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fxus66 kpdt 220521 aaa 

Area forecast discussion
National Weather Service Pendleton or
1030 PM PDT Mon Oct 21 2019

Update...plume of moisture continues to stream into the central
and northern Washington Cascades with some showers still
occurring over the northern Blue Mountains. The band of moisture
will be shifting south overnight and by early Tuesday should be
over central and northeast Oregon and then south of the forecast
area by midday. Snow levels remain above 7000 feet as the band
moves through with only the higher elevations seeing snow. Behind
the front, winds will be increasing across Washington and northern
Oregon through the day. Minor updates this evening to rain
coverage. 93.


Previous discussion... /issued 204 PM PDT Mon Oct 21 2019/

Short term...tonight through Thursday. Northwest flow continues
over the region with cloudy skies this afternoon. Upslope flow
producing steady rain over the Washington Cascades and blues with
light showers over the Columbia Basin. This will continue through
the evening. Water vapor satellite imagery showing a short wave
moving into southern British Columbia. This system will enhance the precipitation
this evening and overnight and will also push the frontal
boundary south across the forecast area later tonight into Tuesday
with clouds and light rain. Models all indicate fairly quick
clearing behind this front later in the day. Stronger westerly
winds aloft will be mixing down to the surface with breezy to
windy conditions later tonight into Tue. Winds will diminish Tue
evening. Upper ridge building offshore will then place the region
in a dry and cooler northerly flow Wednesday and Thursday. Mainly
clear skies with highs in the 50s to lower 60s. Overnight lows
will be in the 20s and 30s.

Long term...Thursday night through Monday...models in fairly good
agreement, especially through the end of the work week. Period
starts off dry and mild as ridge axis overhead through Thursday
night and then flattens and shifts southeast on Friday as an
upper- level trough approaches the pacnw. Will still be dry and
quite warm on Friday with highs in the 60s to low 70s. Cold front
swings through Friday night, bringing breezy winds and mountain
showers. The overall pattern for the weekend becomes highly
amplified with strong upper level ridging building off the West
Coast into western British Columbia. Cold, dry Canadian air filters into the
region for the weekend as a stronger cold front and upper-level
trough drop south along the east side of the ridge and dig over
the western US. Models begin to differ on the overall placement
and timing of this feature, but either way, a few mountain showers
will still be possible for the weekend, especially on Saturday.
Snow levels drop down to 3000- 4000ft but with the system being
fairly moisture starved, only expecting minor snow accumulations.
Cool, dry north to northwest flow continues for early next week.
Temps drop through the weekend into early next week behind the
frontal passages. Highs Saturday in the upper 40s to upper 50s,
only climbing into the 40s to lower 50s Sunday and Monday. Cold
nighttime temps as well with lows in the upper teens to lower 30s
Saturday and Sunday night.

Aviation...06z tafs...VFR conditions expected through the period.
Bkn-ovc clouds with cigs 4-7kft with some light rain showers through
15z, then clouds decreasing with high clouds expected Tuesday night.
Winds will be west to southwest around 10-15 overnight and then
increase to 15-25 with higher gusts through the day on Tuesday,
decreasing after 03z. 93


Preliminary point temps/pops...
PDT 59 50 66 35 / 20 30 40 0
alw 60 51 66 38 / 30 40 50 0
psc 61 52 70 37 / 20 20 20 0
ykm 58 45 67 34 / 30 30 20 0
hri 62 51 69 38 / 20 20 30 0
eln 53 43 60 33 / 50 60 10 0
rdm 61 39 63 29 / 0 0 30 0
lgd 52 43 59 35 / 30 40 50 0
gcd 56 39 59 32 / 10 10 40 10
dls 61 51 67 38 / 20 40 40 0


PDT watches/warnings/advisories...

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