687
FXUS66 KPQR 132103
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
203 PM PDT MON JUL 13 2026
SYNOPSIS
THE NEXT SEVEN DAYS ARE HIGHLIGHTED BY ABOVE NORMAL
TEMPERATURES WITH LOW-LEVEL ONSHORE FLOW REMAINING IN PLACE. MAINLY
DRY WEATHER WILL CONTINUE THROUGH THE WEEKEND, ASIDE FROM LATE
WEDNESDAY INTO THURSDAY WHEN CHANCES FOR RAIN SHOWERS AND ISOLATED
THUNDERSTORMS INCREASE WITH AN APPROACHING UPPER LEVEL LOW.
SHORT TERM...MONDAY AFTERNOON THROUGH THURSDAY NIGHT
SATELLITE AND
SURFACE WEATHER OBSERVATIONS FROM EARLY MONDAY AFTERNOON DEPICTED
CLEAR SKIES ACROSS ALL OF WESTERN WA AND WESTERN OR WITH HIGH
PRESSURE IN PLACE. HOWEVER, AN AREA OF UPPER LEVEL SMOKE COMING FROM
THE EAST EVANS CREEK FIRE BURNING TO THE NORTH OF MEDFORD, OR WAS
BEGINNING TO MOVE INTO EASTERN LANE COUNTY. THIS HAS RESULTED IN
SLIGHTLY HAZY SKIES IN THE LANE COUNTY CASCADES.
OTHERWISE EXPECT MOSTLY CLEAR SKIES TO CONTINUE FOR INLAND AREAS
TONIGHT THROUGH TUESDAY WITH BROKEN LOW CLOUDS AT THE COAST TUESDAY
MORNING. TUESDAY WILL BE ANOTHER WARM DAY WITH AFTERNOON HIGHS IN THE
UPPER 80S TO NEAR 90 DEGREES FOR INLAND VALLEYS, WITH HIGHS AROUND
65-70 DEGREES AT THE COAST DUE TO ONSHORE WINDS. TEMPERATURES WILL BE
NEARLY THE SAME ON WEDNESDAY WITH PLENTY OF SUNSHINE, ASIDE FROM SOME
DEGREE OF LOW MARINE STRATUS AT THE COAST IN THE MORNING. DRY
CONDITIONS WILL ALSO CONTINUE THROUGH WEDNESDAY EVENING, ASIDE FROM A
15-30% CHANCE OF RAIN SHOWERS OVER THE OREGON CASCADES TUESDAY
EVENING/NIGHT AND AGAIN WEDNESDAY AFTERNOON/EVENING. CHANCES FOR
SHOWERS DURING BOTH OF THESE PERIODS ARE TIED TO TWO UPPER LEVEL
IMPULSES AHEAD OF A CLOSED UPPER LEVEL LOW CENTERED SOMEWHERE OVER
THE FAR NORTHEAST PACIFIC. HOWEVER, DRY AIR ENTRAINMENT INTO STORM
UPDRAFTS WILL LIKELY LIMIT VERTICAL GROWTH OF ANY CELLS THAT DO
DEVELOP. IN TURN, THIS WILL LIMIT THE POTENTIAL FOR LIGHTNING AND
SIGNIFICANT RAIN AMOUNTS. THE NBM BACKS THIS UP, PRODUCING ONLY A
5-15% CHANCE OF THUNDERSTORMS ON THE WEST SLOPES OF THE CASCADES WITH
A TRACE TO 0.05 INCHES OF RAIN NEAR THE CASCADE CREST.
CHANCES FOR SHOWERS AND HIGHER RAIN AMOUNTS INCREASE WEDNESDAY NIGHT
INTO THURSDAY ACROSS ALL OF NORTHWEST OR AND SOUTHWEST WA, ESPECIALLY
OVER SOUTHWEST WA AND FAR NORTHWEST OR TO THE NORTH AND EAST OF
SALEM. NBM POPS HAVE INCREASED TO 30-50% IN THESE AREAS, AND 15-30%
TO THE SOUTH OF SALEM THROUGH LANE COUNTY. THIS IS IN RESPONSE TO THE
AFOREMENTIONED UPPER LEVEL LOW OVER THE FAR NORTHEAST PACIFIC
ATTEMPTING TO SLOWLY MOVE INLAND SOMEWHERE OVER NORTHWEST OR AND/OR
WESTERN WA. THE USE OF THE WORD "ATTEMPTING" IN THE PREVIOUS SENTENCE
WAS INTENTIONAL, AS ROUGHLY HALF OF THE ENSEMBLE SPACE FROM THE
GEFS/GEPS/ENS SUGGESTS THIS LOW WILL MOVE NEAR THE COAST OR INLAND,
WHILE THE OTHER HALF KEEP THE LOW STALLED FARTHER OFFSHORE WHILE
WEAKENING. IF THIS LOW DOES MOVE INLAND, TEMPERATURES WOULD TREND
COOLER THAN THE CURRENT DETERMINISTIC FORECAST WITH RAIN SHOWERS AND
ISOLATED THUNDERSTORMS BECOMING MORE PREVALENT. IF THIS LOW STAYS
WELL OFFSHORE, CONDITIONS WOULD TREND MAINLY DRY AND WARMER WEST OF
THE CASCADES. THIS UNCERTAINTY IS HIGHLY EVIDENT IN TOTAL MODEL
SPREAD FOR TEMPERATURES, WITH THE NBM 10TH-90TH PERCENTILE SUGGESTING
INLAND VALLEYS COULD RANGE ANYWHERE FROM AROUND 80 DEGREES TO NEAR 95
DEGREES ON WEDNESDAY AND ANYWHERE FROM 75-100 DEGREES ON THURSDAY.
LARGE MODEL SPREAD IS EVIDENT FOR QPF AS WELL, WITH THE NBM MIN TO
MAX 24-QPF VALUES RANGING FROM NO RAIN AT ALL TO OVER 0.25-0.50
INCHES. IF THE LOW DOES WIND UP MOVING DIRECTLY OVER NORTHWEST OR AND
SOUTHWEST WA, SOME SHOWERS AND THUNDERSTORMS WOULD LIKELY PRODUCE
LOCALLY HEAVY RAINFALL GIVEN PWAT VALUES AROUND 1", CLOUD LAYER WINDS
NEAR 15-20 KT, AND DEEP WARM CLOUD LAYER DEPTHS NEAR 3000-3500
METERS. THAT SAID, PRECIPITATION WOULD BE VERY HIT-OR-MISS GIVEN THE
SHOWERY NATURE, MEANING SOME LOCATIONS WOULD RECEIVE LITTLE TO NO
RAIN WHILE OTHER LOCATIONS RECEIVE 0.25-0.50 INCHES OR MORE. -23
LONG TERM...FRIDAY THROUGH SUNDAY NIGHT
CONFIDENCE IN THE FORECAST
ACTUALLY INCREASES FRIDAY INTO THE WEEKEND COMPARED TO THE WEDNESDAY
NIGHT AND THURSDAY TIMEFRAME, DESPITE TOTAL MODEL SPREAD FOR
TEMPERATURES REMAINING LARGE. OVERALL, MODEL ENSEMBLES ARE IN GOOD
AGREEMENT FOR DRY AND WARM CONDITIONS FRIDAY THROUGH THE UPCOMING
WEEKEND WITH CONTINUED LOW-LEVEL ONSHORE FLOW AND SOUTHWEST FLOW
ALOFT. THE MAIN UNCERTAINTY IN THE LONG TERM FORECAST IS EXACT HIGH
TEMPERATURES FOR INLAND VALLEYS, WHICH COULD RANGE ANYWHERE FROM THE
LOWER 80S TO NEAR 100 DEGREES. THE MOST LIKELY OUTCOME IS FOR HIGHS
SOMEWHERE IN THE MID 80S TO LOWER 90S.
CHANCES FOR HIGHS ABOVE 90 DEGREES PEAK ON SUNDAY AT 40-60% FOR
INLAND VALLEYS, EXCEPT 30-40% OVER THE COWLITZ VALLEY AND LOWER
COLUMBIA. CHANCES FOR HIGHS OF 100 DEGREES OR WARMER RANGE BETWEEN
5-15%. PROBABILITIES FOR A MAJOR HEATRISK OR HIGHER ARE ALSO LOW,
RANGING BETWEEN 5-20%. THIS SUGGESTS EXTREME HEAT WITH SIGNIFICANT
HEAT-RELATED IMPACTS ARE UNLIKELY TO OCCUR. IT IS ALSO WORTH NOTING
THE COAST WOULD REMAIN MUCH COOLER THAN INLAND AREAS REGARDLESS OF
THE OUTCOME DUE TO LIGHT ONSHORE WINDS. BEYOND THE SEVEN DAY
FORECAST, IT IS POSSIBLE THE WARM AND DRY CONDITIONS WILL PERSIST
INTO EARLY NEXT WEEK AS PROBABILISTIC GUIDANCE IS SIMILAR ON MONDAY
WHEN COMPARED TO SUNDAY. -23
AVIATION
VFR CONDITIONS WITH MOSTLY CLEAR SKIES ARE EXPECTED
FOR A MAJORITY OF THE TAF PERIOD. LIGHT NORTH TO NORTHWEST WINDS
5-10 KT EXPECTED. WINDS ALONG THE COAST COULD GUST UP TO 20-25 MPH
AT TIMES THROUGH 03Z TUE. THERE'S A CHANCE OF SHALLOW MVFR/IFR
STRATUS ALONG THE COAST OVERNIGHT INTO TUESDAY MORNING: 20-50%
CHANCE ANYTIME BETWEEN 09-16Z TUE AT KONP AND 20-30% CHANCE
ANYTIME BETWEEN 12-15Z AT KAST.
KPDX AND APPROACHES...VFR WITH MOSTLY CLEAR SKIES AND
NORTHWESTERLY WINDS AROUND 5-8 KT. -03
MARINE
BENIGN CONDITIONS WITH A TYPICAL SUMMERTIME PATTERN
EXPECTED THROUGH THE WEEK. NORTHERLY WINDS 10-15 KT EXPECTED WITH
AFTERNOON GUSTS REACHING TO AROUND 20 KT EACH DAY. SEAS COULD BE
CHOPPY AT TIMES WITH HEIGHTS MAINLY IN THE 4-6 FOOT RANGE BUT
COULD SEE SOME 7 FOOT SEAS AT 8-10 SECONDS. ISOLATED STEEP AND
HAZARDOUS SEAS BUT NOT ENOUGH TO ISSUE A SMALL CRAFT ADVISORY
(SCA).
A SCA IS IN EFFECT FROM 2AM TO 9AM TUESDAY MORNING FOR THE
COLUMBIA RIVER BAR FOR ROUGH SEAS DUE TO A VERY STRONG EBB CURRENT
LEADING TO SEAS OF 6 TO 8 FT. -19/03
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 2 AM TO 9 AM PDT TUESDAY FOR PZZ210.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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