Area Forecast Discussion
Issued by NWS Medford, OR

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000
FXUS66 KMFR 101025
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
325 AM PDT THU JUL 10 2014

.SHORT TERM...THE UPPER LEVEL RIDGE SHOWS NO SIGN OF ABATING THIS
WEEK. AS A RESULT HIGH TEMPERATURES WILL HOVER NEAR 100 FOR
VALLEYS WEST OF THE CASCADES. DEW POINTS CONTINUE TO BE HIGH FOR
THE SEASON AND THIS WILL PROVIDE FOR THE POTENTIAL ENERGY FOR ANY
STORM DEVELOPMENT. THE FORECAST CHALLENGE THEN DEPENDS ON HOW MUCH
CLEARING AND WHETHER/WHEN SHORT WAVE DISTURBANCES MOVE ACROSS THE
FORECAST AREA.

FOR TODAY ANOTHER ROUND OF THE MONSOONAL MOISTURE SPREAD NORTH
INTO THE NORTHERN SACRAMENTO VALLEY...JUST SOUTH OF OUR FORECAST
AREA ALTHOUGH BOTH MODELS SHOW A FINGER OF MOISTURE SWINGING NORTH
INTO SOUTHERN LAKE AND KLAMATH COUNTY. MOST OF OUR FORECAST AREA
WILL HAVE PLENTY OF SUNSHINE FOR MOST OF TODAY. THIS MEANS THERE
IS A GOOD CHANCE FOR THUNDERSTORM TO BREAK OUT ACROSS
SISKIYOU/MODOC COUNTY AND INTO KLAMATH/LAKE COUNTIES. LACK OF
STRONG SHORT WAVE TRIGGERS MEAN COVERAGE OF THESE STORMS SHOULD BE
ISOLATED ALTHOUGH LOCAL STORMS COULD STILL PRODUCE PLENTY OF
LIGHTNING. IF WE GO BY THE THETA-E FIELD..A FEW STORMS COULD
STRAY INTO SOUTHERN JACKSON COUNTY. THURSDAY NIGHT MORE MOISTURE
WILL SPREAD INTO OUR FORECAST AREA AND THIS WILL TRANSLATE INTO
MORE CLOUD COVER. THIS WILL MAKE FOR A TRICKY FORECAST FOR FRIDAY.

ON FRIDAY...BOTH MODELS SHOW TWO DECENT STRENGTH SHORT WAVES
MOVING THROUGH OUR FORECAST AREA. THE FIRST SHORT WAVE WILL BE
MOVING UP THE SIERRA NEVADA INTO THE WARNERS FRIDAY MORNING. THIS
SHORT WAVE IS FORECAST TO MOVE NORTH ACROSS KLAMATH COUNTY INTO
DESCHUTES COUNTY BY FRIDAY EVENING. A SECOND SHORT WAVE WILL MOVE
INTO SW SISKIYOU COUNTY AROUND MID MORNING OF FRIDAY AND THEN
NORTH THROUGH JOSEPHINE COUNTY INTO DOUGLAS COUNTY BY THE END OF
THE DAY. THE AIR MASS WILL BE MUCH MORE UNSTABLE WITH HIGH
PRECIPITABLE WATER. THE NAM IS FORECASTING AROUND 1.50" FOR WEST
OF THE CASCADES AND AROUND 1.00" EAST. IN ADDITION WE WILL ALSO
HAVE SOLID CLOUD DECK. AT PRESENT THE BEST SCENARIO IS TOWARD
SHOWERS WITH EMBEDDED THUNDERSTORMS..SOME OF WHICH MAY PRODUCE
MODERATE TO HEAVY SHOWERS. HAVE REFRAINED FROM ISSUING ANY FIRE
WEATHER PRODUCT AS FUELS MAY BECOME LESS RECEPTIVE FROM THE RAIN.
HOWEVER DAYSHIFT METS WILL NEED TO ASSESS THIS SITUATION MORE
CLOSELY.

WARM AND MOIST AIR MASS CONTINUES INTO SATURDAY UNDER SOUTH TO
SOUTHWEST FLOW. THERE DOESNT APPEAR TO BE ANY STRONG SHORT WAVE IN
THE FLOW TO GENERATE MORE THAN ISOLATED THUNDERSTORM COVERAGE AT
THIS TIME. /FB

.LONG TERM (FROM WEDNESDAY DAYSHIFT)...A SOUTHERLY FLOW ALOFT
PERSISTS INTO THE WEEKEND WITH ANOTHER LOW OFFSHORE OF
CALIFORNIA APPROACHING ON SUNDAY. ISOLATED THUNDERSTORMS REMAIN IN
THE FORECAST IN THIS PATTERN. A RIDGE ALOFT BEGINS TO BUILD EARLY
NEXT WEEK WHICH MEANS AN ENHANCEMENT OF THE SUMMER HEAT AND LESS
THUNDERSTORM ACTIVITY.


&&

.AVIATION...BASED ON THE 10/06Z TAFS...MARINE STRATUS IS WITH MVFR
CEILINGS TRANSITIONING TO IFR CIGS EARLY THIS MORNING FROM CAPE
BLANCO NORTH. THEN CIGS WILL LIFT TO MVFR LATE THIS MORNING...AND
CLEAR BY EARLY AFTERNOON.  VFR CONDITIONS ARE EXPECTED AT
INLAND THROUGH TODAY. THUNDERSTORMS  ARE POSSIBLE AGAIN THURSDAY
AFTERNOON OVER NORTHERN CALIFORNIA AND AREAS ALONG AND EAST OF THE
CASCADES. ANOTHER AFTERNOON OF GUSTY WINDS AT THE COAST IS
EXPECTED...WITH GUSTS TO 30 KT FROM THE NORTH.

THERE IS MODERATE CONFIDENCE IN STRATUS BREAKING UP AT THE COAST
TOMORROW WITH MODELS SUGGESTING STRATUS LASTING ALL DAY...BUT
CLEARING ON RECENT DAYS AND RAP13 HUMIDITY OUTPUT SUGGESTS SOME
AFTERNOON CLEARING...AND THE FORECAST REFLECTS THE LATTER SOLUTION
OF CLEARING. /CC

&&

.MARINE...UPDATED WEDNESDAY 10 JULY 1000 PM PDT...STRONG
OFFSHORE HIGH PRESSURE CONTINUES WITH A THERMAL TROUGH OF LOW
PRESSURE ALONG THE SOUTHERN OREGON COAST. MODERATE TO STRONG NORTH
WINDS WILL CONTINUE INTO THURSDAY WITH STEEP TO VERY STEEP SEAS
OVER THE WATERS. HIGHEST SEAS AND STRONGEST WINDS WILL BE SOUTH OF
CAPE BLANCO. BOTH WINDS AND SEAS ARE EXPECTED TO DECREASE LATE
THURSDAY INTO FRIDAY...WITH LINGERING SHORT PERIOD NORTHWEST SWELL
THURSDAY THROUGH SATURDAY. THE THERMAL TROUGH PATTERN IS EXPECTED TO
REDEVELOP LATE SUNDAY AND STRENGTHEN MONDAY...BRINGING WITH IT
INCREASING WINDS AND WIND DRIVEN SEAS MAINLY SOUTH OF CAPE BLANCO.

&&

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

CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM PDT THIS EVENING FOR
     PZZ350-356-370-376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
     EVENING FOR PZZ350-356.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT FRIDAY
     FOR PZZ370-376.
     HAZARDOUS SEAS WARNING UNTIL 11 AM PDT THIS MORNING FOR PZZ376.

$$

FJB/FJB/MAS






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