692
FXUS66 KMFR 150940
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
ISSUED BY NATIONAL WEATHER SERVICE PORTLAND OR
240 AM PDT THU MAY 15 2025
DISCUSSION
AN EXTENSIVE AREA OF CLOUDS HAS PUSHED INTO THE
COAST AND THE UMPQUA BASIN THIS MORNING AHEAD OF A WEAK FRONT THAT
WILL PUSH TOWARDS THE COAST TODAY. OTHERWISE, SKIES REMAIN MOSTLY
CLEAR ACROSS THE FORECAST AREA, WITH THE EXCEPTION OF A THIN LAYER
OF CIRRUS MOVING OVERHEAD.
THE WEAK FRONT ARRIVES LATER TODAY, WITH LIGHT SHOWERS POSSIBLE
ALONG THE COAST, INTO THE UMPQUA BASIN AND INTO THE CASCADES NORTH
OF CRATER LAKE. A FEW SHOWERS MAY MAKE IT INTO NORTHERN LAKE AND
KLAMATH COUNTIES AS WELL, BUT ANY PRECIPITATION THERE WOULD BE
SPOTTY AT BEST.
DRY WEATHER RETURNS FRIDAY AS WEAK HIGH PRESSURE RETURNS, WITH
MILDER TEMPERATURES IN THE AFTERNOON. SOME BRIEF CLEARING SKIES
ARE POSSIBLE AS WELL, BUT WILL BE SHORT LIVED.
THERE'S GOOD AGREEMENT THAT ANOTHER, BUT STRONGER UPPER TROUGH
WILL MOVE IN FROM THE NORTHWEST FRIDAY NIGHT AND SATURDAY
RESULTING IN COOLER TEMPERATURES AND INCREASING SHOWER CHANCES.
SHOWERS WILL BECOME MORE FREQUENT IN THE AFTERNOON DUE TO DAYTIME
HEATING AND THE RESULTING INCREASED INSTABILITY. ISOLATED
THUNDERSTORMS ARE ALSO POSSIBLE SATURDAY AFTERNOON, BUT THE
GENERAL CONSENSUS IS INSTABILITY WILL BE GREATEST EAST OF THE
CASCADES, THUS HAVE A SLIGHT CHANCE OF STORMS IN THIS AREA.
THE UPPER TROUGH WILL EXIT OUT OF THE AREA SATURDAY NIGHT, BUT
THERE'S SOME QUESTION AS TO THE LOCATION OF ANOTHER WEAK UPPER
TROUGH TO FOLLOW SUNDAY. THE OPERATIONAL GFS SLIDES THE UPPER
TROUGH OVER OUR AREA WHILE THE ECMWF HAS IT FARTHER NORTH WHICH
WOULD FAVOR A DRIER SOLUTION. THE RESPECTIVE INDIVIDUAL ENSEMBLE
MEMBERS PRETTY MUCH FOLLOW THE OPERATIONAL SOLUTIONS.
ADDITIONALLY, THE MAJORITY OF THE CLUSTERS ALSO LEAN TOWARDS A
DRY SOLUTION. THE ONE COMMONALITY IS THEY ALL SHOW DRYING SUNDAY
AFTERNOON. THEREFORE WE'LL KEEP A SLIGHT CHANCE OF SHOWERS FOR THE
NORTHERN CASCADES, AND PORTIONS OF THE COASTAL COUNTIES SUNDAY
MORNING WITH DRY CONDITIONS IN THE AFTERNOON.
THE GENERAL CONSENSUS SHOWS UPPER RIDGING BUILDING IN SUNDAY NIGHT
THROUGH MONDAY. THE OPERATIONAL ECMWF SUGGEST THE RIDGING WILL
FLATTEN OUT AS A SHORTWAVE MOVES IN FROM THE WEST, AND SHOWS SOME
EVIDENCE OF LIGHT PRECIPITATION FOR THE NORTHWEST PART OF THE
AREA. HOWEVER THE MAJORITY OF THE INDIVIDUAL ECMWF ENSEMBLE
MEMBERS AND CLUSTERS FAVOR STRONGER UPPER RIDGING, THUS WE'LL KEEP
THE FORECAST DRY FOR THE START OF NEXT WEEK.
IN FACT MOST, IF NOT ALL OF NEXT WEEK COULD END UP DRY WITH
SUFFICIENT EVIDENCE SUPPORTING STRONGER RIDGING TO AT LEAST KEEP
THE STORM TRACK NORTH OF OUR FORECAST AREA. -PETRUCELLI/BPN
AVIATION...15/12Z TAFS
EXPECT MOSTLY VFR TONIGHT THROUGH
THURSDAY AFTERNOON, WITH SOME AREAS OF MVFR CEILINGS THIS MORNING
ALONG THE COAST, ACROSS THE COASTAL MOUNTAINS, AND IN THE
COQUILLE VALLEY, AND PORTIONS OF THE UMPQUA BASIN. AREAS OF
MOUNTAIN OBSCURATIONS ARE POSSIBLE ACROSS THE COASTAL RANGES, THE
ROGUE/UMPQUA DIVIDE, AND THE WESTERN SLOPES OF THE CASCADES.
LATER TODAY, AREAS OF LIGHT RAIN WITH MVFR CONDITIONS ARE
EXPECTED TO DEVELOP ALONG THE COAST AND INTO DOUGLAS COUNTY.
MOUNTAIN OBSCURATIONS WILL ALSO INCREASE, MAINLY FROM THE CASCADES
WEST, BY THURSDAY EVENING. VFR WILL PREVAIL ELSEWHERE. -BPN
MARINE...UPDATED 200 AM THURSDAY, MAY 15, 2025
GUSTY NORTH
WINDS AND STEEP SEAS WILL CONTINUE THROUGH TONIGHT SOUTH OF CAPE
BLANCO. SEAS DIMINISH A BIT FRIDAY, THEN LOW PRESSURE WILL BRING
CONTINUED GUSTY NORTH WINDS AND AREAS OF FOG AND SHOWERS FRIDAY
NIGHT INTO SATURDAY. INCREASING WEST-NORTHWEST SWELL IS ALSO
EXPECTED THIS WEEKEND. -BPN
MFR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 5 AM PDT FRIDAY
FOR PZZ356-376.
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