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000
FXUS66 KMFR 142153
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
253 PM PDT FRI MAR 14 2014

.SHORT TERM...BEHIND A WEAK SHORTWAVE, AN UPPER RIDGE WILL
BUILD OVER THE AREA TONIGHT. THE RIDGE WILL LINGER ON SATURDAY BUT
WEAKEN SLIGHTLY AS A FRONTAL SYSTEM PUSHES INLAND NORTH OF THE
AREA. THE UPPER RIDGE WILL BRING WARM AND DRY WEATHER TO THE AREA
SATURDAY. THESE CONDITIONS CONTINUE INTO SUNDAY...THEN A MODERATE
AND FAST MOVING SHORTWAVE TROUGH WILL MOVE ACROSS THE AREA SUNDAY
NIGHT INTO MONDAY MORNING...BRINGING A ROUND OF LIGHT TO MODERATE
PRECIPITATION TO THE AREA.

THIS EVENING...LINGERING LOW AND MID CLOUDS WILL GRADUALLY CLEAR.
THEN OVERNIGHT AREAS OF LOW CLOUDS AND PATCHY FOG ARE EXPECTED TO
DEVELOP IN INLAND VALLEYS WEST OF THE CASCADES AND ALONG THE
COAST. LOW CLOUDS AND FOG ARE EXPECTED TO CLEAR IN THE LATE
MORNING WITH MAINLY SUNNY SKIES SATURDAY AFTERNOON. HOWEVER
COASTAL AREAS MAY SEE SOME LOW CLOUDS PUSH INTO THE AREA DURING
THE AFTERNOON AND EVENING SATURDAY AS A WARM FRONT TO THE NORTH
BRINGS MOIST SOUTHWEST FLOW.

THE WARM AND DRY PATTERN CONTINUES INTO SUNDAY WITH A FLAT UPPER
RIDGE OVER THE AREA. A MODERATE SHORTWAVE TROUGH AND FRONT WILL
MOVE ACROSS THE AREA SUNDAY NIGHT INTO MONDAY MORNING. MODELS ARE
SHOWING SOME VARIABILITY ON THE TIMING OF THIS WAVE. THE GFS 12Z
RUN IS SLOWER THAN EITHER THE ECMWF OR NAM. HAVE LEANED TOWARDS
THE FASTER ECMWF AND NAM SOLUTIONS WHICH BRING PRECIPITATION TO
THE COAST SUNDAY EVENING THEN INLAND SUNDAY NIGHT WITH SHOWERS
CONTINUING ON MONDAY. SNOW LEVELS ARE EXPECTED TO LOWER MONDAY
MORNING TO 3000 TO 4000 FEET FROM THE CASCADES WEST. CONTINUED
SHOWERS ARE EXPECTED DURING THIS PERIOD WITH THE UPPER TROUGH OVER
THE AREA AND MOIST ONSHORE FLOW. SHOWERS MAY BRING A COUPLE
INCHES OF SNOW TO THE SOUTHERN OREGON CASCADES. ALSO MOUNTAINS IN
THE SISKIYOUS AND WEST OF CASCADES ABOVE 3000 FEET, MAY SEE AROUND
AN INCH OF SNOW MONDAY MORNING. THEN SHOWER ACTIVITY IS EXPECTED
TO TAPER OFF MONDAY AFTERNOON AND EVENING AS THE TROUGH SHIFTS
EAST.

.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT.

AFTER A FEW DAYS IN A ROW OF WIDELY DISPARATE MODEL SOLUTIONS FOR
THE LONG TERM, THE GFS AND ECMWF SOLUTIONS CAME INTO SOME SEMBLANCE
OF AGREEMENT YESTERDAY AND THEY ARE NOW ON THE SAME
PAGE...ESPECIALLY TUESDAY INTO THURSDAY. THE PATTERN WILL BE ACTIVE
BUT NOT ESPECIALLY STORMY WITH TEMPERATURES THAT WILL BE CLOSER TO
NORMAL. TEMPERATURES WILL EVEN BE BELOW NORMAL ON TUESDAY AND
WEDNESDAY MORNINGS AND THURSDAY AFTERNOON THROUGH FRIDAY MORNING.

A HIGH PRESSURE RIDGE THAT WILL BE OFFSHORE MONDAY NIGHT WILL BUILD
INLAND ACROSS OUR AREA TUESDAY THROUGH TUESDAY NIGHT. THIS WILL
RESULT IN A FEW TO SEVERAL DEGREES OF WARMING OF HIGH TEMPERATURES
ON TUESDAY THEN A WEAK INVERSION WILL DEVELOP ABOVE VALLEYS ON
TUESDAY NIGHT. HIGH CLOUDS WILL INCREASE AND THERE WILL BE
ADDITIONAL WARMING ON WEDNESDAY AHEAD OF THE NEXT UPPER TROUGH. THE
12Z GFS AND ECMWF HAVE EACH TRENDED ABOUT 6 HOURS FASTER WITH THE
ARRIVAL OF AN ASSOCIATED COLD FRONT ON WEDNESDAY NIGHT. POPS WERE
RAISED IN SOUTHWEST OREGON, NORTHERN KLAMATH COUNTY, AND NORTHWEST
SISKIYOU COUNTY INTO THE CHANCE CATEGORY AND THEY MAY NEED TO BE
RAISED FURTHER AS THIS EVENT DRAWS NEARER. PRECIPITATION STILL LOOKS
TO BE ON THE LIGHT SIDE WITH THE HIGHEST QPF OF UP TO A QUARTER OF
AN INCH FROM COOS AND DOUGLAS COUNTIES NORTHWARD WITH SNOW LEVELS
AROUND 4500 TO 5000 FEET.

A COOLER, MOIST/SHOWERY AIR MASS IS EXPECTED BEHIND THE FRONT
THURSDAY WITH PERHAPS A FEW COASTAL AND UMPQUA SHOWERS LINGERING
INTO THURSDAY NIGHT. AS WITH THE FRONT ITSELF, THE HIGHEST
PROBABILITY OF SHOWERS WILL BE FROM THE SOUTHERN OREGON CASCADES
NORTHWARD. WEAK SHORTWAVE RIDGING IS FORECAST THURSDAY NIGHT AHEAD
OF A COLDER UPPER TROUGH THAT WILL BE TRACKING TOWARD VANCOUVER
ISLAND. THE GFS IS A BIT FASTER AND COLDER WITH THE TROUGH AND
ASSOCIATED COLD FRONT THAN THE ECMWF BUT BOTH MODELS INDICATE
PRECIPITATION WILL BE FOCUSED NORTH OF OUR AREA. ONCE AGAIN FRIDAY
INTO FRIDAY NIGHT. PRECIPITATION IN SOUTH CENTRAL OREGON AND
NORTHERN CALIFORNIA WOULD BE VERY LIMITED WHILE COOL, SHOWERY
WEATHER DEVELOPS IN WESTERN OREGON.  DW


&&

.AVIATION...BASED ON THE 14/18Z TAF CYCLE...A COLD FRONT MOVED
INLAND THIS MORNING. BEHIND IT, MVFR CEILINGS HAVE LINGERED INTO
THIS AFTERNOON IN COOS COUNTY, INCLUDING KOTH. MEANTIME, VFR
CEILINGS ELSEWHERE ARE THINNING AS HIGH PRESSURE BUILDS INLAND. THIS
TREND OF DECREASING CLOUDS WILL CONTINUE THIS EVENING. SKIES WILL
REMAIN VFR TONIGHT THROUGH SATURDAY NIGHT...WITH THE EXCEPTION OF
LOW CLOUDS AND PATCHY FOG THAT ARE EXPECTED TO DEVELOP OVER THE WEST
SIDE VALLEYS LATE TONIGHT INTO EARLY SATURDAY MORNING. THIS STRATUS
WILL BE MAINLY ALONG THE COAST AND IN THE UMPQUA VALLEY.  /DW


&&

.MARINE...THE MODELS ARE CONSISTENT AND CONFIDENCE IN THE FORECAST
IS FAIRLY HIGH TODAY. HIGH PRESSURE OVER THE WATERS WILL LEAD TO
RELATIVELY LIGHT WINDS THROUGH TONIGHT. SEAS WILL BUILD TO SMALL
CRAFT ADVISORY LEVELS AS A 10-FOOT WESTERLY SWELL ARRIVES OVERNIGHT.
WE DO EXPECT SOUTH WINDS TO DEVELOP SATURDAY AND INCREASE THROUGH
SUNDAY MORNING AS A FRONT APPROACHES, HOWEVER GRADIENTS ARE WEAK AND
WINDS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS. ANOTHER MUCH
LARGER AND LONG PERIOD SWELL WILL ARRIVE SUNDAY MORNING PUSHING SEAS
TO NEAR WARNING LEVELS BY AFTERNOON. THE FRONT MOVES THROUGH SUNDAY
NIGHT WITH POTENTIAL ADVISORY LEVEL POST-FRONTAL, NORTHWEST WINDS ON
MONDAY. SWELL WILL SUBSIDE, BUT THE COMBINATION OF SWELL AND WIND
WAVE WILL KEEP ADVISORY LEVEL SEAS GOING INTO MONDAY NIGHT. -WRIGHT


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.

CA...NONE.

PACIFIC COASTAL WATERS...HAZARDOUS SEAS WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY
     AFTERNOON FOR PZZ350-356-370-376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING
     TO 11 PM PDT MONDAY FOR PZZ350-356-370-376.

$$

CC