388
FXUS66 KMFR 122004
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
104 PM PDT SUN APR 12 2026
DISCUSSION
SHOWERS ARE STARTING TO POP UP ON RADAR THIS AFTERNOON AS THIS LOW
TRAVERSES OUT FORECAST AREA. DAYTIME HEATING IS HELPING CREATE
SOME INSTABILITY OUT THERE AND WE SHOULD SHOWER COVERAGE CONTINUE
TO INCREASE WITH PERHAPS A FEW EMBEDDED THUNDERSTORMS. THE
PROBABILITY OF CLOUD TO GROUND LIGHTNING IS ABOUT 20% TODAY MAINLY
IN CALIFORNIA AND NEAR THE CALIFORNIA/OREGON BORDER.
THIS UPPER LEVEL LOW EVENTUALLY LEASE THE FORECAST AREA TONIGHT,
ALTHOUGH THERE ARE SHORT WAVES DROPPING DOWN FROM THE NORTH WEST
LATER TONIGHT INTO TOMORROW MORNING. MAIN IMPACT WILL BE THE
CONTINUED 50-60% CHANCE OF SHOWERS ON MONDAY. HOWEVER, THE AREAL
COVERAGE WILL BE LOWER COMPARED TO WHAT WE'VE SEEN OVER THE LAST
FEW DAYS. THE PROBABILITY OF RAIN DECREASES MONDAY NIGHT INTO
TUESDAY AS HIGH PRESSURE BRIEFLY BUILDS. TEMPERATURES REMAIN NEAR
NORMAL ON TUESDAY WITH SOME CLOUD COVER ENTERING THE FORECAST
AHEAD OF THE NEXT SYSTEM.
BY TUESDAY NIGHT INTO WEDNESDAY MORNING, A DEEP TROUGH AND STRONG
COLD FRONT WILL DESCEND UPON THE PACIFIC NORTHWEST. MAIN IMPACTS
WILL BE SNOW ACCUMULATION OVER THE HIGHER CASCADES TUESDAY NIGHT
INTO WEDNESDAY MORNING ABOVE 5000 FEET. WE'VE ISSUED A WINTER
STORM WATCH BECAUSE OF THIS THREAT. SNOW LEVELS WILL DROP LOWER
THAN 5000 FEET BETWEEN TUESDAY NIGHT THROUGH WEDNESDAY, ALTHOUGH
SNOW SHOULD STRUGGLE TO ACCUMULATE DUE TO WARMER GROUND
TEMPERATURES WITH MINOR SNOW ACCUMULATION AROUND 3500 FEET.
THE OTHER THING THAT PUSHED US TO ISSUE A WINTER STORM WATCH WAS
THE EXTREME FORECAST INDEX(EFI) PAINTING VALUES OF 0.8 ALONG THE
CASCADES. ALSO, SNOWFALL RATES COULD REACH 1" AN HOUR FOR 6 TO
PERHAPS 12 HOURS ALONG THE FRONT. A PROLONGED PERIOD OF SNOWFALL
RATES USUALLY RESULTS IN SOME TRAVEL IMPACTS. OVERALL, NOT A
MASSIVELY IMPACTFUL STORM, ALTHOUGH THE TIME OF YEAR AND THE NEAR
1 FOOT OF SNOW AT CRATER LAKE PUSHED US TOWARDS A WINTER STORM
WATCH. THE WARMER GROUND TEMPERATURES COULD REALLY LIMIT THE
AMOUNT OF SNOW ACCUMULATION ON THE OTHER HAND LIKE THE LAST
EVENT. WE'LL HAVE TO WAIT AND SEE.
EVENTUALLY, THE COLD FRONT WILL PASS THROUGH OUR FORECAST AREA
WEDNESDAY AFTERNOON AND THE PRECIPITATION MODE WILL TURN SHOWERY
WITH MINOR SNOW ACCUMULATIONS IN THE CASCADES. THE IMPORTANT NOTE
WILL BE THE COLDER TEMPERATURES MOVING IN BEHIND THE FRONT AS SNOW
LEVELS CRATER TO 1700 FEET!
USUALLY, WE SEE HIGH PRESSURE SET UP BEHIND THESE FRONTS WITH A
STRONG INVERSION BUILD IN. HOWEVER, THIS LOOKS A BIT DIFFERENT AS
THE VERY COLD AIR OFF THE OCEAN SHOULD ALLOW FOR POCKETS OF
SHOWERS TO FORM WITH SOME CLOUD COVER. TEMPERATURES IN NORTHERN
CALIFORNIA WILL DROP BELOW FREEZING DUE TO CLEARER SKIES IN THOSE
VALLEYS. WEST OF THE CASCADES IN OREGON IS MORE UNCERTAIN AT THIS
TIME. THE CHANCE FOR MEDFORD TO DROP BELOW 32F IS 34%. THE THREAT
OF COLD OVERNIGHT LOWS WILL CONTINUE THURSDAY NIGHT. CONDITIONS
ARE ANTICIPATED TO REMAIN DRY THURSDAY THROUGH FRIDAY BEFORE THE
NEXT SYSTEM APPROACHES BY FRIDAY.
AVIATION (18Z TAFS)
IFR CONDITIONS WILL CONTINUE THROUGH EARLY THIS AFTERNOON BEFORE
RELIEF OCCURS THROUGH THE AFTERNOON HOURS. HOWEVER, SHOWERS ARE
EXPECTED AGAIN TODAY/TONIGHT AND WILL LIKELY IMPACT ALL 4 TERMINALS.
MVFR CONDITIONS ARE LIKELY (50%-65%) THROUGH A MAJORITY OF THIS
CYCLE, ESPECIALLY THIS EVENING AND OVERNIGHT AS SHOWERS BECOME
LIKELY BRINGING CEILINGS DOWN. OTHERWISE, EXPECTING OVERALL LIGHT
WIND SPEEDS THROUGH THIS CYCLE, BUT KLMT COULD BE BREEZY AT TIMES
THIS AFTERNOON.
MARINE...UPDATED 100 PM PDT SUNDAY, APRIL 12, 2026
SHOWERS
ARE EXPECTED TO INCREASE IN COVERAGE LATER TODAY/TONIGHT, BUT WE ARE
NOT EXPECTING ANY THUNDERSTORMS AT THIS TIME. THE UNSETTLED WEATHER
WILL KEEP WINDS AND SHORT PERIOD NORTHWEST SWELL DOMINATED SEAS
BELOW ADVISORY LEVEL THROUGH TUESDAY MORNING. STEEP SEAS ARE
POSSIBLE BEGINNING TUESDAY AFTERNOON AS A STRONGER FRONT PASSES
THROUGH THE REGION. THE FRONT WILL BRING INCREASING SOUTHWEST WINDS
AS IT MOVES ACROSS THE WATERS TUESDAY NIGHT INTO EARLY WEDNESDAY. A
DEVELOPING THERMAL TROUGH INLAND WILL BRING INCREASING NORTH WINDS
LATER WEDNESDAY WITH THE STRONGEST WINDS SOUTH OF GOLD BEACH AS SEAS
LIKELY REMAIN STEEP.
MFR WATCHES/WARNINGS/ADVISORIES
OR...WINTER STORM WATCH FROM TUESDAY EVENING THROUGH LATE WEDNESDAY
NIGHT FOR ORZ027.
CA...WINTER WEATHER ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR
CAZ080.
PACIFIC COASTAL WATERS...NONE.
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