419
FXUS66 KPDT 062103
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
203 PM PDT Wed May 6 2026

.KEY MESSAGES...

- Above-normal temperatures and mostly dry conditions through
  this week into next week

- Wind Advisory in effect this afternoon and evening

- Periods of low relative humidity (10-20 percent) coupled with
  breezy to windy westerly winds Thursday and Friday through
  the Cascade gaps and across the Columbia Basin and Blue
  Mountain foothills

&&

.DISCUSSION...

Although a stratus/marine layer and invading cirrus was
overspreading much of the area west of the Cascades, the Eastern
Columbia Gorge. Lower Columbia Basin was virtually cloud free
late this morning, with only the exception of clusters of
cumulus clouds popping off the southern Blue Mountains and
Wallowas. For the Wind Advisory for this afternoon, Ellensburg
is hitting around the lower end of gust criterion and was
gusting between 45 and 50 mph over the last few hours with
sustained speeds in excess of 30 mph. A shortwave is moving
through the upper mean ridge in BC/upper Columbia Basin, through
Tonight before the upper ridge becomes more amplified into
Thursday across WA and OR. ECMWF/GFS20 and AI GFS all agree on
another shortwave late Friday but the dry system will lead to
little more than mountain showers for the Cascades. This wave
should enhance wind gusts through gradients and momentum
transfer on Friday, which could be another wind advisory
afternoon though the Kittitas valley, parts of the foothills of
the Blue Mountains and Simcoe Highlands with roughly 20 to 50%
chances for wind gusts of 45 mph or greater based on NBM
members. Temperatures through Thursday and Friday are not as
warm but still will reach the 70s across the foothills and 80s
through the Yakima Valley, Lower Columbia Basin Central Oregon
and the John Day Basin, driving heat risk in to the Minor
category, affecting individuals most sensitive to heat, and
without cooling or hydration. In addition to the warm temps, the
chances for measurable precipitation are virtually zero over
the area well into next week and the 6 to 10 day outlook offers
50 to 70% chances for above normal temperatures and 40 to 50%
chances for below normal precipitation. Russell/71


&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...

VFR conditions currently across all sites, which will stay the course
through the period. Breezy winds of 20-30kts for all terminals this
afternoon, dissipating later this evening. The only exception will
be KDLS, which will continue to experience breezy 20-30kt winds into
the early morning hours on Thursday. BKN-SCT 25kft ceilings this
evening before clearing out overnight tonight. 75

&&

.FIRE WEATHER...

Warm temperatures will drive down relative humidity with
afternoons becoming breezy and locally windy, resulting in
elevated fire weather conditions through the week. Winds on
Thursday will slacken slightly so risk is lower but a more
breezy Friday will lead to 20 to 50% chances for combined RH and
Wind gusts of 20% and 20 mph. So beyond this afternoon,t he next
most risk day is Friday, followed by a more muted risk on Sunday
as winds are not anticipated to be particularly strong, but much
warmer temperatures will drive down RH down to around 10% across
the Ochoco John Day Highlands. Russell/71

&&

.HYDROLOGY...

Expect a continued fall in the Naches River as the gage at
Naches has already gone below the action level and Cliffdell
gage is forecast to undergo a much slower fall, remaining above
action stage and falling to 16.18 ft by Tuesday afternoon.
Russell/71


&&

.Preliminary Point Temps/PoPs...
PDT  82  52  76  50 /   0   0   0   0
ALW  82  54  76  53 /   0   0   0   0
PSC  89  56  82  55 /   0   0   0   0
YKM  88  50  82  50 /   0   0   0   0
HRI  85  54  79  53 /   0   0   0   0
ELN  80  47  77  47 /   0   0   0   0
RDM  83  43  80  41 /   0   0   0   0
LGD  81  47  74  43 /   0   0   0   0
GCD  81  45  77  43 /   0   0   0   0
DLS  83  53  79  50 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
WA...Wind Advisory until 1 AM PDT Thursday for WAZ024-026-521.
OR...Wind Advisory until 1 AM PDT Thursday for ORZ041-044-507-508-
     510.

&&

$$

DISCUSSION...71
AVIATION...75
FIRE WEATHER...71
HYDROLOGY...71