613
FXUS66 KMFR 301109
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
409 AM PDT SUN MAR 30 2025
DISCUSSION
UNEVENTFUL CONDITIONS UNDER HIGH CLOUDS REMAIN OVER
MOST OF NORTHERN CALIFORNIA AND SOUTHERN OREGON EARLY THIS MORNING.
THE FIRST SHOWERS OF AN APPROACHING WARM FRONT ARE SHOWING UP AN
RADAR OVER WESTERN SISKIYOU COUNTY. PRECIPITATION WILL MAKE ITS WAY
EASTWARD THROUGH THE DAY, WITH THE HIGHEST AMOUNTS OVER CURRY AND
JOSEPHINE COUNTIES AS WELL AS THE MOUNT SHASTA REGION (INCLUDING
WEED, MOUNT SHASTA CITY, DUNSMUIR, AND MCCLOUD). THESE AREAS ARE
FORECAST TO GET BETWEEN 0.5 AND 1.5 INCHES OF RAINFALL THROUGH
TONIGHT. SNOW LEVELS WILL START AT 4000 FEET THEN RISE TO ABOVE 5000
FEET BY THIS EVENING, KEEPING SNOWFALL TO THE HIGHEST PEAKS AND
RIDGELINES. SOME AREAS BETWEEN 4000-5000 FEET MAY SEE LIGHT SNOW
SHOWERS THIS MORNING BEFORE PRECIPITATION TURNS TO RAIN.
WHILE PRECIPITATION MAY NOT BE IMPACTFUL TODAY, THE FRONT WILL BRING
THE POSSIBILITY OF OTHER HAZARDOUS CONDITIONS. GUSTY SOUTHERLY WINDS
ARE FORECAST OVER COASTAL HEADLANDS, ELEVATED TERRAIN WEST OF THE
CASCADES, AND ALL AREAS EAST OF THE CASCADES. ADDITIONALLY, THESE
WINDS ARE EXPECTED TO FUNNEL INTO THE SHASTA VALLEY AND THE SOUTHERN
ROGUE VALLEY. A HIGH WIND WARNING FOR COASTAL HIGHLANDS AND WIND
ADVISORIES FOR INLAND AREAS ARE IN PLACE INTO THIS EVENING TO
HIGHLIGHT POSSIBLE HAZARDOUS CONDITIONS. ADDITIONALLY, THIS FRONT
WILL BRING SLIGHT THUNDERSTORM CHANCES (10-15%) ALONG THE OREGON
COAST THIS EVENING AND TONIGHT WITH LESSER CHANCES FOR INLAND AREAS
WEST OF THE CASCADES.
IMPACTFUL CONDITIONS TURN FROM WIND TO WINTER ON MONDAY AND TUESDAY.
WITH THE FRONT OFF TO THE NORTH, A LOW PRESSURE SYSTEM WILL DRAW
CLOSER TO THEN MOVE OVER THE AREA. A COLD AIR MASS MOVING WITH THIS
SYSTEM WILL BRING COOLER TEMPERATURES AND LOWER SNOW LEVELS ACROSS
THE AREA. SOUTHWESTERLY FLOW ALOFT WILL CONTINUE TO BRING
PRECIPITATION ACROSS THE AREA. SNOW LEVELS ARE FORECAST TO DROP TO
2500-3500 FEET THROUGH MONDAY AND TUESDAY, WITH HAZARDOUS WINTER
WEATHER POSSIBLE IN CERTAIN AREAS. A WINTER STORM WATCH HAS BEEN
UPGRADED TO A WINTER STORM WARNING FOR AREAS IN SISKIYOU COUNTY
ABOVE 4500 FEET, AND WILL BE IN PLACE FROM EARLY MONDAY MORNING
THROUGH TUESDAY EVENING. PEAKS AND RIDGELINES IN SISKIYOU COUNTY
COULD GET 1 TO 3 FEET OF SNOW THROUGH THIS TIMEFRAME. SAWYERS BAR
ROAD WEST OF ETNA COULD SEE OVER 2 FEET OF SNOW IN PLACES. A WINTER
WEATHER ADVISORY COVERS THE CASCADES AND MOUNT ASHLAND IN THE SAME
TIMEFRAME, WITH 12 TO 24 INCHES OF SNOWFALL POSSIBLE IN THESE AREAS.
A SHORTER WINTER WEATHER ADVISORY IS IN PLACE FOR AREAS ALONG I-5
SOUTH OF WEED AND HIGHWAY 89 FROM TUESDAY MORNING THROUGH TUESDAY
EVENING. SNOW LEVELS ARE FORECAST TO REACH THEIR LOWEST IN THIS
PERIOD, POSSIBLY BRINGING IMPACTFUL SNOWFALL TO THESE HIGHWAYS AND
CITIES IN THIS AREA.
FOR OTHER AREAS, GENERALLY LIGHT TO MODERATE PRECIPITATION CONTINUES
ON MONDAY AND TUESDAY. INCREASED THUNDERSTORM CHANCES (15-25%) ARE
FORECAST FOR AREAS WEST OF THE WEST OF THE CASCADES ON MONDAY
AFTERNOON. CURRY AND JOSEPHINE COUNTIES MAY SEE A PERIOD OF
INCREASED PRECIPITATION ON TUESDAY MORNING. GUSTY SOUTHWEST WINDS
ARE FORECAST TO CONTINUE OVER ELEVATED TERRAIN, BUT THAT CHANGE OF
DIRECTION WILL PREVENT FURTHER FUNNELING INTO THE SHASTA AND ROGUE
VALLEYS.
ACTIVE BUT LESS IMPACTFUL WEATHER CONTINUES ON WEDNESDAY, AS AN
UPPER TROUGH MOVES OVER THE AREA. NORTHWEST FLOW ALONG THE BACK EDGE
OF THE TROUGH COULD BRING CONTINUING SHOWERS AND COOL TEMPERATURES
ON WEDNESDAY AND THURSDAY. AS THE UPPER PATTERN CONTINUES TO MOVE
EASTWARD, A HIGH PRESSURE SYSTEM COULD SETTLE OVER THE AREA WHILE
LOW PRESSURE REMAINS OVER THE SOUTHWEST UNITED STATES. THIS REX
BLOCK PATTERN (HIGH PRESSURE POLEWARD/NORTH OF A LOW PRESSURE
SYSTEM) COULD BRING A PERIOD OF WARMER TEMPERATURES AND DRIER
CONDITIONS. METEOGRAM GUIDANCE SUPPORTS THIS, WITH BOTH ECMWF AND
GFS OUTCOMES SHOWING AN ABSENCE OF PRECIPITATION FOR THE FIRST
WEEKEND OF APRIL AND ONLY WEAK SIGNALS FOR THE WEEK BEYOND. -TAD
AVIATION (30/12Z TAFS)
CONDITIONS REMAIN VFR EARLY THIS MORNING,
BUT CEILINGS HAVE DEVELOPED AND BEGUN TO LOWER. ALTHOUGH VFR WILL
STILL BE PREDOMINANT, CONDITIONS WILL CONTINUE TO DETERIORATE THIS
MORNING WITH SOUTHERLY WINDS BECOMING BREEZY, THEN WINDY WITH STRONG
GUSTS AND AREAS OF LOW LEVEL WIND SHEAR. ISOLATED SHOWERS THIS
MORNING WILL BECOME MORE WIDESPREAD THIS AFTERNOON, INCLUDING AREAS
OF MVFR AND A SLIGHT CHANCE OF THUNDERSTORMS DEVELOPING FROM NEAR
SHORE TO THE COAST RANGE INTO THIS EVENING. SNOW LEVELS OF 4500 TO
6000 FT MSL THIS AFTERNOON WILL FALL TO 3000 TO 4000 FT MSL TONIGHT
WITH WIDESPREAD LIGHT TO MODERATE PRECIPITATION AND MOUNTAIN
OBSCURATION. WINDS ARE EXPECTED TO DIMINISH LATE TONIGHT, BUT
OTHERWISE THE NEXT DISTURBANCE WILL CONTINUE THE PRECIPITATION,
MOUNTAIN OBSCURATION, AND AREAS OF MVFR. -DW
MARINE...UPDATED 200 AM SUNDAY, MARCH 30, 2025
SOUTHERLY WINDS
HAVE BEGUN TO INCREASE AHEAD OF A STRONG LOW PRESSURE SYSTEM. THE
LOW WILL TRACK NORTHWARD THROUGH THE WATERS TODAY WITH WINDS AND
SEAS TRENDING HIGHER INTO THIS EVENING. THIS WILL RESULT IN
SOUTHERLY GALES AND VERY STEEP SEAS.
THE NEXT LOW PRESSURE SYSTEM WILL LIKELY MAINTAIN VERY STEEP SEAS
LATE TONIGHT THROUGH MONDAY INTO TUESDAY MORNING, WITH PEAK SEAS OF
13 TO 18 FT AT 12 SECONDS MONDAY NIGHT INTO EARLY TUESDAY. A
TAPERING TO STEEP SEAS FOLLOWS LATE TUESDAY MORNING THROUGH TUESDAY
EVENING. GRADUAL IMPROVEMENT IS EXPECTED TO CONTINUE TUESDAY NIGHT
INTO THE END OF THE WEEK WITH LIGHT TO MODERATE NORTHERLY WINDS.
-DW
MFR WATCHES/WARNINGS/ADVISORIES
OR...WIND ADVISORY FROM 8 AM THIS MORNING TO 8 PM PDT THIS EVENING
FOR ORZ023-024-026-029>031.
HIGH WIND WARNING FROM 11 AM THIS MORNING TO 8 PM PDT THIS
EVENING FOR ORZ021-022.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 5 PM PDT
TUESDAY FOR ORZ026>028.
CA...WINTER STORM WARNING FROM 11 PM THIS EVENING TO 5 PM PDT TUESDAY
FOR CAZ080-082-083.
WIND ADVISORY FROM 8 AM THIS MORNING TO 8 PM PDT THIS EVENING
FOR CAZ081-084-085.
WINTER WEATHER ADVISORY FROM 11 PM MONDAY TO 5 PM PDT TUESDAY
FOR CAZ082.
PACIFIC COASTAL WATERS...GALE WARNING FROM 9 AM THIS MORNING TO 8 PM
PDT THIS EVENING FOR PZZ356-376.
HAZARDOUS SEAS WARNING FROM 8 PM THIS EVENING TO 8 AM PDT
TUESDAY FOR PZZ350-356-370-376.
GALE WARNING FROM NOON TODAY TO 8 PM PDT THIS EVENING FOR PZZ350-
370.
TAD/DW
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