413
FXUS66 KMFR 062048
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
148 PM PDT MON JUL 6 2026
KEY POINTS
* THUNDERSTORM ACTIVITY IS DEVELOPING ALONG AND EAST OF THE
CASCADES. SLIGHT CHANCES FOR THUNDERSTORMS ARE PRESENT OVER
MODOC, SISKIYOU, AND SOUTHERN JACKSON COUNTY AS WELL.
* GENERALLY UNIMPACTFUL WEATHER IS EXPECTED THROUGH THE WEEKEND,
WITH SOME FIRE WEATHER CONCERNS EAST OF THE CASCADES TOWARDS THE
END OF THE WEEK.
* IN THE LONG TERM, A PATTERN CHANGE MAY BRING MONSOONAL MOISTURE
AND ATMOSPHERIC STABILITY. IN THIS OUTCOME, EAST SIDE
THUNDERSTORMS ARE POSSIBLE EARLY NEXT WEEK.
DISCUSSION
UPPER FLOW FROM THE SOUTHWEST IS KEEPING FORECAST
DAYTIME HIGHS ABOUT 5 DEGREES ABOVE NORMAL LEVELS. AREAS OF CLOUD
DEVELOPMENT OVER TERRAIN EAST OF THE CASCADES SHOW THAT MOISTURE AND
INSTABILITY REMAIN IN THE AREA. THIS SUPPORTS 25-35% CHANCES OF
AFTERNOON AND EVENING THUNDERSTORMS OVER NORTHERN LAKE AND KLAMATH
COUNTIES. THIS AREA HAS THE HIGHEST MODELED CAPE VALUES (300-500
J/KG) AS WELL AS WHERE THE MOST MOISTURE IS EXPECTED TO BE.
THUNDERSTORM CHANCES DROP TO 20-25% IN THE SOUTHERN HALVES OF THESE
COUNTIES, WHILE 5-10% CHANCES LINGER IN MODOC, SISKIYOU, AND
SOUTHERN JACKSON COUNTY. THUNDERSTORMS LOOK TO DECREASE INTO THE
EVENING HOURS.
A LATE MORNING WEATHER BALLOON LAUNCH INDICATES ELEVATED INSTABILITY
OVER AN ATMOSPHERIC INVERSION OVER THE ROGUE VALLEY. IF DEVELOPMENT
CAN BREAK THROUGH THAT INVERSION, THUNDERSTORM ACTIVITY OVER THE
ROGUE VALLEY COULD FOLLOW. AS WE SAW ON SUNDAY NIGHT, AN OUTFLOW
BOUNDARY CAN ALSO CONTRIBUTE TO ADDITIONAL ACTIVITY. THUNDERSTORMS
ARE SENSITIVE TO THESE CONDITIONS THAT MAY NOT SHOW UP IN GLOBAL
WEATHER MODELS. AWARENESS OF YOUR LOCAL CONDITIONS IS HIGHLY
ENCOURAGED, GIVEN HOW IMPACTFUL THUNDERSTORMS CAN BE.
DRIER AIR AND LESS INSTABILITY SIGNIFICANTLY REDUCE THUNDERSTORM
CHANCES FOR TUESDAY, WITH ONLY SINGLE DIGIT CHANCES OVER
NORTHERNMOST LAKE AND KLAMATH COUNTIES. ON WEDNESDAY, A DRY FRONT
PRECEDES A SLIGHT SHIFT TO ZONAL/SLIGHTLY NORTHWEST FLOW PATTERN
INTO THURSDAY. THIS WILL BRING TEMPERATURES DOWN TO NORMAL LEVELS
INTO THE WEEKEND, WITH HIGHS WEST OF THE CASCADES IN THE HIGH 80S
TO LOW 90S. TO THE EAST, TEMPERATURES IN THE MID TO HIGH 80S ARE
EXPECTED.
ON FRIDAY AND SATURDAY, AN UPPER LOW APPROACHES BRITISH COLUMBIA
FROM THE GULF OF ALASKA. WHILE WE'RE NOT EXPECTED TO SEE ANY
PRECIPITATION FROM THE TROUGH AROUND THIS LOW, TIGHTENING PRESSURE
GRADIENTS MAY BRING STRONGER AFTERNOON/EVENING WINDS EAST OF THE
CASCADES. WHEN COMBINED WITH ONGOING DRY CONDITIONS, FIRE WEATHER
MAY BECOME A CONCERN TOWARDS THE END OF THE WEEK (PLEASE SEE THE
FIRE WEATHER DISCUSSION BELOW FOR ADDITIONAL DETAILS ON THESE
CONCERNS THROUGH THE FORECAST PERIOD).
FOR SUNDAY AND BEYOND, THE LOW OFF OF CANADA'S WEST COAST WEAKENS
AND MOVES TO THE EAST WHILE HIGH PRESSURE SWINGS OVER THE NORTH-
CENTRAL UNITED STATES. IN THIS CASE, SOUTHWEST FLOW COULD DEVELOP
AND BRING BOTH MONSOONAL MOISTURE AND POCKETS OF INSTABILITY TO THE
AREA AND FUEL AFTERNOON AND EVENING THUNDERSTORM ACTIVITY EARLY NEXT
WEEK. GLOBAL MODEL CLUSTERS SHOW GOOD AGREEMENT FOR THIS OVERALL
PATTERN, WITH SOME VARIATION ON WHERE THE HIGH PRESSURE IS LOCATED.
ECMWF AND GFS MODEL ENSEMBLES ADD SOME CONFIDENCE TO THIS GENERAL
FORECAST, WITH SEASONAL WARMTH FOR AREA FORECAST POINTS AND
AGREEMENT FOR LIGHT SHOWER CHANCES OVER KLAMATH FALLS AND LAKEVIEW
WHILE WEST SIDE AREAS STAY DRIER. -TAD
AVIATION...06/18Z TAFS
MARINE STRATUS REMAINS IN PLACE ALONG THE
OREGON COAST, KEEPING LIFR LEVELS AT BROOKINGS AND IFR CEILINGS AT
NORTH BEND. BROOKINGS MAY SEE A BRIEF PERIOD OF CLEAR SKIES AND
NORTH BEND MAY SEE CEILINGS RISE TO MVFR HEIGHTS BEFORE IFR/LIFR
CONDITIONS RETURN THIS EVENING.
INLAND TERMINALS ARE AT VFR LEVELS, WITH MOSTLY CLEAR SKIES WEST OF
THE CASCADES. EAST OF THE CASCADES, CLOUD DEVELOPMENT INDICATES THE
PRESENCE OF INSTABILITY AND MOISTURE IN THE ATMOSPHERE. THIS
SUPPORTS THUNDERSTORM CHANCES REMAINING IN THE FORECAST, ESPECIALLY
OVER NORTHERN LAKE AND KLAMATH COUNTIES THIS AFTERNOON AND EVENING.
THOSE CHANCES MAY BE IMPACTED BY LINGERING CLOUD OVER IN THE AREA,
ALTHOUGH THOSE CLOUDS LOOK TO BE MOVING AWAY TO THE NORTHEAST WHICH
WOULD ALLOW FOR A PERIOD OF SURFACE WARMING. ANY THUNDERSTORMS THAT
DEVELOP TONIGHT COULD BRING LIGHTING, MODERATE TO HEAVY RAINFALL,
AND ERRATIC GUSTY WINDS. ACTIVITY CHANCES DECREASE INTO NIGHTTIME
HOURS. -TAD
MARINE...UPDATED 200 PM PDT MONDAY, JULY 6, 2026
GUSTY BUT
UNIMPACTFUL WINDS REMAIN SOUTH OF CAPE BLANCO AND WITHIN 30 NM OF
SHORE. LINGERING FRESH SWELL AND A SLIGHT INCREASE IN WESTERLY SWELL
WILL KEEP STEEP SEAS IN ALL WATERS INTO EARLY TUESDAY MORNING. STEEP
SEAS LOOK TO BE LIMITED TO WATERS SOUTH OF CAPE BLANCO FOR TUESDAY
THROUGH WEDNESDAY MORNING.
CURRENTLY, NORTHERLY WINDS START TO INCREASE ON WEDNESDAY MORNING.
THIS MAY BRING ADDITIONAL AREAS OF UNSETTLED SEAS TO AREA WATERS
INTO THE END OF THE WEEK. -TAD
FIRE WEATHER...UPDATED 1200 PM PDT MONDAY, JULY 6, 2026
WARM AND
DRY CONDITIONS WILL CONTINUE FOR THE NEXT WEEK, WITH TYPICAL
AFTERNOON BREEZES EACH DAY. THERE WILL BE A FEW PERIODS OF CONCERN:
THE FIRST THIS AFTERNOON EAST OF THE CASCADES, WHERE ABUNDANT
LIGHTNING IS EXPECTED, AND THE SECOND BEING TWO DRY FRONTAL PASSAGES
THAT WILL BRING GUSTY WINDS AND LOW RH TO PORTIONS OF THE AREA.
YESTERDAY, WE SAW CONVECTION ACROSS MUCH OF THE EAST SIDE AND THE
EASTERN SLOPES OF THE CASCADES, WITH OVER 300 CLOUD-TO-GROUND
LIGHTNING STRIKES OBSERVED. THE STORMS BEGAN ON THE DRY SIDE OVER
EASTERN MODOC AND LAKE COUNTIES, BUT BECAME WETTER AS THEY MOVED
WEST THROUGH THE EVENING. SOME LOCATIONS RECEIVED WETTING RAINS,
PARTICULARLY AROUND BEATTY, WHERE OVER AN INCH OF RAIN WAS MEASURED
(SOME OF WHICH WAS MELTED HAIL).
THERE IS AGAIN A CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS ALONG
AND EAST OF THE CASCADES, FOCUSED MAINLY OVER NORTHERN KLAMATH AND
LAKE COUNTIES, WITH ISOLATED STORMS POSSIBLE ELSEWHERE EAST OF THE
CASCADES, AND OVER NORTHERN CALIFORNIA, INCLUDING THE KLAMATHS,
SISKIYOUS, AND WARNERS. A FEW MODEL RUNS EVEN PLACE AN ISOLATED
THUNDERSTORM IN THE ROGUE VALLEY, SO DESPITE A VERY LOW CHANCE OF
THIS OCCURING, WE CANNOT RULE THAT OUT. STORM MOTION SHOULD BE TO
FROM SOUTHWEST TO THE NORTHEAST, AT ROUGHLY 20 MPH. ALONG WITH
PLENTY OF LIGHTNING, HAIL, AND GUSTY AND ERRATIC WINDS OF UP TO 45
MPH WILL BE A CONCERN FOR ANY STORMS THAT DEVELOP. THESE STORMS
SHOULD ALSO BE WET, GIVEN THE INCREASED MOISTURE IN THE AREA, BUT
LIGHTNING WILL LIKELY STRIKE OUTSIDE THOSE WET CORES. FORTUNATELY,
THE UPPER LEVEL IMPULSE RESPONSIBLE FOR TRIGGERING THESE STORMS IS
EXPECTED TO MOVE OUT OF THE AREA QUICKLY THIS EVENING, SO CONVECTION
SHOULD NOT LINGER AS LATE AS WE SAW YESTERDAY. A RED FLAG WARNING
IS IN EFFECT FOR THIS AFTERNOON, AND DETAILS CAN BE FOUND AT
PDXRFWMFR.
OTHERWISE, HIGH TEMPERATURES REMAIN AROUND 5 TO 10 DEGREES ABOVE
NORMAL, AND AFTERNOON BREEZES REMAIN TYPICAL TO SLIGHTLY ENHANCED
DURING THE NEXT WEEK. THIS WILL RESULT IN VERY DRY CONDITIONS,
GENERALLY JUST SHY OF CRITICAL WIND AND HUMIDITY THRESHOLDS,
ESPECIALLY TUESDAY AND WEDNESDAY AS A DRY COLD FRONT PASSES THROUGH
THE AREA. TUESDAY LOOKS TO BE A WINDIER DAY, WHILE WEDNESDAY APPEARS
DRIER, SO WE MAY GET THROUGH WITHOUT SEE CRITICAL CONDITIONS
DEVELOP. THIS WEEKEND, ANOTHER DRY COLD FRONTS PASSES THROUGH, AND
AT THIS TIME, IT LOOKS TO HAVE EVEN LESS MOISTURE AND STRONGER
WINDS. THUS, THERE IS A MUCH HIGHER LIKELIHOOD OF REACHING CRITICAL
CONDITIONS, PRIMARILY OVER EAST OF THE CASCADES, BUT ALSO
POTENTIALLY IN THE SHASTA/SCOTT AND ROGUE VALLEYS. UPDATES WILL BE
MADE AS NECESSARY OVER THE COMING DAYS.
MFR WATCHES/WARNINGS/ADVISORIES
OR...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR ORZ624-625.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 2 AM PDT TUESDAY
FOR PZZ350-356-370-376.
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