627
FXUS66 KPDT 251724
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1024 AM PDT TUE AUG 25 2026
KEY MESSAGES
- A VERY LOW CHANCE (<20 PERCENT) OF SHOWERS AND THUNDERSTORMS
FROM THE BLUE MOUNTAINS EASTWARD THIS AFTERNOON AND EVENING.
- ABOVE NORMAL TEMPERATURES WITH WIDESPREAD MODERATE HEAT RISK
TODAY AND WEDNESDAY.
- A TIGHTENING PRESSURE GRADIENT IN RESPONSE TO LOW PRESSURE
MOVING INTO BRITISH COLUMBIA WILL BRING INCREASED WINDS
WEDNESDAY AND EVEN BREEZIER CONDITIONS ON THURSDAY. FIRE
WEATHER CONDITIONS WILL APPROACH CRITICAL ON WEDNESDAY OVER
PORTIONS OF THE COLUMBIA BASIN AN GORGE. DESPITE STRONGER
WINDS THURSDAY, RH VALUES WILL BE HIGHER AS WELL.
DISCUSSION
STRONG HIGH PRESSURE OVER THE SOUTHWEST WILL BRING WARM AND
GENERALLY DRY WEATHER TO THE REGION THROUGH WEDNESDAY. THE ONLY
CAVEAT, IS A VERY LOW (<20 PERCENT) CHANCE OF AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS OVER THE BLUE MOUNTAINS AND
WALLOWA COUNTY TODAY AS SOME WEAK SHORT WAVE ENERGY MOVERS
THROUGH.
OTHERWISE, IT WILL BE VERY WARM, WITH AFTERNOON HIGH TEMPERATURES
IN THE LOW TO MID 90S. THESE TEMPERATURES ARE ABOUT 5 TO 10
DEGREES ABOVE NORMAL, DEPENDING ON LOCATION, WITH TODAY'S
TEMPERATURES A TAD WARMER THAN ON WEDNESDAY. HEATRISK IS
EXPECTED TO BE WIDESPREAD MODERATE BOTH DAYS.
BY WEDNESDAY, AN AREA OF LOW PRESSURE WILL BE MOVING NORTHEAST
OFF THE COAST TOWARD BRITISH COLUMBIA AND WILL MOVE INLAND IN
BRITISH COLUMBIA WEDNESDAY NIGHT OR EARLY THURSDAY. AS THIS LOW
MOVES CLOSER, THE PRESSURE GRADIENT WILL INCREASE BETWEEN IT AND
THE STRONG HIGH PRESSURE OVER THE SOUTHWEST. THE INCREASED
PRESSURE GRADIENT WILL CAUSE AN INCREASE IN WINDS BEGINNING
WEDNESDAY AND A FURTHER INCREASE ON THURSDAY.
ADDITIONALLY, WHILE THE MAIN UPPER TROUGH STAYS TO THE NORTH, A
COLD FRONT WILL MOVE THROUGH AND THIS FRONT WILL BRING COOLER
TEMPERATURES ON THURSDAY AND WE WILL GET INTO A MORE SPLIT FLOW
PATTERN, THEN A MORE WESTERLY FLOW THROUGH THE WEEKEND.
WINDS WILL GUST IN THE 25 TO 30 MPH RANGE, POSSIBLY AS HIGH AS
35 MPH IN A FEW SPOTS WEDNESDAY AFTERNOON, MAINLY ACROSS THE
CASCADE GAPS, SIMCOE HIGHLANDS AND COLUMBIA GORGE AND OREGON
COLUMBIA BASIN AND FOOTHILLS OF THE SOUTHERN BLUE MOUNTAINS.
NBM PROBABILITIES OF WIND GUSTS >=25 MPH ARE >80 PERCENT IN
THESE AREAS. HOWEVER, WIND GUSTS >=39 MPH ARE GENERALLY LESS
THAN 30 PERCENT, WITH A FEW LOCAL AREAS >= 50 PERCENT.
THE COMBINATION OF THE WIND GUSTS AND LOW RH VALUES WILL BRING
ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS AND PORTIONS OF THE
COLUMBIA BASIN AND GORGE WILL HAVE TO BE MONITORED FOR FIRE
WEATHER HEADLINES.
ON THURSDAY, WINDS ARE POSSIBLY A TAD STRONGER AND MORE
WIDESPREAD THAN ON WEDNESDAY. A VERY LARGE PORTION OF OUR AREA
HAS PROBABILITIES OF WIND GUSTS >=25 MPH THAT ARE >70 PERCENT.
IT IS MAINLY THE SIMCOE HIGHLANDS, PORTIONS OF THE BASIN, GORGE
AND KITTITAS VALLEY THAT HAVE >50 PERCENT PROBABILITIES FOR
WIND GUSTS >39 MPH. HOWEVER, WITH TEMPERATURES 8 TO 10 DEGREES
COOLER THAN ON WEDNESDAY, RH VALUES WILL BE ABOUT 5 TO 10%
HIGHER ON AVERAGE. THIS WILL KEEP FIRE WEATHER CONDITIONS
ELEVATE BUT SHOULD PRECLUDE ANY CRITICAL CONDITIONS.
FOR THOSE SKY WATCHERS OUT THERE, THIS THURSDAY NIGHT, AUGUST
27TH, THERE WILL BE A PARTIAL (BUT 93%) LUNAR ECLIPSE. WITH
SUNSET BEING AROUND 740 PM OR SO, DEPENDING ON YOUR LOCATION,
THE MOON WILL ALREADY BE IN ECLIPSE WHEN THE SUN GOES DOWN. PEAK
ECLIPSE WILL BE AROUND 912 PM PDT AND THE ECLIPSE WILL END
AROUND 1051 PM PDT. AT THIS POINT, THE SKY LOOKS TO BE
RELATIVELY CLEAR, THE ONLY CONCERN WILL BE IF THERE IS ANY SMOKE
OR HAZE FROM NEARBY WILDFIRES IN YOUR VICINITY.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
VFR CONDITIONS TO
PREVAIL THROUGH THE PERIOD. VERY LOW CONFIDENCE (10-15%) IN
SMOKE IMPACTS TO SITES. MOSTLY LIGHT WINDS THROUGH THE PERIOD.
EXCEPT AT SITES DLS/RDM/BDN WHERE WINDS WILL BE 10-15KTS WITH
GUSTS UP TO 25KTS THIS AFTERNOON. LAWHORN/82
PRELIMINARY POINT TEMPS/POPS
PDT 94 57 93 56 / 0 0 0 0
ALW 95 65 94 63 / 0 0 0 0
PSC 95 62 96 61 / 0 0 0 0
YKM 95 63 96 60 / 0 0 0 0
HRI 95 64 95 62 / 0 0 0 0
ELN 92 61 91 56 / 0 0 0 0
RDM 95 51 91 49 / 0 0 0 0
LGD 97 58 97 56 / 20 20 0 0
GCD 96 58 96 57 / 10 10 0 0
DLS 95 65 89 63 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...AIR QUALITY ALERT UNTIL NOON PDT WEDNESDAY FOR WAZ026-028>030-
522-523.
OR...AIR QUALITY ALERT UNTIL NOON PDT WEDNESDAY FOR ORZ044-502-503-
507.
DISCUSSION...77
AVIATION...82
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page