210
FXUS66 KMFR 272139
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
239 PM PDT THU AUG 27 2026
KEY MESSAGES
* TODAY: CRITICAL FIRE WEATHER CONDITIONS CONTINUE FOR EASTSIDE
AREAS, INCLUDING AREAS OF KLAMATH AND LAKE COUNTIES IN OREGON AND
PARTS OF MODOC COUNTY IN NORTHERN CALIFORNIA.
* TOMORROW: CHANCE (15-30%) FOR THUNDERSTORMS OVER FAR EASTERN MODOC
COUNTY AND SOUTHEAST LAKE COUNTY WITH LIGHTNING BEING THE MAIN
THREAT.
* TEMPERATURES ARE MOSTLY SEASONABLE THROUGH MONDAY (SATURDAY IS A
BIT COOLER), BUT NEXT WEEK IS SHAPING UP TO HAVE BELOW NORMAL
TEMPERATURES THROUGH MUCH OF THE WEEK AS A SYSTEM PASSES THROUGH.
* SYSTEM NEXT WEEK COULD BRING RAINFALL IN ADDITION TO THE COOLER
TEMPERATURES. RAINFALL CHANCES INCREASING MIDWEEK AND CONTINUING
THROUGH LATER PARTS OF NEXT WEEK, ESPECIALLY WESTSIDE AREAS.
DISCUSSION
A CLOSED UPPER LEVEL LOW OFF THE COAST OF BRITISH COLUMBIA WILL
MEANDER OVER THIS GENERAL AREA FOR THE NEXT SEVERAL DAYS. THIS WILL
RESULT IN CONTINUED SOUTHWESTERLY FLOW ALOFT THAT WILL KEEP THE
FORECAST AREA GENERALLY DRY AS THIS TROUGH PATTERN MAINTAINS (SMALL
EXCEPTION FOR TOMORROW). THIS PATTERN WILL MAINTAIN GUSTY WINDS AND
LOW RH TODAY, BUT IMPROVEMENT IN FIRE WEATHER CONDITIONS LOOK TO
DEVELOP FRIDAY AND CONTINUE THROUGH THE WEEKEND.
ON FRIDAY, AN UPPER JET STREAK LOOKS TO DEVELOP BETWEEN THE
AFOREMENTIONED LOW AND AN AREA OF HIGH PRESSURE OVER THE DESERT
SOUTHWEST. THIS COULD HELP TRIGGER A COUPLE THUNDERSTORMS THROUGH
PEAK HEATING AS CONVECTIVE TEMPERATURES WILL BE REACHED. WHILE WE
HAVE INCREASED MOISTURE, PWATS ARE NOT OVERLY IMPRESSIVE, SO NOT
EXPECTING A LOT OF RAIN. MAIN THREAT WILL BE LIGHTNING, BUT IF A
STORM OR TWO CAN MAINTAIN IN OUR AREA, WE COULD HAVE ISOLATED GUSTY
WINDS AS WELL. OVERALL, THE LIMITED INSTABILITY MAY ONLY LEAD TO
ISOLATED CHANCES WITH BETTER CHANCES EAST OF OUR AREA.
BY SUNDAY, IT DOES APPEAR THIS UPPER TROUGH PATTERN WILL SHIFT EAST
AND WE WILL BRIEFLY TRANSITION TO A ZONAL PATTERN, BUT ANOTHER
TROUGH PATTERN LOOKS TO QUICKLY FORM OVER THE WEST COAST BY MONDAY.
IN FACT, IT LOOKS LIKE A COUPLE DISCERNIBLE TROUGHS WILL TRANSITION
THE PACNW NEXT WEEK. THERE IS SOME UNCERTAINTY IN SOME OF THESE
CASES WHERE DETERMINISTIC MODELS VARY ON THE TIMING, ORIENTATION,
AND STRENGTH OF THE UPPER PATTERN, BUT THE OVERALL PATTERN DOES
APPEAR TO FAVOR A TROUGH. THE INCREASED RAINFALL CHANCES DO MAKE
SENSE GIVEN THIS PATTERN, BUT SOME OF THE FINER DETAILS ARE A LITTLE
HAZY AT THIS TIME GIVEN THE MODEL DIFFERENCES. IT DOES ALSO LOOK
LIKE WESTSIDE AREAS WILL BE FAVOR UNDER THIS PATTERN. IT SHOULD ALSO
BE NOTED THIS DOESN'T APPEAR TO MUCH RAINFALL FOR ANY OF OUR
LOCATIONS. WESTSIDE AREAS WILL BE FAVORED, BUT THE HIGHEST
PROBABILITY FOR ANY 24HR TIME PERIOD IS ONLY 60% FOR 0.05" OF
RAINFALL FOR WED/THURS. COASTAL AREAS WOULD BE THE HIGHER
PROBABILITY FOR THIS RAINFALL, ESPECIALLY COOS COUNTY AND WESTERN
DOUGLAS COUNTY. INSTABILITY LOOKS VERY FEEBLE ACROSS OUR FORECAST
AREA, SO NOT EXPECTING MUCH--IF ANY--THUNDERSTORMS UNDER THIS
PATTERN NEXT WEEK. ALL THAT SAID, GIVEN UNCERTAINTY IN THE UPPER
LEVELS, IT IS ADVISABLE TO CHECK BACK AS THE FORECAST MAY CHANGE FOR
BOTH RAINFALL AMOUNTS AND THUNDERSTORM POSSIBILITIES. IF NOTHING
ELSE, INCREASED CLOUD COVER AND COOLER TEMPERATURES IS LOOKING VERY
FAVORABLE TUESDAY THROUGH MIDDLE/LATER PARTS OF NEXT WEEK.
AVIATION...27/18Z TAFS
FAIR WEATHER CUMULUS WILL CONTINUE THIS
AFTERNOON ALONG THE COAST WITH MAINLY CLEAR VFR SKIES FARTHER
EASTWARDS. WE'LL SEE ANOTHER ROUND OF IFR STRATUS AND VISIBILITIES
ALONG THE COAST. FOG DOWN TO 1/4 IS POSSIBLE AT TIMES, ESPECIALLY
CLOSER TO BROOKINGS.
-SMITH
MARINE...UPDATED 100 PM PDT THURSDAY, AUGUST 27, 2026
RELATIVELY
CALM CONDITIONS WITH LIGHT WINDS SWITCHING TO THE NORTH THIS
AFTERNOON AND LOW SEAS ARE EXPECTED THROUGH TOMORROW MORNING. NORTH
WINDS INCREASE TOMORROW 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.
MFR WATCHES/WARNINGS/ADVISORIES
OR...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR ORZ624-625.
CA...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR CAZ285.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FROM 2 PM FRIDAY TO 5
AM PDT MONDAY FOR PZZ356-376.
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