Heavy Snow in Oregon, January 11 to 12, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
328 AM PST SAT JAN 11 2014

.SYNOPSIS...OUR STRONGEST STORM SO FAR THIS SEASON IS PUSHING A COLD
FRONT ONSHORE INTO WASHINGTON AND OREGON THIS MORNING. EXPECT A
PERIOD OF STRONG WINDS AND LOCALLY HEAVY RAIN THIS MORNING AS THE
FRONT MOVES THROUGH...THEN MORE GUSTY WINDS AND SQUALLY SHOWERS AS
THE PARENT LOW MOVES ONSHORE LATER TODAY. SNOW LEVELS WILL FALL BELOW
THE CASCADE PASSES BEHIND THE COLD FRONT...RESULTING IN THE FIRST
HEAVY SNOW IN QUITE SOME TIME FOR THE CASCADES. A WARM FRONT WILL
FOLLOW WITH MORE RAIN SUNDAY...THEN HIGH PRESSURE WILL BRING A DRYING
TREND NEXT WEEK.

&&

.SHORT TERM...AN IMPRESSIVE COMPLEX LOW PRESSURE SYSTEM IS EVIDENT ON
INFRARED SATELLITE IMAGERY WITH A CENTER NEAR 48N/135W. AN ASSOCIATED
OCCLUDED FRONT WRAPS AROUND THIS SYSTEM AND INTO BRITISH
COLUMBIA...WITH A STRONG ATTENDANT COLD FRONT APPROACHING MOVING
ONSHORE INTO WESTERN WA AND NEAR ASTORIA THIS MOMENT. THIS COLD FRONT
WILL MOVE EAST ACROSS THE DISTRICT THIS MORNING...BRINGING A PERIOD
OF LOCALLY HEAVY RAIN AND STRONG WINDS...FOLLOWED BY COLDER AIR AND
LOWERING SNOW LEVELS.

NOT MUCH RAIN HAS FALLEN IN THE WILLAMETTE VALLEY THUS FAR AS DRY
SOUTHERLY FLOW HAS DOMINATED MUCH OF THE NIGHT. THE DRYING PRODUCED
BY THE SOUTHERLY FLOW HAS ALLOWED DECENT MIXING OF THE BOUNDARY LAYER
DESPITE THE FACT IT IS NIGHT TIME. GUSTS HAVE ALREADY REACHED AS HIGH
AS 45 MPH IN THE PORTLAND AREA. THIS WAS ENOUGH TO BRIEFLY KNOCK OUT
POWER TO OUR OFFICE HERE IN PARKROSE/NE PORTLAND...AND A FEW OTHER
POWER OUTAGES HAVE ALREADY BEEN REPORTED IN THE PORTLAND METRO AREA.

THE WINDS HAVE BEEN QUITE A BIT STRONGER ALONG THE COAST AND IN THE
COAST RANGE...ALREADY EXCEEDING OUR PREVIOUS STRONGEST WINDS OF THE
SEASON FROM OUR STORM BACK IN LATE SEPTEMBER. ASTORIA AIRPORT HAS
REPORTED A FEW GUSTS IN EXCESS OF 60 MPH...WITH THE HIGHEST BEING 64
MPH. THE NOAA/NOS WIND SENSOR AT GARIBALDI REPORTED 73 MPH AND AN
ODOT WIND SENSOR ON THE MEGLER BRIDGE NEAR ASTORIA HAS REPORTED A
PEAK GUST OF 79 MPH SO FAR. THE BIG WINNER IS THE BPA SITE ON NASELLE
RIDGE IN PACIFIC COUNTY WA WITH A GUST OF 93 MPH...BUT THIS SITE IS
HIGHLY ELEVATED AT 2000 FT AND EXPOSED. THIS COINCIDES NICELY WITH
THE 75 KT WINDS SHOWN BY THE KLGX DOPPLER RADAR AT AROUND 2000 FT
MSL.

THE FIRST PEAK OF WINDS WILL COME JUST AHEAD OF THE FRONT AS IT MOVES
ONSHORE EARLY THIS MORNING...WITH GUSTS 40-50 MPH POSSIBLE THROUGHOUT
THE INLAND VALLEYS...GUSTS UP TO 65 MPH IN THE COASTAL
COMMUNITIES...AND 70-80 MPH BEACHES AND HEADLANDS. EXPECT A BRIEF
LULL AFTER THE FRONT MOVES THROUGH AS RAIN STABILIZES THE ATMOSPHERE
AND PRESSURE GRADIENTS BRIEFLY SLACKEN.

A SECOND SURGE OF WIND WILL COME THIS AFTERNOON AS AN IMPRESSIVE
BENT-BACK OCCLUSION FEATURE PUSHES ONSHORE. THE RAP MODEL HAS BEEN
DAUNTING WITH 60-70 KT WINDS HOVERING JUST 1500-2500 FT ABOVE THE
VALLEY FLOOR AS THIS FEATURE MOVES ONSHORE. THE LATEST RUNS ONLY SEEM
TO BE GETTING STRONGER. 00Z/06Z NAM BUFR SOUNDINGS ARE A LITTLE MORE
CONSERVATIVE...WITH 55-65 KT WINDS 3000-4000 FT MSL. EITHER WAY THERE
WILL BE THE POTENTIAL FOR ISOLATED GUSTS UP TO 60 MPH IN THE INTERIOR
LOWLANDS TODAY...ESPECIALLY IN SQUALLY SHOWERS AND ISOLATED
THUNDERSTORMS...BUT THESE SHOULD NOT BE WIDESPREAD ENOUGH TO WARRANT
A HIGH WIND WARNING. IT WILL BE CLOSE THOUGH...AND CERTAINLY BEARS
WATCHING. AT THIS POINT IT SEEMS LIKE A SOLID WIND ADVISORY IS THE
BEST WAY TO GO FOR THE INLAND VALLEYS.

THE COAST AND COAST RANGE WILL BE A DIFFERENT STORY...AND THAT IS WHY
WE HAVE THE HIGH WIND WARNING IN EFFECT THROUGH THIS EVENING. EXPECT
GUSTS 55-65 MPH TO IMPACT THE COASTAL COMMUNITIES AS THE LOW AND
BENT-BACK OCCLUSION MOVE ONSHORE...ESPECIALLY ON THE NORTH COAST.

THE GOOD NEWS IS THAT THIS SYSTEM WILL BE A FAST MOVER. THE INITIAL
SHOT OF FOCUSED...HEAVY RAIN WILL PROBABLY BE TO SHORT TO CAUSE HYDRO
ISSUES. THE HIGHER TERRAIN WILL SEE A QUICK INCH OF RAIN FROM THE
COLD FRONT ITSELF THIS MORNING...WHILE THE VALLEYS GET 0.25-0.50
INCH.

BEHIND THE FRONT...COLDER AIR WILL MOVE IN AND DROP THE SNOW LEVELS
TO AROUND 3000-3500 FEET. MEANWHILE FLOW WILL TURN WESTERLY... GREAT
FOR OROGRAPHICS IN THE CASCADES. THIS WILL RESULT IN A MUCH-NEEDED
HEAVY SNOW EVENT IN THE CASCADES...WITH 1 TO 2 FEET OF SNOW FALLING
IN THE HIGHER ELEVATIONS THIS WEEKEND. THE SNOW WILL COME WITH A
SIGNIFICANT AMOUNT OF WIND...CAUSING BLOWING AND DRIFTING OF SNOW.

A WARM FRONT SUNDAY WILL BRING ANOTHER SHOT OF PRECIPITATION SUNDAY.
A DECENT MOISTURE PLUME WILL OVERRUN THE EXISTING COLD AIR AS A MILD
UPPER LEVEL RIDGE SLOWLY BUILDS NORTHWARD OFF THE WEST COAST. THIS
SHOULD RESULT IN ANOTHER SHOT OF RAIN...RANGING FROM ABOUT 0.25-0.50
INCH IN THE VALLEYS TO 1-2 INCHES IN THE HIGHER TERRAIN WITH THE
HIGHEST AMOUNTS IN THE NORTH.

THE WARM FRONT/BAROCLINIC ZONE WILL SLOWLY PUSH NORTH SUN/MON AS THE
UPPER RIDGE BUILDS. THIS SHOULD DRY OUT THE FORECAST AREA FROM SOUTH
TO NORTH...BUT STRENGTHENING INVERSIONS SHOULD ALLOW FOG TO QUICKLY
DEVELOP IN THE VALLEYS. BY MON NIGHT MOST OF SW WASHINGTON AND NW
OREGON SHOULD BE DRY...WITH FOG IN THE VALLEYS AND MILDER CONDITIONS
UP ABOVE.  WEAGLE

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...MONDAY NIGHT
THROUGH FRIDAY...KEPT A SLIGHT CHANCE FOR SOME LINGERING SHOWERS
LATE MONDAY ACROSS THE NORTHERN ZONES. AFTER THIS...MODELS ARE IN
GOOD AGREEMENT THAT AN UPPER LEVEL RIDGE WILL DEVELOP OVER THE
REGION AND DOMINATE THE PATTERN UNTIL NEXT WEEKEND. AS A RESULT...NO
PRECIP IS EXPECTED THROUGH FRIDAY EXCEPT FOR PERHAPS A LITTLE LIGHT
RAIN IN SW WASHINGTON ZONES EARLY WEDNESDAY IN ASSOCIATION WITH A
SHORTWAVE DISTURBANCE PROGGED TO MOVE ACROSS NORTHERN WASHINGTON.
OTHERWISE EXPECT DAILY FOG TO DEVELOP ACROSS THE VALLEY LOCATIONS.
THE UPPER LEVEL RIDGE WILL AMPLIFY BY THURSDAY AND OFFSHORE FLOW
WILL DEVELOP INTO FRIDAY. FORECAST MODELS INDICATE THAT THE NEXT
FRONTAL SYSTEM WILL ARRIVE ACROSS THE PACIFIC NORTHWEST FOR NEXT
WEEKEND. TEMPERATURES WILL BE NEAR SEASONAL NORMS...WITH HIGHS
GENERALLY IN THE UPPER 40S AND LOWS IN THE MID 30S THROUGH THE
EXTENDED PERIOD.  CULLEN

&&

.AVIATION...FRONT NEAR THE COAST BRINGING RAIN...STRONG WINDS AT
THE SURFACE AND ALOFT ALONG WITH MVFR TO IFR CONDITIONS. THE
FRONT IS EXPECTED AT THE COAST AROUND 12Z AND A COUPLE OF HOURS
LATER FOR THE INLAND TAF LOCATIONS. EXPECT MVFR CONDITIONS WITH
THE FRONT...THEN TRENDING TO VFR BEHIND THE FRONT LATER IN THE
MORNING. THERE WILL BE PLENTY OF SHOWERS AROUND THROUGH THE REST
OF THE DAY INTO THE EVENING. EXPECT PERIODS OF MVFR TO DEVELOP IN
SOME OF THESE SHOWERS. THE MOUNTAINS WILL BE OBSCURED THROUGH THE
NEXT 24 HOURS.

THE BIGGEST IMPACT FROM THIS FRONTAL SYSTEM WILL LIKELY BE VERY
GUSTY WINDS AHEAD AND WITH THE FRONT. WIND SHEAR WILL LIKELY BE A
CONCERN FOR MANY SITES AS A LOW LEVEL JET OF 60+ KT IS BEING
ADVERTISED BY THE FCST MODELS BETWEEN 1500 AND 2000 FT. EXPECT THE
GUSTY WINDS TO CONTINUE WELL INTO THE AFTERNOON.

KPDX AND APPROACHES...FRONT NEAR THE COAST SHOULD MOVE ACROSS THE
TERMINAL AROUND 14Z...WITH RAPID IMPROVEMENT TO VFR MID TO LATE
MORNING. EXPECT PLENTY OF SHOWERS AROUND THROUGH THE REMAINDER OF
THE DAY...WITH PERIODS OF MVFR DEVELOPING DURING SHOWERS.
ALSO...LOOK FOR VERY GUSTY S/SW WINDS TO DEVELOP AFTER MIDNIGHT
AND CONTINUE THROUGH MUCH OF THE DAY. PYLE/MH

&&

.MARINE...THE COLD FRONT MOVED THROUGH BUOY 46089 AROUND 09Z...BUT
WINDS THERE HAVE BARELY BEEN GALES. CLOSER IN THERE IS GOOD
EVIDENCE OF A COASTAL JET WITH NEAR SHORE BUOYS AND BEACH WIND
OBSERVATIONS INDICATING STORM FORCE GUSTS AFFECTING THE NORTHERN
COASTAL WATERS AND THE COLUMBIA RIVER ENTRANCE. ON THE CENTRAL
COASTAL WATERS WINDS ARE WEAKER BUT COULD SEE BRIEF STORM FORCE
GUSTS AS THE FRONT MOVES THROUGH. THE FRONT IS EXPECTED TO MOVE
ASHORE 4 TO 5 AM. BEHIND THE FRONT WINDS WILL VEER TO THE
SOUTHWEST AND EASE. THERE COULD BE A PERIOD OF SUB GALE WINDS.
HOWEVER...MODELS HAVE BEEN QUITE CONSISTENT WITH A STRONG
TROUGH FOLLOWING THE FRONT MOVING INTO THE WATERS LATER IN THE
MORNING FOR ANOTHER ROUND OF GALE TO STORM FORCE WIND GUSTS.
ASCAT SATELLITE WINDS FROM THE 06Z PASS MATCHED UP QUITE WELL WITH
THE NAM BOUNDARY LEVEL WINDS. WITH INCREASED CONFIDENCE IN THE
MODELS HAVE DECIDED TO EXTEND THE STORM WARNING FOR THE NORTHERN
WATERS THROUGH THE AFTERNOON...BUT LIKELY IT WILL BE OCCASIONAL
GUSTS TO 45 TO 50 KT MAINLY ASSOCIATED WITH RAIN SHOWERS. ALSO
HAVE LOWERED THE STORM WARNING TO GALES FOR THE CENTRAL COAST
GIVEN THE TRACK THE MODELS ARE TAKING THE TROUGH.

THE SEAS WILL BECOME EXTREMELY HAZARDOUS TODAY AND TONIGHT.
LATEST GUIDANCE CONTINUES THE TREND OF KEEPING MAX SEAS AROUND 30
FT THIS EVENING. THE WESTERLY SWELL WILL CLIMB ABOVE 20 FT THIS
MORNING PEAK NEAR 30 FT THIS EVENING...AND LIKELY DROP BELOW 20 FT
SUN AFTERNOON. THIS LOOKS TO BE A DYNAMIC FETCH SITUATION AND THE
MODELS MAY BE TOO QUICK TO DECAY THE OFFSHORE SEAS. MODELS ALSO
TEND TO BE TOO SLOW BUILDING THE SEAS IN THESE SITUATIONS. WENT A
LITTLE HIGHER ON THE MAX SEAS THAN ENP OR GWW AND DECAYED THEM A
BIT MORE SLOWLY. UNFORTUNATELY THE CORE OF THE HIGHEST SWELL IS IN
A DATA VOID AREA SO THERE IS NO GROUND TRUTH DATA TO PERFORM
FURTHER ANALYSIS AGAINST MODEL OUTPUT IN THE OFFSHORE WATERS.
SINCE THE MODELS HAVE BEEN QUITE CONSISTENT CONFIDENCE IN FORECAST
IS HIGH.

BY SUN WINDS AND SEAS WILL BE WINDING DOWN AS HIGH PRES BUILD TO
THE SOUTHWEST OF OREGON FOR A CALMER PERIOD THROUGH MID NEXT WEEK.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER STORM WARNING FROM 6 AM THIS MORNING TO 4 AM PST SUNDAY
     FOR CASCADES IN LANE COUNTY-NORTHERN OREGON CASCADES.

     WIND ADVISORY UNTIL 10 PM PST THIS EVENING FOR CENTRAL
     WILLAMETTE VALLEY-GREATER PORTLAND METRO AREA-LOWER
     COLUMBIA-SOUTH WILLAMETTE VALLEY.

     HIGH WIND WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL COAST
     RANGE OF WESTERN OREGON-CENTRAL OREGON COAST-COAST RANGE OF
     NORTHWEST OREGON-NORTH OREGON COAST.

     HIGH SURF WARNING FROM 4 PM THIS AFTERNOON TO 10 AM PST SUNDAY
     FOR CENTRAL OREGON COAST-NORTH OREGON COAST.

WA...WINTER STORM WARNING FROM 6 AM THIS MORNING TO 4 AM PST SUNDAY
     FOR SOUTH WASHINGTON CASCADES.

     WIND ADVISORY UNTIL 10 PM PST THIS EVENING FOR GREATER VANCOUVER
     AREA-I-5 CORRIDOR IN COWLITZ COUNTY.

     HIGH WIND WARNING UNTIL 10 PM PST THIS EVENING FOR SOUTH
     WASHINGTON COAST-WILLAPA HILLS.

     HIGH SURF WARNING FROM 4 PM THIS AFTERNOON TO 10 AM PST SUNDAY
     FOR SOUTH WASHINGTON COAST.

PZ...STORM WARNING UNTIL 3 PM PST THIS AFTERNOON FOR COASTAL WATERS
     FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM.

     GALE WARNING UNTIL 3 PM PST THIS AFTERNOON FOR COASTAL WATERS
     FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 AM PST
     SUNDAY.

&&

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.

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE PORTLAND OR
304 AM PST SAT JAN 11 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0148 AM     NON-TSTM WND GST 6 ESE DOWNTOWN PORTLAND 45.50N 122.57W
01/11/2014  M46.00 MPH       MULTNOMAH          OR   DEPT OF HIGHWAYS

            ODOT SENSOR - I-205 AT DIVISION

&&

KDONOFRI

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PORTLAND OR
322 AM PST SAT JAN 11 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0154 AM     NON-TSTM WND GST 1 SSW GARIBALDI         45.55N 123.92W
01/11/2014  M73 MPH          TILLAMOOK          OR   OTHER FEDERAL

            TLBO3 - DATA FROM THE NATIONAL OCEAN SERVICE. PEAK WINDS
            EARLIER THIS MORNING.

&&

KDONOFRI

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PORTLAND OR
347 AM PST SAT JAN 11 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0312 AM     NON-TSTM WND GST 4 ENE LAUREL MOUNTAIN   44.92N 123.47W
01/11/2014  M58.00 MPH       POLK               OR   OTHER FEDERAL

            ROCKHOUSE RAWS IN THE CENTRAL OREGON COAST RANGE. 1797
            FT.

&&

KDONOFRI

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PORTLAND OR
511 AM PST SAT JAN 11 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0412 AM     NON-TSTM WND GST 4 ENE LAUREL MOUNTAIN   44.93N 123.46W
01/11/2014  M74.00 MPH       POLK               OR   OTHER FEDERAL

            ROCKHOUSE RAWS - ELEV 1797 FT.

0436 AM     TSTM WND GST     HILLSBORO               45.53N 122.94W
01/11/2014  M46.00 MPH       WASHINGTON         OR   ASOS

            HILLSBORO AIRPORT ASOS

0447 AM     NON-TSTM WND GST SCAPPOOSE               45.75N 122.88W
01/11/2014  M47.00 MPH       COLUMBIA           OR   ASOS

            SCAPPOOSE AIRPORT ASOS

&&

SWEAGLE

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE PORTLAND OR
513 AM PST SAT JAN 11 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0436 AM     NON-TSTM WND GST HILLSBORO               45.53N 122.94W
01/11/2014  E46.00 MPH       WASHINGTON         OR   ASOS

            HILLSBORO AIRPORT ASOS

&&

SWEAGLE

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE PORTLAND OR
518 AM PST SAT JAN 11 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0436 AM     NON-TSTM WND GST HILLSBORO               45.53N 122.94W
01/11/2014  M46.00 MPH       WASHINGTON         OR   ASOS

            HILLSBORO AIRPORT ASOS

&&

SWEAGLE