985
FXUS66 KPDT 041825 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED.
NATIONAL WEATHER SERVICE PENDLETON OR
1125 AM PDT TUE AUG 4 2026
KEY MESSAGES
- ELEVATED TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS CONTINUE
THROUGH THE WEEK WITH OVERLAPPING BREEZY WINDS AND DRY AIR IN
THE REGION.
- WIDESPREAD SMOKE AND HAZE PREVAIL FORM LOCAL AND REGIONAL
WILDFIRES IN THE AREA, GIVING OFF SUB-PAR AIR QUALITY.
- HEATRISK INCREASES THROUGH THE MID-WEEK AS A WARMING TREND
CONTINUES THROUGH THURSDAY.
DISCUSSION
SATELLITE AND NIGHT PHYSICS CONTINUE TO ADVERTISE WIDESPREAD
SMOKE AND HAZE ACROSS THE REGION FROM REGIONAL AND LOCAL
WILDLAND FIRES. AN UPPER-LEVEL RIDGE WILL CONTINUE TO CONTRIBUTE
POOR MIXING IN THE ATMOSPHERE OVER THE NEXT FEW DAYS, ALLOWING
SUB- PAR AIR QUALITY ACROSS THE FORECAST AREA. THE UPPER LEVEL
RIDGE WILL CONTINUE TO AMPLIFY OVER THE NEXT COUPLE OF DAYS,
ALLOWING SMOKE TRANSPORT TO PERSIST IN THE AREA AND SETTLE
THROUGH AT LEAST THE MIDDLE TO LATE WEEK (>90% CONFIDENCE). AS
SUCH, LOCAL AGENCIES FROM WASHINGTON AND OREGON HAVE MAINTAINED
AIR QUALITY ALERTS/ADVISORIES HIGHLIGHTS UNTIL FURTHER NOTICE.
THE UPPER LEVEL RIDGE WILL CONTINUE TO MOVE EAST WITH THE AXIS
OVER THE AREA PUSHING OVERHEAD IN THE THURSDAY/FRIDAY TIME
FRAME. AN EXPECTED WARMING TREND (>90% CONFIDENCE) WILL CONTINUE
THROUGH THE WEEK, WITH HIGH TEMPERATURES PEAKING THURSDAY WITH
PARTS OF THE COLUMBIA BASIN REACHING TRIPLE DIGIT HEAT (70-80%
CONFIDENCE). OUTLOOKS HAVE PLACED WIDESPREAD >90% CHANCES OF
'MODERATE' HEATRISK DEVELOPING. WITH THAT IN MIND, SMOKE CAN
EFFECT THE HIGH TEMPERATURE WITH PLACES INHIBITING
HEAVIER/THICKER SMOKE PLUMES WILL SEE "COOLER" THAN EXPECTED
TEMPERATURES.
GUIDANCE IN THE SYNOPTIC LEVEL THROUGH FRIDAY IS IN GOOD
AGREEMENT THAT THE PATTERN WILL TURN INTO A ZONAL/QUASI-ZONAL
FLOW WITH TIGHTER PRESSURE GRADIENTS, RESULTING IN BREEZY TO
LOCALLY WINDY CONDITIONS DEVELOPING LATE THIS WEEK. WITH DRY AIR
LINGERING WITH MINIMUM RELATIVE HUMIDITIES STILL IN THE 10-18
PERCENT RANGE FRIDAY, CHANCES OF CRITICAL WEATHER CONDITIONS
DEVELOPING GO UP WITH 50-70% CONFIDENCE.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
AVIATION CONCERNS
REVOLVE AROUND SMOKE AND SMOKE LAYERS ALOFT FROM AREA WILDFIRES.
LATEST SATELLITE SHOWS SMOKE ALOFT IS LARGELY TRANSLUCENT. SMOKE IS
COMMONLY REDUCING VISIBILITY DOWN TO MVFR 3SM-5SM AT MANY SITES WITH
SMOKE LAYERS CENTRAL IN CENTRAL AND NORTH CENTRAL OR AROUND 3-4
KFT/LOW-END VFR. EASTERLY-NORTHEASTERLY FLOW REGIME ALOFT WILL
CONTINUE TO KEEP SMOKE AT SITES, HOWEVER, SOME IMPROVEMENT OWING TO
A LOWER TRANSPORT OF SMOKE IS EXPECTED TO WORK INTO NORTHEAST OR
TERMINALS BASED ON HI-RES GUIDANCE. HIGHEST CONFIDENCE IN KPDT AND
KALW THOUGH A MODERATE SIGNAL IS SEEN IN CENTRAL OR.
OTHERWISE, WINDS WILL REMAIN LARGELY LIGHT AND PREDOMINANTLY N-E
WITH INCREASED WINDS IN THE AFTERNOON/EVENING BEFORE LESSENING
OVERNIGHT.
PRELIMINARY POINT TEMPS/POPS
PDT 88 52 94 58 / 0 0 0 0
ALW 90 58 96 64 / 0 0 0 0
PSC 91 56 96 60 / 0 0 0 0
YKM 90 59 95 62 / 0 0 0 0
HRI 90 58 96 61 / 0 0 0 0
ELN 88 59 94 62 / 0 0 0 0
RDM 89 48 97 53 / 0 0 0 0
LGD 89 52 97 56 / 0 0 0 0
GCD 90 53 98 57 / 0 0 0 0
DLS 92 63 98 65 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...AIR QUALITY ALERT UNTIL 5 AM PDT TUESDAY FOR WAZ024-026>030-
521>523.
OR...AIR QUALITY ALERT UNTIL 5 AM PDT TUESDAY FOR ORZ041-044-049-
050-502-503-505>507-509>511.
DISCUSSION...95
AVIATION...80
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