059
FXUS66 KMFR 192331
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
431 PM PDT TUE MAY 19 2026
UPDATE AVIATION DISCUSSION
AVIATION...20/00Z TAFS
VFR CONDITIONS WILL PREVAIL INTO THIS
EVENING, THEN A WEAK IMPULSE WILL PASS OVER THE REGION TONIGHT, WITH
A MARINE PUSH EXPECTED THROUGH THE MORNING HOURS. THIS WILL RESULT
IN IFR/MVFR CEILINGS OVER THE MARINE WATERS AND ALONG THE COAST, AND
EVENTUALLY THE COASTAL VALLEYS AND UMPQUA BASIN, INCLUDING AT NORTH
BEND AND ROSEBURG. MARINE LAYER DEPTH (UP TO AROUND 5000 FEET)
ALLOWS FOR THE POTENTIAL FOR SOME CLOUDS TO FORM AND BANK UP AGAINST
THE SISKIYOUS WEDNESDAY MORNING. THESE MAY CAUSE LOCAL TERRAIN
OBSCURATION BUT SHOULD BE VFR ABOVE MEDFORD. ELSEWHERE, VFR
CONDITIONS WILL PREVAIL THROUGH WEDNESDAY MORNING. -SPILDE
PREV DISCUSSION
/ISSUED 1259 PM PDT TUE MAY 19 2026/
KEY MESSAGES...
- WARM, DRY WEATHER PREVAILS THROUGH LATE THIS WEEK AND INTO THIS
WEEKEND. WARMEST DAYS THU-SUN WITH TEMPERATURES ABOUT 10-15F
ABOVE NORMAL.
- AFTERNOON/EVENING BREEZES SHOULD BE FAIRLY TYPICAL, THOUGH
OCCASIONALLY GUSTY ALONG THE COAST.
- WHILE THE WARM, DRY CONDITIONS ELEVATE FIRE WEATHER RISK, FUELS
ARE STILL IN GREEN-UP/CURING PROCESS AND PRESENT GENERALLY LOW
TO MODERATE FIRE DANGER.
- POTENTIAL FOR A STRONGER TROUGH EARLY NEXT WEEK (MEMORIAL DAY)
BRINGING PRECIPITATION POTENTIAL, GUSTY WINDS AND A COOL DOWN.
DISCUSSION...HIGH PRESSURE AND DRY NW FLOW ALOFT WILL KEEP DRY
WEATHER GOING THROUGH THE REMAINDER OF THIS WEEK ALONG WITH A
WARMING TREND. OVERALL, HIGH TEMPERATURES TODAY AND WEDNESDAY
WILL BE A FEW TO SEVERAL DEGREES ABOVE NORMAL, BUT WARMER AIR
ALOFT WILL BRING TEMPERATURES AROUND 10-15F ABOVE NORMAL THU-SUN.
THE AIR MASS IS PRETTY DRY, BUT WE'LL GET MARINE PUSHES FROM TIME
TO TIME THAT WILL BRING BOUTS OF NIGHTTIME/MORNING STRATUS TO THE
COAST, COASTAL VALLEYS AND UMPQUA BASIN. ONE SUCH MARINE PUSH IS
COMING TONIGHT, WHICH COULD BE DEEP ENOUGH TO CAUSE SOME SPILLOVER
CLOUDS AROUND THE ROGUE VALLEY WEDNESDAY MORNING, BUT THAT'S
ABOUT IT. BY FRIDAY PM/EVE, MODELS ARE SHOWING A WEAK IMPULSE
OFFSHORE AND SOME MOISTURE/WEAK INSTABILITY NEAR THE NORCAL
MOUNTAINS (MAINLY SOUTH OF HERE -- SIERRA). THIS RAISES THE IDEA
OF THUNDER, BUT THE PROBABILITY OF ANYTHING OCCURRING THIS FAR
NORTH IS 10% OR LESS. SAME GOES FOR SATURDAY PM/EVE.
LOOKING AHEAD, THERE ARE INDICATIONS THAT THE RIDGE WILL BEGIN TO
BREAK DOWN OVER THE WEEKEND, WITH THE POTENTIAL FOR A MORE ROBUST
TROUGH TO ENTER THE PACIFIC NORTHWEST AROUND MEMORIAL DAY THAT
COULD BRING PRECIPITATION AND COOLER TEMPERATURES TO THE FORECAST
AREA. MODEL SUITES STILL ARE NOT IN SOLID AGREEMENT WITH THIS
SCENARIO, WITH SEVERAL DIFFERENCES PRIMARILY IN TROUGH STRENGTH,
BUT ALSO ITS TIMING, SO CONFIDENCE IS ALSO STILL ON THE LOW SIDE.
THIS WILL WARRANT A CLOSE EYE FOR THOSE WITH PLANS FOR THE
MEMORIAL DAY HOLIDAY. MOST INLAND AREAS SHOULD HAVE A 5-10F COOL
DOWN ALONG WITH ENHANCED TO LOCALLY GUSTY WINDS, AND A CHANCE OF
SHOWERS. -SPILDE
MARINE...UPDATED 200 PM PDT TUESDAY, MAY 19, 2026...A THERMAL
TROUGH WILL BRING GUSTY NORTH WINDS AND STEEP TO VERY STEEP SEAS
OVER THE COASTAL WATERS THROUGH FRIDAY NIGHT. WINDS WILL BE
STRONGEST AND SEAS WILL BE HIGHEST DURING THE AFTERNOONS/EVENINGS.
THROUGH THIS STRETCH, VERY STEEP SEAS OF 10-12 FT ARE MOST LIKELY
SOUTH OF CAPE BLANCO WITH STEEP SEAS (6-9 FT) NORTH OF CAPE
BLANCO. GUIDANCE SHOWS WINDS WILL STRENGTHEN WEDNESDAY/THURSDAY
WITH THE POTENTIAL (35-55% CHANCE) FOR GALES (GUSTS) ACROSS
PORTIONS OF THE SOUTHERN WATERS, ESPECIALLY FROM AROUND GOLD BEACH
SOUTH.
THE PATTERN WILL EASE SOME THIS WEEKEND AS AN UPPER TROUGH PUSHES IN
FROM THE NW. THIS SHOULD BRING LIGHTER WINDS AND LOWER SEAS,
ESPECIALLY BY SUNDAY. MODEL SCENARIOS INDICATE ANOTHER TROUGH MOVING
THROUGH SUNDAY NIGHT INTO MONDAY, BUT THE STRENGTH OF THE TROUGH IS
THE MAIN SOURCE OF UNCERTAINTY AT THIS TIME. WE SHOULD GET A BETTER
HANDLE ON THIS IN THE COMING DAYS. -SPILDE
MFR WATCHES/WARNINGS/ADVISORIES
OR...CA...NONE.
PACIFIC COASTAL WATERS...HAZARDOUS SEAS WARNING UNTIL 11 PM PDT
FRIDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY UNTIL 11 PM PDT FRIDAY FOR PZZ350-370.
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