902
FXUS66 KPDT 140456
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
956 PM PDT SAT JUN 13 2026
KEY MESSAGES
- WARMING TREND INTO NEXT WEEK, PEAKING MONDAY.
*HEAT ADVISORIES ISSUED*
- BREEZY AFTERNOON WINDS EXTEND THROUGH MIDWEEK.
- ISOLATED FIRE WEATHER CONCERNS SUNDAY, WIDESPREAD TUESDAY.
DISCUSSION
CURRENT RADAR AND VISIBLE SATELLITE IMAGERY SHOWS DRY CONDITIONS
AND CLEAR SKIES ACROSS THE REGION. THIS IS IN RESPONSE TO AN
UPPER LEVEL RIDGE OF HIGH PRESSURE OFFSHORE, THAT WILL
CONTINUE TO BUILD THROUGH THE WEEKEND BEFORE SLOWLY MOVING
ONSHORE EARLY MONDAY. CLEAR SKIES AND WARMING TEMPERATURES WILL
PERSIST AS AN INVERTED SURFACE THERMAL TROUGH BUILDS ALONG THE
COAST ASSOCIATED WITH THE UPPER LEVEL HIGH PRESSURE. AS A
RESULT, HIGH TEMPERATURES ACROSS THE LOWER COLUMBIA BASIN,
CENTRAL OREGON, COLUMBIA GORGE, BLUE MOUNTAIN FOOTHILLS, AND THE
YAKIMA/KITTITAS VALLEYS WILL REACH INTO THE MID-TO UPPER 80S
TODAY, UPPER 80S TO LOW 90S SUNDAY, AND IN THE MID-TO UPPER 90S
ON MONDAY. MONDAY MORNING LOWS ARE EXPECTED TO DROP INTO THE
MID-50S AND LEAD TO WIDESPREAD MODERATE HEATRISK (2 OF 4)
ACROSS THE AREA. THERE ARE ALSO ISOLATED POCKETS OF MAJOR
HEATRISK (3 OR 4) THROUGH THE COLUMBIA GORGE AND THE YAKIMA
VALLEY. THUS, A HEAT ADVISORY HAS BEEN ISSUED FROM 10 AM TO 10
PM MONDAY FOR THE COLUMBIA GORGE, CENTRAL OREGON, AND THE
YAKIMA/KITTITAS VALLEYS. TEMPERATURES WILL STILL BE WARM TUESDAY
WITH LOWS IN THE LOW TO MID-60S AND HIGHS IN THE LOW TO
MID-90S, BUT A PASSING COLD FRONT IN THE AFTERNOON/EVENING WILL
BRING RELIEF OVERNIGHT AND INTO WEDNESDAY AS TEMPERATURES COOL
ABOUT 5 DEGREES.
AS THE RIDGE BUILDS THROUGH THE EARLY PART OF THE WEEK, A
SHORTWAVE EJECTS FROM AN UPPER LEVEL SYSTEM OFF THE COAST OF
ALASKA, BRINGING AN INCREASE IN CLOUD COVER EARLY MONDAY MORNING
AND BREEZY AFTERNOON WINDS. THE INCOMING SHORTWAVE APPROACHES ON
MONDAY, HELPING TO SUPPRESS THE UPPER LEVEL RIDGE AND TIGHTEN
THE PRESSURE GRADIENT BETWEEN THE TWO SYNOPTIC FEATURES. THIS
PRESSURE GRADIENT IS EXPECTED TO PEAK LATE TUESDAY MORNING AND
PERSIST THROUGH THE DAY AS THE GFS AND SREF HIGHLIGHT A 10-14 MB
GRADIENT BETWEEN PDX AND GEG. THIS WILL LEAD TO WIND GUSTS OF UP
TO 55 MPH ACROSS THE SIMCOE HIGHLANDS, NORTH-CENTRAL OREGON, AND
THE BLUE MOUNTAIN FOOTHILLS, AND UP TO 65 MPH THROUGH THE
KITTITAS VALLEY. THE NBM ADVERTISES A 70-90% CHANCE OF
ADVISORY-LEVEL WIND GUSTS (45+ MPH) ACROSS THE SIMCOE HIGHLANDS,
NORTH-CENTRAL OREGON, AND THE BLUE MOUNTAIN FOOTHILLS, AND A
40-60% CHANCE OF WARNING-LEVEL WIND GUSTS (58+ MPH) THROUGH THE
KITTITAS VALLEY. CONFIDENCE IS IMPROVING IN THE LIKELIHOOD OF
WIND PRODUCTS BEING ISSUED ON TUESDAY AS ONLY 19% OF ENSEMBLE
MEMBERS HINT AT SLIGHTLY HIGHER WIND VALUES AND 18% OF MEMBERS
SHOWCASE SLIGHTLY LOWER VALUES DUE TO VARIABILITY RELATED TO THE
STRENGTH OF THE INCOMING SHORTWAVE TROUGH AND ATTENDANT COLD
FRONT PASSAGE.
THE HEIGHTENED WINDS, HOT TEMPERATURES, AND LOW HUMIDITIES WILL
ELEVATE FIRE WEATHER CONCERNS ON TUESDAY. ISOLATED CONCERNS ARE
PRESENT THROUGH MONDAY OVER NORTH-CENTRAL OREGON, BUT BECOME
MORE WIDESPREAD ON TUESDAY. IN FACT, ALL FIRE WEATHER ZONES
(WA/OR691, OR700, OR704, AND OR705) IN WHERE FUELS ARE RECEPTIVE
FOR FIRE START AND SPREAD MAY HAVE WINDS AND HUMIDITY VALUES
THAT WOULD CORRELATE TO THE NEED FOR A RED FLAG WARNING PRODUCT.
HOWEVER, THE INCOMING COLD FRONT SHOULD HELP IN BRINGING COOLER
TEMPERATURES ACROSS THE AREA THAT WOULD INCREASE HUMIDITIES,
BUT THIS AID MAY ARRIVE LATER IN THE EVENING. 50% OF ENSEMBLE
MEMBERS SUGGEST EITHER A FASTER INCOMING SHORTWAVE OR A MORE
SUPPRESSED RIDGE TUESDAY AFTERNOON/EVENING, WHICH WOULD RELATE
TO HIGHER AFTERNOON HUMIDITY VALUES THAN CURRENTLY FORECAST.
THUS, THIS WOULD NEED TO BE FURTHER ANALYZED AS THE EVENT NEARS
FOR MORE MODEL CONSISTENCY IN THE TIMING OF THE INCOMING
SHORTWAVE.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
VFR CONDITIONS ARE FORECAST AT ALL SITES THROUGH THE PERIOD.
SKIES ARE EXPECTED (95 PERCENT CONFIDENCE) TO BE CLEAR TO
MOSTLY CLEAR, WITH SOME PASSING CIRRUS. WINDS WILL BE DIURNALLY
DRIVEN, MOSTLY LIGHT OVERNIGHT FOLLOWED BY BREEZY (10-15 KTS)
NORTHERLY TO EASTERLY WINDS WITH HIGHER GUSTS (15-20 KTS)
DURING THE AFTERNOON AND EVENING HOURS.
FIRE WEATHER
AS STATED IN THE ABOVE DISCUSSION, FIRE WEATHER ZONES WITH FUELS
THAT ARE RECEPTIVE TO FIRE INITIATION AND SPREAD (WA/OR691,
OR700, OR704, AND OR705) MAY REQUIRE FIRE WEATHER PRODUCTS ON
TUESDAY RELATED TO LOW AFTERNOON HUMIDITIES AND HIGH WINDS.
THERE IS GOOD CONFIDENCE (70-90%) THAT WINDS WILL BE HIGH ENOUGH
TO WARRANT CONCERNS, BUT ONLY MARGINAL CONFIDENCE (50%) IS
PRESENT WHEN ANALYZING MINIMUM AFTERNOON HUMIDITIES. CURRENT
TIMING OF CONCERN WOULD BE BETWEEN 1000 AND 2200 TUESDAY.
PRELIMINARY POINT TEMPS/POPS
PDT 50 87 53 92 / 0 0 0 0
ALW 54 87 57 92 / 0 0 0 0
PSC 56 91 57 96 / 0 0 0 0
YKM 57 91 60 98 / 0 0 0 0
HRI 54 90 56 95 / 0 0 0 0
ELN 53 87 59 94 / 0 0 0 0
RDM 47 86 49 92 / 0 0 0 0
LGD 48 84 49 89 / 0 0 0 0
GCD 45 86 47 91 / 0 0 0 0
DLS 61 93 64 99 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...HEAT ADVISORY FROM 10 AM TO 10 PM PDT MONDAY FOR WAZ024-026-
027.
OR...HEAT ADVISORY FROM 10 AM TO 10 PM PDT MONDAY FOR ORZ041-511.
DISCUSSION...75
AVIATION...86
FIRE WEATHER...75
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