318
FXUS66 KPDT 040518
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1018 PM PDT Tue Jun 3 2025

.UPDATED AVIATION...06Z TAFs...VFR conditions will persist through
the forecast period. CIGs will be mostly SKC and Few 25 kft with
winds below 10 kts across all sites except DLS. DLS is currently
sitting at 13kts from the west-northwest and will remain between
13-17 kts with gusts near 26 kts through 03Z. Bennese/90


&&

.PREV DISCUSSION... /issued 428 PM PDT Tue Jun 3 2025/

SHORT TERM...Today through Thursday...Warm dry conditions
continue through the next couple of days with the persistent
northwesterly flow. The NWP guidance shows a weak short wave
clipping over our forecast area Wednesday, but with little to no
moisture. Locally windy conditions (25-35 mph) may develop across
the Cascade gaps this afternoon before becoming breezy (15-25 mph)
later in the evening. NBM CONUS favor a 50-70% probability of
wind gusts of 30 mph for the Gorge and Kittitas Valley. Otherwise,
winds will be relatively breezy tomorrow onwards.

High temperatures will be 5-10 degrees above average with Columbia
Basin reaching to the low-high 80s and mid 70s to low 80s for the
remaining forecast area. This, along with decreasing RH values (30%
or below), will bring portions of the Columbia Basin to Moderate
Heat Risk for Thursday night into Friday morning. Feaster/97

LONG TERM...Friday through Tuesday...The ridge will move across
the PacNW and last until Monday night when the shortwave trough
begins approaching to the PacNW. The persistent warm dry
conditions will assist in increasing the temperatures to the 80s
for most of the forecast area and 90s around the Columbia Basin.
The NBM probabilities has a 90%+ prob for temps to reach above 90
degrees Friday into Monday and 30-40% prob of temps reaching to
100 degrees for Sunday and Monday. Nonetheless, the weekend will
be our warmest and driest days of this term. And with high temps
and low RHs dropping below 25%, this will bring the Columbia Basin
to mainly Moderate Heat Risk (2 of 4 level) but with pockets of
Major Heat Risk (3 of 4 level) around the Lower Basin area, which
could warrant for a Heat Advisory or Extreme Heat Warning.

The short wave trough will then approach the PacNW Monday night
into Tuesday that could bring isolated thunderstorms over the
Blues and eastern mountains. Although abundant CG lightning and
gusty winds may be the main threats, chances will be low (<30%)
due to lack of support from low moisture level and weak
instability (CAPE values of 500 or less). Winds will be fairly
light with occasional breezes through most of this period.
However, Monday night could get gusty at the the Gorge, Yakima and
Kittitas Valley at 25-35 mph (>50% confidence). Feaster/97

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  50  79  51  86 /   0   0   0   0
ALW  53  79  54  84 /   0   0   0   0
PSC  50  83  51  89 /   0   0   0   0
YKM  51  82  53  87 /   0   0   0   0
HRI  51  83  51  89 /   0   0   0   0
ELN  50  80  52  86 /   0   0   0   0
RDM  40  75  41  81 /   0   0   0   0
LGD  44  75  48  80 /   0  10   0   0
GCD  42  77  46  81 /   0   0   0   0
DLS  53  76  54  88 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&

$$

SHORT TERM...97
LONG TERM....97
AVIATION...90