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Area forecast discussion...updated 
National Weather Service Pendleton or
954 am PST Friday Feb 12 2016

Updated aviation discussion

Short term...morning update...the next Pacific system will move
across the region today and tonight. The system's cold front is
currently moving through western Washington and Oregon. This front
should move through eastern Washington and Oregon this afternoon and
early this evening. Expect the potential for isolated showers to
persist ahead of the main precipitation band associated with the cold
front. Shower coverages with the front will mainly run in the
scattered to numerous ranges. Have made shower coverage adjustments
for today based on these trends. Fog around the area is mainly
lowering visibilities to the 2-6 mile range, with only locally lower
reductions below 2 miles. Thus have reduced fog wording to patchy.
This fog will gradually dissipate through the rest of the morning,
with a few locations hanging on to some fog into the early
afternoon. 90

Long term...previous west/northwest flow
continues as high pressure to the south shifts over southern
CA/NV/AZ. Sunday night into Monday morning will still have decent
moisture associated...but drier air will attempt to intrude as we
move into middle day Monday and Tuesday. For this probability of precipitation have been scaled
back a bit from previous forecast. Also...winds aloft expected to
range from 30-50kts and may mix down to make for breezy to windy
conditions across the lower elevations Monday afternoon and evening.

As we move into middle week on Wednesday...the high pressure will have
shifted far enough east that our area will start to move into a
moist southwest flow. Probability of precipitation have picked up for this time period...but
snow levels will still remain above 7000 feet mean sea level...and will lower
slightly Wednesday evening. The cold front that previous models had
moving in on Thursday has now been backed off until Friday night
into Saturday. As a result have adjusted snow levels to remain above
5000 feet mean sea level through the extended forecast.


Aviation...18z tafs...recent precipitation has moistened up the
lower levels and fog developed at Columbia Basin taf sites
overnight. The fog is clearing but will continue to create MVFR/IFR
for another hour or two, particularly at kdls. A warm front has
crossed the area and a cold front has moved ashore west of the
Cascades. Isolated showers are still developing so have vcsh at most
taf sites with showers increasing late this afternoon and this
evening. Expecting mainly VFR conditions but all taf sites except
krdm, kbdn and kpsc may have MVFR/IFR conditions during the heavier
rain showers. Rain will taper off from 03z-06z though it will linger
on until 10z-12z at kalw and kpdt. With the end of the showers,
ceilings will partially clear and rise to VFR levels. Winds will
generally remain below 12 kts though kpsc, kalw and kpdt will
increase to 10 to 15 kts after 10z. Perry


Preliminary point temps/pops...
PDT 52 39 55 42 / 20 30 10 70
alw 52 43 55 44 / 20 30 20 80
psc 51 38 56 41 / 20 20 10 50
ykm 49 33 52 34 / 30 10 10 40
hri 53 39 56 41 / 20 20 10 50
eln 42 33 46 34 / 40 20 20 50
rdm 55 31 52 37 / 30 20 10 40
lgd 51 34 49 37 / 20 40 20 70
gcd 55 33 50 36 / 10 20 10 60
dls 54 40 54 40 / 30 30 20 50


PDT watches/warnings/advisories...
or...air stagnation advisory until 10 am PST Saturday for orz041-044-

Washington...air stagnation advisory until 10 am PST Saturday for waz024-


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