842
FXUS66 KMFR 011824
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
1124 AM PDT WED APR 1 2026
DISCUSSION
A POTENT COLD FRONT AND UPPER LEVEL LOW PRESSURE
SYSTEM IS SWINGING THROUGH THE REGION TODAY THROUGH TONIGHT,
BRINGING MODERATE/HEAVY RAIN, MOUNTAIN SNOW AND GUSTY WINDS.
PRESSURE GRADIENTS WILL PEAK THIS AFTERNOON, WITH MID-LEVEL WINDS
PEAKING AROUND 55 KT. IT WILL BE WINDY EVERYWHERE TODAY, WITH
GUSTS OF 20-30 MPH COMMON, EVEN FOR WEST SIDE AREAS. WE EXPECT
WIDESPREAD PEAK WIND GUSTS IN THE 40-50 MPH RANGE FOR AREAS FROM
THE CASCADES EASTWARD, PERHAPS 55 MPH IN SOME AREAS. WIND
ADVISORIES HAVE BEEN ISSUED FOR PORTIONS OF LAKE/MODOC COUNTIES
WHERE WINDS WILL BE STRONGEST, AND NOW ALSO INCLUDE THE SHASTA
VALLEY WHERE A QUICK BURST OF PRE-FRONTAL SOUTH WINDS (WITH GUSTS
TO 45 MPH) ARE EXPECTED TODAY BEFORE THEY SHIFT TO SOUTHWEST
DURING THE AFTERNOON. STRONG WINDS ARE ALSO EXPECTED ALONG THE
COAST, BUT SHOULD REMAIN JUST BELOW WARNING LEVELS. WITH MODEL
PRESSURE GRADIENTS (OTH-ACV) SHOWING -8 TO -9, IT'S POSSIBLE THAT
THE CAPES AND HEADLANDS, ESPECIALLY CAPE BLANCO, COULD BRIEFLY SEE
GUSTS UP TO 60 MPH, BUT OVERALL, GUSTS IN THE 40-50 MPH RANGE ARE
THE MORE LIKELY SCENARIO FOR THE MAJORITY OF THE IMMEDIATE
COASTLINE.
THE SHARP COLD FRONT WILL BLAST THROUGH THE AREA THIS AFTERNOON AND
THIS WILL BRING PERIODS OF MODERATE RAINFALL ALONG WITH HEAVY
MOUNTAIN SNOW (MOSTLY ABOVE 5000 FEET). THE HEAVIEST PRECIPITATION
IS EXPECTED FROM THE COAST TO THE CASCADES THROUGH THIS AFTERNOON.
OTHER THAN SOME MINOR/TYPICAL NUISANCE PONDING OF WATER ON ROADWAYS,
WE ARE NOT CONCERNED ABOUT FLOODING SINCE RIVER LEVELS ARE VERY LOW
FOR THIS TIME OF YEAR. MOST OF THE RAIN EXPECTED FROM THIS SYSTEM
WILL BE BENEFICIAL/WELCOME. AMOUNTS OF 1-3 INCHES ARE LIKELY ALONG
THE COAST, WITH 0.50-1.00 INCH COMMON INLAND TO THE CASCADES WITH
0.25-0.50 INCH OVER THE EAST SIDE. SNOW LEVELS CURRENTLY HOVER
AROUND 5000-5500 FT, BUT WILL DROP TO 2500-3000 FEET BY THURSDAY
MORNING. WE HAVE WINTER STORM WARNINGS UP FOR THE CASCADES WHERE
SNOWFALL RATES COULD BE 1-2" PER HOUR AT TIMES THIS AFTERNOON DURING
THE HEIGHT OF THE PRECIP. TIMING FOR HIGHEST SNOWFALL RATES APPEARS
TO BE 1-5 PM. IT SHOULD BE NOTED THAT AS THE COLD POOL ALOFT MOVES
IN BEHIND THE COLD FRONT, INSTABILITY INCREASES OVER THE MARINE
WATERS AND INLAND LATE THIS AFTERNOON INTO TONIGHT. THIS COULD
GENERATE ISOLATED THUNDERSTORMS, MOST LIKELY ALONG THE COAST (50-70%
CHANCE) WITH LOWER PROBABILITIES INTO THE UMPQUA AND EAST OF THE
CASCADES (20-40%).
WITH SNOW LEVELS CRASHING DOWN TO AROUND 2500 FEET TONIGHT, WINTER
WEATHER ADVISORIES ARE ALSO UP FOR THE SISKIYOU MOUNTAINS AND FOR
THE "SPILLOVER" AREA EAST OF THE CASCADES (HIGHWAY 97 CORRIDOR) AND
THE MOUNTAINS EAST OF THERE (WARNERS), WHERE A FEW TO SEVERAL INCHES
COULD ACCUMULATE. ALL IN ALL, EXPECT SIGNIFICANT WINTER TRAVEL
IMPACTS IN THE MOUNTAINS AND OVER SOME OF THE HIGHER PASSES,
ESPECIALLY AT LAKE OF THE WOODS BY THURSDAY MORNING. MAIN I-5 PASSES
SHOULD BE OK, BUT SOME SLIPPERY SPOTS COULD DEVELOP AT SISKIYOU
SUMMIT AND/OR AROUND MT SHASTA CITY/SNOWMAN SUMMIT EARLY THURSDAY
MORNING. THERE COULD BE A LITTLE DUSTING OF SNOW TOO FOR SOME OF THE
LOWER SPOTS IN NORCAL AND OVER THE EAST SIDE, BUT GROUND
TEMPERATURES ARE WARM, SO MOST NON-MOUNTAINOUS LOCATIONS WON'T SEE
ROAD ACCUMULATION (EXCEPTION CHILOQUIN NORTHWARD). EVEN SOME OF THE
HIGHER SPOTS AROUND THE WEST SIDE VALLEYS (~2500 FEET) COULD SEE
SNOWFLAKES IN THE AIR THURSDAY MORNING, BUT SNOW ACCUMULATIONS ARE
UNLIKELY GIVEN THE WARM GROUND TEMPERATURES AND RELATIVELY LIGHT
PRECIPITATION RATES BEING UNABLE TO OVERCOME THESE WARM GROUND
TEMPERATURES.
WITH THE CORE OF THE UPPER LEVEL COLD POOL SHIFTING INTO NORTHEAST
OREGON AND IDAHO ON THURSDAY, SHOWERS AND PERHAPS AN ISOLATED
THUNDERSTORM WILL CONTINUE FOR A WHILE INTO THE AFTERNOON, BUT THEN
DIMINISH RAPIDLY AROUND SUNSET AS HIGH PRESSURE BUILDS IN. MODELS
CONTINUE TO SHOW A HIGH PROBABILITY (70-90% CHANCE) OF TEMPERATURES
DROPPING INTO THE LOW TO MID 30S FOR THE WEST SIDE VALLEYS BY FRIDAY
MORNING. SO, THAT WILL BRING FROST/FREEZE RISK, DEPENDING ON HOW
QUICKLY CLOUD COVER DIMINISHES THURSDAY NIGHT. GREATEST RISK OF THAT
OCCURRING IS IN THE ILLINOIS VALLEY (CAVE JUNCTION/OBRIEN/SELMA),
BUT ALSO HERE IN THE ROGUE VALLEY. THE PROBABILITY OF TEMPERATURES
LESS THAN 28F HAVE ALSO INCREASED, A 10-20% CHANCE HERE, WITH AROUND
40% CHANCE FROM AROUND CAVE JUNCTION SOUTHWARD. WE'VE GONE FORWARD
WITH A FREEZE WATCH FOR JACKSON/JOSEPHINE COUNTIES AS WELL AS THE
KLAMATH RIVER VALLEY IN WESTERN SISKIYOU. CLIMATOLOGICALLY SPEAKING,
AREAS EAST OF THE CASCADES AND IN THE SHASTA/SCOTT VALLEYS STILL
FREQUENTLY SEE FROST/FREEZE CONDITIONS THIS TIME OF YEAR, SO NO
PRODUCTS ARE CONSIDERED FOR THOSE AREAS AT THIS TIME. WE MAY NEED TO
CONSIDER THE NEED FOR FROST ADVISORIES FOR PORTIONS OF THE UMPQUA
BASIN AND POTENTIALLY ALONG THE COAST, BUT CONFIDENCE IS LOWER FOR
THOSE AREAS ON THERE BEING ENOUGH CLEAR SKIES TO LEAD TO FROST
CONDITIONS. STAY TUNED FOR UPDATES.
MODELS ARE SHOWING THE UPPER RIDGE REBUILDING ACROSS THE AREA FRIDAY
INTO THE WEEKEND, SO LOOK FOR TEMPERATURES TO REBOUND TO ABOVE
NORMAL LEVELS AGAIN (HIGHS IN THE 70S AND EVEN LOW 80S AGAIN WEST
SIDE VALLEYS) ALONG WITH LITTLE TO NO CHANCE AT PRECIPITATION. NEXT
CHANCE AT PRECIP WON'T BE UNTIL MONDAY AT THE EARLIEST, BUT MORE
LIKELY TUESDAY/WEDNESDAY NEXT WEEK. EARLY INDICATIONS SHOW THAT THE
NEXT POTENTIAL PRECIP EVENT WILL BE SHORTER-LIVED THAN THE CURRENT
SYSTEM, WITH LOWER AMOUNTS AND ALSO LESS WIDE-SPREAD. -SPILDE/BR-Y
AVIATION...(18Z TAFS)
A PASSING FRONT TODAY WILL BRING WIDESPREAD PRECIPITATION AND
LOW/MID LEVEL CLOUDS WHICH WILL RESULT IN WIDEPSREAD MVFR.
CONDITIONS WILL REMAIN THIS WAY THROUGH MOST OF THIS CYCLE, BUT
SHOWERS SHOULD START TO THIN OUT TONIGHT AND BECOME MORE ISOLATED.
THE FRONT WILL ALSO BRING BREEZY WIND SPEEDS WITH A SHIFT EXPECTED
LATER THIS AFTERNOON BEHIND THE FRONT. GUST AROUND 15-25 MPH WILL BE
COMMON TODAY, BUT A BRIEF GUST OF 30 KNOTS IS NOT OUT OF THE
QUESTION. ALSO, WITH THE FRONT PASSING WE COULD HAVE PERIOD OF LOW
LEVEL WIND SHEER, BUT THIS THREAT SHOULD DIMINISH THIS AFTERNOON
WHEN MIXING OCCURS. LASTLY, ISOLATED THUNDERSTORMS WILL BE POSSIBLE
THIS AFTERNOON AS WELL.
MARINE...UPDATED 1100 AM PDT WEDNESDAY, APRIL 1, 2026
A STRONG
COLD FRONT WILL MAINTAIN SOUTH GALES (GALE WARNING IN EFFECT) AND
VERY STEEP SEAS ALONG WITH PERIODS OF RAIN AND REDUCED VISIBILITY
THROUGH EARLY THIS AFTERNOON. ISOLATED THUNDERSTORMS ARE POSSIBLE
THIS AFTERNOON AND TONIGHT. WHILE WINDS ARE EXPECTED TO EASE THIS
EVENING, VERY STEEP SEAS ARE EXPECTED TO CONTINUE THROUGH THURSDAY
MORNING. A HAZARDOUS SEAS WARNING IS IN EFFECT UNTIL 2 PM THU. SWELL-
DOMINATED SEAS GRADUALLY SUBSIDE, BUT REMAIN STEEP THROUGH THURSDAY
EVENING. ADVISORY STRENGTH NORTH WINDS ARE LIKELY TO RETURN LATE
THIS WEEK INTO THE WEEKEND WITH STEEP, WIND-DRIVEN SEAS.
MFR WATCHES/WARNINGS/ADVISORIES
OR...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 11 AM PDT
THURSDAY FOR ORZ029-030.
FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
ORZ024-026.
WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR ORZ031.
WINTER STORM WARNING UNTIL 5 PM PDT THURSDAY FOR ORZ025-027-028.
CA...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 11 AM PDT
THURSDAY FOR CAZ080-085.
FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
CAZ080.
WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR CAZ081-085.
PACIFIC COASTAL WATERS...GALE WARNING UNTIL 2 PM PDT THIS AFTERNOON
FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 11 AM PDT THURSDAY FOR PZZ350-356-
370-376.
MNF/JWG
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