084
FXUS66 KPDT 010941
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
241 AM PDT Mon Jul 1 2024

.SHORT TERM...Today through Wednesday...Nighttime and water vapor
satellite imagery show a shortwave trough dropping into the PacNW
tonight, though radar returns show little to no shower activity.

The shortwave passing over the region today will bring slight
chances (15-20%) of isolated showers to the WA Cascade crest and
the Wallowa mountains. An tightened cross Cascade pressure
gradient will be reinforced by the shortwave passage this
afternoon, with winds of 20-30mph and gusts generally up to 40mph
in the Cascade gaps and portions of the OR Columbia Basin, with
15-20mph winds and gusts between 25-30mph elsewhere in the lower
elevations. While there is a lack of jet support between
700mb-850mb, NBM probabilities of peak wind gusts meeting or
exceeding 45mph are between 50-80% in the aforementioned areas,
suggesting gusts will mostly be localized and infrequent with low
confidence (20%) in widespread and frequent gusts exceeding
45mph. Fire weather concerns will remain elevated today with the
breezy winds, but a marine layer up to 850mb is expected to spill
through the Cascade gaps, keeping RHs above critical red flag
thresholds (confidence 75-85%).

Tuesday through Wednesday, upper level ridging will be amplifying
across the eastern Pacific with persistent northwest flow aloft.
While conditions will mostly be quiet during this period, an
inverted thermal trough extending into southeastern OR Tuesday will
promote another afternoon/evening of a strengthening cross
Cascade pressure gradient. Winds 20-30mph and gusts up to 40mph
through the Cascade gaps into far western portions of the OR
Columbia Basin (confidence 70-80%). Wednesday, while breezy winds
will develop through the Cascade gaps once again, sustained winds
will generally be between 15-25mph and gusts up to 35mph
(confidence 60-70%). While fire weather concerns will remain
elevated through Wednesday, the aforementioned marine layer west
of the Cascades will linger through Wednesday evening and continue
to support marine pushes through the Cascade gaps each day,
precluding the need of any fire weather headlines (confidence
60-70%). Lawhorn/82


.LONG TERM...Thursday through Monday...The extended period is
characterized by an upper-level ridge across the region with above
normal temperatures and breezy winds. Starting Friday,
temperatures will be in the low 100s around the Columbia Basin and
90s across the rest of the forecast area. Confidence increases
with EFI values greater than 0.90 showing an extreme event.
Through Sunday, the heat could be problematic with the HeatRisk
product showing moderate categories over most of the forecast area
with a few small patches of major categories in some portions of
the Columbia Basin. That said, heat advisory may be considered for
Friday through the weekend. Models and ensembles are in great
agreement with this week`s pattern, despite having 20% or less
total members favoring a trough for Friday through Saturday and
zonal for the rest of this period.

Through Monday, breezy conditions will occur with occasional wind
gusts between 15-25 mph around the Cascade Gaps and Lower Columbia
Basin. However, the combination of increased northwesterly winds and
low relative humidity in the teens to lower 20s could raise concerns
for areas of elevated fire weather potential. And for 4th of July,
winds will be light but critically low relative humidity will
develop later in the afternoon. Feaster/97


&&

.AVIATION...Previous Discussion...06Z TAFs...VFR conditions will
prevail through the period. Breezy conditions will remain the
primary focus with winds gusting to near 20 to 25+ kts with the
exception of PSC which will remain below 10 kts. CIGs are mostly
high giving way to clear skies. Bennese/90


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  83  54  82  51 /   0   0   0   0
ALW  86  57  85  55 /   0   0   0   0
PSC  89  59  88  56 /   0   0   0   0
YKM  85  53  86  53 /   0   0   0   0
HRI  88  57  87  55 /   0   0   0   0
ELN  78  53  78  53 /   0   0   0   0
RDM  80  46  81  44 /   0   0   0   0
LGD  78  49  79  47 /   0   0   0   0
GCD  80  47  82  46 /   0   0   0   0
DLS  83  56  80  55 /   0   0   0   0

&&

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

$$

SHORT TERM...82
LONG TERM....97
AVIATION...90