FXUS66 KMFR 240408
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
800 PM PST WED DEC 23 2009

.DISCUSSION...AREAS OF LOW CLOUDS DEVELOPING VICINITY OF ROSEBURG 
THEN SOUTH TO VICINITY OF GRANTS PASS THIS EVENING. EXPECT AREAS OF 
FOG TO DEVELOP AFTER MIDNIGHT IN THE ROGUE AND ILLINOIS VALLEYS THEN 
PERSIST THROUGH THURSDAY MORNING AS VALLEY INVERSIONS STRENGTHEN. 
THE REMAINDER OF THE FORECAST REGION SHOULD STAY MOSTLY CLEAR AS THE 
500MB RIDGE AXIS SHIFTS INLAND OVER WESTERN OREGON THURSDAY 
AFTERNOON. SINCE ATMOSPHERIC CONDITIONS WILL NOT CHANGE 
MUCH...EXPECT FOG/LOW CLOUDS TO REDEVELOP SOUTHWEST OREGON VALLEYS 
THURSDAY NIGHT INTO CHRISTMAS MORNING.

&&

.AVIATION...SATELLITE SHOWS IFR CEILINGS DEVELOPING VICINITY OF 
ROSEBURG AND SOUTH NEAR SEXTON SUMMIT...CLEAR ELSEWHERE AT THIS 
TIME. EXPECT AREAS OF VALLEY FOG/IFR CONDITIONS TO DEVELOP OVERNIGHT 
MAINLY SOUTHWEST OREGON INTERIOR.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FREEZE WARNING FROM 10 PM THIS EVENING TO 9 AM PST THURSDAY FOR 
     ORZ021.
     AIR STAGNATION ADVISORY UNTIL 4 PM PST SATURDAY FOR ORZ023-
     ORZ024-ORZ025-ORZ026-ORZ029-ORZ030-ORZ031.
     FROST ADVISORY FROM 10 PM THIS EVENING TO 9 AM PST THURSDAY FOR 
     ORZ022.

CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 1 AM 
     PST THURSDAY FOR PZZ376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST THURSDAY 
     FOR PZZ370-PZZ376.

$$

RH