Area Forecast Discussion
Issued by NWS Medford, OR

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000
FXUS66 KMFR 192136
AFDMFR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
236 PM PDT FRI SEP 19 2014

.DISCUSSION...TEMPERATURES ARE 5 TO 10 DEGREES ABOVE WARMER THAN
YESTERDAY AT THIS TIME...AND THIS REPRESENTS THE BEGINNING OF A
BRIEF WARMING TREND WHICH WILL PEAK TOMORROW WITH NEAR-RECORD
TEMPERATURES EXPECTED. TOMORROW WILL BE HOT AND DRY ACROSS THE
CWA. 98 DEGREES IS FORECAST FOR MEDFORD...AND THE RECORD IS 98.
AFTER EXAMINING RECORDS ACROSS THE FORECAST AREA...IT LOOKS LIKE
MANY PLACES WILL GET CLOSE TO DAILY RECORD HIGH TEMPERATURES FOR
TOMORROW...SEP 20.

LATE SATURDAY INTO SUNDAY AN UPPER LOW OVER SOUTHERN CALIFORNIA WILL
MOVE NORTHEAST OVER NEVADA.  THE ENERGY FROM THIS LOW...AND
FAVORABLE DIFFLUENT UPPER WINDS IN THE FORM OF A COL AREA...WARRANT
A SLIGHT CHANCE OF THUNDERSTORMS OVER MODOC AND SOUTHERN LAKE
COUNTIES. THESE STORMS COULD PRODUCE SOME LIGHT RAIN BUT WON`T BE
BIG RAIN-PRODUCERS...AND AGAIN...A SLIGHT CHANCE. SUNDAY WILL
FEATURE ABOUT A 5 DEGREE COOLING TREND FROM THE HEAT OF
SATURDAY...AND THE MARINE LAYER WILL LIKELY MAKE ITS RETURN TO THE
COAST SATURDAY NIGHT INTO SUNDAY...BRINGING SOME FOG TO THOSE AREAS.

ON MONDAY 500MB HEIGHTS WILL FALL AS A WEAKENING COLD FRONT
APPROACHES THE COAST...CONTINUING A GRADUAL COOLING TREND AND
BRINGING SOME INCREASING WINDS TO AREAS EAST OF THE CASCADES. THE
ECMWF BRINGS A SHORTWAVE TROUGH ALONG THE COAST AND JUST ENOUGH
ENERGY AND INSTABILITY MAY EXIST OVER THE CASCADES FOR A
THUNDERSTORM OR TWO. THEREFORE...HAVE KEPT THAT IN THE FORECAST.
THIS WEAK FRONT SHOULD PAVE THE WAY FOR A STRONGER FRONTAL SYSTEM
ARRIVING TUESDAY NIGHT INTO WEDNESDAY. THIS SYSTEM HAS THE POTENTIAL
TO BRING WETTING RAINS TO MOST OF THE FORECAST AREA...FIRST FROM A
COLD FRONT THAT WILL LIKELY AFFECT AREAS ALONG AND WEST OF THE
CASCADES WEDNESDAY. THEN...THE UPPER TROUGH AXIS SWINGS OVER THE
AREA WEDNESDAY NIGHT INTO THURSDAY WITH ENOUGH MOISTURE AND
INSTABILITY TO BRING SHOWERS TO BOTH THE WEST AND EAST SIDE. THIS
WOULD BE THE FIRST SIGNIFICANT RAIN EAST OF THE CASCADES IN MORE
THAN A MONTH...SO AGRICULTURAL INTERESTS SHOULD TAKE NOTE IF MAKING
DECISIONS THAT ARE BASED ON RAINFALL POTENTIAL. ITS STILL EARLY AND
CONFIDENCE IN THESE TRANSITION SEASON RAIN EVENTS IS TYPICALLY
LOW...AND CONFIDENCE IN THIS SYSTEM IS LOW TO MODERATE. FAVORING THE
RAIN IS THE FACT THAT MODELS ARE IN GENERALLY GOOD AGREEMENT WITH
GOOD RUN TO RUN CONSISTENCY. CURRENT PROJECTIONS SUGGEST AN INCH
OF RAIN POSSIBLE AT THE COAST WITH A HALF INCH OVER HIGH TERRAIN
AREAS INCLUDING THE CASCADES AND WESTERN SISKIYOU COUNTY...AND A
QUARTER INCH POSSIBLE OVER VALLEYS.

MODEL AGREEMENT FALLS AWAY BEHIND THIS SYSTEM...WITH THE GFS
SUGGESTING UPPER RIDGING AND THE ECMWF SHOWING ANOTHER FRONTAL
SYSTEM MOVING IN.  THE NAEFS SHOWS CONSIDERABLE SPREAD IN ENSEMBLE
MEMBER SOLUTIONS FOR SATURDAY AND SUNDAY. THUS...WE HAVE TRENDED
TOWARDS CLIMATOLOGY FOR PRECIPITATION CHANCES ON SATURDAY.


&&

.AVIATION...CEILINGS WILL REMAIN VFR TODAY. THE COMBINATION OF
EAST WINDS AND A DRIER AIR MASS IS EXPECTED TO PREVENT THE RETURN
OF CLOUD COVER TONIGHT. GUSTY NORTH WINDS WILL DEVELOP ALONG THE
COAST THIS AFTERNOON AND CONTINUE THROUGH THIS EVENING. SMOKE FROM
AREA WILDFIRES WILL INCREASE AGAIN OVER THE NEXT 24 HOURS,
PARTICULARLY NEAR AND WEST OF HAPPY CAMP. BTL/DW

&&

.MARINE...UPDATED 230 PM PDT FRI 19 SEP 2014...A THERMAL TROUGH
WILL CONTINUE TO STRENGTHEN THROUGH THIS EVENING. EXPECT GUSTY
NORTH WINDS THROUGH TONIGHT, WITH THE STRONGEST WINDS OVER THE
OUTER WATERS SOUTH OF CAPE BLANCO. WINDS SHOULD STAY BELOW GALE
STRENGTH, BUT WILL BE ON THE HIGH END OF SMALL CRAFT ADVISORY
CRITERIA. STEEP TO VERY STEEP WIND DRIVEN SEAS WILL ALSO CONTINUE
INTO TONIGHT. WINDS WILL DECREASE AND BECOME SOUTHERLY ON SATURDAY
MORNING AS THE THERMAL TROUGH WEAKENS, BUT SEAS WILL REMAIN STEEP
AS NORTHWEST SWELL BUILDS INTO THE WATERS. LIGHT TO MODERATE
SOUTHERLY WINDS AND DIMINISHING SEAS ARE FORECAST FOR SUNDAY INTO
TUESDAY MORNING. A SERIES OF FRONTS WILL BEGIN TO IMPACT THE AREA
TUESDAY, WITH PERIODS OF INCREASED WINDS AND HEAVY SEAS THROUGH
THE REMAINDER OF THE WEEK. -BPN



&&

.CLIMATE...THIS SUMMER CONTINUES TO BE ON PACE TO BE THE HOTTEST
SUMMER ON RECORD FOR MEDFORD...WHEN AVERAGING HIGH AND LOW
TEMPERATURES FROM JUNE 21 THROUGH TODAY. IN FACT...RIGHT NOW THE
AVERAGE TEMPERATURE SO FAR THIS SUMMER IS A SIGNIFICANT 1.3
DEGREES ABOVE THE PREVIOUS RECORD HOTTEST SUMMER...WHICH IS 2013.
WITH NEAR-RECORD HEAT EXPECTED TOMORROW...ITS ALMOST A CERTAINTY
THAT 2014 WILL REGISTER AS THE HOTTEST SUMMER ON RECORD FOR
MEDFORD. ITS NOT SURPRISING THAT WITH THE DROUGHT AND THIS
RECORD-HEAT...WHICH ARE LIKELY CLOSELY RELATED...THIS HAS BEEN AN
ACTIVE FIRE SEASON WITH WILDFIRES STILL ONGOING.


&&

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

CA...NONE.

PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 2 AM PDT SATURDAY FOR
     PZZ350-356.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SATURDAY
     FOR PZZ350-356-370.
     SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM PDT SATURDAY FOR
     PZZ370-376.
     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT SATURDAY
     FOR PZZ376.
     HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376.

$$

NSK/NSK/BTL






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