379
FXUS66 KMFR 281026
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
326 AM PDT FRI AUG 28 2026
KEY MESSAGES
* TODAY: CHANCE (15-20%) FOR SHOWERS AND THUNDERSTORMS OVER FAR
EASTERN MODOC COUNTY AND FAR SOUTHEAST LAKE COUNTY WITH
LIGHTNING BEING THE MAIN THREAT.
* TEMPERATURES ARE GENERALLY SEASONABLE THROUGH MONDAY, EXCEPT
COOLER/SLIGHTLY BELOW NORMAL TEMPERATURES ON SATURDAY.
* A LOW PRESSURE SYSTEM NEXT WEEK MAY BRING RAINFALL AND COOLER
TEMPERATURES. RAINFALL CHANCES INCREASING MIDWEEK AND CONTINUING
THROUGH LATER PARTS OF NEXT WEEK, ESPECIALLY FOR COASTAL AND
WESTSIDE AREAS.
DISCUSSION
TODAY, AN UPPER LEVEL JET IS LOCATED OVER THE
REGION WITH A CLOSED UPPER LEVEL LOW CENTERED TO THE NORTHWEST
OVER BRITISH COLUMBIA AND AN AREA OF HIGH PRESSURE CENTERED TO
THE SOUTHEAST OVER THE DESERT SOUTHWEST. WITH MOISTURE ADVECTING
INTO SOUTHEAST PORTIONS OF THE AREA, A FEW SHOWERS AND
THUNDERSTORMS MAY DEVELOP LATE TODAY DURING PEAK HEATING WHEN
CONVECTIVE TEMPERATURES WILL BE REACHED. ALTHOUGH PRECIPITABLE
WATER HAS INCREASED, WE NOT EXPECTING A LOT OF RAIN WITH ANY
SHOWERS OR THUNDERSTORMS THAT DEVELOP. SO, THE MAIN THREAT WILL BE
LIGHTNING ALONG WITH A POTENTIAL FOR ISOLATED GUSTY WINDS. THE
BETTER CHANCES FOR STORMS WILL REMAIN EAST AND SOUTHEAST OF OUR
AREA.
ON SATURDAY, THE LOW MOVES OVER THE PACIFIC NORTHWEST, BRINGING
COOLER CONDITIONS WITH SLIGHTLY BELOW NORMAL HIGH TEMPERATURES.
DRY WEATHER IS EXPECTED, WITH PRECIPITATION REMAINING WELL TO THE
EAST.
ON SUNDAY, THE UPPER TROUGH WILL SHIFT EASTWARD AND EXPECT A
ZONAL PATTERN OVER THE AREA. THIS PATTERN WILL RESULT IN NEAR
NORMAL TEMPERATURES.
AN TROUGH PATTERN IS EXPECTED TO DEVELOP JUST OFF THE COAST ON
MONDAY. THEN A STRONGER LOW IS FORECAST TO MOVE DOWN FROM THE GULF
OF ALASKA AND INTO THE REGION WEDNESDAY INTO THURSDAY. THERE IS
SOME UNCERTAINTY IN THE ENSEMBLES WITH THE TIMING, ORIENTATION AND
STRENGTH OF THIS SYSTEM. OVERALL, THE PATTERN FAVORS TROUGHING
WITH COOLER TEMPERATURES AND INCREASED RAINFALL CHANCES,
ESPECIALLY FROM THE CASCADES WEST. THERE IS SIGNIFICANT VARIABILITY
IN ENSEMBLE SOLUTIONS ON THE AMOUNT OF RAINFALL. SO, WE WILL
CONTINUE TO MONITOR THIS FOR THE POTENTIAL OF LIGHT/MODERATE RAIN.
INSTABILITY IS WEAK SO THERE ARE ONLY LOW CHANCES FOR
THUNDERSTORMS BUT GIVEN THE VARIABILITY IN THE FORECAST, THERE IS
POTENTIAL FOR THIS TO CHANGE. CONTINUE TO MONITOR THE FORECAST FOR
THE LATEST CHANGES.
AVIATION...28/06Z TAFS
AREAS OF IFR/LIFR STRATUS AND FOG WILL
IMPACT THE COAST FROM CAPE BLANCO NORTHWARD, INCLUDING
NORTH BEND, AND ALSO FROM AROUND GOLD BEACH SOUTHWARD, TONIGHT INTO
FRIDAY MORNING. THEN, CONDITIONS IMPROVE TO VFR BEFORE LOWERING
AGAIN FRIDAY EVENING.
THERE SHOULD BE ENOUGH MOISTURE TO CAUSE MVFR CEILINGS TO DEVELOP IN
THE UMPQUA BASIN, AROUND ROSEBURG, FOR AT LEAST SEVERAL HOURS LATE
TONIGHT INTO FRIDAY MORNING BEFORE CLEARING TO VFR IN THE AFTERNOON.
PATCHY CLOUDS COULD DEVELOP IN PARTS OF THE ILLINOIS VALLEY OR
NEAR GRANTS PASS, BUT IT SHOULD REMAIN VFR IN MEDFORD. WHILE
KLAMATH FALLS WILL HAVE SOME HIGH CLOUDS AT TIMES TONIGHT/FRIDAY,
VFR WILL PREVAIL THERE AS WELL.
COASTAL AREAS WILL HAVE GUSTY N BREEZES (~20-25 KT) FRIDAY
AFTERNOON/EVENING, WHILE AREAS EAST OF THE CASCADES AND IN NE
CALIFORNIA HAVE GUSTY S-SW AFTERNOON WINDS (20-30 KT). ISOLATED
SHOWERS/THUNDERSTORMS COULD GRAZE FAR SE SECTIONS OF THE AREA FRIDAY
AFTERNOON/EVENING, ESPECIALLY OUT AROUND THE WARNER MTNS OF
MODOC/SOUTHERN LAKE COUNTIES. -SPILDE
MARINE...UPDATED 100 AM PDT FRIDAY, AUGUST 28, 2026
RELATIVELY
CALM CONDITIONS WITH LIGHT NORTH WINDS AND LOW SEAS ARE EXPECTED
THROUGH THIS MORNING. NORTH WINDS INCREASE THIS AFTERNOON WITH
STEEP SEAS DEVELOPING SOUTH OF CAPE BLANCO. THESE STEEP SEAS AND
GUSTY WINDS WILL PERSIST THROUGH THE WEEKEND. WINDS WILL BE
STRONGEST EACH AFTERNOON AND EARLY EVENING FRIDAY THROUGH SUNDAY.
CONDITIONS ARE LIKELY TO IMPROVE MONDAY AFTERNOON.
FIRE WEATHER
UPDATED 200 AM PDT FRIDAY, AUGUST 28,
2026...ASIDE FROM A BRIEF PERIOD OF ZONAL FLOW WITH SLIGHT
WARMING AND DRYING ON SUNDAY, UPPER LEVEL TROUGHING WILL DOMINATE
THE WEATHER THROUGH THE FORECAST PERIOD. THIS WILL MAINTAIN GUSTY
AFTERNOON/EVENING WINDS, THOUGH GENERALLY WEAKER THAN
YESTERDAY/RECENT DAYS. ADDITIONALLY, RHS WILL TREND HIGHER AS
TEMPERATURES CONTINUE TRENDING COOLER, WHICH WILL LIMIT CRITICAL
FIRE WEATHER CONDITIONS.
MEANWHILE, ONSHORE FLOW WILL GENERALLY MAINTAIN MODERATE TO GOOD
RECOVERIES WITH NIGHTLY MARINE PUSHES FOR COASTAL ZONES.
A SLIGHT CHANCE OF THUNDERSTORMS REMAINS IN THE FORECAST TODAY
FOR SOUTHEAST PORTIONS OF THE AREA, MAINLY FAR SOUTHEASTERN FWZ
625 AND FAR EASTERN FWA 285. MODELS CONTINUE TO SHOW AN AREA OF
REMNANT TROPICAL MOISTURE MOVING INTO NORTHEAST/CENTRAL
CA AND NORTHWEST NV, WHICH IS EXPECTED TO CLIP THE SOUTHEASTERN
PORTIONS OF THE AREA AND SOME SHOWERS AND LOW CHANCES (15-20%)
FOR ISOLATED THUNDERSTORMS THIS AFTERNOON/EVENING. THE BETTER
INSTABILITY AND INCREASED CHANCES FOR THUNDERSTORMS WILL REMAIN
SOUTH AND EAST OF THE AREA. DRIER AIR IN THE MID- LEVELS RETURNS
SATURDAY AND THUNDERSTORMS SHIFT EASTWARD.
A STRONGER TROUGH ARRIVES NEXT WEEK, BRINGING COOLER/BELOW NORMAL
TEMPERATURES, HIGHER HUMIDITIES AND THE POTENTIAL FOR RAINFALL.
THE BEST CHANCES FOR RAINFALL WILL BE ALONG THE COAST AND FROM THE
CASCADES WEST. INSTABILITY IS WEEK AND THERE ARE LOW CHANCES
(5-10%) FOR THUNDERSTORMS DURING THIS PERIOD. HOWEVER, THERE
REMAINS VARIABILITY IN THE MODELS ON THE FORECAST FOR THIS PERIOD.
SO WILL CONTINUE TO MONITOR THIS PERIOD FOR CHANGES.
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FROM 2 PM THIS
AFTERNOON TO 5 AM PDT MONDAY FOR PZZ356-376.
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