049 
FXUS66 KPDT 112303 AAA
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
402 PM PDT Mon Sep 11 2023

.Updated aviation discussion

.SHORT TERM...Tonight through Wednesday...Models continue to 
be in good agreement on the evolving weather pattern as an upper 
level trough has begun moving into the region. This is ushering in 
some mid and high level clouds and producing a weak marine push with 
breezy winds through the Columbia Gorge and Kittitas Valley to 
locally breezy elsewhere along the east slopes of the Cascades. 
Could cover and the advection of slightly cooler air is resulting 
in cooler high temperatures today. The trough axis will approach 
Tuesday with passage overnight. This will cause a further increase 
in westerly winds. Fortunately, min humidities will only be down to 
around 25-30% so do not see this as a Red Flag event but local 
winds of 15 to 30 mph along the east slopes of the Cascades will 
still be capable of causing control issues should fire start. Winds 
will become lighter Wednesday as we transition to a more NE-E flow. 
High temperatures Tuesday and Wednesday will be near normal which is 
upper 70s to near 80 in the Basin and low 70s in the mountains. 
Precipitation threat is low with only the Washington Cascade crest 
likely to see some light rain Tuesday night. 


.LONG TERM...Thursday through Monday...Not much change in the long 
term, which remains quiet as ensembles continue to key in on high 
pressure extending from the end of the work week through most of the 
weekend. We'll see a bit of a warming trend as a result, with highs 
reaching the lower 90s throughout most of our population centers by 
the weekend. This runs about 10 to 15 degrees above average for the 
time of year, but periods of dry and warm conditions are certainly 
not unheard of around here for September. Sensible weather concerns 
remain limited due to high pressure, as winds will remain light even 
as RHs dip into the teens to lower 20s. Outside of potentially 
deteriorating air quality due to area smoke under subsidence aloft, 
much of the period looks to be quiet. 

Ensembles hint at a shortwave arriving around the tail end of the 
period, potentially bringing showers to our high mountain zones. 
This system, should guidance verify, will also reverse our warming 
trend to start off the next work week, but forecast confidence is 
low as much can change with subsequent model runs between now and 
day 7 onward. Evans/74

&&

.AVIATION...00Z TAFs...VFR conditions will persist through 
the next 24 hours. There will be some mid clouds from 100-150, and 
CIGs from 200-250 through the period. Winds will increase at times 
this evening to mostly northwest at least 10-20 Kts, and then winds 
will increase again by 18-20Z Tuesday to at least 15-25 mph. KYKM 
and KPSC has the best chance of winds remaining light and under 10 
Kts through the forecast period. 88

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  55  79  52  76 /   0   0   0   0 
ALW  59  81  55  78 /   0   0   0   0 
PSC  61  84  59  81 /   0   0   0   0 
YKM  55  82  51  80 /   0   0   0   0 
HRI  60  83  56  81 /   0   0   0   0 
ELN  56  79  55  76 /   0   0   0   0 
RDM  49  78  45  77 /   0   0   0   0 
LGD  54  79  50  75 /   0   0   0   0 
GCD  51  82  48  77 /   0   0   0   0 
DLS  59  82  57  82 /   0   0   0   0 

&&

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

&&

$$

SHORT TERM...91
LONG TERM....74
AVIATION...88