Area Forecast Discussion
Issued by NWS Medford, OR

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FXUS66 KMFR 241642
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
942 AM PDT FRI OCT 24 2014

.DISCUSSION...AN UPDATE TO THE FORECAST IS NOT NECESSARY THIS MORNING.
BUT, THERE IS SIGNIFICANT WEATHER ON THE WAY WITH A FOCUS ON FINE
TUNING THE DETAILS OF THE FORECAST FOR THIS EVENING THROUGH
SATURDAY NIGHT.

A WARM FRONT IS ORIENTED SOUTHWEST TO NORTHEAST FROM WESTERN
SISKIYOU COUNTY ACROSS THE SOUTHERN OREGON CASCADES INTO NORTHERN
KLAMATH AND NORTHWEST LAKE COUNTIES. IT WILL CONTINUE TO LIFT
NORTHWARD TODAY WITH LIGHT RAIN LINGERING LONGEST (THROUGH THIS
AFTERNOON) TO THE WEST AND NORTH OF JACKSON COUNTY. MEANTIME,
CLOUDS WILL DECREASE ELSEWHERE WITH SOUTHERLY WINDS INCREASING
THIS AFTERNOON. OUR AREA WILL BE RAIN-FREE THIS EVENING BUT WINDS
WILL BECOME STRONG OVER THE COASTAL WATERS, OVER THE HIGHER
TERRAIN, IN THE SHASTA VALLEY, AND ACROSS MUCH OF THE EAST SIDE
AS THE ASSOCIATED/TRAILING COLD FRONT APPROACHES FROM THE WEST-
SOUTHWEST.

MODERATE TO HEAVY RAIN WITH A SLIGHT CHANCE OF THUNDERSTORMS WILL
REACH THE COAST LATE TONIGHT THEN SPREAD INLAND SATURDAY WITH THE
HEAVIEST PRECIPITATION OCCURRING WEST OF THE CASCADE CREST AND
WIND SPEEDS BUILDING TO A PEAK IN THE AFTERNOON. THESE SOUTHERLY
WINDS WILL BE THE MOST IMPACTFUL FEATURE OF THE STORM WITH SPEEDS
OF 25 TO 35 MPH AND GUSTS TO 45 MPH EXPECTED IN THE ROGUE VALLEY
AND 35 TO 45 MPH WITH GUSTS TO 65 MPH OVER THE HIGHER TERRAIN,
SHASTA VALLEY, AND THE EAST SIDE. AS IS TYPICAL, TERRAIN
INFLUENCES WILL PRODUCE THE STRONGEST WINDS IN THE VICINITY OF
WEED IN THE SHASTA VALLEY AND SUMMER LAKE IN NORTHWEST LAKE COUNTY.

WINDS AND RAINFALL AMOUNTS WILL DIMINISH SATURDAY NIGHT BUT A
SHOWERY AIR MASS WILL PERSIST INTO SUNDAY. WEAK RIDGING IS
EXPECTED MONDAY BEFORE ANOTHER STRONG FRONT REACHES THE COAST
MONDAY NIGHT WITH MODERATE TO HEAVY WEST-SIDE FOCUSED RAINFALL
THROUGH TUESDAY NIGHT.

&&

.AVIATION...FOR THE 24/12Z TAF CYCLE...A WARM FRONT IS LIFTING
NORTH ACROSS SOUTHWEST OREGON AND NORTHERN CALIFORNIA THIS
MORNING, BRINGING WIDESPREAD LIGHT TO MODERATE RAIN. THE HEAVIEST
RAIN CURRENTLY LIES ALONG THE OREGON/CALIFORNIA BORDER AND WILL
MOVE NORTH THROUGH THE MORNING. MVFR CIGS AND VIS CAN BE EXPECTED
AT THE TERMINALS THIS MORNING, BUT BRIEF IFR CONDITIONS ARE
POSSIBLE DURING HEAVIER PERIODS OF RAIN. THE FRONT WILL LIFT
NORTH OF THE AREA THIS AFTERNOON WITH CONDITIONS BECOMING VFR AT
ALL TERMINALS LATE THIS AFTERNOON THROUGH THIS EVENING. AS THE
RAIN ENDS, GUSTY SOUTH TO SOUTHEAST WINDS ARE EXPECTED TO DEVELOP,
ESPECIALLY EAST OF THE CASCADES. -WRIGHT

&&

.MARINE...THERE IS HIGH CONFIDENCE THAT HIGH END GALES WILL OCCUR
TONIGHT THROUGH EARLY SATURDAY, AND SOME STORM FORCE GUSTS WILL
ALSO BE POSSIBLE. HOW LONG INTO SATURDAY THE STRONG WINDS CONTINUE
WILL DEPEND ON THE ULTIMATE TRACK OF THE LOW. AT THIS TIME, IT
LOOKS LIKE WINDS WILL SHIFT WEST AND BEGIN TO EASE IN THE LATE
SATURDAY AFTERNOON. THIS IS SUBJECT TO CHANGE, BUT THE IMPORTANT
POINT IS THAT AT LEAST 12-18 HOURS OF STRONG GALES TO LOW END
STORM FORCE WINDS ARE NEARLY CERTAIN OVER MUCH OF OUR WATERS. VERY
STEEP AND CHAOTIC SEAS WILL ALSO ACCOMPANY THE HIGH WINDS.

THINGS WILL QUIET DOWN SUNDAY, BUT ANOTHER FRONT MAY AFFECT THE
WATERS LATE MONDAY INTO TUESDAY. -WRIGHT

&&

.PREV DISCUSSION... /ISSUED 416 AM PDT FRI OCT 24 2014/

DISCUSSION...THE FRONT THAT MOVED THROUGH THE AREA THURSDAY
AFTERNOON IS NOW LIFTING BACK NORTH AS A WARM FRONT AND STEADY
PRECIPITATION IS ALSO MOVING NORTH. THE WARM FRONT WILL CONTINUE TO
LIFT NORTH AND AS IT DOES PRECIPITATION WILL DECREASE, THEN END FROM
SOUTH TO NORTH. THERE IS ALSO A CHANCE FOR SOME CLEARING TO DEVELOP
THIS AFTERNOON AND TEMPERATURES COULD END UP MILDER THAN WHAT`S IN
THE FORECAST.

OUR NEXT ATTENTION WILL BE TONIGHT THROUGH SATURDAY. THE MAIN
CONCERN WILL BE INCREASING WINDS OVER MUCH OF THE FORECAST AREA,
ESPECIALLY EAST OF THE CASCADES...SHASTA VALLEY AND PARTS OF THE
ROGUE VALLEY. MODELS ALL SHOW INCREASING 700 MB WINDS INCREASING
FRIDAY AFTERNOON THROUGH SATURDAY MORNING. THEY ARE EXPECTED TO PEAK
OUT BETWEEN 65-75 KTS EARLY SATURDAY MORNING THEN DECREASING LATE
SATURDAY AFTERNOON FROM WEST TO EAST AS THE COLD FRONT MOVES
THROUGH. THEREFORE WE`LL BE ISSUING A HIGH WIND WARNING AND WIND
ADVISORIES FOR EAST OF THE CASCADES...NORTHERN CALIFORNIA INCLUDING
THE SHASTA VALLEY. ALSO A HIGH WIND WARNING WILL BE IN EFFECT FOR
PARTS OF THE CASCADES AND SISKIYOUS. IN ADDITION THE NAM INDICATES
THAT A STRONG SURFACE PRESSURE GRADIENT WILL DEVELOP ALONG WITH 35
TO 45 KT SOUTH WINDS AT 850 MB FOR AREAS WEST OF THE CASCADES IN
SOUTHERN OREGON FRIDAY NIGHT INTO SATURDAY. THIS IS EXPECTED TO
BRING GUSTY WINDS INTO WESTERN VALLEYS, ESPECIALLY FOR THE SOUTHERN
ROGUE VALLEY. MODEL SOUNDING SHOW A WEAK INVERSION EARLY SATURDAY
MORNING, SO IT`S POSSIBLE WINDS COULD START OUT LIGHT, BUT THEY WILL
INCREASE FROM LATE MORNING THROUGH THE AFTERNOON. SO HAVE ISSUED A
WIND ADVISORY. DETAILS ON ALL OF THE WIND PRODUCTS CAN BE FOUND AT
NPWMFR.

ALONG THE COAST, WINDS ARE EXPECTED TO REMAIN BELOW HIGH WIND
WARNING LEVELS BUT COASTAL HEADLANDS MAY EXPERIENCE HIGH WINDS WITH
GUSTS TO 60 MPH LATE FRIDAY NIGHT AND SATURDAY.

IN ADDITION, TO WIND IMPACTS, THIS STRONG LOW WILL BRING RAIN
INTO THE AREA ON SATURDAY. ALSO COLD AIR ALOFT IMMEDIATELY BEHIND
THE FRONT AND ASSOCIATED INSTABILITY WILL BRING A CHANCE FOR
THUNDERSTORMS TO THE AREA AS WELL ON SATURDAY. OF NOTE IS THAT ANY
THUNDERSTORMS THAT OCCUR MAY BRING STRONG GUSTY WINDS DUE TO THE
STRONG WINDS ALOFT.

POST FRONTAL SHOWERS WILL CONTINUE SATURDAY NIGHT INTO SUNDAY WITH
MOST SHOWERS EXPECTED TO BE ALONG AND WEST OF THE CASCADES. WINDS
WILL ALSO DECREASE SATURDAY NIGHT EAST OF THE CASCADES AND ARE NOT
EXPECTED TO BE A CONCERN ON SUNDAY. A BREAK IN THE WEATHER IS
EXPECTED MONDAY WITH DRY CONDITIONS AND MILDER TEMPERATURES, THEN
ANOTHER FRONT WILL IMPACT THE AREA MONDAY NIGHT INTO TUESDAY
BRINGING ANOTHER ROUND OF MODERATE TO HEAVY PRECIPITATION TO THE
COAST AND COASTAL MOUNTAINS. -PETRUCELLI

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING FROM 11 PM THIS EVENING TO 11 PM PDT SATURDAY
     FOR ORZ029>031.
     HIGH WIND WARNING FROM 11 PM THIS EVENING TO 5 PM PDT SATURDAY
     FOR ORZ028.
     WIND ADVISORY FROM 5 AM TO 5 PM PDT SATURDAY FOR ORZ026.

CA...HIGH WIND WARNING FROM 11 PM THIS EVENING TO 5 PM PDT SATURDAY
     FOR CAZ082.
     HIGH WIND WARNING FROM 11 PM THIS EVENING TO 5 PM PDT SATURDAY
     FOR CAZ081.
     HIGH WIND WARNING FROM 11 PM THIS EVENING TO 11 PM PDT SATURDAY
     FOR CAZ083-085.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 2 PM
     THIS AFTERNOON TO 11 PM PDT THIS EVENING FOR PZZ350-356-370-376.
     HAZARDOUS SEAS WARNING FROM 11 PM THIS EVENING TO 5 PM PDT
     SATURDAY FOR PZZ350-356-370.
     GALE WARNING FROM 11 PM THIS EVENING TO 5 PM PDT SATURDAY FOR
     PZZ350-356-370.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM THIS AFTERNOON
     TO 11 PM PDT THIS EVENING FOR PZZ350-356-370-376.
     GALE WARNING FROM 2 PM THIS AFTERNOON TO 5 PM PDT SATURDAY FOR
     PZZ376.
     HAZARDOUS SEAS WARNING FROM 2 PM THIS AFTERNOON TO 5 PM PDT
     SATURDAY FOR PZZ376.

$$

DW/SBN/SBN






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