985
FXUS66 KMFR 131232
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
ISSUED BY NATIONAL WEATHER SERVICE PORTLAND OR
334 AM PDT TUE MAY 13 2025
DISCUSSION
SHOWERS WERE NUMEROUS ACROSS THE CWA YESTERDAY, AS A
STRONG COLD POOL ALOFT MOVED OVERHEAD. THIS WAS ABLE TO BRING 0.47
OF AN INCH OF RAINFALL HERE AT THE AIRPORT, WHICH FELL JUST SHORT
OF THE RECORD OF 0.59 OF AN INCH SET IN 1913. NORMAL RAINFALL FOR
THE MONTH OF MAY IS 1.34 INCHES. DURING SOME OF THE HEAVIER
SHOWERS, GRAUPEL OR SOFT HAIL WAS OBSERVED.
LOW PRESSURE WILL MOVE INTO THE GREAT BASIN TODAY WITH NORTHERLY
FLOW TAKING HOLD OVER SW OREGON AND NORTHERN CALIFORNIA. ENERGY ON
THE BACK SIDE OF THE LOW WILL CONTINUE TO GENERATE ISOLATED TO
SCATTERED SHOWERS, SOME AS FAR WEST AS THE COAST AND COASTAL
WATERS THIS MORNING, BUT THEN MAINLY NEAR THE MOUNTAINS AND OVER
THE EAST SIDE THIS AFTERNOON/EVENING. WE CAN'T COMPLETELY RULE
OUT A THUNDERSTORM OVER THERE EITHER, WITH ABOUT A 15-20% CHANCE
NEAR THE WARNER MTNS UP TO AROUND LAKEVIEW AND ACROSS SOUTHERN
LAKE COUNTY. WE'RE EXPECTING ANOTHER COOL DAY WITH HIGHS IN THE
LOW TO MID 60S OVER THE WEST SIDE AND IN THE LOW TO MID 50S OVER
THE EAST SIDE.
SHOWER COVERAGE WILL DIMINISH AND END IN MOST AREAS THIS
EVENING WITH DRY WEATHER OVERNIGHT. THE EXCEPTION WILL BE AT THE
COAST WHERE SHOWERS MAY RETURN AS ANOTHER WEAK FRONT APPROACHES
THE COAST. THERE IS A SLIGHT CHANCE (15-25%) OF SHOWERS INTO THE
UMPQUA BASIN WEDNESDAY MORNING, THEN PERHAPS THE CASCADE FOOTHILLS
NORTH OF CRATER LAKE WEDNESDAY AFTERNOON, BUT MOST OF THE AREA
STAYS DRY. TEMPERATURES WILL REMAIN ON THE COOL SIDE OF NORMAL
WITH HIGHS IN THE MID TO UPPER 60S FOR THE WEST SIDE VALLEYS AND
IN THE UPPER 50S TO LOW 60S EAST OF THE CASCADES.
THURSDAY TURNS A BIT MILDER WITH TEMPERATURES CLOSER TO THE MID-
MAY NORMALS. ANOTHER WEAK DISTURBANCE WILL SKIM BY TO THE NORTH,
SO THERE IS A ABOUT A 20-40% CHANCE OF SHOWERS IN THE MOUNTAINS
NORTH OF CRATER LAKE AND ALSO FROM WINTER RIM EASTWARD DURING
THURSDAY NIGHT. FRIDAY IS PROBABLY DRY, BUT THEN A MORE
SUBSTANTIAL DISTURBANCE WILL ARRIVE SATURDAY WITH A BETTER CHANCE
OF SHOWERS AND THUNDERSTORMS. HIGHEST PROBABILITY OF
SHOWERS/THUNDER AS OF NOW WILL BE FROM THE CASCADES EASTWARD
(50-70% CHANCE). POPS FROM THE COAST TO THE CASCADES GENERALLY IN
THE 20-50% RANGE. -SPILDE
AVIATION
13/12Z TAFS..ISOLATED TO SCATTERED SHOWERS WILL
PERSIST THIS MORNING, DECREASING IN COVERAGE WEST OF THE
CASCADES THIS AFTERNOON, BUT CONTINUING INTO THIS EVENING
FROM THE CASCADES EASTWARD. AN ISOLATED THUNDERSTORM IS ALSO
POSSIBLE NEAR OR EAST OF THE WARNER MOUNTAINS THIS AFTERNOON.
OVERALL, EXPECT A MIX OF MVFR/VFR CEILINGS WITH LOCAL IFR THIS
MORNING, GRADUALLY BREAKING TO VFR MOST AREAS THIS AFTERNOON. EVEN
SO, ANY STRONGER SHOWER COULD STILL BRING BRIEF MVFR CONDTIONS.
AREAS OF IFR/MVFR ARE EXPECTED TO DEVELOP ALONG THE COAST THIS
EVENING WITH VFR CONTINUING FOR INLAND AREAS. PATCH MVFR MAY ALSO
DEVELOP INLAND OVERNIGHT. ISOLATED SHOWERS MAY ALSO RETURN TO
THE COAST AND UMPQUA LATE TONIGHT OR EARLY WEDNESDAY. -SPILDE
MARINE...UPDATED 200 AM TUESDAY, MAY 13, 2025
STEEP SEAS
CONTINUE TODAY. SCATTERED SHOWERS THIS MORNING WILL DIMINISH IN
COVERAGE AND END THIS AFTERNOON. A PATTERN CHANGE WILL COME ON
WEDNESDAY WITH THE RETURN OF A THERMAL TROUGH AND ASSOCIATED
GUSTY NORTH WINDS AND STEEP, HAZARDOUS SEAS. HIGHEST WINDS AND
SEAS WILL BE SOUTH OF CAPE BLANCO BEGINNING WEDNESDAY AFTERNOON
AND CONTINUING THROUGH FRIDAY MORNING. -SPILDE
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 5 AM PDT
WEDNESDAY FOR PZZ350-356-370-376.
MAS/MAS/MAS
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