Pasco, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

466
FXUS66 KPDT 282102
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
202 PM PDT Sat Jun 28 2025

.SHORT TERM...Today through Monday night...Quiet weather is
forecast for the remainder of today and Sunday as an upper-level
ridge of high pressure builds into the Pacific Northwest. Breezy
winds through the Cascade gaps this afternoon and evening will
diminish overnight with a reversal to a lighter offshore flow
anticipated Sunday into Monday.

Ensemble NWP is very confident (95% or greater) that the
aforementioned upper-level ridge will amplify through Monday, and
an upper-level closed low will develop off the central California
coast Sunday through Monday, setting the stage for area-wide heat
and convection in southern/eastern Oregon for Monday and Tuesday.
CAMs suggest the bulk of the convective activity Monday will be
across south-central Oregon with limited extension northward into
central Oregon due to weak forcing aloft. That said, have
introduced a slight chance (15%) of thunderstorms in the forecast
for the east slopes of the Oregon Cascades roughly from Santiam
Pass south, and across the Ochocos and John Day Highlands.

Anticipated warming under the upper-level ridge has prompted the
issuance of Heat Advisories for most of our lower-elevation areas
across northern Oregon and south-central Washington for Monday
through Tuesday. Widespread Moderate (level 2 of 4) to Major
(level 3 of 4) HeatRisk is on tap due to forecast high
temperatures of 90-103 degrees and overnight low temperatures of
59-73 degrees. Will note there is some uncertainty in high and low
temperatures Tuesday, (and especially Wednesday in the "LONG
TERM") due to potential cloud cover -- convective debris or
otherwise. Plunkett/86

&&

.LONG TERM...Tuesday through Friday...Confidence is high that an
upper-level ridge of high pressure will be overhead Tuesday.
Above-normal temperatures are expected region-wide, and mostly dry
conditions are anticipated outside of the Blue Mountains region
where a slight chance (15-24%) to chance (25-30%) of showers and
thunderstorms has been included due to the combination of
sufficient mid-level moisture, instability, and modest upper-
level forcing.

Wednesday through Friday, analysis of ensemble clusters indicates
there is more uncertainty (timing and amplitude of 500-hPa
heights) in pattern details, but guidance is strongly suggesting
one or more shortwaves embedded within broadly southwesterly flow
aloft. This pattern favors showers and thunderstorms for the Blue
Mountains region, so have added a slight chance (15%) of thunder
each afternoon.

Otherwise, breezy to windy westerly winds are favored through the
Cascade gaps Wednesday through Friday. Confidence in surface
moisture (dew point and relative humidity) is still low (<30%)
due to aforementioned uncertainty in pattern details so will hold
off on mentioning potential for any fire weather highlights.
Plunkett/86

&&

.AVIATION...18Z TAFs...VFR conditions are forecast through the
period for all TAF sites. FEW-BKN stratocumulus, mainly across
central Oregon, are expected to dissipate through the day with
SKC for all sites by tonight.

Diurnally and terrain-driven winds are forecast through the
period, strongest this afternoon and evening for DLS/BDN/RDM/YKM.
Plunkett/86

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  55  92  60  99 /   0   0   0   0
ALW  59  90  64  97 /   0   0   0   0
PSC  56  92  59 100 /   0   0   0   0
YKM  55  90  61  98 /   0   0   0   0
HRI  56  93  59 101 /   0   0   0   0
ELN  54  91  59  97 /   0   0   0   0
RDM  45  90  52  96 /   0   0   0   0
LGD  51  87  56  94 /   0   0   0   0
GCD  50  90  57  98 /   0   0   0   0
DLS  59  94  64  99 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory from 9 AM Monday to 9 PM PDT Tuesday for ORZ041-
     044-507-508-510.

WA...Heat Advisory from 9 AM Monday to 9 PM PDT Tuesday for WAZ024-
     026>029-521.

&&

$$

SHORT TERM...86
LONG TERM....86
AVIATION...86