009
FXUS66 KMFR 011200
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
500 AM PDT WED APR 1 2026
DISCUSSION
UPDATED AVIATION DISCUSSION.
AVIATION...01/12Z TAFS
A PRE-FRONTAL TROUGH IS CROSSING THE AREA
EARLY THIS MORNING WITH PERIODS OF LIGHT RAIN, AND A MIX OF VFR/MVFR
CEILINGS/HIGHER TERRAIN OBSCURATION. STRONGER WINDS ALOFT WILL RESULT
IN POTENTIAL LOW-LEVEL WIND SHEAR ALONG THE COAST AND INTO PORTIONS
OF THE UMPQUA BASIN THROUGH THIS MORNING (UNTIL 19-20Z) BEFORE WINDS
SURFACE. A STRONG, SHARP COLD FRONT WILL MOVE ONSHORE LATER THIS
MORNING, SHIFTING ACROSS THE AREA THIS AFTERNOON AND TONIGHT. THIS
WILL BRING PERIODS OF MODERATE TO HEAVY PRECIPITATION (SNOW IN
THE MOUNTAINS), WITH MORE WIDESPREAD MVFR CEILINGS, HIGHER TERRAIN
OBSCURATIONS AND GUSTY WINDS. WIND GUSTS OF 25-35 KT WILL BE COMMON.
WE'LL BE MONITORING WINDS TODAY FOR THE POTENTIAL FOR AIRPORT
WEATHER WARNINGS (MAINLY KLAMATH FALLS, BUT POSSIBLE MEDFORD AS
WELL). ISOLATED THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON AND
TONIGHT AS THE COLD POOL ALOFT MOVES IN. SNOW LEVELS DROP TO AROUND
2500 FEET TONIGHT, SO EXPECT MORE MVFR CEILINGS AND TERRAIN
OBSCURATION. -SPILDE
PREV DISCUSSION
/ISSUED 310 AM PDT WED APR 1 2026/
DISCUSSION...RADAR AT THIS EARLY HOUR IS SHOWING A BAND OF MOSTLY
LIGHT RAIN MOVING INLAND ACROSS THE WEST SIDE WITH JUST SOME
LIGHT SHOWERS EAST OF THE CASCADES. THIS IS ASSOCIATED WITH A
PRE-FRONTAL TROUGH THAT WILL PUSH EAST OF THE CASCADES LATER THIS
MORNING AND INTO IDAHO THIS AFTERNOON. EXPECT SOME RAIN SHADOWING
HERE IN THE ROGUE VALLEY INITIALLY, SO PRECIP AROUND HERE WILL BE
LIGHT THROUGH MID-LATE MORNING.
MEANWHILE, A STRONG COLD FRONT OFFSHORE WILL MOVE IN QUICKLY
BEHIND THIS TROUGH AND THIS WILL GENERATE A BAND OF MODERATE TO
HEAVY PRECIPITATION. THIS WILL MOVE ONSHORE LATER THIS MORNING
ALONG WITH SOME STRONG, GUSTY WINDS. IT WILL BECOME BREEZY TO
WINDY ACROSS A LARGE PORTION OF THE FORECAST AREA, ESPECIALLY THIS
AFTERNOON IN ADVANCE OF THE COLD FRONT. A WIND ADVISORY WAS ADDED
TO THE SHASTA VALLEY AS IT APPEARS THERE WILL BE A QUICK BURST OF
PRE-FRONTAL SOUTH WINDS (WITH GUSTS TO 45 MPH) BEFORE THEY SHIFT
TO SOUTHWEST DURING THE AFTERNOON. WIND HEADLINES WERE ALSO
CONSIDERED FOR THE COAST SINCE MODEL GRADIENTS (OTH-ACV) ARE
AROUND -8 TO -9 MB. WHILE IT WILL BE WINDY WITH SOME GUSTS OF
45-55 MPH, THESE ARE JUST BELOW WARNING CRITERIA, SO WE DECIDED
AGAINST THE WARNING AT THIS TIME. THAT SAID, COASTAL HEADLANDS
(CAPE BLANCO) COULD SEE WIND GUSTS NEAR 60 MPH, SO BE AWARE OF
THAT IF YOU DECIDE TO VENTURE OUT TO THE IMMEDIATE COAST.
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). 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. SNOW LEVELS CRASH DOWN TO AROUND 2500 FEET
TONIGHT, SO 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.
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. 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'LL BE EVALUATING THAT FOR
POTENTIAL FROST/FREEZE PRODUCTS.
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. -SPILDE/BR-Y
AVIATION...01/06Z TAFS...SCATTERED SHOWERS CONTINUE TO MOVE OVER
NORTHERN CALIFORNIA AND SOUTHERN OREGON, BUT INSTABILITY HAS EASED
AND ADDITIONAL THUNDERSTORMS ARE NOT EXPECTED. MVFR CEILINGS ARE
PRESENT IN SOME AREAS, NOTABLY AT NORTH BEND AS WELL AS OVER SOME
EAST SIDE AREAS, AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM.
THIS LOW PRESSURE SYSTEM WILL BRING ACTIVE WEATHER THROUGH THE TAF
PERIOD. INITIAL ACTIVITY IS EXPECTED OVER CURRY COUNTY AND THE
CASCADES, WITH PRECIPITATION BECOMING MORE WIDESPREAD INTO THE
AFTERNOON AFTERNOON. MODERATE TO HEAVY RAIN SHOWERS ARE POSSIBLE
WEST OF THE CASCADES. SNOW LEVELS START AT 6000 FEET EARLY WEDNESDAY
MORNING, THEN LOOK TO START DROPPING IN THE AFTERNOON AND REACHING
3000 FEET BY WEDNESDAY NIGHT. THIS WILL ALLOW FOR SNOW SHOWERS OVER
HIGHER TERRAIN IN WESTERN SISKIYOU COUNTY AS WELL AS OVER AND EAST
OF THE CASCADES. RAIN AND SNOW SHOWERS COULD BRING LOCALLY LOWER
CEILINGS AND VISIBILITIES ACROSS THE AREA AS WELL AS OBSCURE
ELEVATED TERRAIN.
MOST AREAS WILL SEE SOME AMOUNT OF GUSTY WINDS, WITH THESE WINDS
PERSISTING INTO THE END OF THE TAF PERIOD ALONG THE COAST AND EAST
OF THE CASCADES. GUIDANCE SHOWS AREAS OF LOW LEVEL WIND SHEAR
DEVELOPING ALONG THE OREGON COAST THEN OVER ELEVATED TERRAIN FROM
WEST TO EAST THROUGH THE DAY. THE INCLUSION OF WIND SHEAR IN THE
FORECAST FOR NORTH BEND COVERS THE DURATION OF SHEAR OVER COASTAL
AREAS. OTHER TERMINALS ARE NOT EXPECTED TO HAVE SHEAR OVERHEAD.
-TAD
MARINE...UPDATED 230 AM PDT WEDNESDAY, APRIL 1, 2026...A STRONG
COLD FRONT WILL BRING SOUTH GALES AND VERY STEEP SEAS ALONG WITH
PERIODS OF RAIN AND REDUCED VISIBILITY THROUGH EARLY THIS
AFTERNOON. A GALE WARNING IS IN EFFECT. 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. -SPILDE
MFR WATCHES/WARNINGS/ADVISORIES
OR...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 11 AM PDT
THURSDAY FOR ORZ029-030.
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.
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 FROM 2 PM THIS AFTERNOON TO 11 AM PDT
THURSDAY FOR PZZ350-356-370-376.
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