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000
FXUS66 KPDT 211726 AAA
AFDPDT

Area Forecast Discussion...Updated
National Weather Service Pendleton OR
926 AM PST Mon Jan 21 2019

Updated Aviation Discussion

.SHORT TERM...Last night`s shortwave has exited the region
followed by a drier northerly flow aloft. Other than isolated
mountain snow showers, today will be dry with scattered to broken
clouds and afternoon temperatures in the mid-30s to mid-40s.
Areas of fog and freezing fog this morning should burn off by the
afternoon sun. However, areas of fog and freezing will likely
return tonight in the lower elevations. Overnight temperatures
will fall into the teens and 20s. Forecast for the next 24 hours is
on track with only minor updates.

Clouds will increase late tonight and Tuesday morning ahead of an
approaching warm front. Precipitation will spread to the
Washington and the northern Oregon Cascades Tuesday morning then
over the remainder of the forecast area Tuesday afternoon and
evening. The southern portion of the forecast area (i.e. south of
Mt. Jefferson, Condon, and Ukiah) should receive little to no
precipitation with the system. Current forecast has snow levels
rising to around 4500 feet across south central and southeast WA
and northeast Oregon. Therefore, the eastern valleys of the WA
Cascades should observe snow changing to rain, including I-90 up
to Snoqualmie Pass. Current forecast has 5-7 inches Tuesday night
through Wednesday afternoon which is under advisory criteria. If
higher amounts are expected, winter highlights may be needed.

The upper level ridge will flatten and allow a northwest flow
aloft to increase across the region. Strong winds aloft and a
tight pressure gradient will cause winds to increase across the
forecast area. Gusts to 30-40 mph are expected at this time.
Scattered to numerous showers will continue over the mountains
with snow above 4500 feet. Wister


&&

.AVIATION...18Z Tafs.  Patchy fog and ST will lift this
afternoon, then return overnight in the Columbia Basin affecting
PSC, ALW, and PDT. YKM/DLS/RDM/BDN will increasing high clouds this
evening. Winds will generally be under 12 kts except 10-15 at DLS
this afternoon. 76

&&

.PREV DISCUSSION... /issued 220 AM PST Mon Jan 21 2019/

LONG TERM...Wednesday night through Sunday. Some mountain showers
will linger over the area Wednesday night in northwest flow. A
ridge of high pressure will be building over the area through the
rest of the week and should continue through the weekend. Models
are all a little different with position and strength of the ridge
and when some moisture may work through, but overall idea will be
for dry conditions. As the ridge persists, there will be fog and
low clouds develop in the Columbia Basin and spread to surrounding
valleys. Temperatures should be near to above normal, especially
in the mountains, but may need to be adjusted in the valleys as
fog and low cloud areas are better defined. 93

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  41  28  41  37 /   0   0  30  50
ALW  42  31  43  40 /  10   0  40  60
PSC  43  32  43  40 /   0   0  30  40
YKM  41  27  40  34 /   0   0  30  40
HRI  43  31  44  38 /   0   0  30  50
ELN  38  26  37  32 /   0   0  30  40
RDM  39  24  42  32 /  10   0  30  30
LGD  37  23  39  34 /  10   0  30  60
GCD  38  24  41  34 /  20  10  30  40
DLS  43  32  42  38 /   0   0  50  60

&&

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

$$

85/