Wildfire in Washington, June 27 to 28, 2018

Area Forecast Discussion...Updated
National Weather Service Pendleton OR
320 PM PDT Wed Jun 27 2018

Updated Aviation Discussion

.SHORT TERM...Tonight through Saturday...An upper level trough is
approaching the Washington/Oregon coast this afternoon and a cold
front has already moved ashore along the Olympic Peninsula.
Observations along the coast are not showing any precipitation yet
and do not expect any precipitation in our area tonight except along
the Washington Cascade crest with just a couple of hundredths of an
inch of rain at most. The main impact will be winds late this
afternoon and evening as pressure gradients are already tightening
up. The Kittitas Valley and Columbia Gorge should reach 20 to 30 mph
with 10 to 20 mph in the Columbia Basin and central Oregon. Winds
will decrease this evening and overnight. Also expect partly to
mostly cloudy skies to replace the current clear skies. The trough
will slowly cross the area tomorrow and exit to the east Thursday
night. Rain showers tomorrow will remain confined to the immediate
Washington Cascade crest. Pressure gradients will remain tight along
the Cascades and expect winds tomorrow to be similar to today. The
trough will bring in cooler air and expect highs tomorrow to be
about 5 degrees cooler than today with highs in the upper 70s and
lower 80s in the Columbia basin and in the mid 60s to mid 70s
elsewhere. The trough will be nearly stationary over Idaho and
western Montana Thursday night through Friday night while high
pressure builds out in the Pacific. This will develop a northwest
flow over our area. A slight chance of showers will be possible
along the Cascade crest and in the higher terrain of the eastern
Oregon mountains with the rest of the area dry. Afternoon winds on
Friday will be lighter than today or Thursday with northwest winds
of 10 to 20 mph expected. Temperatures on Friday will be a degree or
two warmer than Thursday. On Saturday the trough will finally move
off to the east and the offshore ridge will move a little closer to
the coast. We will still be under a northwest flow but do not expect
any showers except along the Washington Cascade crest once again. A
weak disturbance will bring breezy to windy conditions again
Saturday afternoon. Saturday will see warming with highs in the
lower to mid 80s with 70s in the mountains. Perry

.LONG TERM...Saturday night through Wednesday...A dry northwesterly
flow will dominate the weather pattern Saturday night and Sunday.
The main storm track will remain in Canada. Sunday night an upper
level low will drop south along the Canadian coast. This system will
reach northwest WA (GFS) or southern British Columbia (ECMWF) Monday
then swing east into southern Canada Tuesday. This low and
associated troughing will bring some slightly cooler air back into
eastern WA and OR but the only precipitation expected with it will
be along the WA Cascades. Another low will develop offshore Tuesday
(ECMWF) or Wednesday (GFS) but will have little effect on eastern WA
and OR.  Coonfield

&&

.AVIATION...0Z TAFs...A cold front will move through eastern
WA and OR this evening with increasing westerly winds and some mid
level clouds 10K-15K feet MSL. Cross Cascade pressure gradients will
keep higher winds at KDLS and KELN tonight. Elsewhere winds 5-10kt
increasing after frontal passage to 12-25kt then decreasing late
overnight.  76

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  55  76  54  77 /   0   0  10  10
ALW  57  79  56  79 /  10   0  10  10
PSC  59  81  57  82 /  10   0  10  10
YKM  52  76  52  79 /  10  10  10  10
HRI  57  80  57  82 /   0   0  10  10
ELN  53  70  52  74 /  10  10  10  10
RDM  46  74  44  77 /  10   0  10  10
LGD  50  72  49  71 /  10  10  10  20
GCD  51  71  47  72 /   0  10  10  10
DLS  57  74  57  78 /  10  10  10  10

&&

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

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