122
FXUS66 KPQR 131026
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
326 AM PDT WED MAY 13 2026
SYNOPSIS
THE PASSAGE OF A WEATHER SYSTEM, THAT STARTED
OVERNIGHT AND WILL CONTINUE THROUGH TODAY WILL RESULT IN A VERY
A NOTICEABLE PATTERN CHANGE AS COOLER AND SLIGHTLY WETTER
CONDITIONS DEVELOP. LIGHT SHOWERS EXPECTED TO CONTINUE THROUGH
THE DAYTIME HOURS. AFTERWARDS, EXPECT DRIER CONDITIONS TO BE
INTERLACED WITH PERIODS OF SHOWERS THROUGH THE END OF THE WEEK.
THEN ANOTHER LOW FROM THE GULF OF ALASKA INCREASES PRECIPITATION
CHANCES (30-70%) FOR THE START THE WEEKEND WHILE MAINTAINING
NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES FOR MAY.
DISCUSSION...TODAY THROUGH TUESDAY
A SHORTWAVE TROUGH MOVING
THROUGH THE REGION IS RESPONSIBLE FOR THE ADDED CLOUD COVER AND
SLIGHTLY COOLER DAYTIME TEMPERATURES. WHILE THIS SHORTWAVE
BROUGHT SOME LIGHTNING AND THUNDER TO THE REGION LAST NIGHT,
WHAT CAN BE EXPECTED THROUGH LATE THIS AFTERNOON IS A MORE
STABLE PATTERN, WITH LIGHT PRECIPITATION EXPECTED ACROSS THE CWA
THROUGH TONIGHT. TOTAL PRECIPITATION AMOUNTS RANGE FROM AROUND
0.10-0.25 INCHES ALONG THE COAST AND COAST RANGE, 0.05-0.20
INCHES WITHIN THE WILLAMETTE VALLEY AND 0.20-0.40 INCHES FOR THE
CASCADES. THE ADDED CLOUD COVER, WESTERLY FLOW, AND COOLER
AIRMASS LIKELY PUSHES HIGH TEMPERATURES DOWN INTO UPPER 50S TO
MID 60S FOR MUCH OF THE AREA. LOOKING TOWARDS THURSDAY AND
FRIDAY, A MORE ZONAL FLOW PATTERN IN THE UPPER LEVELS OF THE
ATMOSPHERE WILL HELP TO KEEP TEMPERATURES NEAR OR BELOW NORMAL
FOR MAY. WITHIN THE UPPER LEVEL FLOW, PERTURBATIONS CAN BE
OBSERVED AND THESE WILL KEEP VERY LIGHT SHOWERS IN THE FORECAST
FOR THE COAST, CASCADES AND NORTHERN WILLAMETTE VALLEY THROUGH
FRIDAY, WITH LITTLE TO NO ACCUMULATION EXPECTED.
LATE FRIDAY/EARLY SATURDAY MOST DETERMINISTIC AND ENSEMBLE
GUIDANCE SHOWS ANOTHER, MORE ROBUST SHORTWAVE TROUGH DROPPING
DOWN FROM THE GULF OF ALASKA INTO THE PAC NW. THIS SYSTEM WILL
LIKELY INCREASES CHANCES FOR PRECIPITATION ACROSS THE CWA AND
CONTINUE TO COOLING TREND INTO MAINLY THE 50S TO NEAR 60S BY
SATURDAY AFTERNOON. LOOKING TOWARDS THE START OF NEXT WEEK,
DAYTIME TEMPERATURES ARE EXPECTED TO WARM BACK INTO THE 60S AND
70S AS THERE IS MODERATE CONFIDENCE IN A RIDGE OF HIGH PRESSURE
BEGINNING TO BUILD BACK OVERHEAD BY EARLY NEXT WEEK. /42-99
AVIATION
A SHORTWAVE TROUGH MOVING INTO THE REGION THIS MORNING
WILL BRING GENERALLY VFR CONDITIONS ACROSS THE AIRSPACE, ALONG
WITH INTERMITTENT POCKETS OF MVFR/IFR CONDITIONS. IN ADDITION TO
THE VARIABLE FLIGHT CONDITIONS EXPECT SHOWERY PRECIPITATION
THROUGH THE TAF PERIOD. SHOWERS WILL TAKE A SOUTHWEST TO NORTHEAST
TRACK OVER THE AIRSPACE, WITH THE MAJORITY OF PRECIPITATION
EXPECTED TO BE OUT OF THE AIRSPACE AROUND 00Z THURSDAY.
WINDS INCREASE OUT OF THE SOUTHWEST BEHIND THE FRONT. LOOK FOR
THE WIND INCREASE STARTING AROUND 12Z WEDNESDAY FOR SOUTHERN
INLAND TAF LOCATIONS, REACHING KSLE AROUND 15Z WEDNESDAY, REACHING
KPDX AROUND 16Z WEDNESDAY. COASTAL LOCATIONS SHOULD SEE THESE
SOUTHWESTERLY WINDS STARTING AROUND 12Z WEDNESDAY. EXPECT
SOUTHWESTERLY GUSTS UP TO 25 KT ALONG THE COAST STARTING AROUND
14Z-16Z WEDNESDAY AND STARTING AROUND 15Z-17Z WEDNESDAY FOR INLAND
LOCATIONS. GUSTS SHOULD START TO SUBSIDE AROUND 00Z THURSDAY.
KPDX AND APPROACHES...VFR CONDITIONS EXPECTED TO CONTINUE WITH
INTERMITTENT MVFR CONDITIONS AS PRECIPITATION CONTINUES TO STREAM
INTO THE REGION FROM THE SOUTHWEST THROUGH AROUND 00Z THURSDAY.
WINDS INCREASE OUT OF THE SOUTHWEST BEHIND THE FRONT, REACHING
KPDX AROUND 16Z WEDNESDAY. EXPECT SOUTHWESTERLY GUSTS UP TO 25 KT
STARTING AROUND 18Z WEDNESDAY. /42
MARINE
RELATIVELY BENIGN CONDITIONS EXPECTED THROUGH THE WEEK.
SOUTHERLY WINDS EARLY THIS MORNING WILL DEVELOP INTO WESTERLY
WIND BY SUNRISE. AFTERWARDS, PREDOMINATELY WESTERLY WINDS THROUGH
THE END OF THE WEEK, WITH NORTHWESTERLY WINDS EXPECTED BY THE
WEEKEND, MAINLY UNDER 10 KTS.
AN UPPER LEVEL TROUGH AND ASSOCIATED FRONT MOVES THROUGH THE
WATERS ON TODAY, WHICH WILL RESULT IN A 35-50% CHANCE OF ISOLATED
SMALL CRAFT GUSTS UP TO 25 KT ACROSS ALL WATERS. THIS WILL MAINLY
BE WHEN THE FRONT IS PASSING BETWEEN 4 AM-12 PM TODAY. NOT
EXPECTING GUSTS TO LAST LONG ENOUGH OVER ANY SPECIFIC AREA TO
ISSUE A SMALL CRAFT ADVISORY AT THIS TIME, THOUGH WE WILL CONTINUE
TO MONITOR CONDITIONS. WINDS REMAIN WESTERLY BUT DECREASE ONCE
AGAIN TONIGHT. SEAS GENERALLY BELOW 8 FT AROUND 10-12 SECONDS
THROUGH THE MAJORITY OF WEEK, BUT COULD SEE SEAS CLOSE TO 10 FT BY
FRIDAY/SATURDAY. /42
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