High Surf in Oregon, April 15, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
955 AM PDT FRI APR 15 2016

.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO BUILD OVER NORTHWEST
OREGON AND SOUTHWEST WASHINGTON FOR DRY WEATHER STARTING TODAY.
HOWEVER...MOIST ONSHORE WINDS WILL HELP MAINTAIN SOME CLOUDS AROUND
THE FORECAST AREA. THE RIDGE WILL AMPLIFY THIS WEEKEND AND RESULT IN
DRY AND WARM WEATHER THROUGH EARLY NEXT WEEK. TEMPERATURES WILL WARM
INTO THE 80S INLAND SUNDAY AND MONDAY.

&&

.SHORT TERM...TODAY THROUGH SUNDAY...RESIDUAL SHOWERS OVER THE
CASCADES HAVE GENERALLY ENDED THIS MORNING AS THE UPPER LEVEL LOW
CONTINUES TO MOVE TOWARDS THE FOUR CORNERS. WILL CONTINUE TO SEE SOME
ISOLATED AREAS OF PATCHY FOG THROUGH AROUND NOON TODAY DUE TO
ABUNDANT SURFACE MOISTURE AND LIGHT WINDS. ONCE THIS LINGERING FOG
CLEARS EXPECT A BEAUTIFUL SPRING DAY TODAY WITH PARTLY CLOUDY SKIES.
ONSHORE FLOW AND LINGERING CLOUDS SHOULD KEEP WARMING TO A MINIMUM
TODAY...WITH AFTERNOON HIGHS IN THE MID 50S AT THE COAST AND IN THE
LOW 60S INLAND.

THE UPPER RIDGE CONTINUES TO AMPLIFY ALONG THE COAST TONIGHT AND
SATURDAY FOR DRY WEATHER AND CLEARING SKIES. HOWEVER...EXPECT MOIST
SURFACE CONDITIONS AND LIGHT WINDS TO CONTINUE TONIGHT. THIS WILL
LIKELY LEAD TO THE REDEVELOPMENT OF PATCHY FOG OVERNIGHT UNDER A
STABILIZING LOWER ATMOSPHERE. TEMPS SATURDAY SHOULD WARM UP INTO THE
LOWER 70S INLAND.

THE MODELS ALSO CONTINUE TO SHOW A WARM FRONT NEARING THE FAR
NORTHWEST PART OF THE FORECAST AREA TONIGHT AND SATURDAY...BUT THEY
GENERALLY KEEP ANY CHANCE OF PRECIPITATION OVER THE OFFSHORE WATERS.

UPPER RIDGING CONTINUES THROUGH SUNDAY FOR MORE DRY WARM WEATHER.
MODELS SHOW OFFSHORE FLOW DEVELOPING THROUGH THE COLUMBIA RIVER GORGE
SATURDAY NIGHT AND SUNDAY. THAT COMBINED WITH THE BUILDING UPPER
RIDGE SHOULD PUSH INLAND TEMPS INTO THE LOWER 80S INLAND SUNDAY AND
AROUND 80 AT THE COAST. /64/BOWEN/TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SUNDAY NIGHT
THROUGH THURSDAY...DRY AND WARM CONDITIONS CONTINUE THROUGH MONDAY
WITH POSSIBLE RECORD WARMTH IN THE VALLEY. RECORDS ARE IN THE LOW TO
MID 80S AND TEMPERATURES ARE LOOKING LIKE THEY MAY HIT THE MID 80S.
SOME UNCERTAINTY ABOUT MONDAY TEMPERATURES IN THE SOUTH VALLEY AROUND
EUGENE AND CORVALLIS WITH SOME MODELS INDICATING A MARINE INTRUSION
CUTTING OFF HEATING MONDAY AFTERNOON...SO MAY ONLY SEE UPPER 70S TO
AROUND 80 DEGREES THERE. THE UPPER RIDGE WILL MOVE EASTWARD WITH AN
UPPER LOW MOVING NORTH OVER EAST PACIFIC LATE MONDAY. STILL SOME
SIGNIFICANT DISCREPANCIES AMONG MODELS REGARDING THE SPECIFIC TRACK
OF THIS LOW...BUT GENERAL AGREEMENT THAT IT WILL MOVE ACROSS THE
REGION ON TUESDAY...BRINGING INCREASED CLOUDS...AT LEAST SLIGHT RAIN
CHANCES...AND COOLER TEMPERATURES. SHOWERS MAY CONTINUE THROUGH A
GOOD PORTION OF THE WEEK...BUT CONFIDENCE IS PARTICULARLY LOW FOR THE
MIDDLE OF NEXT WEEK AS FORECAST MODELS DIVERGE QUITE A BIT...WITH THE
ECMWF SUGGESTING MUCH HIGHER RAIN CHANCES WHILE THE GFS WOULD
INDICATE DRIER WEATHER. TRIED TO SPLIT THE DIFFERENCE FOR MIDWEEK BUT
ENDED UP NUDGING TOWARD CLIMO POPS (35-45 PERCENT) TOWARDS LATER NEXT
WEEK DUE TO HIGH UNCERTAINTY. BOWEN

&&

.AVIATION...GENERALLY VFR THROUGH SAT MORNING. THERE WILL BE SOME
LOCALIZED MVFR/IFR VIS RESTRICTIONS UNTIL 18Z OR SO IN THE INTERIOR
VALLEYS. QUESTION THEN BECOMES WILL FOG OR LOW CLOUDS DEVELOP
TONIGHT. MODELS INDICATE MID AND HIGH LEVEL MOISTURE TONIGHT INTO SAT
MORNING WHICH WOULD REDUCE THE THREAT OF FOG OR LOW CLOUDS.
HOWEVER...DUE TO THE RECENT RAINFALL WOULD EXPECT LOCAL IFR
CONDITIONS LATE TONIGHT INTO SAT MORNING.

KPDX AND APPROACHES...VFR CONDITIONS TO PREVAIL THROUGH SAT
MORNING. MID AND HIGH LEVEL MOISTURE TONIGHT WILL LIMIT THE FOG
THREAT...BUT STILL CANNOT RULE OUT LOCAL IFR CONDITIONS AFTER 10Z
SAT...ESPECIALLY AT KHIO. WEISHAAR

&&

.MARINE...AFTER A COUPLE DAYS OF RATHER CHAOTIC SEA CONDITIONS...THE
NEXT FEW DAYS WILL BE QUIET. WIND SPEEDS GENERALLY 10 KT OR LESS
THROUGH AT LEAST EARLY NEXT WEEK. A WEAK SURFACE THERMAL TROUGH TRIES
TO DEVELOP ALONG THE S OREGON COAST LATE TONIGHT AND SAT...BUT STILL
ONLY LOOKING AT 10 TO 15 KT WIND SPEEDS AT BEST FROM HECETA HEAD TO
FLORENCE.

WAVE HEIGHTS CONTINUE TO SUBSIDE...DOWN TO AROUND 10 FT AS OF 15Z.
WILL CARRY THE SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS THROUGH 18Z.
SEAS LOWER TO 5-6 FT BY THIS EVENING AND REMAIN IN THAT RANGE THROUGH
EARLY NEXT WEEK. WEISHAAR

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT THIS
     MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 2 PM
     PDT THIS AFTERNOON.

&&

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.