Wildfire in Washington, July 2 to 7, 2017

Area Forecast Discussion...Updated Aviation Discussion
National Weather Service Pendleton OR
1020 AM PDT Sun Jul 2 2017

.UPDATE...An upper trough has just about exited the area into
Idaho this morning and a quiet weather pattern will develop over
the forecast area for the next few days. Skies will be clear and
there is no significant chance of precipitation in any model
through the Fourth of July. Afternoon winds will be 5 to 15 mph
except for 15 to 25 mph in the Columbia Gorge and Kittitas
Valley. Temperatures today will be similar to yesterday in the
Columbia Basin and 3 to 5 degrees warmer in Central Oregon and
the mountains. This will mean upper 80s to mid 90s in the Columbia
Basin, around 90 in Central Oregon and mainly in the 80s in the
mountains. Monday will be a couple of degrees cooler but the
Fourth will rebound back to around today's temperatures. Have left
today and tonight's forecasts mostly unchanged but did make a few
minor temperature and wind adjustments. Forecast update has
already been issued. Perry

AVIATION...18Z TAFs...VFR conditions will prevail at all TAF sites
for the next 24 hours. Mostly clear skies and light winds will
prevail. Only location with stronger winds will be KDLS with winds
13-17kt with gusts to 25kt. 93

&&

.PREV DISCUSSION... /issued 500 AM PDT Sun Jul 2 2017/

SHORT TERM...Today through Tuesday...An upper level low will
gradually push east into western Canada today through Monday. As
such the Pacific Northwest will be under an increasingly dry
westerly flow. Thus will see fair and dry conditions through Monday
with locally breezy winds. The strongest winds will be in and near
the Columbia River Gorge and the Kittitas valley. Low temps will be
near seasonal, while high temps will be 4-8 degrees warmer than
seasonal. The air mass over the region will be quite dry Monday. The
upper ridge over the 4 Corners region will begin to build north and
northwest into the region Monday night into Tuesday. Thus expect
continued dry conditions, though there could be enough moisture for
a few high based cumulus clouds over some of the mountains Tuesday
afternoon. Temps will warm a few degrees over today and Monday.
Winds will be lighter on Tuesday. 90

LONG TERM...Tuesday night through Saturday...Hot and mainly dry
conditions through Saturday due to a mid/upper level ridge of high
pressure over the four corners, which amplifies and builds northward
over the interior Pacific Northwest and the Rockies. In addition, a
large mid/upper level low pressure system remains in the Gulf of
Alaska with the southern extension of the low digging southward thus
developing into a mid/upper level longwave trough offshore. The
longwave trough in the NE Pacific and the ridge over the Rockies
backs flow aloft to the south over eastern Oregon. The offshore
trough pinwheels counterclockwise Wednesday night through Thursday
night, which transports mid level monsoon moisture around the high
pressure Wednesday/Wednesday night and then northward into the
forecast area on Thursday. As such I increased the areal coverage a
tad for a slight chance of showers and thunderstorms in the NE
Oregon mountains for Thursday afternoon/evening. High temperatures
at lower elevations will be in the mid to upper 90s and may reach
100 on Friday in the Lower Columbia Basin. Overnight lows in the
lowlands will be in the mid 50s to mid 60s. The mountains will have
highs in the mid 70s to lower 90s with lows in the upper 40s to
upper 50s.  Polan

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  91  58  90  54 /   0   0   0   0
ALW  91  64  91  60 /   0   0   0   0
PSC  96  61  94  55 /   0   0   0   0
YKM  95  60  93  56 /   0   0   0   0
HRI  95  61  93  53 /   0   0   0   0
ELN  90  62  87  54 /   0   0   0   0
RDM  90  46  89  47 /   0   0   0   0
LGD  90  52  88  49 /   0   0   0   0
GCD  93  54  92  53 /   0   0   0   0
DLS  89  63  88  58 /   0   0   0   0

&&

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

83/99/99