Area Forecast Discussion
Issued by NWS Medford, OR

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000
FXUS66 KMFR 261538
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
838 AM PDT SAT JUL 26 2014

.DISCUSSION...NO UPDATES THIS MORNING. EXCEPT FOR A LITTLE STRATUS
OVER WESTERN UMPQUA AND COOS COUNTIES, SKIES ARE CRYSTAL CLEAR
THIS MORNING. SOUNDINGS (BOTH ACTUAL AND MODEL) INDICATE THE
AIRMASS IS WAY TOO DRY FOR ANY CONVECTION TODAY, DESPITE SOME
LOW LEVEL INSTABILITY. THERE IS ALSO A MODERATE TO STRONG CAP
STARTING AT AROUND 750 MILLIBARS WHICH IS BELOW THE LCL AND THUS
WILL LIKELY PRECLUDE EVEN CUMULUS FORMATION TODAY. THE EXCEPTION
MAY BE OVER THE CASCADES AROUND CRATER LAKE WHERE FORECAST
SOUNDINGS COME CLOSEST TO BREAKING THE CAP, THUS SOME CUMULUS WILL
BE POSSIBLE THERE. TEMPERATURES WILL CONTINUE THEIR CLIMB TODAY
WITH MOST LOCATIONS TOPPING OUT ABOUT 5 DEGREES ABOVE NORMAL (96F
FOR A HIGH TODAY IN MEDFORD, FOR EXAMPLE).

THINGS WILL GRADUALLY BECOME MORE VOLATILE SUNDAY THROUGH THE
UPCOMING WEEK AS MOISTURE AND INSTABILITY INCREASE. THE BIGGEST
FORECAST CHALLENGE TODAY WILL THUS BE TRYING TO NARROW DOWN WHICH
DAYS WILL HAVE THE BEST CHANCE FOR THUNDERSTORM ACTIVITY. -WRIGHT

&&

.AVIATION...BASED ON THE 26/12Z TAFS...

EARLY MORNING 11-3.9 FOG SATELLITE PRODUCT AND NASA SPORT
MODIS-VIIRS NIGHTTIME MICROPHYSICS IMAGERY INDICATING PATCHY FOG AND
LIFR STRATUS FORMING FROM THE COQUILLE BASIN NORTHWARD ALONG THE
COAST AND INTO THE COASTAL VALLEYS OF COOS AND WESTERN DOUGLAS
COUNTIES. FOR THIS REASON, HAVE LIFR IN THE KOTH TAF FOR A COUPLE OF
HOURS EARLY THIS MORNING. SUSPECT THE FOG AND CIGS WILL QUICKLY
ERODE 14-15Z AS THE SUN RISES. THE REMAINDER OF THE AREA WILL BE VFR
FOR THE NEXT 24 HOURS. SPILDE

&&

.MARINE...UPDATED 500 AM PDT 26 JULY 2014...

A THERMAL TROUGH PATTERN WILL BRING MODERATE TO STRONG NORTH WINDS
AND STEEP TO VERY STEEP WIND DRIVEN SEAS TODAY THROUGH MONDAY. WINDS
MAY DECREASE SLIGHTLY ON TUESDAY BUT THEN ARE EXPECTED TO INCREASE
AGAIN WEDNESDAY THROUGH LATE NEXT WEEK. THE STRONGEST WINDS AND
HIGHEST SEAS WILL OCCUR IN THE OUTER WATERS SOUTH OF CAPE BLANCO,
BUT MAY NUDGE INTO THE SOUTHERN INNER WATERS AT TIMES IN THE
AFTERNOONS AND EVENINGS. SPILDE

&&

.PREV DISCUSSION... /ISSUED 437 AM PDT SAT JUL 26 2014/

DISCUSSION...IN THE VERY SHORT TERM THE CHALLENGE IS IF AND WHERE
STRATUS WILL FORM THIS MORNING AT THE COAST AND IN THE UMPQUA
VALLEY. LAST NIGHT THE CLOUDS BEGAN FORMING BY 09Z. THE SURFACE
TEMPERATURE-DEWPOINT SPREADS ARE SIMILAR WITH LIGHT NORTHERLY
BOUNDARY LAYER FLOW AGAIN. THE MODELS PREDICT HIGH BOUNDARY LAYER
RH THIS MORNING. DESPITE THIS, WILL KEEP THE LOW CLOUDS CONFINED
TO THE COAST NORTH OF CAPE BLANCO BUT CONFIDENCE IS RELATIVELY LOW
ABOUT WHETHER STRATUS WILL FORM FARTHER INLAND.

HAVE MADE VERY FEW CHANGES TO THE ONGOING FORECAST. THERE ARE ONLY
SLOW CHANGES TO THE AIR MASS OCCURRING THIS WEEK. WINDS ARE
GENERALLY LIGHT AWAY FROM THE COAST AS THE UPPER RIDGE BUILDS
NORTHWEST. THE MODEL CROSS SECTIONS SHOW HIGH LEVEL MOISTURE
BEGINNING TO INCREASE ON SUNDAY...AND THEN MID AND HIGH LEVEL
MOISTURE INCREASES EARLY NEXT WEEK. THE AIR MASS BECOMES UNSTABLE
BEGINNING SUNDAY AFTERNOON AND THEN REMAINS UNSTABLE INLAND FOR
MUCH OF NEXT WEEK UNDER WEAK MOSTLY SOUTHERLY FLOW. THESE
CONDITIONS IN LATE JULY WILL RESULT IN A SLIGHT CHANCE FOR
THUNDERSTORMS EACH DAY. THE THUNDERSTORM FORECAST CAN BE REFINED
ON A DAY-TO-DAY BASIS AS SATELLITE AND MODELS PINPOINT THE
DISTURBANCES.

THE ADVERTISED WARMING TREND WILL PUSH HIGHS IN THE ROGUE VALLEY
TO AROUND 100 FOR A GOOD PART OF NEXT WEEK. MEDFORD WILL LIKELY
BREAK THE ALL-TIME WARMEST JULY MONTHLY RECORD THAT WAS SET JUST
LAST YEAR. THE AVERAGE MONTHLY JULY TEMPERATURE (HIGHS AND LOWS
AVERAGED) COULD END UP CLOSE TO 80 DEGREES IN MEDFORD. THIS DOES
NOT SEEM SO BAD WHEN YOU CONSIDER THAT PHOENIX, ARIZONA IS
AVERAGING 96 DEGREES SO FAR THIS MONTH. SANDLER

&&

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

CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM
     PDT MONDAY FOR PZZ356-376.
     HAZARDOUS SEAS WARNING UNTIL 11 PM PDT MONDAY FOR PZZ356-376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT MONDAY
     FOR PZZ356-376.
     SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT MONDAY FOR
     PZZ350-370.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT MONDAY
     FOR PZZ350-370.
     GALE WARNING UNTIL 11 PM PDT MONDAY FOR PZZ376.

$$






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