396
FXUS66 KPQR 061041
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
341 AM PDT SAT JUN 6 2026
SYNOPSIS
A SERIES OF FRONTAL SYSTEMS CONTINUE PROGRESS
THROUGH PACIFIC NORTHWEST INTO NEXT WEEK FACILITATING COOLER
THAN NORMAL TEMPERATURES AND PERIODIC ROUNDS OF SHOWERS THROUGH
WEDNESDAY, JUNE 10. THERE IS ALSO A 15-35% CHANCE OF SHORT-
LIVED THUNDERSTORMS THIS AFTERNOON AND A 10-20% CHANCE TUESDAY
AFTERNOON. UPPER LEVEL RIDGING WILL BRING A WARMING AND DRYING
TREND THURSDAY ONWARD (JUNE 11-15), WITH A GROWING POTENTIAL FOR
HEAT RELATED CONCERNS JUNE 12-15.
SHORT TERM...NOW THROUGH MONDAY NIGHT
CURRENTLY SATELLITE
AND RADAR OBSERVATIONS EARLY THIS MORNING SHOW OUR NEXT WEATHER
SYSTEM IN THE FORM OF AN UPPER-LEVEL TROUGH BEGINNING TO
INCREASE SHOWERS ACROSS THE REGION, A TREND ANTICIPATED TO
CONTINUE AS THE DAY PROGRESSES. THE LATEST CONVECTIVE ALLOWING
MODEL (CAM) GUIDANCE HIGHLIGHTS AN INCREASE DURING THE MIDDAY
AND AFTERNOON HOURS, LIKELY THE RESULT OF A DAYTIME HEATING,
COOLING TEMPERATURES ALOFT, AND ADDED SYNOPTIC SCALE LIFT AS
THE AXIS OF THE UPPER LEVEL TROUGH COMES ONSHORE. THESE
CONDITIONS SUPPORT A 15-30% CHANCE OF THUNDERSTORMS OVER
NORTHWEST OR AND SOUTHWEST WA INTO EARLY EVENING HOURS (MAINLY
NORTH OF A LINE EXTENDING FROM FLORENCE TO EUGENE TO OAKRIDGE).
BASED ON DETERMINISTIC MODEL SOUNDINGS, MUCAPE VALUES OF
200-400J/KG SHOULD EXTEND INTO THE -10 TO -20C MIXED-PHASED
REGION OF THE ATMOSPHERE FACILITATING CHARGE SEPARATION AND
THUS LIGHTNING PRODUCTION WITHIN THE STRONGEST CELLS. AS SUCH,
THE STRONGEST CELLS THIS AFTERNOON WILL HAVE THE POTENTIAL TO
PRODUCE BRIEF HEAVY RAIN, SMALL HAIL, GUSTY OUTFLOW WINDS, AND A
FEW FLASHES OF LIGHTNING. IT IS WORTH NOTING THAT ANY GIVEN
STRONGER CONVECTION WILL BE SHORT-LIVED AND SUB-SEVERE AS WIND
SHEAR IS LIMITED AND ORGANIZED CONVECTION IS NOT EXPECTED.
THERE WILL ALSO BE BREAKS IN PRECIPITATION IN BETWEEN SHOWERS,
SO THOSE SPENDING TIME ON OUTDOOR ACTIVITIES SHOULD NOT EXPECT
AN ALL-DAY WASHOUT. NEVERTHELESS, HAVE YOUR RAIN JACKETS HANDY
AS IT IS UNLIKELY ANY GIVEN LOCATION WILL STAY DRY THE ENTIRE
DAY. AS ALWAYS, WHEN THUNDER ROARS GO INDOORS.
COME SATURDAY EVENING INTO EARLY SUNDAY MORNING, DETERMINISTIC
AND ENSEMBLE MODELS REMAIN IN GOOD AGREEMENT DEPICTING THE
UPPER LEVEL TROUGH AXIS QUICKLY SHIFTING EAST OF THE CASCADES,
ALLOWING FOR A WEAK TRANSITORY RIDGE OF HIGH PRESSURE TO PASS
OVERHEAD. THIS LEADS TO A PERIOD OF DRY WEATHER FOR MUCH OF
SUNDAY. HOWEVER, OUR NEXT PACIFIC FRONTAL SYSTEM ARRIVES LATE
IN THE DAY AND/OR OVERNIGHT INCREASING CHANCES FOR STEADY LIGHT
STRATIFORM RAINFALL. THERE IS STILL NOTEWORTHY MODEL
UNCERTAINTY REGARDING THE EXACT ARRIVAL OF THE RAINFALL WITH
THIS FEATURE. A SUBSET OF GUIDANCE SHOWS RAIN BEGINNING AS EARLY
AS 4-9 PM SUNDAY WHILE OTHER GUIDANCE PUSHES THE BEGINNING OF
RAINFALL BACK AS LATE AS 7-10 AM MONDAY. ALL MEMBERS FROM THE
ENS/GEFS/GEPS DO EVENTUALLY SHOW RAIN ARRIVING WITH THIS NEXT
SYSTEM, DESPITE THE TIMING DIFFERENCES. ONCE THE RAIN BEGINS,
EXPECT A TRANSITION TO MORE SHOWERY PRECIPITATION FOR MONDAY
AFTERNOON. -99/23
LONG TERM...TUESDAY THROUGH FRIDAY
THE LONG TERM FORECAST
STARTS OUT WITH COOLER THAN AVERAGE TEMPERATURES AND OCCASIONAL
SHOWERS FOLLOWED BY GROWING CONFIDENCE IN A SUBSTANTIAL WARMING
AND DRYING TREND LATE IN THE WEEK. DESPITE THE MODEL TIMING
DIFFERENCES DISCUSSED ABOVE WITH THE ARRIVAL OF A FRONTAL SYSTEM
LATE SUNDAY INTO MONDAY, ENSEMBLE GUIDANCE IS IN GOOD AGREEMENT
THE AREA WILL BE SOLIDLY WITHIN A POST-FRONTAL SHOWER
ENVIRONMENT TUESDAY THROUGH WEDNESDAY UNDER A BROAD UPPER LEVEL
TROUGH PARKED OVERHEAD. EXPECT THE CONTINUATION OF COOLER THAN
NORMAL TEMPERATURES AND OCCASIONAL RAIN WITH HIGH TEMPERATURES
MOST LIKELY IN THE 60S. AS THE AXIS OF THE LARGER TROUGH FEATURE
PASSES OVERHEAD AROUND TUESDAY, TEMPERATURES ALOFT BOTTOM OUT
WITH THE NBM SUGGESTING A 10-20% CHANCE OF THUNDERSTORMS DURING
THE TUESDAY AFTERNOON TIME PERIOD. THE LATEST NBM 48-HR
PROBABILITIES FOR RAIN AMOUNTS OVER 0.50" PEAK BETWEEN 5 PM
SUNDAY AND 5 PM TUESDAY, SHOWING ANYWHERE FROM A 50-75% CHANCE
FOR MOST LOCATIONS IN SOUTHWEST WA AND NORTHWEST OR, EXCEPT AN
80-90% CHANCE IN THE CASCADES AND IN THE COAST RANGE/WILLAPA
HILLS.
OUR FOCUS THEN SHIFTS TO A NOTICEABLE WARMING AND DRYING TREND
FROM THURSDAY ONWARD. CLUSTER ANALYSIS FOR JUNE 11-15 FOR 500 MB
HEIGHTS GENERALLY SUGGEST UPPER LEVEL RIDGING WILL GRADUALLY
DEVELOP OVER THE REGION. THIS WILL BRING A PROLONGED STRETCH OF
DRY WEATHER, WITH TEMPERATURES LIKELY WARMING EACH DAY. WHILE
CONFIDENCE IS HIGH TEMPERATURES WILL WARM SIGNIFICANTLY COMPARED
TO EARLY IN THE WEEK, CONFIDENCE IS LOW REGARDING EXACTLY HOW
WARM TEMPERATURES WILL GET. THE NBM ENSEMBLE SPREAD REFLECTS
THIS UNCERTAINTY WELL, FOR EXAMPLE THE NBM 10TH-90TH PERCENTILE
FOR HIGH TEMPERATURES SATURDAY JUNE 13 THROUGH MONDAY JUNE
15, RANGE FROM LOW 80S TO NEAR 100 DEGREES FOR THE INLAND
VALLEYS AND UPPER 60S TO UPPER 80S FOR COASTAL LOCATIONS. BUT,
COMPARED TO PRIOR NBM RUNS YESTERDAY THIS SPREAD HAS SHRUNK BY
2-5 DEGREES, ALBEIT IN THE "WARMER" DIRECTION. PROBABILITIES
FOR MAJOR HEATRISK BEGIN TO HIT 10-25% ACROSS IN THE INLAND
VALLEYS STARTING SATURDAY JUNE 13 BEFORE INCREASING TO 20-45% BY
MONDAY JUNE 15TH. THOSE WHO ARE SENSITIVE TO HEAT AND/OR HAVE
OUTDOOR PLANS SHOULD DEFINITELY KEEP AN EYE ON THE FORECAST
OVER THE NEXT WEEK. -99/23
AVIATION
EXPECT MAINLY VFR CONDITIONS ACROSS THE REGION TODAY
ALTHOUGH WITH SOME CAVEATS. EARLY THIS MORNING RADAR IMAGERY SHOWS
AMPLE SHOWER ACTIVITY BEGINNING TO PUSH INLAND WITH CIGS
GENERALLY HOLDING AROUND 4-6KFT AS OF 11Z. HEADED THROUGH THE DAY
SOME OF THESE SHOWERS COULD BE HEAVIER, CAUSING BRIEF PERIODS OF
MVFR CIGS OR VIS. ADDITIONALLY, THERE'S A 20-35% CHANCE OF
THUNDERSTORMS NEAR AND NORTH OF KSLE AND KTMK AND 10-20% CHANCE
ELSEWHERE WEST OF THE CASCADES BETWEEN ROUGHLY 16-18Z THROUGH 00Z
SUN. BEST CHANCES WILL BE IN THE 18-22Z TIME PERIOD WITH SHOWER
AND THUNDERSTORM CHANCES DIMINISHING AFTER. ANY STRONGER ACTIVITY
COULD PRODUCE HEAVY RAIN THAT COULD CAUSE BRIEF PERIODS OF
MVFR/IFR CONDITIONS, SMALL HAIL, GUSTY AND ERRATIC WINDS, AND
LIGHTNING. CONFIDENCE IS HIGH LINGERING SHOWERS TAPER OFF AROUND
INLAND SITES BY 03-05Z SUN WITH DRY CONDITIONS AFTERWARD. WINDS
MAY BE A BIT BREEZY AT TIMES WITH A SOUTHERLY COMPONENT THIS
MORNING IN THE WILLAMETTE VALLEY BEFORE TURNING MORE WESTERLY LATE
IN THE AFTERNOON.
KPDX AND APPROACHES...VFR CONDITIONS ARE FAVORED THROUGH THE TAF
PERIOD. SHOWERS LIKELY CONTINUE AT TIMES THROUGH THE DAY WITH A
30-35% CHANCE OF THUNDERSTORMS BETWEEN 18-22Z SAT. ANY STRONGER
SHOWER OR THUNDERSTORMS COULD PRODUCE HEAVY RAIN THAT COULD CAUSE
BRIEF PERIODS OF MVFR CONDITIONS, SMALL HAIL, GUSTY/ERRATIC WINDS,
AND LIGHTNING. SHOWER AND THUNDERSTORM CHANCES DIMINISH AROUND
00-03Z SUN. WINDS REMAIN OUT OF THE SOUTHWEST THIS MORNING,
INCREASING AND SHIFTING WESTERLY AFTER 18-22Z. -99
MARINE
A FAIRLY PROGRESSIVE WEATHER PATTERN CONTINUES INTO
NEXT WEEK AS A SERIES OF FRONTAL SYSTEMS BRING INCREASING WINDS
AND BUILDING SEAS. SEAS THIS MORNING CURRENTLY HOLD IN THE 5-8 FT
RANGE AT ~10 SECONDS . ANOTHER SYSTEM MOVES THROUGH TODAY
BRINGING A SLIGHT INCREASE IN NORTHWESTERLY WINDS. HOWEVER, WIND
GUSTS ONLY HAVE AROUND A 10-35% CHANCE FOR SMALL CRAFT ADVISORY
WIND GUSTS WITH THE HIGHEST PROBABILITIES IN THIS RANGE ACROSS THE
OUTER WATERS. MINIMAL CONFIDENCE IN SMALL CRAFT CONDITIONS. AFTER
A LULL DURING THE DAY ON SUNDAY AS HIGH PRESSURE BRIEFLY RETURNS,
WINDS INCREASE YET AGAIN ON MONDAY AS A COMPARATIVELY STRONGER
SYSTEM MOVES OVER THE WATERS BRINGING SOUTH WIND GUSTS UP TO 21-25
KT AND SEAS APPROACHING 5-8 FT. CONDITIONS THEN GRADUALLY CALM
INTO THE MIDDLE THE OF THE WEEK AS A RIDGE OF HIGH PRESSURE
ATTEMPTS TO REBUILD OVERHEAD AND NORTHWESTERLY WINDS RETURN WHILE
SEAS HOLD AROUND 5-7FT AROUND 9-11 SECONDS. TOWARDS THE END OF
NEXT WEEK, THOSE NORTHWESTERLY WINDS LIKELY (60-80%) PUSH ABOVE
21 KNOTS ACROSS THE OUTER WATERS SOUTH OF CAPE FALCON AND WILL BE
A FEATURE TO WATCH IN THE LONG-TERM. -99
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
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