FXUS66 KMFR 241003
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
200 AM PST THU DEC 24 2009

.DISCUSSION...
STRONG INVERSIONS THANKS TO A DOMINATE UPPER LEVEL RIDGE WILL 
KEEP SKIES CLEAR APART FROM PERSIST VALLEY FOGS IN SOUTHWEST
OREGON. THIS PATTERN WILL BRING A STAGNANT AIR SITUATION TO
MANY VALLEYS BOTH EAST AND WEST OF THE CASCADES AS WELL AS 
COLD NIGHT TIME TEMPS TO THE COAST.

SATURDAY THROUGH TUESDAY THE MODELS INDICATE A NUMBER OF WEAK
SYSTEMS WILL MOVE THROUGH. DETAILS ARE RATHER UNCERTAIN AS FOR
TIMING BUT IN GENERAL PRECIPITATION AMOUNTS WILL BE ON THE LIGHT
SIDE AND SNOW LEVELS FAIRLY HIGH. A STRONGER STORM SYSTEM MAY
ARRIVE THURSDAY PER THE GFS BUT THE ECMWF INDICATES A SOMEWHAT
DIFFERENT SCENARIO WITH A JET ARRIVING WEDNESDAY.

&&

.AVIATION...
FOG AND FREEZING FOG IS FORMING IN THE VALLEYS OF SOUTHWEST OREGON
RESULTING IN IFR AND LIFR CONDITIONS THROUGH MOST IF NOT ALL OF
TODAY...AND LIKELY FRIDAY AND MOST OF SATURDAY. THE REST OF THE
REGION WILL BE VFR UNDER HIGH PRESSURE ALOFT.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZE WARNING UNTIL 9 AM PST THIS MORNING FOR ORZ021.
     AIR STAGNATION ADVISORY UNTIL 4 PM PST SATURDAY FOR ORZ023-
     ORZ024-ORZ025-ORZ026-ORZ029-ORZ030-ORZ031.
     FROST ADVISORY UNTIL 9 AM PST THIS MORNING FOR ORZ022.

CA...NONE.

PACIFIC COASTAL WATERS...NONE.

$$

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