FXUS66 KMFR 151114
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
314 AM PST TUE DEC 15 2009

.DISCUSSION...MOIST SOUTH TO SOUTHWEST FLOW ALOFT IS THE MAIN
PLAYER. LOW PRESSURE OFFSHORE WILL SLOWLY APPROACH THE NORTHWEST
THIS AFTERNOON THROUGH EVENING WITH LITTLE IN THE WAY OF COLD AIR
HEADED FOR OUR REGION. SNOW LEVELS CURRENTLY BETWEEN 4000 AND
5000 FEET SHOULD TAKE A SIZEABLE JUMP UPWARD TODAY FOR SOUTHWEST
OREGON...BUT FOR AREAS FROM MOUNT SHASTA THROUGH SOUTH-CENTRAL
OREGON THE JUMP WON'T BE NEARLY AS GREAT....AND WILL STRUGGLE TO
LIFT OFF THE VALLEY FLOORS.

PRECIPITATION RATES WILL INCREASE BETWEEN 4AM AND 10AM THIS
MORNING...HIGHEST OVER THE SOUTH COAST THROUGH WESTERN AND SOUTH-
CENTRAL SISKIYOU COUNTY. THE PLUME SEEN IN WATER VAPOR EXTENDS
DOWN TO 30N AND BLENDED TPW PRODUCT SHOWS VALUES OF 1 TO 1.25"
STREAMING IN. HENCE HAVE LEANED TOWARD THE HEAVIER TOTALS
ADVERTISED BY THE NAM12...BUT IT STILL LOOKS A TAD EXCESSIVE.

HAVE LEFT THE COASTAL HIGH WIND WARNING AND SHASTA VALLEY WIND
ADVISORY IN TACT AND THEY LOOK GOOD. LATEST MEDFORD TO REDDING
GRADIENT SHOWS 6.8 MILLIBARS WITH GUSTS TO 50 MPH OCCURRING AT
WEED. SOME OF THE AREAS OFF THE VALLEY FLOOR IN JACKSON COUNTY
WILL LIKELY EXPERIENCE SOME LOCALLY GUSTY WINDS TODAY AS WELL.
THERE IS A CHANCE THE COAST HEADLINE MIGHT NEED TO BE EXTENDED A
FEW HOURS...BUT CONFIDENCE WASN'T HIGH ENOUGH TO DO THAT YET. 

AS FOR THE WINTER WEATHER HIGHLIGHTS...BASED ON CURRENT 
OBSERVATIONS...WE RAISED THE SNOW LEVELS A BIT FOR SOUTHWEST
OREGON...BUT THERE IS A SHARP GRADIENT BETWEEN MEDFORD AND KLAMATH
FALLS. ALSO THE MODELS ARE SHOWING A FAIR AMOUNT OF PRECIPITATION
COMING IN DURING THE 10AM - 4PM PERIOD AND EXPECT THAT SNOW RATES
WILL CONTINUE HEAVY ENOUGH DURING THIS TIME TO WARRANT THE
HEADLINES EXTENDING INTO THE MID AFTERNOON. SO THAT WAS DONE.

LIGHT RAIN/SNOW AMOUNTS CONTINUE INTO EARLY WEDS...BUT THE PRECIP
WILL END FOR MOST AREAS WEDS NIGHT THROUGH THURS UNDER A RIDGE.
THE FLOW THEN REMAINS ONSHORE AND UNSETTLED THROUGH THE
WEEKEND...BUT IT LOOKS SOMEWHAT TAME AS FAR AS IMPACTS GO. STAVISH

&&

.AVIATION...GENERALLY MVFR CIGS AND VSBY IN RAIN AND SNOW AREAS-
WIDE THROUGH THE NEXT 24 HOURS. LOCAL IFR CIGS VSBY IN SNOW AT
TIMES SOUTH AND EAST OF MEDFORD OVER THE HIGHER TERRAIN. ALSO...LOCAL
LOW LEVEL WIND SHEAR WILL AFFECT THE COAST AND INLAND PROTECTED
VALLEYS AS UPPER FLOW REMAINS STRONG. CONDITIONS WILL IMPROVE WEDS.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR ORZ030-
     ORZ031.
     HIGH WIND WARNING UNTIL 1 PM PST THIS AFTERNOON FOR ORZ021-
     ORZ022.
     WINTER WEATHER ADVISORY UNTIL 3 PM PST THIS AFTERNOON FOR ORZ027-
     ORZ028-ORZ029.

CA...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR CAZ085.
     WINTER WEATHER ADVISORY UNTIL 3 PM PST THIS AFTERNOON FOR CAZ084.
     WINTER STORM WARNING UNTIL 3 PM PST THIS AFTERNOON FOR CAZ082-
     CAZ083.
     WIND ADVISORY UNTIL 10 PM PST THIS EVENING FOR CAZ081.

PACIFIC COASTAL WATERS...GALE WARNING UNTIL 10 PM PST THIS EVENING 
     FOR PZZ350-PZZ356-PZZ370-PZZ376.
     HAZARDOUS SEAS WARNING UNTIL 4 AM PST THURSDAY FOR PZZ350-PZZ356-
     PZZ370-PZZ376.

$$