118
FXUS66 KMFR 292157
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
257 PM PDT WED APR 29 2026
DISCUSSION
AN UPPER RIDGE IS KEEPING CONDITIONS WARM AND DRY
TODAY AND THROUGH THURSDAY. DAYTIME HIGHS FOR TODAY LOOK TO BE IN
THE LOW TO MID 60S ALONG THE COAST AND THE LOW 70S IN WEST SIDE
VALLEYS. EAST SIDE AREAS HAVE FORECAST HIGHS IN THE MID TO HIGH 60S.
WITH THE RIDGE AXIS MOVING OVERHEAD ON THURSDAY, ADDITIONAL WARMING
IS EXPECTED. COASTAL AREAS AND EAST SIDE AREAS LOOK TO SEE HIGHS IN
THE MID TO HIGH 60S, WITH SOME EAST SIDE BASINS REACHING THE LOW
70S. WEST SIDE VALLEYS HAVE FORECAST HIGHS IN THE HIGH 70S TO LOW
80S. WHILE THESE VALUES DO NOT THREATEN EXISTING RECORDS FOR THE
AREA, THEY DO REPRESENT A MINOR HEATRISK LEVEL. PEOPLE WHO ARE
EXTREMELY SENSITIVE TO HEAT MAY EXPERIENCE HEAT-RELATED ILLNESSES.
IN SPITE OF A MORE ACTIVE PERIOD FORECAST ON FRIDAY AND BEYOND,
SURFACE TEMPERATURES WILL STAY SIMILARLY WARM THROUGH SUNDAY.
ON FRIDAY, A CUTOFF LOW WILL DEVELOP TO THE NORTH AND DESCEND ALONG
THE PACIFIC COAST, WHICH WILL BRING SOUTHERLY FLOW ALOFT AS WELL AS
ATMOSPHERIC INSTABILITY. THESE CONDITIONS WILL BRING AREAS OF
THUNDERSTORM CHANCES STARTING FRIDAY AFTERNOON AND EVENING, THEN
CONTINUING THROUGH THE WEEKEND AND INTO THE FOLLOWING MONDAY. FOR
FRIDAY, THE CHANCES ARE FAIRLY SLIGHT. CURRENT GUIDANCE HAS 10-15%
CHANCES ACROSS WESTERN SISKIYOU COUNTY, JACKSON COUNTY, AND ALONG
THE CASCADES. THESE CHANCES DEVELOP LATER INTO THE AFTERNOON AND
DISSIPATE QUICKLY INTO THE EVENING. CURRENT FORECAST CAPE VALUES FOR
FRIDAY ARE IN THE 200-400 J/KG RANGE, WHICH DOES NOT SUGGEST SEVERE
ACTIVITY. ON SATURDAY, CHANCES INCREASE ALONG THIS LINE TO 20-25%,
WHILE 10-15% CHANCES ARE PRESENT OVER MODOC AND EASTERN SISKIYOU
COUNTIES. CAPE VALUES ON SATURDAY APPROACH 600 J/KG IN PLACES.
PRECIPITABLE WATER VALUES FOR BOTH DAYS ARE IN THE 0.5-0.8 INCH
RANGE, WHICH CAN HELP TO BRING RAIN SHOWERS AS WELL.
ON SUNDAY AND MONDAY, THIS CUTOFF LOW DROPS TO CENTRAL CALIFORNIA
AND START TO TRAVEL TO THE EAST. WRAPAROUND FLOW IS EXPECTED TO
BRING WIDESPREAD RAIN SHOWERS RATHER THAN CELLULAR ACTIVITY, BUT
EMBEDDED THUNDERSTORMS ARE STILL POSSIBLE. ON SUNDAY, CHANCES FOR
THUNDERSTORMS ARE HIGHEST WEST OF THE CASCADES (20-25%), BUT SOME
LOWER CHANCES (10-20%) ARE PRESENT OVER EAST SIDE AREAS. ON MONDAY,
CHANCES LOWER TO THE WEST OF THE CASCADES (10-15%) AND INCREASE TO
THE EAST (20-25%). THE HIGHEST FORECAST RAINFALL AMOUNTS ARE OVER
ELEVATED TERRAIN ALONG AND EAST OF THE CASCADES, WITH AN INCH OF
RAINFALL POSSIBLE.
GIVEN THAT THE BEHAVIOR OF CUTOFF LOWS CAN BE ERRATIC AND ANY SLIGHT
SHIFT IN ITS PATH COULD CHANGE THE EXPECTED IMPACTS, THESE CHANCES
MAY SHIFT DAY BY DAY. PLEASE STAY TUNED TO UPCOMING FORECASTS TO SEE
OUR MOST RECENT EXPECTATIONS ON WHERE THUNDERSTORMS ARE POSSIBLE.
A FEW SHOWERS MAY LINGER EAST OF THE CASCADES INTO TUESDAY MORNING,
WHILE WEST SIDE AREAS WILL BE UNDER THE INFLUENCE OF A DEVELOPING
RIDGE. DETERMINISTIC IMAGERY KEEPS THIS RIDGE IN CONTROL INTO THE
LONG TERM FORECAST, WHICH IS SUPPORTED MY ECMWF AND GFS METEOGRAM
GUIDANCE SHOWING MANY OUTCOMES WITH WARM TEMPERATURES. USING MEDFORD
AS AN EXAMPLE, FORECAST HIGHS REMAIN NEAR 80 DEGREES THROUGH MUCH OF
NEXT WEEK. PRECIPITATION METEOGRAMS SHOW FEW CHANCES OF
PRECIPITATION, SUPPORTING THE EXPECTED INFLUENCE OF A PACIFIC RIDGE.
DETERMINISTIC IMAGERY DOES SHOW THE RIDGE MOVING TO THE EAST AS
OTHER FEATURES SHIFT AROUND IT, HINTING AT A SLOW PROGRESS IN THE
UPPER PATTERN IS POSSIBLE RATHER THAN ANY BLOCKING PATTERN. -TAD
AVIATION...29/18Z TAFS
LINGERING CLOUDS ARE CLEARING OUT OF THE
UMPQUA VALLEY, LEADING TO VFR LEVELS ACROSS THE AREA UNDER A STABLE
UPPER PATTERN. GUSTY WINDS ARE EXPECTED ALONG THE OREGON COAST THIS
AFTERNOON BEFORE EASING IN THE EVENING, WITH MARINE STRATUS BRINGING
MVFR LEVELS BY EARLY THURSDAY MORNING. VFR LEVELS LOOK TO CONTINUE
FOR OTHER AREAS THROUGH THE TAF PERIOD. -TAD
MARINE...UPDATED 200 PM PDT WEDNESDAY, APRIL 29, 2026.
A THERMAL
TROUGH PATTERN WILL BRING STRONG NORTH WINDS THROUGH SATURDAY. THE
STRONGEST WINDS AND VERY STEEP SEAS ARE EXPECTED SOUTH OF OPHIR THIS
AFTERNOON AND EVENING. SEAS WILL BE STEEP ELSEWHERE. A SIMILAR
PATTERN IS EXPECTED ON THURSDAY AND FRIDAY, WITH THE HIGHEST WIND
SPEEDS CREEPING UP DAILY. WINDS START TO EASE ON SATURDAY BUT
UNSETTLED SEAS MAY CONTINUE.
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 AM PDT FRIDAY
FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ356-
376.
TAD/TAD/TAD
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page