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fxus66 kpdt 191634 aaa 

Area forecast discussion...updated
National Weather Service Pendleton or
934 am PDT Thu Apr 19 2018

Updated aviation discussion

Short term...upper level low pressure continues to dig southeast
across central California into the southern Great Basin. Wrap around
moisture is exiting far eastern or, and have trimmed pops down
across most areas. Clouds will continue to decrease through the
day as ridging builds in, with seasonal high temperatures in the
60s lowlands to mainly 50s mountains.


Aviation...18z tafs...VFR conditions will prevail for the next
24 hours. Wraparound moisture from a system over central California
may produce occasional ceilings of 030-040 kbdn and krdm, otherwise
scattered high clouds. Winds will be less than 12 kts with some
higher gusts in the afternoon. Earle


Previous discussion... /issued 259 am PDT Thu Apr 19 2018/

Short through upper low is moving
ashore in central California at this time and an associated trough
remains over the Pacific northwest. The low will move into southern
Nevada this afternoon and this will drag the trough eastward and out
of our area by this evening. Rain and snow showers are winding down
but there will still be isolated to scattered showers in central
Oregon and the ochoco-John Day Highlands this morning tapering off
to just a few isolated lingering showers in the afternoon.
Precipitation will just be a few hundredths of an inch. Snow levels
will be around 4000 to 4500 feet this morning then rise to 5000 to
5500 feet in the afternoon. This evening a ridge will build over the
area and this should give US fair and dry weather Thursday night and
Friday. By Friday night, another system will be moving towards the
coast and there will be a chance of rain and snow showers mainly
along the Washington Cascades perhaps reaching Ellensburg by
sunrise. The system will be passing mainly to the north and showers
on Saturday will stay mainly in the Cascades. Precipitation amounts
will be light away from the Washington Cascade crest. The main
impact will be breezy to windy conditions of 15 to 25 mph in the
Kittitas Valley and Columbia Basin Saturday afternoon. Temperatures
today will be in the mid to upper 60s with 50s and lower 60s in the
mountains. Friday will be a couple of degrees warmer. Saturday will
cool to the lower to mid 60s with 50s in the mountains. Perry

Long term...Saturday night through upper trough will
be exiting the region to the east with just some lingering showers
over the central Washington Cascades. Otherwise dry weather will
prevail over the County Warning Area until around Monday night. The long range
models are in pretty good agreement with this scenario. Temperatures
during this period will be near to above normal...mid 60s to lower
70s. An upper trough will then move into the region late Monday
night into Tuesday bring possible light precipitation to mainly the
southern areas and the mountains. Models are in good agreement with
this trough as well as the preceding dry period. The atmosphere will
be moisture limited though, so precipitation will be very light and
spotty. A ridge of high pressure will return by Wednesday and
continue into Thursday for dry conditions again with slightly above
normal temperatures in the upper 60s to lower 70s in the lower
elevations. Winds will be gusty at times, first behind the exiting
trough Saturday night and then again on Monday night through Tuesday
with that trough that moves through the region. 88


Preliminary point temps/pops...
PDT 62 39 66 44 / 0 0 0 10
alw 65 41 68 46 / 0 0 0 10
psc 68 41 70 47 / 0 0 0 10
ykm 66 41 68 43 / 0 0 0 10
hri 67 40 70 46 / 0 0 0 10
eln 62 39 64 40 / 0 0 10 20
rdm 58 32 66 36 / 10 0 0 10
lgd 60 38 63 43 / 10 0 0 10
gcd 57 35 64 40 / 10 0 0 10
dls 66 45 68 46 / 0 0 0 20


PDT watches/warnings/advisories...

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