041
FXUS66 KPDT 032021
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
121 PM PDT FRI OCT 3 2025
DISCUSSION
SKIES ARE CLEARING ACROSS THE BASIN THIS AFTERNOON AS
A FRONT MOVES OUT OF THE PACNW, WHILE CLOUDS BUILD ACROSS THE
CENTRAL AND EASTERN MOUNTAINS OF OREGON AS NW FLOW ALOFT STARTS TO
PREVAIL. AS A RESULT, EXPECT LOW-END CHANCES (20-40%) FOR RAIN
ACROSS OUR MOUNTAIN ZONES, FOLLOWED BY A GRADUAL COOLDOWN THAT MAY
RESULT IN THE FIRST HARD FREEZE OF THE SEASON ACROSS OUR ELEVATED
VALLEY ZONES BY MONDAY MORNING.
NBM PROBABILISTIC GUIDANCE SUGGESTS STRONG ODDS (>70%) OF BELOW
FREEZING TEMPS ACROSS CENTRAL OREGON AND THE WALLOWA VALLEY EARLY
MONDAY MORNING - TWO AREAS THAT HAVE FLIRTED WITH A FREEZE THESE
LAST FEW WEEKS BUT HAVE BEEN SAVED PARTIALLY BY DOWNSLOPING WINDS
OVERNIGHT. WITH THE FLOW PERHAPS SHIFTING DUE NORTH BY MONDAY, THIS
MAY ALLOW ENOUGH CLEARING OVERNIGHT, COMBINED WITH COLD AIR
ADVECTION, TO COUNTER THE WARMING EFFECT OF ANY DOWNSLOPE WIND. A
LITTLE MORE UNCERTAINTY EXISTS FOR THE GRANDE RONDE VALLEY, WHICH
TYPICALLY SEES A MORE PRONOUNCED DOWNSLOPE EFFECT OVERNIGHT AND IS
THUS A BIT MORE SHELTERED FROM RADIATIONAL COOLING ON NIGHTS LIKE
THIS, BUT THE NBM DOES MARK THEM FOR HIGH FREEZING ODDS
NEVERTHELESS. IT'S TOO EARLY AS OF NOW TO ISSUE A FREEZE WATCH, BUT
COULD VERY LIKELY SEE SOME ISSUED TOMORROW IF THE FORECAST OUTLOOK
REMAINS THE SAME (WHICH IT'S EXPECTED TO DO).
ENSEMBLES THEN BRING IN HIGH PRESSURE TO KICK OFF NEXT WORK WEEK,
BEFORE BRINGING IN THE NEXT ROUND OF WIDESPREAD PRECIP AROUND THE
MIDWEEK IN THE FORM OF AN OFFSHORE LOW. IT'S TOO EARLY TO MAKE
CONFIDENT PREDICTIONS ON PRECIP AMOUNTS, BUT GIVEN THE ONGOING HAZE
ACROSS THE BASIN AND YAKIMA VALLEY, THE FIRES ACROSS THE WA CASCADES
ARE STILL IN NEED OF WETTING RAINS BEFORE WE CAN FINALLY PUT A WRAP
ON THIS WILDFIRE SEASON. EVANS/74
AVIATION...18Z TAFS (PREVIOUS DISCUSSION)
VFR CONDITIONS
EXPECTED AT MOST SITES, HOWEVER AREA HAZE AND SMOKE FROM REGIONAL
WILDFIRES MAY MAKE FOR SUB-VFR CONDITIONS AT YKM AND PSC DURING
THE DAY TODAY. RISK IS HIGHER AT YKM, WHERE THE SMOKE IS LESS
ELEVATED. ELSEWHERE, EXPECT GENERALLY W/NW WINDS AT 8-12 KTS,
EXCEPT FOR DLS, WHERE WINDS COULD GUST AS HIGH AS 25 KTS THIS
AFTERNOON. SKIES WILL CLEAR DURING THE DAY TODAY, BEFORE A SCT-BKN
MID-LEVEL CEILING MOVES IN THIS EVENING. EVANS/74
PRELIMINARY POINT TEMPS/POPS
PDT 47 66 42 65 / 0 20 10 0
ALW 50 66 44 65 / 10 20 20 10
PSC 47 71 43 69 / 0 10 0 0
YKM 47 70 43 67 / 20 10 0 0
HRI 48 69 43 68 / 0 10 0 0
ELN 43 66 38 65 / 30 0 0 0
RDM 36 62 32 62 / 10 10 0 0
LGD 40 60 37 63 / 0 30 20 10
GCD 40 59 37 63 / 0 20 10 0
DLS 53 71 48 71 / 20 30 10 10
PDT WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
SHORT TERM...74
LONG TERM....74
AVIATION...74
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