467
FXUS66 KPDT 040005
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
505 PM PDT WED SEP 3 2025
UPDATE
THE PRESENCE OF A PYROCB CLOUD ASSOCIATED WITH THE
WILDCAT FIRE IN WA695 HAS PROMPTED THE ISSUANCE OF A RED FLAG
WARNING FOR HOT, DRY, AND UNSTABLE CONDITIONS THROUGH 9 PM PDT
THURSDAY. PLUNKETT/86
AVIATION...00Z TAFS
PREDOMINANTLY VFR CONDITIONS ARE FORECAST
THROUGH THE PERIOD FOR ALL SITES. HOWEVER, SUB-VFR CONDITIONS WILL
BE POSSIBLE AT BDN/RDM THIS AFTERNOON AND EVENING IN SHOWERS
AND/OR THUNDERSTORMS (30% CHANCE). ELSEWHERE, INCREASING SMOKE
FROM AREA WILDFIRES MAY REDUCE SFC VSBYS TO SUB-VFR OVERNIGHT
THROUGH THURSDAY, BUT CONFIDENCE IN TIMING/MAGNITUDE OF VSBY
REDUCTIONS WAS TOO LOW TO INCLUDE IN THE 00Z TAFS. OVERALL,
CONFIDENCE IN VSBY FORECAST AT TERMINALS IS LOW-MEDIUM (20-50%).
WINDS WILL BE MOSTLY DIURNALLY AND TERRAIN-DRIVEN AT 12 KTS OR
LESS, OUTSIDE OF CONVECTIVE OUTFLOW WHICH HAS REACHED GUSTS UP TO
40 KTS IN CENTRAL OREGON. PLUNKETT/86
PREV DISCUSSION
/ISSUED 212 PM PDT WED SEP 3 2025/
DISCUSSION...RADAR SHOWS GENERALLY CLEAR CONDITIONS, EXCEPT A
BAND OF SHOWERS NEAR DESCHUTES COUNTY THANKS TO AN UPPER LEVEL
LOW THAT MOVED FROM NORTH CALIFORNIA TO SOUTHERN OREGON. A POP-UP
OF MIXED WET/DRY THUNDERSTORMS IS POSSIBLE OVER THE NEXT SEVERAL
HOURS AS PEAK DAYTIME HEATING STARTS TO TAKE EFFECT. CAMS SHOW A
LITTLE AGGRESSION IN THE LATER PART OF THE AFTERNOON FOR >40 DBZ
PAINTBALLS, BUT WILL WAIT AND SEE IF THIS VERIFIES THE RFW.
OVERALL, A HAZY AND SILKY SETTING HAS TAKEN PLACE OVER THE CWA
THANKS TO THE ABUNDANCE OF WILDFIRE SMOKE AROUND AND IN THE AREA.
IN FACT, THE WA DEPT OF ECOLOGY WENT AHEAD AND ISSUED AIR QUALITY
ALERTS UNTIL FURTHER NOTICE FOR ALL WA COUNTIES IN THE CWA DUE TO
DECREASED AIR QUALITY LEVELS. HEAT HIGHLIGHTS CONTINUE THROUGH
TODAY AS THE UPPER RIDGE CONTINUES TO DOMINATE THE PACNW, WITH
EXPECTED TRIPLE DIGIT HIGHS IN PARTS OF THE BASIN. HIGHS WILL COOL
OFF VERY SLIGHTLY THROUGH TOMORROW WITH "MAJOR" IMPACTS BEING
LESS WIDESPREAD (BUT STILL IMPACTFUL) GOING INTO TOMORROW.
THUNDERSTORMS TOMORROW WILL NOT BE INFLUENCED BY THE UPPER LOW,
INSTEAD BE MORE DIURNALLY DRIVEN. CAMS HINTING SIGNS OF
CONVECTION FOR CENTRAL OR AND PARTS OF THE SOUTHERN BLUES AND
CASCADES. WENT AHEAD AND ADDED POP THUNDER (15-20% CHANCE) FOR
THOSE AREAS TOMORROW AFTERNOON. WASN'T TOO CONFIDENT IN ISSUING
RFW FOR PARTS OF THE OR CASCADES AND OTHER PARTS NEAR CENTRAL OR
GIVEN THE UNCERTAINTY OF THE STRENGTH OF THESE STORMS. GOING
THROUGH THE NEXT SEVERAL DAYS, WE'LL SEE AN OPPOSITE PATTERN THAN
THE DRY/HOT SET-UP WE'VE HAD THIS WEEK. THE RIDGE WILL PUSH OFF TO
THE EAST WHILE A TROUGH WILL BEGIN TO INFLUENCE THE PATTERN.
COOLER HIGHS WILL ENTER THE PICTURE BY THE WEEKEND WITH HIGHS IN
THE LOW TO MID 80S, WITH POSSIBLE SUB-80 DEGREE HIGHS BY THE
BEGINNING OF NEXT WEEK. AT THE EXPENSE, WE'LL SEE MORE WIDESPREAD
PRECIPITATION FOR MULTIPLE DAYS THAT WILL EXTEND TO MUCH OF THE
FORECAST AREA. COULD SEE SOME STORMS TURN INTO THUNDERSHOWERS OR
THUNDERSTORMS DURING THE PEAK HEATING PHASE, ESPECIALLY ACROSS THE
MOUNTAIN REGIONS. THIS WILL BRING RELIEF TO THE SMOKE AND HAZE
WE'VE WITNESSED FOR THE PAST SEVERAL DAYS. ALTHOUGH I'M NOT
CONFIDENT JUST YET (~35% CHANCE) OF IT COMPLETELY CLEARING THE AIR
BY ROUND-UP WEEK STARTING. WINDS REMAIN LIGHT UP TO 12 KNOTS,
ALBEIT WILL BE A BIT STRONGER NEXT WEEK WITH THE NEXT DISTURBANCE
PUSHING THROUGH, ESPECIALLY THE CASCADE GAPS.
PRELIMINARY POINT TEMPS/POPS
PDT 66 97 65 94 / 0 0 10 0
ALW 71 98 69 95 / 0 0 0 0
PSC 63 99 64 97 / 0 0 0 0
YKM 68 99 67 96 / 0 0 0 0
HRI 66 99 65 96 / 0 0 0 0
ELN 64 98 62 93 / 0 0 0 0
RDM 56 93 56 90 / 20 10 20 30
LGD 61 96 61 94 / 10 0 10 10
GCD 62 93 60 92 / 10 10 10 10
DLS 71 99 69 97 / 10 10 10 10
PDT WATCHES/WARNINGS/ADVISORIES
OR...EXTREME HEAT WARNING UNTIL 8 PM PDT THURSDAY FOR ORZ041-044-507-
508-510.
HEAT ADVISORY UNTIL 8 PM PDT THURSDAY FOR ORZ049-050-502-505.
RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR ORZ705.
WA...EXTREME HEAT WARNING UNTIL 8 PM PDT THURSDAY FOR WAZ024-026>029-
521.
HEAT ADVISORY UNTIL 8 PM PDT THURSDAY FOR WAZ030-523.
RED FLAG WARNING UNTIL 9 PM PDT THURSDAY FOR WAZ695.
UPDATE...86
SHORT TERM...95
LONG TERM....95
AVIATION...86
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