574
FXUS66 KMFR 130001
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
501 PM PDT TUE MAY 12 2026
DISCUSSION
UPDATED AVIATION DISCUSSION.
AVIATION...13/00Z TAFS
VFR PREVAILS ACROSS THE REGION LATE
THIS AFTERNOON WITH SOME HIGH CLOUDS STREAMING THROUGH. MVFR/LOCAL
IFR CONTINUES ALONG THE COAST AND OVER THE COASTAL WATERS. GUSTY
SOUTH TO SOUTHWEST BREEZES (25-35 KT) CONTINUE IN NORCAL AND EAST OF
THE CASCADES, BUT THERE WILL ALSO BE SOME GUSTY NORTHWEST BREEZES
FOR AREAS WEST OF THE CASCADES INTO THIS EVENING (INCLUDING HERE IN
MEDFORD).
WITH SOUTHERLY FLOW IN PLACE OVER THE REGION AND SOME INSTABILITY
THIS EVENING, ISOLATED SHOWERS (PERHAPS EVEN A THUNDERSTORM) COULD
DEVELOP IN SOME SPOTS FROM WESTERN SISKIYOU COUNTY UP ACROSS THE
SISKIYOUS TO THE CASCADES (THUNDER PROBABILITY IS ABOUT 10-20% IN
THESE AREAS). WITH DECENT MID-LEVEL FLOW ANYTHING THAT GETS GOING
EARLY THIS EVENING COULD DRIFT NORTHWARD OVER THE ROGUE VALLEY OR
FAR EASTERN DOUGLAS COUNTY, BUT SHOULD REMAIN EAST OF THE ILLINOIS
VALLEY AND UMPQUA BASIN NEAR ROSEBURG.
OVERNIGHT, AN UPPER TROUGH WILL MOVE ONSHORE WITH MORE WIDESPREAD
MVFR CLOUDS AND COASTAL SHOWERS SPREADING INLAND BY WEDNESDAY
MORNING. THE SHOWERS COULD REACH NORTHERN KLAMATH AND LAKE COUNTIES
WEDNESDAY MORNING, BUT AREAS SOUTH AND EAST OF THE MOUNTAINS WILL
LARGELY REMAIN DRY WITH VFR. THINGS MOSTLY DRY OUT WITH A MUCH
COOLER AIR MASS WEDNESDAY AFTERNOON. -SPILDE/BR-Y
PREV DISCUSSION
/ISSUED 234 PM PDT TUE MAY 12 2026/
KEY POINTS...
* STRONG GUSTY WINDS TODAY - GUSTS OF 25-35 MPH COMMON ACROSS THE
REGION WITH GUSTS 40-45 MPH POSSIBLE ACROSS THE HIGHEST TERRAIN
EAST OF THE CASCADES.
* HEIGHTENED FIRE WEATHER CONCERNS TODAY - STRONG WINDS AND LOW RHS
EAST OF THE CASCADES AND IN THE SHASTA VALLEY. ALSO, HOT, DRY AND
UNSTABLE CONDITIONS ARE EXPECTED ACROSS NORTHERN CALIFORNIA AND
EAST SIDE.
* ISOLATED SHOWERS/THUNDERSTORMS POSSIBLE THIS EVENING OVER THE
SISKIYOUS AND CASCADE CREST, SHIFTING NORTH OF THE AREA TONIGHT.
* HOTTEST DAY OF THE FORECAST PERIOD IS TODAY, WITH A COOLING TREND
BACK TO SEASONAL NORMALS EXPECTED FOR WEDNESDAY ONWARD. BELOW
NORMAL TEMPERATURES ARE POSSIBLE OVER THE WEEKEND.
* LIGHT RAIN (<=0.10") EXPECTED TONIGHT INTO EARLY WEDNESDAY MAINLY
ALONG THE COAST AND NORTH OF THE ROGUE-UMPQUA DIVIDE.
DISCUSSION...LOW PRESSURE IS APPROACHING THE REGION THIS
AFTERNOON, INDUCING SOUTHERLY FLOW OVER THE FORECAST AREA AND
TIGHTENING PRESSURE GRADIENTS. THIS IS RESULTING IN STRONG GUSTY
WINDS ACROSS THE REGION WITH GUSTS OF 20-30 MPH FAIRLY COMMON AWAY
FROM THE COAST. IT'S ANOTHER WARM DAY TODAY WITH TEMPERATURES
RUNNING ABOUT 5 TO 8 DEGREES WARMER THAN THIS TIME YESTERDAY.
INCREASING CLOUD COVER SHOULD LIMIT THE WARMING TREND SOME, BUT
EXPECT ANOTHER AFTERNOON OF UPPER 80S FOR THE WEST/LOWER 80S FOR
THE EAST. DUE TO THE STRONG WINDS TODAY, WE ARE HIGHLIGHTING SOME
HEIGHTENED FIRE WEATHER CONCERNS TODAY, ESPECIALLY EAST OF THE
CASCADES AND IN NORTHERN CALIFORNIA WHERE HUMIDITIES WILL BE
LOWEST THIS AFTERNOON. PLEASE USE EXTRA CAUTION TODAY IF USING
ANYTHING WITH AN OPEN FLAME.
WITH SOUTHERLY FLOW OVER THE REGION, THERE'S A LOW CHANCE (10-20%)
FOR ISOLATED SHOWERS/THUNDERSTORMS LATER TODAY INTO THE EVENING.
INSTABILITY WILL BE MOST FAVORABLE OVER WESTERN SISKIYOU/SISKIYOU
MOUNTAINS AND ALONG THE CASCADES CREST. STEERING FLOW IS FAIRLY
STRONG TODAY, OUT OF THE SOUTHWEST AROUND 35-45 KTS, SO ANYTHING
THAT DEVELOPS OVER THE SISKIYOUS WILL MOVE INTO THE ROGUE/ILLINOIS
VALLEYS. IT'S LOW CHANCE, AS MOISTURE IS FAIRLY MARGINAL, BUT STILL
WORTH MENTIONING. THE THUNDERSTORM THREAT SHIFTS NORTH OF THE
FORECAST AREA TONIGHT.
LOW PRESSURE WILL SWING INLAND TONIGHT THROUGH EARLY WEDNESDAY.
GUSTY WINDS WILL EASE SOME AFTER SUNSET, BUT REMAIN BREEZY INTO
EARLY WEDNESDAY. 700 MB WINDS PEAK (45-55KT) OVERNIGHT TONIGHT AS
THE LOW SWINGS INLAND, BUT SINCE IT'S COMING THROUGH IN THE
OVERNIGHT HOURS, THIS SHOULD LIMIT MIXING OF THE STRONGEST WINDS
DOWN TO MOST PLACES. THE HIGHER TERRAIN WILL LIKELY SEE STRONGER
GUSTY WINDS CARRY INTO THE OVERNIGHT HOURS AND STRAIGHT INTO
WEDNESDAY MORNING. A COLD FRONT WILL MOVE THROUGH THE AREA, BRINGING
SOME LIGHT RAIN (<=0.10") TO THE COAST AND UMPQUA BASIN. THERE COULD
BE SOME SPRINKLES AS FAR SOUTH AS THE OR/CA BORDER, BUT WE DON'T
EXPECT A SOAKING RAIN BY ANY MEANS. AREAS EAST OF THE CASCADES AND
SOUTH OF THE OR/CA BORDER HAVE A VERY HIGH CHANCE OF REMAINING DRY.
THE BULK OF THE PRECIPITATION, SUCH THAT IT IS, SHOULD BE WINDING
DOWN AROUND SUNRISE INTO EARLY WEDNESDAY MORNING. SNOW LEVELS WILL
LOWER TO AROUND 5000 FT, SO THERE COULD BE SOME LIGHT FLURRIES IN
THE CASCADES EARLY WEDNESDAY MORNING, BUT WINTER IMPACTS ARE NOT A
CONCERN. SOME SHOWERS COULD LINGER INTO THE LATE MORNING HOURS,
PRIMARILY ALONG THE COAST AND NORTH OF THE ROGUE-UMPQUA DIVIDE, BUT
WE'LL BE ON THE BACK SIDE OF THE TROUGH BY WEDNESDAY AFTERNOON SO
THE ATMOSPHERE WILL BEGIN DRYING OUT. WEDNESDAY WILL BE NOTICEABLY
COOLER COMPARED TO RECENT DAYS, AND WE'LL SEE AFTERNOON HIGHS RETURN
CLOSER TO SEASONAL NORMS (LOW-MID 70S WEST/LOW-MID 60S EAST).
WEDNESDAY NIGHT WILL ALSO BE QUITE COOL EAST OF THE CASCADES, WITH
FREEZING TEMPERATURES RETURNING TO THE FORECAST.
ZONAL FLOW PERSISTS THROUGH THE END OF THE WEEK, SO AFTERNOON HIGHS
WILL TREND A FEW DEGREES WARMER THURSDAY AND FRIDAY, WITH OVERNIGHT
LOWS HOVERING NEAR SEASONAL NORMS. DRY CONDITIONS ARE EXPECTED FOR
THE REMAINDER OF THE WEEK, BUT A WEAK FRONT ON THURSDAY SHOULD BRING
A DECENT MARINE PUSH AND THERE COULD BE SOME DRIZZLE ALONG THE COAST
WITH THAT.
OVER THE WEEKEND, BROAD TROUGHING SETTLES OVER THE PACIFIC
NORTHWEST, WHICH WILL BRING ANOTHER COOLING TREND WITH AFTERNOON
HIGHS BEING SOMEWHAT BELOW NORMAL. SHORTWAVES WITHIN THIS BROAD
TROUGH WILL PROVIDE GLANCING PRECIPITATION CHANCES ACROSS
NORTHERN/NORTHWESTERN AREAS SATURDAY AND SATURDAY NIGHT. THE OVERALL
CHANCE FOR ANY WIDESPREAD WETTING RAINFALL IS LOW AT THIS TIME, BUT
WE'LL HAVE TO WATCH MODEL TRENDS WITH THIS TROUGH TO SEE IF THERE
ARE ANY SOUTHWARD SHIFTS IN SHORTWAVES.
MARINE...UPDATED 815 AM PDT TUESDAY, MAY 12, 2026...RELATIVELY
CALM CONDITIONS ARE EXPECTED TODAY WITH SUB-ADVISORY SEAS AND
WINDS SHIFTING TO SOUTHWEST BY THIS AFTERNOON. AN INCOMING LOW
PRESSURE SYSTEM WILL BRING SHOWERS LATE TONIGHT INTO WEDNESDAY,
ALONG WITH INCREASING WEST WINDS AND WEST SWELL. DESPITE THIS,
BELOW ADVISORY CONDITIONS ARE EXPECTED TO PERSIST AS SEAS INCREASE
SOME, BUT REMAIN SWELL DOMINATED. GUSTY NORTH WINDS COULD RETURN
THURSDAY WITH STEEP SEAS POSSIBLE BY FRIDAY.
MFR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...NONE.
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