467
FXUS66 KPDT 161018
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
318 AM PDT SUN AUG 16 2026
KEY MESSAGES
1. CONTINUED SOUTHWEST FLOW WILL BRING CHANCES OF THUNDERSTORMS AND
SHOWERS THROUGH MONDAY.
2. INCREASED GAP WINDS MONDAY NIGHT AND TUESDAY
DISCUSSION
CURRENT NIGHTTIME SATELLITE SHOWS MID LEVEL CLOUDS OVER A VAST
MAJORITY OF THE REGION. RADAR SHOWS THE LAST OF THE CELLS TO BE
TAPERING OF AND NOT PRODUCING ANY LIGHTNING OR RAINFALL WITH THEM.
THE OVERCAST CONDITIONS THROUGH THE NIGHT WILL HELP TO KEEP
OVERNIGHT LOW IN THE LOW TO MID 50S WITH AREAS IN THE BASIN SEEING
LOW 60S.
MODELS SHOW SOUTHWEST FLOW TO REMAIN OVER THE REGION THROUGH MONDAY.
THIS WILL ALLOW MOISTURE TO CONTINUE TO MOVE INTO THE REGION. CAMS
MODELS SHOW THERE TO BE SOLID CHANCES OF THUNDERSTORMS EACH DAY
THROUGH MONDAY. MODELS INDICATE CHANCES (15-25%) FOR THUNDERSTORMS
TODAY AFTER 1100 ACROSS PORTIONS OF UNION COUNTY INTO THE EAGLE CAPS
AND EVEN WALLOWA VALLEY. LOOKING AT RAP FORECASTED SOUNDINGS, THERE
IS MORE THAN ENOUGH MUCAPE TO FIRE OFF A FEW STORMS ACROSS THE AREA.
MODELS SHOW MUCAPE OVER 700 J/KG, LAPSE RATES BETWEEN 8-10 C/KM, LIS
AT -4 TO -6 AND SHEAR NEARING 30 KTS. THIS COUPLED WITH THE
OROGRAPHIC LIFT COULD LEAD TO A FEW STRONGER STORMS POPPING UP OVER
THE AREA THIS AFTERNOON. MODELS SHOW ROUGHLY THE SAME SET UP THE
NEXT DAY WITH CONTINUED SOUTHWEST FLOW. HOWEVER, FORECAST SOUNDINGS
ARE A BIT WEAKER THAN PREVIOUS DAYS WITH MUCAPE IN THE 400-700 J/KG
RANGE WITH LIS OF -3 TO -4 AND LAPSE RATES OF 7-9 C/KM AND SHEAR
BELOW 25 KTS. THIS IS STILL MORE THAN ENOUGH TO ALLOW THUNDERSTORMS
TO OCCUR, HOWEVER, CONFIDENCE IN THUNDERSTORMS OCCURRING IS 10-20%.
BY TUESDAY MODELS BEGIN TO SHOW AN UPPER LEVEL LOW PUSHING INTO THE
REGION FROM THE NORTH BRINGING SPLIT FLOW ACROSS THE REGION. AS THAT
UPPER LEVEL LOW CONTINUES TO DIG SOUTH, GRADIENTS ALONG THE WA
CASCADES BEGIN TO TIGHTEN WITH THE NORTHWEST FLOW ALOFT. WINDS ARE
EXPECTED TO INCREASE THROUGH THE CASCADE GAPS ON TUESDAY AS THE
SYSTEM MOVES OVER THE CASCADES. NBM RAW ENSEMBLES SHOW WINDS TO BE
BETWEEN 20-25 MPH WITH 50-70% CONFIDENCE. GUSTS TO 30-45 THROUGH THE
GAPS AS WELL.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
VFR CONDITIONS WILL PERSIST THROUGH THE FORECAST PERIOD.
WINDS WILL BE GENERALLY BELOW 10 KTS WITH SOME GUSTY WINDS AT
RDM/BDN THIS AFTERNOON. DLS WILL REMAIN BREEZY THROUGH THE PERIOD
WITH SUSTAINED WINDS 12-15 KTS AND GUSTS TO NEAT 25 KTS. UPPER LEVEL
SMOKE MAY LINGER, BUT LITTLE CONFIDENCE IN SURFACE SMOKE CAUSING ANY
VIS ISSUES AT ANY OF THE TAF SITES.
FIRE WEATHER
DRY CONDITIONS WILL CONTINUE OVER THE AREA THROUGH
THE WEEK AND FIRE WEATHER CONCERNS WILL REMAIN ELEVATED. THREAT OF
THUNDERSTORMS IS 15-25% ALONG THE FAR EASTERN MOUNTAINS AND INTO
WALLOW TODAY AND AGAIN ON MONDAY. AFTER MONDAY, THE THREAT OF
THUNDERSTORMS DIMINISH. DAYTIME HUMIDITIES WILL RANGE FROM 15-25%
EACH DAY. WINDS WILL INCREASE TUESDAY WITH SUSTAINED WINDS THROUGH
THE GAPS OF 20-25 MPH AND GUSTS 30-35 MPH. WITH THE INCREASED WINDS
ON TUESDAY, THERE ARE SOME ISOLATED AREAS THAT MAY REACH CRITICAL
CONDITIONS, MAINLY ALONG THE SOUTHERN BLUE FOOTHILLS.
PRELIMINARY POINT TEMPS/POPS
PDT 88 57 89 60 / 0 0 0 0
ALW 89 63 90 66 / 0 0 0 0
PSC 93 60 93 60 / 0 0 0 0
YKM 91 61 93 63 / 0 0 0 0
HRI 91 61 92 63 / 0 0 0 0
ELN 86 59 89 60 / 0 0 0 0
RDM 87 51 88 49 / 0 0 0 0
LGD 89 57 91 56 / 10 0 10 20
GCD 91 56 91 55 / 0 0 0 0
DLS 89 61 92 63 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...AIR QUALITY ALERT UNTIL NOON PDT MONDAY FOR WAZ026-522-523.
OR...AIR QUALITY ALERT UNTIL NOON PDT MONDAY FOR ORZ041-503-505-506-
508>511.
DISCUSSION...90
AVIATION...90
FIRE WEATHER...90
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page