Hazardous Seas Warning 48, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
858 AM PST TUE NOV 15 2011

.DISCUSSION...VERY LIGHT RAIN AND MOUNTAIN SNOW IS OCCURRING FROM
THE COAST INTO THE WEST SIDE AND CASCADES THIS MORNING WITH A WEAK
FRONTAL BOUNDARY DRAPED NEARBY AND A FAST JET STREAM ABOVE MOVING
WEAK SHORTWAVES THROUGH. SNOW LEVELS ARE NEAR 4500 FEET THIS
MORNING LOOKING THROUGH THE OBS AND ROAD CAMS THIS MORNING. LIGHT
AMOUNTS OF RAIN AND HIGH MOUNTAIN SNOW WILL CONTINUE ACROSS THIS
AREA AND INTO WESTERN SISKIYOU COUNTY TODAY WITH SNOW LEVELS
RISING ABOVE 5000 FEET. NO UPDATES ARE NEEDED TO THE CURRENT
FORECAST THIS MORNING. WE WILL BE FOCUSING ON THE HEAVIER RAIN SET
TO ARRIVE WEDNESDAY INTO WEDNESDAY NIGHT WITH LOWERING SNOW LEVELS
LATE THURSDAY THROUGH FRIDAY WITH THE AFTERNOON PACKAGE.

&&

.AVIATION...MAINLY WIDESPREAD MVFR THROUGH THE MORNING HOURS TODAY
WITH WIDESPREAD HEAVY MOUNTAIN OBSCURATIONS AND SPOTTY LIGHT
RAIN OR HIGH MOUNTAIN SNOW. MODERATE CONFIDENCE ON WIDESPREAD VFR
DEVELOPING TOWARD 20Z AND INTO THE AFTERNOON. AREAS OF MVFR WILL
PERSIST AT THE COAST. TONIGHT CONDITIONS ARE LIKELY TO FALL BACK
TO MVFR WITH SOME LOWERING VIS IN LIGHT RAIN AND/OR BR AS WARM
FRONTAL RAINS INCREASE OVER AREAS FROM OTH TO RBG.

&&

.PREV DISCUSSION... /ISSUED 356 AM PST TUE NOV 15 2011/

DISCUSSION...LITTLE CHANGE MADE OVERALL IN THE FORECAST PACKAGE
THIS MORNING...AS THE OBSERVED WEATHER AND MODEL FORECASTS HAVEN'T
SHOWN ANY SIGNIFICANT SWAYS FROM EARLIER IDEAS. A DIFFUSE AND
DISSIPATING FRONTAL BOUNDARY IS DRAPED OVER THE REGION...ABOVE WHICH
A 100+ KT UPPER JET WILL CONTINUE RACING ACROSS OREGON INTO THE
BACK SIDE OF A DEEP TROUGH ACROSS THE CENTRAL PORTION OF THE
COUNTRY. THIS FAST UPPER FLOW IS PUSHING A WEAK SHORTWAVE SOUTH
WITH THE JET SLIGHTLY DIGGING AND SENDING LOTS OF PACIFIC MOISTURE
ONSHORE INTO OREGON. IT LOOKS LIKE WIDESPREAD LIGHT PRECIPITATION
IS IN STORE FOR THE CASCADES AND WEST IN OREGON. HAVE INCREASED
PROBABILITIES FOR LIGHT RAIN AMOUNTS ACROSS THE HIGHER TERRAIN.
SNOW LEVELS WILL BE RISING FROM NEAR 4500 TO 5500 FEET TODAY SO
ANY SIGNIFICANT TRAVEL IMPACTS ARE UNLIKELY...THOUGH VISIBILITY IN
FOG COULD BE A FACTOR ACROSS MOUNTAIN PASSES THIS MORNING.

THE FRONT GATHERS STEAM AS A WARM FRONT LIFTING NORTH OFFSHORE AND
ACROSS PORTIONS OF WESTERN OREGON TONIGHT THROUGH WEDNESDAY. THE
COASTAL PRESSURE GRADIENT TIGHTENS QUITE A BIT AND THE MODEL
FORECASTS SHOW A 50+ 925 MB JET FORMING OVER THE COAST/WESTERN
DOUGLAS AREA BY LATE WEDS AFTERNOON AND EVENING. WE DON'T FEEL THE
WINDS WILL DEVELOP STRONG ENOUGH TO WARRANT A HIGH WIND WATCH AT
THIS POINT...BUT FUTURE SHIFTS SHOULD MONITOR. A HIGH WIND WATCH
HAS BEEN ISSUED BY THE PORTLAND OFFICE FOR THE COAST REGION FROM
FLORENCE NORTHWARD.

RAIN SHOULD BECOME HEAVIER AND WIDESPREAD AS THE WARM FRONT PUSHES
NORTH AND OVERRUNNING INCREASES WEDNESDAY AFTERNOON AND NIGHT.
CURRY COUNTY SHOULD RECEIVE A PERIOD OF HEAVY RAIN. A COLD FRONT
WILL THEN DROP SOUTH INTO WESTERN OREGON BY 4 AM THURSDAY AND
CONTINUE SOUTH AND EAST THROUGH EASTERN OREGON AND NORTHERN
CALIFORNIA THROUGH THURSDAY AND THURSDAY NIGHT. THE AIRMASS WILL
GET FAIRLY CHILLY WITH SNOW LEVELS EXPECTED TO DIP TO AROUND 2000
FEET THROUGH FRIDAY MORNING. IN THE THURSDAY THROUGH FRIDAY
PERIOD...SNOWFALL OF 4-8 INCHES LOOKS FAIRLY REASONABLE FOR THE
CASCADES AND SISKIYOUS...WITH THE HIGHEST AMOUNTS AROUND CRATER
AND DIAMOND LAKES. UP TO A FEW INCHES LOOK POSSIBLE ACROSS THE
EAST...AND ACROSS THE WEST SIDE ABOVE ABOUT 2500 FEET. A LITTLE TOO
SOON TO PUT MUCH STOCK IN THE FINE DETAILS. COLD AIR SETTLES WELL
INTO THE REGION BY FRIDAY MORNING WITH THE FASTER FLOW ALOFT
DROPPING SOUTH AND AN UPPER TROUGH ARRIVING OVERHEAD. IT SHOULD AT
LEAST PARTIALLY CLEAR OUT AND GET RATHER COLD MOST AREAS SATURDAY
MORNING...BUT A TRAILING SHORTWAVE SHOULD FOLLOW SATURDAY THROUGH
SATURDAY NIGHT DIGGING JUST OFF THE COAST WITH SOME POPS REMAINING
AND POSSIBLE LOW ELEVATION SNOW. WE'VE COORDINATED TO REDUCE POPS
SUNDAY THROUGH MONDAY WHICH IS LOOKING LIKE A DRIER PERIOD WITH
RISING SNOW LEVELS UNDER RIDGING. STAVISH

&&

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

CA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST THIS
     EVENING FOR PZZ356-376.
     GALE WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR
     PZZ350-370.
     HAZARDOUS SEAS WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
     EVENING FOR PZZ350-370.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST WEDNESDAY
     FOR PZZ350-370.

MAW