Hazardous Seas Warning 48, NWS Medford, OR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
102 PM PDT SUN SEP 23 2012

.DISCUSSION...23/12Z NAM/GFS IN.

THE SYSTEM NOW SWEEPING THROUGH THE PACIFIC NORTHWEST DID A GOOD
JOB KILLING OFF THE MARINE LAYER. THERE ARE SOME MID LEVEL CLOUDS
OVER THE SOUTHERN AND EASTERN PORTIONS OF THE MEDFORD CWA WITH
SOME ISOLATED SHOWERS...BUT THE REST OF THE AREA IS MOSTLY CLEAR.
SEVERAL STATIONS EAST OF THE CASCADES HAVE REPORTED 0.01 INCHES OF
RAIN IN THE PAST 3 HOURS. WHILE THERE ARE SHOWERS IN THE
AREA...THE THUNDERSTORMS REMAIN TO THE EAST. THERE WILL PROBABLY
BE SOME GUSTY WINDS OVER THE RIDGES AND EAST OF THE CASCADES
THROUGH THIS EVENING...BUT RELATIVE HUMIDITIES WILL BE HIGH
ENOUGH TO STAVE OFF A RED FLAG WARNING.

THE UPPER LOW NOW OVER NORTH CENTRAL OREGON WILL MOVE SLOWLY
SOUTHEAST TO SOUTHEAST OREGON THIS EVENING...INTO NORTHERN NEVADA
MONDAY MORNING...AND THEN INTO UTAH MONDAY EVENING. AS IT MOVES
OUT A SHORT WAVE RIDGE WILL BUILD INTO THE PACIFIC NORTHWEST
TONIGHT INTO MONDAY...FOLLOWED BY A WEAK TROUGH MONDAY NIGHT.

EXPECT SOME SHOWERS TO PERSIST EAST OF THE CASCADES INTO THIS
EVENING...BUT NO THUNDERSTORMS. THE AIR MASS WILL STABILIZE
TONIGHT AS THE RIDGE BUILDS IN...WITH SOME WEAK OFFSHORE LOW LEVEL
FLOW CONTRIBUTING TO THE DRYING PROCESS. MEANWHILE THE MARINE
LAYER WILL BE SETTING BACK UP OFFSHORE. FROST WILL BE A CONCERN
OVER SOME EAST SIDE LOCATIONS TONIGHT AND AN ADVISORY WILL BE
ISSUED LATER THIS AFTERNOON FOR THAT. THE SHORT WAVE TROUGH WILL
PUSH A WEAK FRONT ONSHORE MONDAY AFTERNOON AND EVENING. THIS WILL
BRING THE MARINE LAYER BACK TO THE COAST. IT WILL BE A DRY FRONT
EXCEPT FOR SOME POSSIBLE DRIZZLE ALONG THE COAST. THE MODELS SHOW
SOME WEAK INSTABILITY EAST OF THE CASCADES TUESDAY AFTERNOON AND
EVENING. THERE WILL BE SOME MOISTURE AVAILABLE...BUT IT WILL STILL
BE PRETTY DRY. WILL PUT SOME SILENT POPS IN THERE FOR NOW AND SEE
HOW THE MODELS TREND.

ONCE THAT UPPER TROUGH DEPARTS TUESDAY...A REX BLOCK WILL SET UP
JUST OFFSHORE WITH RIDGING OVER THE PACIFIC NORTHWEST. THE REX
BLOCK WILL THEN TRANSITION TO AN OMEGA BLOCK NEXT WEEKEND WHICH
WILL PERSIST INTO NEXT WEEK...ACCORDING TO THE GFS.

THE GFS ALSO PUSHES A WEAK FRONT ONSHORE DURING THE TRANSITION
FROM REX TO OMEGA...BUT THIS WILL LIKELY BE A DRY FRONT.

THE EC PAINTS A DIFFERENT PICTURE FROM FRIDAY THROUGH NEXT
WEEKEND...SETTING UP FLAT ZONAL FLOW OVER THE AREA WITH THE STORM
TRACK WELL NORTH OF THE MEDFORD CWA. THE EC HAS SHOWN MORE RUN TO
RUN VARIABILITY THEN THE GFS.

EITHER SCENARIO SUPPORTS CONTINUED DRY WEATHER FOR THE MEDFORD
CWA...ALTHOUGH THE EC SCENARIO WOULD MAKE FOR COOLER TEMPERATURES.

&&

.AVIATION...PATCHY IFR CIGS/VSBYS WILL DEVELOP ALONG THE COAST
NORTH OF CAPE BLANCO AND IN THE ADJACENT COASTAL VALLEYS LATE
TONIGHT THROUGH MID-MORNING MONDAY. OTHERWISE...VFR CONDITIONS
WILL PREVAIL THROUGH MONDAY.

&&

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

CA...NONE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT TUESDAY FOR
        PZZ356.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT TUESDAY
        FOR PZZ356.
     GALE WATCH FROM MONDAY AFTERNOON THROUGH WEDNESDAY MORNING FOR
        PZZ376.
     SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 PM PDT MONDAY FOR PZZ376.
     HAZARDOUS SEAS WATCH FROM MONDAY AFTERNOON THROUGH WEDNESDAY
        MORNING FOR PZZ376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 PM PDT MONDAY
        FOR PZZ376.

15/15/16