154
FXUS66 KPDT 302059
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
159 PM PDT Wed Jul 30 2025

.DISCUSSION...The upper ridge will persist through Saturday before
weakening when the shortwave trough moves over to the PacNW Sunday
onwards. Given the ongoing S/SW flow aloft, isolated to scattered
thunderstorms will continue flaring up today during afternoon and
evening hours across majority of this region. Not much had changed
with the instability parameters remaining elevated (MUCAPE values of
500-1000 J/Kg, effective shear at 20-30kts and anomalously high
PWATs (>0.70 inches)). With these conditions, they may be enough
to develop strong storm cells as well. These storms may
significantly produce severe outflow winds, given the persistent
wind parameters (DCAPE above 900, steep lapse rates, and
inverted-V sounding profiles). Chances of wetting rain (CWR)
continues to be less than 0.10 inches, bringing our concerns for
abundant lightning. However, there is a 15-30% chance that some
of these storms could become wet over southern part of Deschutes
County as well. Due to potential abundant lightning again today,
a Red Flag Warning will continue through this evening for WAZ695
and into Thursday evening for ORZ697>700-704-705.

Wet, isolated to scattered thunderstorms will become widespread
across our region Thursday with CWR reaching up to 0.20 inches (40-
50% chance). We are looking at CG lightning and gusty winds up to 30-
35 mph being our main threats. Showers will develop across our
region Friday morning before thunderstorms return around Friday
afternoon into evening over the central OR, eastern mountains,
portions of the Foothills of the Blues-OR and the Upper Slopes of WA
Cascades before moving further eastward into the eastern mountains
Friday evening. By Friday night, convective activity should be
out of our area with lingering showers over the Lower Columbia
Basin (<30%). Showers may develop over the weekend through Monday
across the eastern mountains with a slight chance (<20%) of
thunderstorms around afternoon and evening hours. Otherwise, we
might have a break from convective storms starting Tuesday and
Wednesday, though with slight chances of showers over the Upper
Slope of WA Cascades.

High temperatures will be in the triple digits (low 100s) through
tomorrow around the Columbia Basin, peaking at 105 degrees. The Heat
Advisory will remain for this afternoon into evening for ORZ041-508-
510, ORZ044-507, WAZ024-521 and WAZ695. Temps, however, will then
cool Friday onwards by a few degrees. Lastly, breezy winds will
remain (15-25 mph) into next week with the Gorge and Kittitas
Valley being locally windy conditions. Feaster/97

&&

.AVIATION...18Z TAFs(Previous Discussion)...VFR conditions
throughout the TAF period for most sites. However, KRDM/KBDN may
have isolated thunderstorms with breezy winds (up to 18kts) this
afternoon into evening hours (<30% chance). VSBYs may remain VFR,
but might reduce to MVFR or lower if rainfall increases. KDLS will
have sustained winds of 12-20kts with gusts at 20-25kts this
afternoon through evening. Winds should decrease around 05Z before
returning Thursday morning up to 25kts. Otherwise, winds will
generally be less than 12 kts for the remaining sites.

Site KBDN observation station is currently not reporting
observations, therefore amendments for changing conditions will not
be issued. Feaster/97

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  66  96  66  91 /  10  10  40  40
ALW  70  97  69  89 /  10  10  40  40
PSC  65 100  66  93 /  10  10  30  20
YKM  69  99  68  91 /  10  20  40  40
HRI  67  98  68  93 /   0  10  40  30
ELN  68  96  65  88 /  10  30  40  30
RDM  57  88  54  88 /  40  40  40  20
LGD  64  93  62  84 /  20  30  50  60
GCD  61  90  60  87 /  40  40  60  40
DLS  70  91  68  90 /  10  20  30  20

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory until 11 PM PDT this evening for ORZ041-508-510.

     Heat Advisory until 11 PM PDT Thursday for ORZ044-507.

     Red Flag Warning until 11 PM PDT Thursday for ORZ697>700-704-705.

WA...Heat Advisory until 11 PM PDT this evening for WAZ024-521.

     Heat Advisory until 11 PM PDT Thursday for WAZ026>029.

     Red Flag Warning until 9 PM PDT this evening for WAZ695.

     Red Flag Warning from 11 AM to 8 PM PDT Thursday for WAZ695.

&&

$$

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