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000
FXUS66 KPDT 232252 AAA
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
350 PM PDT Wed May 23 2018

Updated Aviation Discussion

.SHORT TERM...Today through Saturday...A filling upper level low is
drifting over eastern WA. A short wave moving around the low has
triggered lightning strikes today everywhere in the CWA except the
Yakima Valley and Columbia Basin. Scattered showers and
thunderstorms are occurring along the Cascades and from central OR
to the northwest Blue Mountains and Wallowa County. The steering
flow aloft is weak so storms will be slow moving and tend to hang up
on higher terrain. Localized flooding in the mountains is possible
By Thursday low will move into northwestern MT while an upper low
off the California coast will bring a moist southwesterly flow over
the area. Central Oregon and the Oregon mountains will have chance
to likely showers and a slight chance of thunderstorms in the
afternoon and evening. Rain amounts will again run 0.15-0.25 inch in
central to NE OR tapering off as you go north. By Friday the low
will be near San Francisco with a short wave spinning off the low
into eastern OR. This will spread showers and few thunderstorms
across eastern OR and southeastern WA. As the low drifts east into
NV Saturday convection will decrease shift to the eastern part of
the CWA.

Highs Thursday will be in the mid to upper 80s in the Columbia Basin
with 70s and lower 80s elsewhere. Friday a weak marine push will
increase westerly winds and cool the Columbia Basin to the upper 70s
to mid 80s. Temperatures will cool even more Saturday.  Coonfield

.LONG TERM...Saturday night through Wednesday.  Upper low pressure
system will remain nearly stationary over northeast Nevada through
Sunday, before weakening and shifting northeast on Monday. This will
keep a few linger showers and afternoon thunderstorm over extreme
northeast Oregon through Monday.  Models continue to have some
differences in speed of a trough of low pressure to move through
Monday night/Tuesday with with a weak frontal system.  Most of the
moisture won`t make it past the Cascades, with some slight chances
of showers/afternoon thunderstorms over the Blue Mountains.  Main
effect looks to be a little cooler temperatures and some locally
breezy winds.  Temperatures warm through the first part of the week
and then cooler a few degrees Tuesday and Wednesday, but remain
above normal. 93

&&

.AVIATION...00Z TAFs...Mainly VFR conditions through the period.
Showers and isolated thunderstorms through about 04Z across the
area, but outside of KRDM AND KBDN, low confidence of a thunderstorm
at specific taf sites. KRDM AND KBDN will have showers and a slight
chance of a thunderstorm through 04z,  Overnight, showers remain
possible at KRDM AND KBDN with sct-bkn 070-090 clouds across the
region. Afternoon showers and isolated thunderstorms possible again
Thursday afternoon, but expect general area to be a little further
south with KRDM and KBDN again in the best area to see a
thunderstorm. Winds will generally be 10 kts or less, except KDLS 10-
15 kts. 93


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  60  83  57  78 /  30  20  20  20
ALW  61  85  59  79 /  30  30  20  20
PSC  62  88  60  83 /  20  10  10  10
YKM  60  87  59  82 /  20  10  10  10
HRI  62  87  59  82 /  20  10  20  20
ELN  57  85  55  80 /  20  10  10  10
RDM  54  79  51  66 /  60  40  50  50
LGD  53  78  52  74 /  40  50  40  30
GCD  54  78  52  70 /  60  40  50  70
DLS  63  84  60  76 /  20  10  20  20

&&

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

$$

76/83/83