,
INCLUDING THE CASCADE FOOTHILLS, WHERE AMOUNTS CLOSER TO 0.50-1.00
INCH OF TOTAL (48-HR) RAINFALL ARE POSSIBLE.
MOST AREAS SHOULD EXPECT CONDITIONS TRENDING DRIER ON SUNDAY, WITH
MORE SUN BREAKS THROUGH THE CLOUDS BY THE AFTERNOON. TEMPERATURES
STILL REMAIN ON THE COOLER SIDE WITH HIGHS REACHING THE LOWER TO MID-
60S INLAND. MODELS AND THEIR ENSEMBLES ARE COMING INTO BETTER
AGREEMENT THAT A WEAK FRONT BRINGS ANOTHER ROUND OF LIGHT RAIN
ACROSS THE REGION ON MONDAY. CLUSTER ANALYSIS ALSO SHOWING MORE ZONAL
FLOW LIKELY ON TUESDAY, KEEPING THE DOOR OPEN FOR SOME LIGHT
SHOWERS. BUT STILL, UNCERTAINTY REMAINS INTO THE MIDDLE OF NEXT WEEK
AS ABOUT 60% OF THE CLUSTERS SHOW SOME TYPE OF WEAK RIDGING. STILL,
THE NBM SUGGEST TEMPERATURES ARE LIKELY TO TREND CLOSER TO NORMAL.
/DH
AVIATION
CURRENTLY VFR CONDITIONS THROUGHOUT THE AIRSPACE,
WITH A LOW VFR OVERCAST DECK AROUND 4000-5000 FT AGL, AND WESTERLY
WINDS AROUND 5-10 KTS FOR ALL TERMINALS. THE NEXT FRONT IS CURRENTLY
IN THE PROCESS OF MOVING INTO THE AREA, WITH RAIN EXPECTED TO BEGIN
BY 00Z AT LATEST. AT THAT TIME COASTAL TERMINALS WILL DROP TO MVFR
WITH 60-80% CONFIDENCE, WHILE INLAND TERMINALS SEE A 30-50% CHANCE
OF MVFR CEILINGS BEGINNING CLOSER TO 05-08Z FRI. WINDS REMAIN UNDER
10 KTS WHILE THE FRONT IS IMPACTING THE AREA, BUT WILL SLOWLY TURN
SOUTHERLY OVER THE COURSE OF THURSDAY NIGHT.
PDX AND APPROACHES...VFR CONDITIONS THROUGH THURSDAY DAYTIME HOURS,
WITH A LOW OVERCAST AROUND 5000 FT AGL. AROUND 06Z FRI, THE NEXT
SYSTEM BEGINS MOVING IN, BRINGING SOME RAIN SHOWERS AND A 30-50%
CHANCE OF MVFR CIGS. INTERMITTENT VFR/MVFR CIGS EXPECTED THROUGH THE
END OF THE PERIOD. WINDS WILL TURN FROM WESTERLY TO SOUTHERLY OVER
THE COURSE OF THURSDAY NIGHT, THOUGH REMAINING UNDER 10 KTS
THROUGHOUT. /JLIU
MARINE
SEAS OF 5-7 FT AT 10 SECONDS WILL CONTINUE TO SLOWLY
SUBSIDE TO 4-6 FT BY EARLY FRIDAY MORNING. NORTHWEST WINDS OF LESS
THAN 10 KT WILL BACK OUT OF THE SOUTHWEST TO SOUTH THROUGH
TONIGHT, INCREASING TO 10-15 KT ON FRIDAY AS A REINVIGORATED
NORTHWEST SWELL ARRIVES AHEAD OF A FRONTAL SYSTEM. SOUTH TO
SOUTHWEST FLOW AHEAD OF THE FRONT WILL VEER BACK OUT OF THE
NORTHWEST IN ITS WAKE, WITH A 25-45% CHANCE OF GALE-FORCE GUSTS
BEYOND 30 NM ON SATURDAY, DECREASING TO 5-20% ON SUNDAY. 70-90%
AGREEMENT IN AT LEAST SMALL CRAFT CRAFT WINDS DURING THAT TIME.
AFTERWARDS THE NEXT DISTURBANCES ARRIVES MONDAY, MARKING A RETURN
TO SOUTHERLY WINDS AROUND 10-15 KTS. -PICARD/JLIU
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