155
FXUS66 KPQR 190603 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1003 PM PST TUE FEB 18 2025
UPDATED AVIATION, MARINE, AND WWA SUMMARY...
SYNOPSIS
LIGHT RAIN RETURNS THIS EVENING AS A FRONTAL SYSTEM
PUSHES ACROSS THE REGION THROUGH WEDNESDAY. BREEZY WINDS LIKELY
WEDNESDAY, WITH GUSTS UP TO 50 MPH ALONG THE COAST AND UP TO 40
MPH INLAND. ANOTHER ROUND OF SNOW EXPECTED FOR THE CASCADES
THROUGH WED NIGHT, WITH 4 TO 8 INCHES OF SNOW EXPECTED AT PASS
LEVEL. THEN, TRENDING DRIER AND SLIGHTLY WARMER THURSDAY INTO
FRIDAY. LATER SATURDAY, POTENTIAL FOR HEAVIER RAIN RETURNS
THROUGH EARLY NEXT WEEK AS A MODERATE ATMOSPHERIC RIVER TAKES
AIM AT THE PACIFIC NW.
SHORT TERM...NOW THROUGH WEDNESDAY NIGHT
WATER VAPOR
SATELLITE IMAGERY THIS AFTERNOON SHOWS AN AMPLIFIED UPPER LEVEL
PATTERN SHIFTING EAST ACROSS THE PACIFIC TOWARD PACIFIC NW. WE
SEE TO SOME EXTENT A BAROCLINIC LEAF DEVELOPING DOWNSTREAM OF A
PV ANOMALY AT THE BASE OF THE UPPER LEVEL TROUGH. A WEAK SURFACE
LOW WILL LIKELY DEVELOP TONIGHT AS THE WEATHER SYSTEM
APPROACHES THE REGION. THIS LOW MOVES NORTH TOWARD VANCOUVER
ISLAND WHILE A WARM FRONT LIFTS ACROSS THE AREA, WITH LIGHT RAIN
THROUGH THIS EVENING. THE MAIN UNCERTAINTY COMES WITH THE
POTENTIAL OF A SECONDARY, COMPACT SURFACE LOW DEVELOPING NEAR
THE OREGON COAST WEDNESDAY MORNING. THIS WOULD BRING THE
POTENTIAL FOR MORE IMPACTFUL SOUTH TO SOUTHWESTERLY WINDS.
FORTUNATELY, THE LATEST MODEL RUNS HAVE BEEN TRENDING AWAY FROM
THIS SOLUTION. STILL, WILL LIKELY SEE WINDS INCREASING WEDNESDAY
MORNING. THE HREF SHOWS SOUTHERLY WINDS WITH GUSTS UP TO 40-50
MPH ALONG THE COAST BECOMING WESTERLY BY THE AFTERNOON. AND
ALTHOUGH THERE IS STILL POTENTIAL FOR A LOW TO SPIN UP QUICKLY
NEAR THE COAST, THE PROBABILITY OF EXCEEDING 60 MPH IS QUITE
LOW, AROUND 10%. BREEZY SOUTHERLY WINDS LIKELY THROUGH THE
WILLAMETTE VALLEY AS WELL MID-DAY WEDNESDAY, WITH GUSTS UP TO
30-40 MPH. THOSE IN THE COLUMBIA RIVER GORGE AND EAST
PORTLAND/VANCOUVER METRO WILL ALSO NOTICE THE EASTERLY WINDS
PICK-UP WED MORNING AS THE KTTD-KDLS PRESSURE GRADIENT INCREASES
TO AROUND -7 TO -8 MB.
PRECIPITATION RATES WILL LIKELY INCREASE ON WEDNESDAY AS THE UPPER
TROUGH PUSHES AN OCCLUDING FRONT ACROSS THE REGION. SNOW LEVELS
ABOVE 5000 FT WEDNESDAY MORNING WILL GRADUALLY FALL TO AROUND 3500-
4000 FT BY WEDNESDAY EVENING. THE HIGHER CASCADES ARE EXPECTED TO
PICK UP ANOTHER ROUND OF SNOW, WITH AROUND 4 TO 8 INCHES OF SNOW
LIKELY AT PASS LEVEL, THEREFORE HAVE ISSUED A WINTER WEATHER
ADVISORY FOR THE CASCADES. HEAVIEST SNOWFALL RATES EXPECTED BETWEEN
8 AM AND 4 PM ON WEDNESDAY.
THE UPPER HOOD RIVER VALLEY WILL POTENTIALLY SEE A MIX OF WINTRY
WEATHER TONIGHT INTO EARLY WED MORNING. PROBABILITIES HAVE DECREASED
AS FORECASTED TEMPERATURES MARGINALLY FALL TO BELOW FREEZING. BUT
THERE REMAINS A LOW CHANCE (10-30%) OF AREAS ABOVE 1000 FT TO SEE A
FREEZING RAIN WITH ICE ACCUMULATIONS UP TO A TENTH AN INCH OR SNOW
UP TO A HALF INCH. /DH
LONG TERM...THURSDAY THROUGH TUESDAY
MODELS AND THEIR ENSEMBLES
REMAIN IN GOOD AGREEMENT OF UPPER LEVEL RIDGING BUILDING OVER THE
REGION LATER THIS WEEK. EXPECT A MOSTLY DRY DAY ON THURSDAY. BUT
WITH CLOUDS, TEMPERATURES ONLY WARM INTO THE LOWER 50S. MOST
CLUSTERS KEEP THE AREA DRY ON FRIDAY, ALTHOUGH THERE IS AROUND A 40%
CHANCE THAT A FRONT IS ABLE TO PUSH RAIN BACK INTO SOUTHWEST
WASHINGTON AND FAR NW OREGON BY FRIDAY AFTERNOON. TEMPERATURES ARE
LIKELY TO CONTINUE THE GRADUAL WARMING TREND INTO THE MID TO UPPER
50S INTO THE WEEKEND AND EARLY NEXT WEEK.
LIGHT RAIN SHOWERS LATE FRIDAY INTO SATURDAY TURNS TO HEAVIER RAIN
LATER IN THE WEEKEND AS THE NEXT WEATHER SYSTEM WILL LIKELY BE
ASSOCIATED WITH A MODERATE ATMOSPHERIC RIVER, POTENTIALLY PERSISTING
THROUGH MONDAY. BOTH THE GEFS AND THE EUROPEAN ENSEMBLE SUGGESTS
MEAN PWAT AMOUNTS OF AROUND 1.1-1.2 INCH NOW. UNCERTAINTY REMAINS
WITH WHERE THE BAND OF HEAVIER MOISTURE SETS UP. THE HIGHEST CHANCES
OF IVT VALUES > 500 KG/M/S (OF AROUND 70-90%) HAVE SHIFTED SLIGHTLY
SOUTHWARD, ACCORDING TO THE CW3E IVT LANDFALL TOOL, TO MUCH OF THE
CENTRAL AND NORTHERN OREGON COAST. ALTHOUGH LATEST HEFS FORECASTS
SHOW A 5-15% CHANCE OF LOCAL TRIBUTARY RIVERS REACHING MINOR FLOOD
STAGE, WILL NEED TO MONITOR THE FLASHIER RIVERS AS WE GET CLOSER TO
SUNDAY. /DH
AVIATION
WIDESPREAD VFR CONDITIONS BEING REPORTED AS OF 05Z
WED AS A BAND OF LIGHT WARM FRONTAL PRECIP LIFTS NORTH ACROSS THE
AREA. THIS BAND SHOULD DEPART 08-10Z, LEAVING SCATTERED SHOWERS
AS VFR PERSISTS THROUGH THE REMAINDER OF THE NIGHT. EXPECT LLWS TO
DEVELOP AT THE COASTAL TERMINALS OVERNIGHT AS SOUTHERLY WINDS
INCREASE ALOFT AHEAD OF APPROACHING COLD FRONT WHILE SURFACE
WINDS REMAIN E-SE. STEADY RAIN ASSOCIATED WITH THE COLD FRONT WILL
PUSH INLAND 12-16Z WED, WITH CONDITIONS TRENDING DOWN TO MVFR AS
A RESULT. EXPECT SOUTHERLY WINDS TO INCREASE TO 10-15 KT AT THE
INLAND TERMINALS ROUGHLY 15-22Z, BUT UNIDIRECTIONAL FLOW SHOULD
HELP LIMIT ANY LLWS CONCERNS IN THE WILLAMETTE VALLEY. RAIN TAPERS
TO SHOWERS BEHIND THE FRONT 20-23Z WED AS FLIGHT CONDITIONS
GRADUALLY IMPROVE BACK TOWARDS VFR 00-06Z THU.
PDX AND APPROACHES...MAINLY VFR EXPECTED THROUGH 15-16Z WED, BUT
CIGS WILL CONTINUE TO STRADDLE FL040 AND HAMPER VISUAL APPROACHES.
LIGHT RAIN ASSOCIATED WITH A WARM FRONT WILL DEPART THE TERMINAL
08-10Z, LEAVING SHOWERY CONDITIONS AND 10-15 E-SE WINDS OVERNIGHT.
COLD FRONTAL RAIN BAND WILL REACH THE TERMINAL AROUND 16Z WED AND
TURN WINDS MORE SOUTHERLY AS CONDITIONS LOWER TO MVFR. FRONT
DEPARTS 21-23Z WED, LEAVING SHOWERY WEATHER AND CIGS IMPROVING
BACK TO VFR FOR THE REST OF THE PERIOD. /CB
MARINE
EVENING UPDATE: GALES WINDS ON TRACK PER LATEST BUOY
OBSERVATIONS. UPGRADED TO A GALE WARNING FOR NEARSHORE WATERS NORTH
OF CAPE FALCON AND MOVED START TIME UP TO 4 AM AS 00Z HI-RES
GUIDANCE HAS COME INTO BETTER AGREEMENT. GUIDANCE HAS ALSO CONTINUE
TO BACK OFF OF SOLUTIONS DEPICTING A COMPACT SURFACE LOW MOVING ONTO
THE CENTRAL COAST WEDNESDAY MORNING. THIS MAY ALLOW GALES TO END A
BIT SOONER THAN DEPICTED IN CURRENT FORECAST AS WINDS SHIFT TO
WESTERLY LATE WEDNESDAY MORNING. WILL EVALUATE THIS POSSIBILITY IN
THE NEXT FORECAST CYCLE. /CB
PREVIOUS DISCUSSION FOLLOWS...A FRONTAL SYSTEM MOVING ONSHORE
THIS EVENING INTO WEDNESDAY WILL BRING GUSTY WINDS AND BUILDING
SEAS. GALE WARNINGS HAVE BEEN EXPANDED TO INCLUDE ALL INNER WATERS
SOUTH OF CAPE FALCON AFTER 4 AM WEDNESDAY, IN ADDITION TO ALL
OUTER WATERS AS OF 4 PM TODAY. A STRONG COLD FRONT SWEEPING
THROUGH THE REGION WILL PRODUCE SOUTHERLY GUSTS OF 35 TO 45 KT,
INITIALLY BEYOND 10NM, AND SUBSEQUENTLY TO NEAR-SHORE ZONES AS
WINDS TURN OUT OF THE SOUTH-SOUTHWEST. FURTHER GUSTS OF 35 TO 45
KT ARE EXPECTED AS WINDS TURN OUT OF THE WEST BEHIND THE
APPROACHING COLD FRONT.
A SMALL CRAFT ADVISORY IS IN EFFECT AS OF 4 PM TODAY FOR INNER
WATERS NORTH OF CAPE FALCON AND WITHIN THE COLUMBIA RIVER BAR. A
GALE WATCH HAS ADDITIONALLY BEEN ISSUED FOR INNER WATERS NORTH OF
CAPE FALCON AFTER 7 AM WEDNESDAY, WITH ISOLATED TO SCATTERED GUSTS
OF 35 KT POSSIBLE, MOST LIKELY BEHIND THE COLD FRONTAL PASSAGE AS
WINDS TURN OUT OF THE WEST. WITHIN THE COLUMBIA RIVER BAR, CHOPPY
SEAS GROWING TO 11 TO 13 FT ARE EXPECTED THROUGH WEDNESDAY DESPITE
MODEST EBB TIDES AS GUSTY SOUTHERLY WINDS TURN WESTERLY WEDNESDAY
AFTERNOON. THERE REMAINS SOME UNCERTAINTY IN THE STRENGTH OF WINDS
AS WELL AS RESULTANT WAVE HEIGHTS BEYOND WEDNESDAY AFTERNOON DUE
TO ASSOCIATED UNCERTAINTY IN THE LOCATION OF THE PARENT SURFACE
LOW.
FOLLOWING A QUIETER THURSDAY AND FRIDAY, ADDITIONAL GALES ARE
EXPECTED AS ANOTHER SURFACE LOW AND STRONG COLD FRONT TRACK ACROSS
THE NORTHEAST PACIFIC ON SATURDAY. IN FACT, THERE APPEARS TO BE A
40-50% CHANCE IN STORM-FORCE WINDS IN OUTER WATERS ON SATURDAY,
THOUGH THERE REMAINS UNCERTAINTY GIVEN THE LEAD TIME. -PICARD
PQR WATCHES/WARNINGS/ADVISORIES
OR...WINTER WEATHER ADVISORY FROM 4 AM WEDNESDAY TO 4 AM PST THURSDAY
FOR ORZ126>128.
WA...WINTER WEATHER ADVISORY UNTIL 4 AM PST THURSDAY FOR WAZ211.
PZ...SMALL CRAFT ADVISORY UNTIL 4 PM PST WEDNESDAY FOR PZZ210.
SMALL CRAFT ADVISORY UNTIL 4 AM PST WEDNESDAY FOR PZZ251>253.
GALE WARNING FROM 4 AM TO 4 PM PST WEDNESDAY FOR PZZ251>253.
GALE WARNING UNTIL 4 PM PST WEDNESDAY FOR PZZ271>273.
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