000
FXUS66 KMFR 211703
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
903 AM PST SAT NOV 21 2009

.DISCUSSION...CURRENT FORECAST LOOKS GOOD OVER REGION WITH FRONT
ENTERING THE COASTAL WATERS TONIGHT...USHERING WINDY CONDITIONS
OVER THE COASTAL WATERS AND INTO THE COOS AND CURRY COUNTIES. HIGH
WIND WATCH IS ACCURATELY PORTRAYING CONDITIONS FOR TONIGHT AS
STRONG WINDS WILL IMPACT THE COASTAL COUNTIES...AND WILL LIKELY BE
ISSUING HIGH WIND WARNING FOR THAT AREA WITH THE AFTERNOON PACKAGE.
WILL BE LOOKING AT THE DATA AND PROGRESSION OF UPSTREAM DEVELOPING
STORM FURTHER TO DECIDE ON ANY POSSIBLE WIND ADVISORY FOR DOUGLAS
COUNTY AREA WITH NAM INTENSIFYING LOW A BIT ON RECENT MODEL RUNS.
ALSO...WILL BE FINE TUNING SNOW FORECAST FOR KLAMATH FALLS AREA
AND LOOKING AT SNOW ADVISORY FOR THAT AREA LATE TONIGHT INTO
SUNDAY MORNING. MODELS ARE STILL AGREEING ON DRY SOLUTION FOR
MONDAY THROUGH WEDNESDAY WITH A WEAK FRONT ENTERING THE AREA
THURSDAY. CURRENT SNOW LEVEL IS ABOUT 3500 FEET PER MFR
SOUNDING...AND LEVELS WILL RISE A BIT AHEAD OF FRONT AND THEN DROP
BEHIND THE FRONT TOMORROW MORNING.

.AVIATION...FOG IN THE ROGUE VALLEY AND UMPQUA BASIN...RESULTING
IN IFR CONDITIONS...WILL LIFT TO VFR BY LATER THIS MORNING. VFR
CONDITIONS WILL BE SHORT-LIVED AS ANOTHER FRONT DROPS MOST
TERMINALS TO MVFR IN LOW CLOUDS AND SHOWERS BY THIS EVENING.
MOUNTAINS AND EAST SIDE WILL HAVE SNOW REDUCING VISIBILITIES
TONIGHT AND SUNDAY MORNING. MOUNTAIN OBSCURATION WILL BE
WIDESPREAD BY TONIGHT THROUGH SUNDAY AS DEEP MOISTURE PUSHES INTO
THE REGION.

.PREV DISCUSSION... /ISSUED 405 AM PST SAT NOV 21 2009/

DISCUSSION...A FEW SHOWERS WILL LINGER ACROSS THE HIGHER TERRAIN
OF THE FORECAST AREA THIS MORNING BUT THE TREND IS FOR BRIEF
DRYING THIS AFTERNOON. BY EARLY EVENING ANOTHER PACIFIC FRONT WILL
MOVE INTO THE COASTAL WATERS. FIRST THE WARM FRONT WILL BRING
GUSTY SOUTH WINDS TO THE COAST TONIGHT. BOTH THE NAM AND GFS SHOW
BOUNDARY LAYER WINDS TO BE IN THE 40 TO 50 MPH RANGE. AS A RESULT
HAVE ISSUED A HIGH WIND WATCH AT THE COAST. THE STRONGEST WINDS
SHOULD OCCUR BETWEEN 10PM AND MIDNIGHT TONIGHT. FARTHER EAST
SOUTHWEST WINDS WILL ALSO PICK UP AHEAD OF THE FRONT. PART OF
HIGHWAY 31 RUNNING FROM PAISLEY TO SUMMER LAKE IN LAKE COUNTY IS
EXPECTED TO SEE ANOTHER ROUND OF GUSTY WINDS AND WIND ADVISORY MAY
BE NEEDED LATER. GUIDANCE ALSO INDICATES INCREASING WINDS IN THE
SHASTA VALLEY THIS EVENING ALTHOUGH WIND DIRECTION DOES NOT APPEAR
AS CONDUCIVE TO THE SPEED REACHING WARNING CRITERIA.

THE COLD FRONT WILL MOVE INTO SOUTHWEST OREGON THIS EVENING WITH
PRECIPITATION SPREADING INTO THE ROGUE VALLEY IN THE EARLY
EVENING. STEADY PRECIPITATION IS EXPECTED TO BE OVERNIGHT TONIGHT
AND THROUGH SUNDAY MORNING. SOUTHERLY WIND AHEAD OF THE FRONT
COULD DELAY COLD AIR FROM FILTERING INTO KLAMATH FALLS BUT BY LATE
TONIGHT THE FRONT IS EXPECTED TO BRING COLD AIR INTO THE EAST
SIDE. IF THE CURRENT QPF FORECAST HOLDS...WE MAY NEED A SNOW
ADVISORY FOR NORTHERN KLAMATH COUNTY FROM DIAMOND LAKE JUNCTION
NORTH THROUGH CHEMULT. BY SUNDAY AFTERNOON PRECIPITATION SHOULD
TAPER OFF TO SHOWERS AND BE CONFINED MAINLY IN UPSLOPE AREA AND
HIGHER TERRAIN.

THE LATEST GFS AND ECMWF CONTINUES WITH THE DRYING TREND FOR MOST
OF NEXT WEEK AS THE STORM TRACK SHIFTS NORTH. THE ECMWF BRINGS THE
NEXT COLD FRONT INLAND ON THANKSGIVING BUT THE GFS HOLDS THE FRONT
OFFSHORE BEFORE BRINGING THE FRONT INLAND DURING THAT NIGHT. HAVE
INTRODUCED A CHANCE POPS FOR THANKSGIVING DAY BUT CONFIDENCE ON
TIMING IS NOT VERY HIGH.

AVIATION...WIDESPREAD MVFR AT THE COAST THIS EVENING THROUGH
TONIGHT IN FREQUENT MODERATE RAIN. WINDS ALONG THE COAST WILL ALSO
BE VERY STRONG OVERNIGHT WITH LLWS POSSIBLE. MVFR CIGS AND VIS
SPREAD INLAND AND ARE MORE LIKELY AFTER 06Z TONIGHT. HIGHER MOUNTAINS
WILL BE OBSCURED OVERNIGHT.

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WATCH FROM 4 PM PST THIS AFTERNOON THROUGH LATE
     TONIGHT FOR ORZ021-ORZ022.

CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 1 PM
     PST THIS AFTERNOON FOR PZZ350-PZZ356-PZZ370-PZZ376.
     GALE WARNING FROM 1 PM THIS AFTERNOON TO 4 AM PST SUNDAY FOR
     PZZ356-PZZ376.
     HAZARDOUS SEAS WARNING UNTIL 4 PM PST SUNDAY FOR PZZ350-PZZ356-
     PZZ370-PZZ376.
     STORM WARNING FROM 4 PM THIS AFTERNOON TO 4 AM PST SUNDAY FOR
     PZZ350-PZZ370.
     GALE WARNING FROM 1 PM TO 4 PM PST THIS AFTERNOON FOR PZZ350-
     PZZ370.

NK