Hazardous Seas Warning 2, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
906 AM PST WED JAN 14 2015

.DISCUSSION...NO UPDATES PLANNED THIS MORNING. SOUTH WINDS
OVERNIGHT KEPT FOG AT BAY FOR THE MEDFORD AREA. HOWEVER, GRANTS
PASS AND THE OTHER WEST SIDE VALLEYS ARE FOGGED IN AND FREEZING
FOG IS BEING REPORTED IN MONTAGUE. ELSE WHERE SKIES ARE CLEAR WITH
ONLY A THIN LAYER OF CIRRUS MOVING OVER THE FORECAST AREA. TODAY
WILL BE A QUIET DAY, WEATHER WISE, BEFORE A CHANGE TO WETTER
WEATHER BY TOMORROW AFTERNOON. SEE THE PREVIOUS DISCUSSION FOR
MORE DETAILS ON THE WET WEEKEND AHEAD. MND

&&

.AVIATION...FOR THE 14/12Z TAF CYCLE...IFR/LIFR CONDITIONS WILL
CONTINUE THIS MORNING IN THE WEST SIDE VALLEYS INCLUDING THE SHASTA
VALLEY NEAR KSIY, THE UMPQUA VALLEY INCLUDING KRBG, THE LOWER ROGUE
VALLEY NEAR GRANTS PASS AND THE ILLINOIS VALLEY. ISOLATED IFR CIGS
AND VISIBILITIES IN FOG ARE POSSIBLE IN THE ROGUE VALLEY NEAR KMFR
AS WELL  EARLY THIS MORNING. HOWEVER CONFIDENCE IS ONLY LOW TO
MODERATE FOR FOG TO DEVELOP NEAR KMFR SINCE LIGHT SOUTH TO SOUTHEAST
WINDS MAY KEEP CONDITIONS MAINLY VFR. CONDITIONS FOR THESE AREA ARE
EXPECTED TO IMPROVE TO VFR LATE THIS MORNING AND EARLY THIS
AFTERNOON. ELSEWHERE...EXPECT MAINLY VFR CONDITIONS TO PERSIST
TODAY.  AREAS OF MVFR/IFR CIGS ARE EXPECTED TO REDEVELOP THIS
EVENING AND OVERNIGHT IN THE UMPQUA VALLEY WITH ISOLATED IFR/MVFR
POSSIBLE IN OTHER WEST SIDE VALLEYS OVERNIGHT. HOWEVER A WEAK
DISTURBANCE MOVING INLAND TONIGHT AND EARLY THURSDAY MORNING WILL
BRING MID TO HIGH CLOUDS INTO THE AREA WITH SOME LIGHT RAIN POSSIBLE
NEAR COASTAL AREAS. SO EXPECT MAINLY VFR CONDITIONS EXPECTED OVER
THE AREA OVERNIGHT WITH LOWER CHANCES FOR FOG TO DEVELOP IN WESTERN
VALLEYS. /CC

&&

.MARINE...UPDATED AT 500 AM, WEDNESDAY JANUARY 14, 2015...LIGHT
SOUTH TO SOUTHEAST WINDS ARE EXPECTED TODAY WITH SOUTH WINDS
INCREASING THIS EVENING AS A WEAK LOW MOVES INTO THE WATERS.
MODERATE SWELL WILL MOVE INTO THE WATERS TODAY WITH AREAS OF STEEP
SEAS EXPECTED TO DEVELOP TONIGHT, MAINLY FOR THE WATERS BEYOND 10 NM
FRO SHORE.  THEN MODELS CONTINUE TO INDICATE THAT SOUTH WINDS WILL
INCREASE FURTHER ON THURSDAY AHEAD OF A STRONG FRONT WITH GALE WINDS
AND VERY STEEP 10 TO 14 FT SEAS POSSIBLE FROM CAPE BLANCO NORTH.
SMALL CRAFT ADVISORY WINDS AND STEEP TO VERY STEEP SEAS ARE EXPECTED
SOUTH OF CAPE BLANCO.  ANOTHER FRONTAL SYSTEM IS EXPECTED TO MOVE
INTO THE WATERS SATURDAY AND SUNDAY BRINGING ADDITIONAL RAIN, GUSTY
SOUTH WINDS AND STEEP SEAS. /CC

&&

.PREV DISCUSSION... /ISSUED 505 AM PST WED JAN 14 2015/

DISCUSSION...A RETURN TO WETTER WEATHER IS ON THE WAY...BUT NOT
BEFORE A HEALTHY AREA OF HIGH PRESSURE OVER IDAHO INFLUENCES
LOCAL WEATHER FOR A FEW MORE DAYS. A RELATIVELY TIGHT EAST TO
WEST PRESSURE GRADIENT IS BRINGING SOME GUSTY WINDS TO HIGHER
TERRAIN WEST OF THE CASCADES THIS MORNING. WITH THE THOUGHT THIS
WILL CONTINUE THROUGH EARLY MORNING...HAVE BUMPED UP TEMPERATURES
IN THE SOUTH BEAR CREEK VALLEY AREA AROUND ASHLAND GIVEN THE
INVERSION IS NOT LIKELY TO FULLY SET UP THERE...AND THE DAY WILL
GET OFF TO A WARM START. ELSEWHERE...IN MORE SHELTERED VALLEY
AREAS...INVERSIONS ARE SETTING UP AND FOG HAS BEEN OBSERVED IN
GRANTS PASS AND THE ILLINOIS VALLEY. MOST VALLEYS ARE EXPECTED TO
EXPERIENCE FOG OR FREEZING FOG THIS MORNING...BUT GIVEN THAT THIS
WILL BE THE FIRST DAY OF UPPER RIDGING OVER THE AREA...DO NOT
EXPECT THE FOG TO LAST THROUGH THE MORNING BEFORE CLEARING OCCURS.
THE MOST LIKELY AREA TO HAVE CLOUDS LINGER THROUGH THE MORNING IS
THE UMPQUA VALLEY NEAR ROSEBURG. SO...IN SUMMARY...AFTER MORNING
VALLEY FOG...SKIES SHOULD CLEAR MOST PLACES AND TEMPERATURES
SHOULD TO ABOVE NORMAL READINGS.

MUCH OF THIS EVENING HAS BEEN SPENT DETERMINING POTENTIAL IMPACTS OF
THE UPCOMING COUPLE ROUNDS OF PRECIPITATION...BEGINNING LATE
THURSDAY...BREAKING LATE FRIDAY...AND RETURNING ON SATURDAY.
FIRST...MODELS HAVE COME INTO AGREEMENT THAT THE FIRST SURGE OF
MOISTURE WILL BRING THE MOST PRECIPITATION AND LOWEST SNOW LEVELS.
LOWEST HOWEVER ONLY MEANS THAT SNOW LEVELS WILLS GENERALLY BE
BETWEEN 6000 AND 7000 FEET FROM THE CASCADES WEST...AND ABOUT 5000
TO 6000 FEET EAST OF THE CASCADES. LATE THURSDAY NIGHT INTO FRIDAY
MORNING THERE IS A CHANCE THAT ENOUGH COLD AIR LINGERS WHERE SNOW
COULD AFFECT SOME EAST SIDE VALLEY LOCATIONS SUCH AS LAKEVIEW. THIS
WILL HAVE TO BE EXAMINED IN SUBSEQUENT SHIFTS. THE CURRENT THINKING
IS SNOW LEVELS SHOULD REMAIN ABOUT 5000 FEET SO THIS WOULD BE HIGHER
THAN MOST OF HIGHWAY 97 AND THE POPULATED EAST SIDE AREAS...SO NO
ADVISORIES ARE CONSIDERED AT THIS TIME. LATEST MODEL SOUNDINGS AND
SREF POST-PROCESSED OUTPUT SUPPORT THIS IDEA.

HIGHEST ELEVATIONS IN THE CASCADES SHOULD SEE ABOUT 6 INCHES OF SNOW
LATE THURSDAY THROUGH FRIDAY. GIVEN THIS AR IS ROBUST WITH VALUES OF
600 KG/M/S EXPECTED TO TAKE AIM AT THE COAST...A PERIOD OF HEAVY
RAIN THURSDAY NIGHT IS EXPECTED. THE FAVORED CURRY COAST AND JUST
INLAND COULD SEE HIGH RAINFALL RATES WITH 2 INCHES OF RAIN IN AREAS
LIKE RED MOUND...AROUND 1.5 INCHES IN BROOKINGS...AND ABOUT AN INCH
IN NORTH BEND. A QUARTER TO HALF INCH OF RAIN IS EXPECTED IN WEST
SIDE VALLEYS...WITH LESS THAN A QUARTER INCH EAST OF THE CASCADES.
THE FRONT THURSDAY NIGHT INTO FRIDAY WILL BRING SOME GUSTY WINDS TO
THE MARINE WATERS...SHASTA VALLEY...AND EAST SIDE. RIGHT NOW IT
DOESN'T SEEM ADVISORY CRITERIA WILL BE MET...BUT WE'RE HEADED IN
THAT DIRECTION.

THE FRONT MOVES THROUGH ON FRIDAY WITH A PAUSE IN THE STEADY
PRECIPITATION...AND THEN A WARMER SURGE OF MOISTURE REACHES THE AREA
SATURDAY. MODELS HAVE TRENDED FURTHER NORTH WITH THE FRONT...MEANING
SNOW LEVELS HAVE TRENDED SOMEWHAT HIGHER...AROUND 8000 FEET BY
SATURDAY AFTERNOON. THIS FRONT WILL FEATURE A LONGER-DURATION OF
PRECIPITATION WITH SEEMINGLY LOWER PRECIPITATION RATES BUT HIGHER
TOTAL AMOUNTS FOR MOST AREAS. RAIN WILL START SATURDAY AND END LATE
SUNDAY AS A COLD FRONT MOVES THROUGH...LOWERING SNOW LEVELS TO ABOUT
5000 FEET. DRY WEATHER IS EXPECTED LATE SUNDAY THROUGH THE MIDDLE OF
NEXT WEEK AS RIDGING MOVES OVERHEAD.

&&

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

CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM THURSDAY TO 4 AM PST
     FRIDAY FOR PZZ350-356-370-376.
     HAZARDOUS SEAS WATCH FROM THURSDAY AFTERNOON THROUGH LATE
     THURSDAY NIGHT FOR PZZ350-356-370-376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 AM THURSDAY TO 4
     AM PST FRIDAY FOR PZZ356.
     GALE WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY NIGHT
     FOR PZZ350-370.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 PM THIS AFTERNOON
     TO 1 PM PST THURSDAY FOR PZZ370.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 PM THIS AFTERNOON
     TO 4 AM PST FRIDAY FOR PZZ376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 4 AM TO 1 PM PST
     THURSDAY FOR PZZ350.

MND/NSK/CC