Area Forecast Discussion
Issued by NWS Medford, OR

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000
FXUS66 KMFR 301609
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
909 AM PDT SAT AUG 30 2014

.DISCUSSION...CURRENT FORECAST ON TRACK WITH COOLER TEMPERATURES
AND MORE CLOUD COVER TODAY DUE TO A SHORTWAVE MOVING ACROSS OREGON
TODAY AND THIS EVENING. A BUILDING RIDGE AND ASSOCIATED DRYING
WILL OCCUR SUNDAY AND THE RIDGE WILL CONTINUE TO BUILD ON LABOR
DAY FOR DRY AND WARM DAYS AND COOL NIGHTS.

THE MARINE LAYER SHOULD BE DEEPER TONIGHT INTO THE UMPQUA BASIN
BUT WILL LIKELY NOT SEND CLOUDS OVER THE UMPQUA DIVIDE INTO THE
ROGUE BASIN.

THE SMOKE FROM FIRES IN SISKIYOU COUNTY EXTENDS FROM JUST NORTH OF
YREKA DOWN TO MT SHASTA CITY AND THE CASTLE CRAGS OVER TO MODOC
COUNTY. THE 5000 TO 10000 FEET ABOVE SEA LEVEL LAYER WINDS NEAR THE
FIRES IN SISKIYOU COUNTY ARE FROM THE WEST-NORTHWEST TODAY
VEERING MORE TO THE NORTHWEST AND THEN NORTH ON SUNDAY AND
MONDAY. THIS WILL KEEP THE SMOKE AWAY FROM THE ROGUE VALLEY (AND
MUCH OF SOUTHERN OREGON) THROUGH THE LABOR DAY HOLIDAY. WINDS MAY
BACK TO LIGHT SOUTHWESTERLY ON TUESDAY SO SMOKE COULD RETURN TO
PARTS OF SOUTHWEST OREGON. ALSO...THERE ARE A COUPLE OF LARGE
FIRES IN THE SOUTHERN CASCADES THAT COULD SEND SMOKE ACROSS PARTS
OF THE SOUTHERN CASCADES AND KLAMATH COUNTY.
SANDLER

&&

.AVIATION...BASED ON THE 30/12Z TAF CYCLE...IFR MARINE STRATUS IS IN
PLACE IN COOS COUNTY AND SOUTHERN CURRY COUNTY COAST. EXPECT SLOW
SPREAD INTO WESTERN UMPQUA VALLEY THIS MORNING WITH LCL MVFR CIGS
NEAR KRBG. IFR CIGS AT THE COAST MAY BURN OFF TO VFR MID TO LATE
AFTERNOON BUT ARE EXPECTED TO REFORM TONIGHT. ELSEWHERE, VFR
CONDITIONS WILL PREVAIL EXCEPT FOR AREAS OF WILDFIRE SMOKE PRODUCING
MVFR/IFR VISIBILITIES IN SISKIYOU COUNTY AND THE KLAMATH AND
TULELAKE BASINS. STEERING WINDS WILL VEER FROM SOUTHWEST TO
NORTHWEST BY THIS EVENING WHICH SHOULD HELP PUSH THE FOCUS OF THE
SMOKE PLUME SOUTH OF KLMT. /FB

&&

.MARINE...UPDATED 810 AM PDT SAT 30 AUG 2014...WINDS AND SEAS WILL
REMAIN RELATIVELY CALM THROUGH THE REST OF THE WEEKEND. HOWEVER,
MODELS ARE IN FAIRLY GOOD AGREEMENT SHOWING THE RETURN OF THE THERMAL
TROUGH. THIS WOULD OF COURSE RESULT IN NORTH WINDS INCREASING MONDAY
AFTERNOON IN THE SOUTHERN WATERS WITH STEEP WIND DRIVEN SEAS.

&&


.FIRE WEATHER...THE MAIN WIND FLOW WILL TURN TO THE NORTHWEST BEHIND
THE FRONT THAT HAD MOVED THROUGH ON FRIDAY AFTERNOON, AND ANOTHER
ROUND OF  BREEZY WINDS IS EXPECTED, ESPECIALLY OVER RIDGELINES, AND
ALONG ANY VALLEYS OR DRAINAGES ORIENTED FROM THE NORTHWEST TO
SOUTHEAST. A BRIEF PERIOD OF WARMER AND DRIER CONDITIONS WILL RETURN
LATE THIS WEEKEND INTO EARLY NEXT WEEK, THEN ANOTHER DRY COLD FRONT
IS EXPECTED MIDWEEK, ONCE AGAIN PROVIDING GUSTY WINDS AND SOME
TEMPERATURE AND HUMIDITY RELIEF. THERE IS NO INDICATION OF ANYTHING
MORE THAN A VERY SLIGHT CHANCE OF PRECIPITATION FOR AT LEAST THE
NEXT WEEK. /FB

&&

.PREV DISCUSSION... /ISSUED 100 AM PDT SAT AUG 30 2014/

DISCUSSION...30/00Z NAM/GFS IN.

AREAS OF LOW CLOUDS ALONG THE COAST AND IN THE COQUILLE VALLEY THIS
MORNING...ALONG WITH SOME HIGH CLOUDS STREAMING THROUGH. THERE IS
ALSO A LOT OF SMOKE COMING OFF THE WESTERN SISKIYOU COUNTY FIRES.

THE FIRST OF TWO SHORT WAVES MOVED ONSHORE FRIDAY...AND THIS
BROUGHT GUSTY WINDS TO AREAS EAST OF THE CASCADES. THE FORECAST
SPEEDS OF 15-25 MPH WITH GUSTS TO AROUND 30 MPH VERIFIED WELL.
SEVERAL STATIONS ALONG THE COAST GOT MEASURABLE PRECIPITATION THIS
MORNING...BUT NONE GOT MORE THAN 0.03 INCHES EXCEPT FOR ONE
QUESTIONABLE REPORT OF 0.06 INCHES. THIS WAS LIKELY MOSTLY
DRIZZLE.

USUALLY SYSTEMS LIKE THIS CAUSE THE MARINE LAYER DEPTH TO
INCREASE...BUT THIS DOESN`T APPEAR TO BE THE CASE THIS TIME
AROUND...MOSTLY IFR CIGS PREVAIL ALONG THE COAST. SO...DON`T
EXPECT MUCH INLAND COVERAGE OF LOW LEVEL CLOUDS LATER THIS
MORNING.

HOWEVER...IT MAY STILL OCCUR SATURDAY NIGHT AS THE SECOND SHORT
WAVE WILL MOVE ONSHORE LATE THIS MORNING...PUSHING A FRONT ONSHORE
WITH IT. THIS FRONT LOOKS A BIT WETTER THAN THE PREVIOUS ONE AND
MORE COASTAL STATIONS WILL SEE SOME MEASURABLE PRECIPITATION. A
FEW IN THE UMPQUA BASIN MAY MEASURE AS WELL. EXPECT ANOTHER ROUND
OF GUSTY WINDS FOR THE EAST SIDE SIMILAR TO WHAT HAPPENED FRIDAY.
HIGH TEMPERATURES INLAND WILL RANGE FROM AROUND NORMAL TO AROUND 5
DEGREES BELOW NORMAL.

THE SHORT WAVE WILL CLEAR OUT TONIGHT AND ANY LINGERING SHOWERS
WILL END AT THAT TIME. EXPECT MARINE CLOUDS TO FILL UP THE UMPQUA
BASIN SATURDAY NIGHT...BUT IT LIKELY WON`T BE THICK ENOUGH TO
SPILL OVER INTO THE ROGUE VALLEY. WEAK OFFSHORE FLOW WILL DEVELOP
ALONG THE SOUTH COAST...SO MOST OF THAT AREA WILL REMAIN CLEAR.

A BROAD LONG WAVE RIDGE WILL BUILD IN FROM THE WEST AS THE WAVE
MOVES OUT. THE MEDFORD CWA WILL REMAIN UNDER DRY NORTHWEST FLOW
ALOFT SUNDAY AND MONDAY. THE MARINE LAYER DEPTH WILL DECREASE IN
RESPONSE TO STRONGER SUBSIDENCE ALOFT. SUNDAY TEMPERATURES INLAND
WILL BE ABOUT THE SAME AS SATURDAY...BUT A WARMING TREND WILL
COMMENCE MONDAY AS THE RIDGE BUILDS IN MORE STRONGLY. INLAND HIGHS
MONDAY WILL RANGE FROM AROUND NORMAL TO AROUND 5 DEGREES ABOVE
NORMAL.

EXTENDED DISCUSSION...TUESDAY THROUGH FRIDAY. THE WARMING TREND
WILL CONTINUE INTO TUESDAY AS HIGH PRESSURE HOLDS IN
PLACE...EXCEPT FOR THE COAST AND UMPQUA BASIN WHERE INCREASED
MARINE CLOUD COVERAGE WILL MAKE FOR A COOLER DAY. ONLY SUBTLE
DIFFERENCES ARE SHOWN IN THE MODELS THEREAFTER WITH ANOTHER
DIGGING TROUGH ADVERTISED THROUGH LATE WEEK WITH A POSSIBLE CLOSED
LOW POSITIONING SOMEWHERE NEAR NORTHERN CA TOWARD NEXT WEEKEND.
FAIRLY LOW CONFIDENCE AT THIS POINT HOW THAT WILL TURN OUT...BUT
THIS COULD MEAN A CHANCE FOR THUNDERSTORMS (MAINLY NRN CA) PERHAPS
AS SOON AS THURSDAY AFTERNOON. IN ADDITION, OFFSHORE FLOW COULD
KICK UP FOR A SHORT SPELL.

AVIATION...BASED ON THE 30/06Z TAF CYCLE...IFR MARINE STRATUS IS IN
PLACE ALONG THE DOUGLAS AND COOS COUNTY COAST AND LOCALLY ALONG THE
CURRY COUNTY COAST. THIS STRATUS WILL EXPAND AND SPREAD INTO THE
COASTAL VALLEYS AND AT LEAST THE WESTERN PORTION OF THE UMPQUA
VALLEY OVERNIGHT. CLOUDS WILL INCREASE NORTH OF THE UMPQUA DIVIDE ON
SATURDAY MORNING WITH A MIX OF MVFR AND VFR CEILINGS PERSISTING
THROUGH THE AFTERNOON. ELSEWHERE, VFR CONDITIONS WILL PREVAIL
WITH SCATTERED MID AND HIGH LEVEL CLOUDS EXCEPT FOR AREAS OF
WILDFIRE SMOKE PRODUCING MVFR/IFR VISIBILITIES IN SISKIYOU COUNTY.
THE PLUME FROM THOSE FIRES WILL ALSO PRODUCE AREAS OF HAZE AND
REDUCED VISIBILITY DOWNWIND...TO THE EAST. THIS REDUCED VISIBILITY
WILL BE MAINLY ACROSS THE REST OF NORTHERN CALIFORNIA AND INTO THE
KLAMATH BASIN. MODELS SHOW STEERING WINDS VEERING FROM WEST TO
NORTHWEST BY SATURDAY EVENING WHICH SHOULD HELP PUSH THE FOCUS OF
THE SMOKE PLUME SOUTH OF KLMT. /DW

MARINE...UPDATED 100 AM PDT SAT 30 AUG 2014...CURRENT OBSERVATIONS
AT BUOY 15 SHOWS A NORTH TO NORTHEAST WINDS NEAR 10 KTS AND THE
LATEST ASCAT PASS SHOWS WINDS NEAR 10 KTS IN THE SOUTHEAST PART OF
PZZ376. THE BUOYS ARE ALSO SHOWING LOW SEA HEIGHTS, AND THE COVERAGE
AREA OF THE SMALL CRAFT FOR SEAS TO THE SOUTHERN OUTER WATERS ONLY.
GUIDANCE SHOWS INCREASING NORTHWEST SWELL SATURDAY AFTERNOON AND
NIGHT, BUT ONLY TO AROUND 6 FEET WITH A PERIOD BETWEEN 10-11 SEC, SO
DO NOT ANTICIPATE ANY HEADLINES. MODELS ARE IN FAIRLY GOOD AGREEMENT
SHOWING NORTH WINDS INCREASING MONDAY AFTERNOON IN THE SOUTHERN
WATERS WITH STEEP WIND DRIVEN SEAS.

FIRE WEATHER...THE MAIN WIND FLOW WILL TURN TO THE NORTHWEST BEHIND
THE FRONT THAT HAD MOVED THROUGH ON FRIDAY AFTERNOON, AND ANOTHER
ROUND OF BREEZY WINDS IS EXPECTED, ESPECIALLY OVER RIDGELINES, AND
ALONG ANY VALLEYS OR DRAINAGES ORIENTED FROM THE NORTHWEST TO
SOUTHEAST. A BRIEF PERIOD OF WARMER AND DRIER CONDITIONS WILL
RETURN LATE THIS WEEKEND INTO EARLY NEXT WEEK, THEN ANOTHER DRY
COLD FRONT IS EXPECTED MIDWEEK, ONCE AGAIN PROVIDING GUSTY WINDS
AND SOME TEMPERATURE AND HUMIDITY RELIEF. THERE IS NO INDICATION
OF ANYTHING MORE THAN A VERY SLIGHT CHANCE OF PRECIPITATION FOR AT
LEAST THE NEXT WEEK. /FB

&&

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

CA...NONE.

PACIFIC COASTAL WATERS...NONE.

$$

RES/RES/RES






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