Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 260904
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
205 AM PDT SAT JUL 26 2014

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL CONTINUE TO BUILD INLAND OVER
THE PACIFIC NORTHWEST...ESPECIALLY OVER THE WEEKEND...AND REMAIN NEAR
THE FORECAST AREA THROUGH MUCH OF NEXT WEEK. THIS WILL BRING WARM AND
DRY WEATHER...EXCEPT FOR A SLIGHT CHANCE FOR THUNDERSTORMS IN THE
CASCADES NEAR THE CREST BEGINNING SUNDAY AFTERNOON AND EVENING AS A
FEW WEAK DISTURBANCES LIFT NORTHEAST THROUGH THE REGION. THE MARINE
LAYER WILL BECOME MORE CONFINED TO THE COAST.
&&

.SHORT TERM...CLOUDS FRI EVENING CLEARED OUT MOST OF THE FORECAST
AREA...AND THROUGH THE EARLY MORNING HOURS HAVE YET TO REFORM. WITH
A LIGHT NNW ONSHORE SURFACE PRES GRADIENT EXPECT SOME CLOUDS LIKELY
TO REFORM ALONG THE N PART OF THE COAST BY MORNING...BUT EXPECT
LITTLE IN THE WAY CLOUDS INLAND. GIVEN THE SLOW START TO CLOUDS THIS
MORNING AND AN APPARENTLY SIMILAR SITUATION FOR SUN MORNING EXCEPT A
STRENGTHENING RIDGE...WILL BACK OFF SOME ON CLOUDS FOR SUN MORNING A
BIT TOO. AS THE UPPER RIDGE STRENGTHENS OVER THE PACIFIC NW AND H8
TEMPS CLIMB A FEW DEGREES EACH DAY...EXPECT AFTERNOON TEMPS TO WARM
TODAY AND SUN...WITH H8 TEMPS BY SUN SUGGESTING 90 POSSIBLE AGAIN
INLAND VALLEY.

MODELS CONTINUE TO SUGGEST SHORTWAVES TO BEGIN LIFTING N INTO OREGON
BY SUN AFTERNOON. FORECAST STABILITY PARAMETERS AND SOUNDINGS
INDICATE MARGINAL INSTABILITY OVER THE OREGON PART OF THE CASCADES.
SHORTWAVES IN A SOUTHERLY MID LEVEL FLOW SUGGEST SOME POTENTIAL FOR
CONVECTION...BUT WITH STABILITY AND MOISTURE SOURCE QUESTIONABLE
WILL LIMIT POPS TO SLIGHT CHANCE CATEGORY OVER THE CASCADES. SIMILAR
SITUATION BUT WITH FLOW A BIT MORE W OF S MON SUGGESTS A MORE
LIMITED THREAT OF CONVECTION MON AFTERNOON.

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...MONDAY NIGHT
THROUGH FRIDAY. MODELS REMAIN IN GENERAL AGREEMENT THAT THE REGION
WILL REMAIN BETWEEN AN UPPER LOW IN THE GULF OF ALASKA AND A
DEVELOPING UPPER RIDGE OVER THE WESTERN CONUS THROUGH MUCH OF NEXT
WEEK. THE RIDGE OF HIGH PRES WILL AMPLIFY AND RETROGRADE WITH THE
AXIS ALIGNED NEAR THE ROCKIES OR EASTERN GREAT BASIN BY MID WEEK.
SOME VARIATION REMAINS IN THE POSITION OF THE RIDGE AXIS IN THE FCST
MODELS AND AMONG ENSEMBLE MEMBERS...WHICH WILL IMPACT WHERE THE
THERMAL TROUGH DEVELOPS. SO WHILE SOME OF THE FINER DETAILS WILL BE
WORKED OUT IN TIME...CONFIDENCE IS INCREASINGLY HIGH IN THE GENERAL
PICTURE. NAMELY...TEMPERATURES ABOVE NORMAL THROUGH THE WEEK AND WITH
MOSTLY CLEAR SKIES ACROSS THE INTERIOR EACH DAY...WITH GUSTY WINDS
ALONG THE COAST IN THE AFTERNOON/EVENING HOURS. MODELS CONTINUE TO
INDICATE POTENTIAL FOR THUNDERSTORMS...PRIMARILY ALONG THE CENTRAL
OREGON AND LANE COUNTY CASCADES AND FOOTHILLS. EXPANDED AREAS FOR WED
ONWARD IN THESE LOCATIONS...GENERALLY IN THE AFTERNOON/EVENING HOURS
BUT ALSO WITH A SLIGHT CHANCE FOR SOME LINGERING OVERNIGHT
THUNDERSTORMS. THEREFORE...GENERALIZED THE AREAS AND TIMING OF
POTENTIAL FOR NOW AND WILL FINE TUNE THIS PART OF THE FORECAST AS WE
GET CLOSER TO NEXT WEEK.  CULLEN
&&

.AVIATION...HIGH PRES OVER REGION...WITH DRY NLY FLOW IN LOW
LEVELS. MAY SEE PATCHY STRATUS AND/OR FOG THIS AM JUST ABOUT
ANYWHERE...BUT SEEMS BEST THREAT IS ALONG THE COLUMBIA RIVER
BETWEEN KAST AND KPDX. AGAIN...WITH LOW TIDES AROUND 5 TO 6 AM
TODAY...WILL SEE SHALLOW PATCHY FOG ON/NEAR COASTAL BAYS AS MUDS
WILL BE EXPOSED TO COOL AIR UNTIL 8 AM.

KPDX AND APPROACHES...VFR TODAY WITH DRY FLOW ALOFT. MAY SEE
PATCHY SHALLOW FLOW AROUND OPS AREA BETWEEN 12Z AND 15Z...MAINLY
TO N OF FIELD.                                        ROCKEY
 &&

.MARINE...HIGH PRES OVER THE NE PAC...WITH THERMAL LOW PRES OVER
N CALIF. LITTLE CHANGE IN PATTERN INTO NEXT WEEK. THIS PATTERN
WILL RESULT IN GUSTY NORTH WINDS OF 25 TO 30 KT ACROSS THE
CENTRAL OREGON WATERS...THAT MAY PERIODICALLY EXTEND UP IN THE
NORTHERN WATERS ON SUN.

SEAS OF 2 TO 4 FT WILL BECOME MORE WIND DOMINATED AND LIKELY PUSH
INTO THE 5 TO 7 FT RANGE...ESPECIALLY FOR THE CENTRAL OREGON
WATERS LATER THIS WEEKEND AS NORTHERLY WINDS STRENGTHEN AND
EXPAND IN AREAL COVERAGE.
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FOR THIS AFTERNOON UNTIL
         LATER TONIGHT ON CENTRAL COASTAL WATERS...OR FROM
         CASCADE HEAD TO FLORENCE.
&&

$$

MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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.


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