188
FXUS66 KMFR 172104
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
204 PM PDT SAT MAY 17 2025
DISCUSSION
SHOWERS CONTINUE UNDER A PASSING UPPER TROUGH THIS
AFTERNOON. AMOUNTS WILL BE GENERALLY LIGHT, WITH MORE CONSTANT
SHOWERS OVER THE CASCADES, THE WARNER MOUNTAINS, AND SOUTHERN LAKE
COUNTY. SLIGHT THUNDERSTORM CHANCES REMAIN IN THE FORECAST FOR
DOUGLAS AND JACKSON COUNTY (10-15%) AS WELL AS EAST MODOC AND
SOUTHEAST LAKE COUNTIES (15-20%). ANY THUNDERSTORMS THAT DO DEVELOP
THIS AFTERNOON AND EVENING ARE MOST LIKELY TO BE ISOLATED AND NOT
SEVERE. GUSTY WINDS, LOCALLY HEAVY SHOWERS, AND CLOUD-TO-GROUND
LIGHTNING STRIKES MAY BE POSSIBLE. LATE NIGHT SNOW SHOWERS ARE
POSSIBLE OVER THE HIGHEST ELEVATIONS OF THE CASCADES, BUT
ACCUMULATION AT PASS LEVELS IS NOT EXPECTED.
ACTIVITY DECREASES OVERNIGHT INTO SUNDAY, WITH A FEW LAST SHOWERS
POSSIBLY LINGERING OVER DOUGLAS COUNTY OR THE CASCADES UNTIL THE
AFTERNOON. DAYTIME HIGHS WILL INCREASE A FEW DEGREES FOR WEST SIDE
VALLEYS, BUT TEMPERATURES WILL STAY BELOW SEASONAL LEVELS.
CONDITIONS THROUGH THE WEEK LOOK TO BE DEFINED BY ZONAL FLOW ALOFT.
TEMPERATURES RISE TO SEASONAL LEVELS ON MONDAY, WITH MID 60S ALONG
THE OREGON COAST AND LOW TO MID 70S FOR WEST SIDE VALLEYS. EAST SIDE
AREAS LOOK TO BE IN THE MID TO HIGH 60S. A WEAK FRONT LOOKS TO BRING
LIGHT SHOWERS TO COOS, CURRY, AND DOUGLAS COUNTIES AS WELL AS THE
CASCADES THROUGH THE DAY MONDAY. A BUNDLE OF UPPER LEVEL INSTABILITY
LOOKS TO PASS OVER THE AREA ON LATE WEDNESDAY OR EARLY THURSDAY, BUT
EXPECTED DRY CONDITIONS OFFER LITTLE TO FUEL ANY DEVELOPMENT.
ISOLATED OR SCATTERED SHOWERS ARE POSSIBLE WEST OF THE CASCADES, BUT
CHANCES ARE MODERATE TO LOW (10-50%). BY FRIDAY, WEST SIDE VALLEYS
WARM TO MID TO HIGH 70S, WITH HIGH 60S TO MID 70S EAST OF THE
CASCADES.
AN UPPER RIDGE LOOKS TO DEVELOP OVER THE WEEKEND, BRINGING A PERIOD
OF DRY, STABLE WEATHER. ADDITIONAL WARMING IS POSSIBLE ON SATURDAY,
WHILE GUIDANCE POINTS TO SUNDAY BEING NOTICEABLY WARMER. THERE'S
STILL SOME UNCERTAINTY WITH HOW WARM TEMPERATURES WILL GET OVER THE
WEEKEND , WHICH DEPENDS ON WHERE THE RIDGE DEVELOPS. USING MEDFORD
AS AN EXAMPLE, ECMWF AND GFS METEOGRAMS FAVOR HIGH 70S TO MID 80S
WHILE NBM PROBABILISTIC GUIDANCE HAS A 55% CHANCE FOR SUNDAY HIGHS
TO EXCEED 85 DEGREES. THE FORECAST BEYOND NEXT SUNDAY REMAINS
UNCERTAIN AS WELL, WITH ECMWF METEOGRAM GUIDANCE STARTING TO SHOW
UNIFORM SIGNALS FOR LIGHT SHOWERS AT NORTH BEND FOR MEMORIAL DAY.
THE GFS AND NBM SHOW LOWER CHANCES BUT THE CHANCES THAT DO APPEAR
MATCH UP WELL WITH THE ECMWF. -TAD
AVIATION (12Z TAFS)...
A MIXTURE OF MVFR AND VFR WILL BE PRESENT THROUGH THE VALID TAF
CYCLE. UPPER LEVEL SYSTEM TROUGH AXIS IS ESSENTIALLY EAST OF THE
TERMINALS, BUT WE HAVE LINGERING SHOWERS AND LOW/MID LEVEL CLOUDS
PRESENT ACROSS THE REGION UNDER NORTHWESTERLY FLOW ALOFT. EXPECTING
THESE CONDITIONS TO PERSIST THROUGH TONIGHT WITH SOME CLEARING
EXPECTED TOMORROW. TYPICAL AFTERNOON BREEZES EXPECTED TODAY ON THE
BACKSIDE OF THE DEPARTING TROUGH.
-GUERRERO
MARINE....UPDATED 200 PM SATURDAY, MAY 17, 2025...EXPECTING
RELATIVELY QUIET CONDITIONS THROUGH THE REMAINDER OF THE WEEKEND. A
WEAK FRONTAL SYSTEM WILL MOVE THROUGH THE AREA MONDAY AFTERNOON WITH
WINDS VEERING FROM THE SOUTH TO NORTHWEST. THESE NORTHERLY WINDS
WILL INCREASE ON TUESDAY IN CONJUNCTION WITH THE DEVELOPMENT OF A
THERMAL TROUGH. BUILDING SEAS ON TUESDAY MAY BECOME HIGH AND STEEP
WITH THE COMBINATION OF WIND WAVES AND A BUILDING WEST-NORTHWEST
SWELL AROUND 13 SECONDS. CONDITIONS MAY IMPROVE SLIGHTLY STARTING
WEDNESDAY AND CONTINUE THROUGH LATER PARTS OF THE WEEK.
MFR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...NONE.
TAD/JWG
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