Winter Weather in Washington, September 29 to 30, 2019

Area Forecast Discussion
National Weather Service Pendleton OR
107 PM PDT Sun Sep 29 2019

.SHORT TERM...Tonight through Tuesday...Ongoing light rain/snow showers
continue to diminish in coverage and intensity. Expect this trend
to continue overnight with best chances for continued light precipitation
confined to the east slopes of the Cascades with only slight
chances elsewhere. Winter weather advisories continue for the east
slopes through midnight tonight; however, with showery nature of
snow overnight have gone ahead and canceled winter weather
advisory that was in effect for the Blue/Wallowa Mountains. Upper
level low will continue to weaken and move east/northeast through
the day Monday with slight chances for showers, mainly over higher
elevations of northeast Oregon. Cold temperatures still on track
for much of the area overnight tonight and again for Monday night
as low temperatures drop in the lower to middle 30s for the lower
elevations with teens & 20s expected for the mountains. Dry
conditions return by Tuesday with afternoon high temperatures
moderating into the upper 50s to lower 60s across the lower
elevations with 40s/50s for the mountains. Richards

.Long Term (Tuesday Night through Sunday)...
As we enter medium to long range period, a drier and milder
weather pattern can be expected. The persistent slow moving upper
low will finally lift north and east, allowing for a weak shortwave
ridge to move across the Pacific Northwest Wednesday into early
Thursday. A fast moving upper trough looks to affect the region
Thursday night into Friday, bringing a wave of showers and mountain
snow for elevations above 5000 ft. The Columbia Basin looks to
remain mostly dry with this system. As we head into next weekend,
long range guidance suggests upper ridging may attempt to build in
over the area from the Pacific Ocean. This should promote a
mild and dry weekend, assuming it materializes. Temperatures
throughout the long range period generally look to remain rather
pleasant with highs in the 60s and lower 70s lower elevations and
40s/50s in the mountains. Lows should generally remain in the low to
mid 40s for most areas outside the mountains. Models diverge
substantially beyond the weekend, though both show another upper
storm system forming off the coast of British Columbia, poised to
impact Washington and Oregon by the middle of next week.

79/Austin

&&

.AVIATION...18z TAFs: A complex aviation period is expected with
ceilings varying from VFR to IFR/LIFR at times. This and brief
showers reducing visibilities will lead to less than optimal flight
conditions. Expect conditions to gradually improve overnight tonight
and into Monday as drier air slowly moves in.
79/Austin

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  32  50  33  56 /  20  20  10   0
ALW  34  51  34  57 /  20  20  10   0
PSC  37  56  36  61 /  20  10  10   0
YKM  33  55  30  60 /  30  20  10   0
HRI  35  55  35  61 /  20  20  10   0
ELN  34  52  31  58 /  40  20  10   0
RDM  27  48  26  54 /  30  20  10   0
LGD  29  48  31  52 /  20  20  10   0
GCD  29  49  29  52 /  20  30  10   0
DLS  39  57  37  63 /  20  20  10   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Winter Weather Advisory until midnight PDT tonight for ORZ509.

     Freeze Warning from midnight tonight to 10 AM PDT Monday for
     ORZ049-505-507-508-510-511.

WA...Winter Weather Advisory until midnight PDT tonight for WAZ520-
     521.

     Freeze Warning from midnight tonight to 10 AM PDT Monday for
     WAZ026-027-029-521.

&&

75/79/79