338
FXUS66 KPDT 061714
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1014 AM PDT Sun Jul 6 2025

.AVIATION...VFR conditions will persist through the forecast
period. Mostly sunny with high clouds scattered across some of the
TAF sites. Winds are mainly light and variable across the region
with only DLS seeing winds nearing 10kts. Bennese/90

&&

PREV DISCUSSION... /issued 139 PM PDT Sat Jul 5 2025/


SHORT TERM...This afternoon through Monday...The short term will
be characterized by calm weather. An upper ridge of high pressure
will settle over the region bring hot and dry temperatures across
the region. Dry and warming conditions will continue through
Monday ahead of a dry cold front. Temperatures will be steadily
rising with models todays high temperatures will be in the upper
80s to low 90 across the vast majority of the region with upper
60s to low 70s along the Blues and eastern mountains with 80-100%
of the ensembles are in agreement. As we move into Sunday and
Monday, models show high temperatures to become more widespread
with 80-100% of the raw ensembles showing only the ridges of the
mountains remaining below 80 degrees. Forecast HeatRisk ranges
from Moderate (level 2 of 3) on Monday.

LONG TERM...Models are showing an upper level dry cold front
making its way into the PacNW Tuesday. Tuesday is set to be the
hottest day of the long term with models showing temperatures
cresting 100-105 through the Columbia Basin, Yakima Valley and
along the foothills of the Northern Blues of OR & WA. Ensembles
show 80-100% agreement that the aforementioned area will see these
temperatures. Forecast HeatRisk ranges on Tuesday to Major (level
3 of 4). This level of heat would support Heat Advisories for the
Yakima/Kittitas valleys, lower Columbia Basin, and foothills of
the northern Blue Mountains on Tuesday. Overnight lows from Monday
into Tuesday still range low to moderate leading to the potential
for heat advisories.

With the incoming dry cold front, models are showing an increase
in stability as it pushes inland. Ensembles are showing 75-80%
probabilities of the southern portion of the CWA from Deschutes
county and across the eastern mountains into Wallowa County seeing
the potential for thunderstorms Tuesday. Models and ensembles
surface CAPE values between 200-500 J/kg,lapse rates over 9C/km
and LIs of -2. Looking at dry thunderstorm probabilities,
ensembles show 10% probabilities in the southern portion of
Deschutes, Crook and Grant Counties. 12 hour probabilities of
thunder is a bit higher with 15%. Looking at the model derived
sounding, the PWATs are a bit high at 0.53 inches of precipitable
water within the mix. We cannot rule out the probability that any
storm produced will be dry in nature. The remainder of the long
term will be continued dry and warm.

Also, with the arrival of the cold front, winds through the
Cascade Gaps will increase. The Gorge on Tuesday will likely see
winds increasing to near 20 mph with gusts to 30 mph with 40-60%
of the ensembles in agreement. Kittitas Valley will also see an
increase in the winds ahead of the front with sustained winds of
20 with gusts to 30 mph with 60-70% of the ensembles in agreement.
Bennese/90

FIRE WEATHER...Though there will be hot and dry conditions through
the forecast period, no fire weather concerns are present through
Monday. With that said, the incoming potential for thunderstorms
Tuesday will be closely monitored for any fire weather products
needed. Bennese/90

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  90  59  97  65 /   0   0   0   0
ALW  89  64  96  69 /   0   0   0   0
PSC  91  59  98  63 /   0   0   0   0
YKM  91  61  96  64 /   0   0   0   0
HRI  93  59  99  65 /   0   0   0   0
ELN  89  59  96  64 /   0   0   0   0
RDM  88  50  96  55 /   0   0   0   0
LGD  86  55  94  60 /   0   0   0   0
GCD  88  55  96  60 /   0   0   0   0
DLS  91  63  98  65 /   0   0   0   0

&&

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

$$

SHORT TERM...90
LONG TERM....90
AVIATION...89