008
FXUS66 KMFR 241152
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
452 AM PDT FRI APR 24 2026
..UPDATED AVIATION SECTION FOR 12Z TAFS
DISCUSSION
THIS FORECAST PERIOD IS LARGELY DEFINED BY THE
PRESENCE AND LOCATION OF AN OMEGA BLOCK PATTERN, WITH AN UPPER RIDGE
CURRENTLY OVER THE PACIFIC PINNED BETWEEN TWO LOW PRESSURE SYSTEMS,
ONE WEST OF ALASKA AND THE OTHER OVER CENTRAL CANADA AND THE
NORTHERN UNITED STATES.
CURRENTLY, NORTHWEST FLOW ALOFT IS ALLOWING FOR GENERALLY SEASONABLE
CONDITIONS ACROSS THE AREA. AREAS OF LOCALIZED FROSTY TEMPERATURES
AND PATCHY FOG ARE POSSIBLE IN WEST SIDE VALLEYS, BUT THESE ARE NOT
EXPECTED TO BECOME WIDESPREAD. WEST SIDE VALLEYS WILL SEE A FEW
DEGREES OF WARMING FROM THURSDAY'S DAYTIME HIGHS, BRINGING LOW TO
MID 70S FOR MOST OF THESE LOWER ELEVATION AREAS. COASTAL AREAS WILL
ALSO SEE WARMING, WITH HIGH TEMPERATURES EXPECTED TO REACH THE MID
60S. AREAS EAST OF THE CASCADES STAY COOLER, WITH TEMPERATURES IN
THE HIGH 50S TO MID 60S.
UNSETTLED AIR LOOKS TO SWING AROUND THE CONTINENTAL LOW PRESSURE
SYSTEM AND MOVE OVER THE AREA THROUGH SATURDAY AND SUNDAY. THIS
LOOKS TO BRING A FEW DEGREES OF COOLING DURING THE DAY, WITH THE
POSSIBILITY OF LOCALIZED FROST CONDITIONS FOR SOME WEST SIDE VALLEYS
AGAIN. WHILE THIS DISTURBANCE WON'T BRING WIDESPREAD RAINFALL, THE
INSTABILITY IS SUPPORTING THUNDERSTORM CHANCES ON BOTH SATURDAY AND
SUNDAY AFTERNOON. FOR SATURDAY, THESE CHANCES ARE SLIGHT (10-20%)
AND LIMITED TO SOUTHEASTERN SISKIYOU AND SOUTHERN MODOC COUNTIES.
THESE AREAS MAY SEE ISOLATED SHOWERS SATURDAY NIGHT INTO SUNDAY
MORNING. THERE'S SOME DISAGREEMENT FOR ACTIVITY ON SUNDAY, WITH GFS
OUTCOMES SHOWING CAPE VALUES OF 300-500 J/KG OVER DOUGLAS COUNTY AND
100-300 J/KG OVER MOST OTHER AREAS, WHICH COULD BRING ISOLATED TO
SCATTERED THUNDERSTORMS OVER A WIDER AREA. ECMWF MODELING KEEPS
ACTIVITY GENERALLY TO SISKIYOU AND MODOC COUNTIES. CONVERSELY,
ECMWF IMAGERY SHOWS SOME LIGHT SHOWERS ACROSS THE AREA ON MONDAY
WHILE GFS MODELING SHOWS THE INSTABILITY DISSIPATING, KEEPING THE
AREA DRY. SEVERE ACTIVITY IS NOT EXPECTED.
THE UPPER PATTERN SHIFTS EASTWARD THROUGH NEXT WEEK, WITH THE
UPPER RIDGE PASSING TO THE NORTH AND A CUTOFF LOW PASSING TO THE
SOUTH. WITH THE FLOW SPLITTING AROUND THE AREA, A PERIOD OF MORE
STABLE WEATHER IS POSSIBLE. MEAGER PRECIPITATION CHANCES LINGER
OVER THE CASCADES AND LAKE COUNTY ON TUESDAY, WITH THE REST OF THE
WEEK LOOKING DRY ACROSS THE AREA. TEMPERATURES WARM INTO MIDWEEK,
AND MAY REMAIN WARM INTO THE END OF THE WEEK. LOMG-TERM
METEOGRAMS HINT AT SOME FORM OF ACTIVITY IN EARLY MAY, BUT
AGREEMENT ON TIMING AND QUANTITY IS SPARSE. -TAD
AVIATION...24/12Z TAFS
WITH STABLE WEATHER EXPECTED THROUGH THE
TAF PERIOD, VFR LEVELS WITH CLEAR SKIES AND NORMAL DIURNAL WINDS ARE
EXPECTED FOR MOST AREA IN NORTHERN CALIFORNIA AND SOUTHERN OREGON
THIS TAF PERIOD. THE ONLY NOTE IS FOR A PERIOD OF GUSTY WINDS
EXPECTED AT THE NORTH BEND TERMINAL THIS AFTERNOON. THESE WINDS
SHOULD EASE THIS EVENING. -TAD
MARINE...UPDATED 300 AM PDT FRIDAY, APRIL 24, 2026
GUSTY
NORTHERLY WINDS CONTINUE TO BUILD STEEP SEAS IN ALL AREA WATERS
TODAY, WITH THE STRONGEST WINDS SOUTH OF CAPE BLANCO. WINDS AND SEAS
LOOK TO REACH BELOW ADVISORY LEVEL LATE SATURDAY MORNING. SLIGHT
CHANCES OF MARINE SHOWERS ARE PRESENT SUNDAY.
NO SIGNIFICANT WEATHER IS EXPECTED EARLY NEXT WEEK. NORTHERLY WINDS
WILL PERSIST WHILE A LOW NORTHWEST SWELL COMBINES WITH A FRESH,
SHORTER PERIOD NNW SWELL. STEEP SEAS COULD RETURN AROUND MID-WEEK
WHEN THERE COULD BE AN UPTICK IN NORTHERLY WINDS AND AN INCREASING
NORTHWEST SWELL MOVES INTO THE WATERS.
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY
FOR PZZ350-356-370-376.
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