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Area forecast discussion 
National Weather Service Pendleton or
240 PM PDT Sat Jul 4 2015

Short through Tuesday...another hot and dry afternoon
out there today with near record high temperatures expected. An area
of middle to high level clouds continues to gradually move north across
much of our Oregon forecast zones this afternoon. The most extensive
and thicker cloud cover is confined to the ochoco-John Day Highlands
and central Oregon...where temperatures are being held down somewhat
compared to yesterday. These clouds are expected to lift north into
extreme southern Washington this evening before shifting back south
through the day on Sunday as an upper level trough moves through
shifting the flow to north-northwesterly. This disturbance is not
expected to bring any precipitation to the area...however winds are
forecast to increase across the northern Columbia Basin of
Washington...the Kittitas and Yakima valleys during the evening and
overnight hours. See the fire weather section below for more details
on expected wind speeds. This increase in wind speeds may cause
patchy areas of blowing dust in these areas starting late this
evening through the early afternoon hours Sunday. Behind this weak
disturbance conditions will remain breezy through at least the early
afternoon hours on Sunday...temperatures are expected to be a few
degrees cooler tomorrow...with highs mainly 95-101 in the lower
elevations and 80s to lower 90s in the mountains. By Sunday
afternoon and early evening there will be a slight chance for a
shower or thunderstorm over the Wallowa Mountains and extreme
southern Deschutes counties...otherwise it should remain dry. Monday
and Tuesday will continue to see above average temperatures with
highs expected to be in the middle-90s to lower 100s for the valleys
and basins each day. There will also be a slight chance for for
afternoon/evening showers and thunderstorms across the southern
portion of our County Warning Area on Monday and especially Tuesday as more
instability and moisture work into the area ahead of an upper level
low. 77

Long term...Tuesday night through Saturday. Upper level low pressure
system will be approaching the region by Wednesday and is expected
to move through the area by Saturday. On Wednesday the low is still
far enough south and west of the area with only a slight chance of
thunderstorms over southern Oregon. As the low moves inland
scattered showers and thunderstorm will spread north and east across
Oregon...but it will remain dry and warm over eastern Washington.
The low pressure system will be moving out of the region Friday
night and early Saturday with cooler temperatures and some gusty
winds. 93


Aviation...00z tafs...VFR conditions will prevail over the next 24
hours. Scattered-broken cirrus at 25k feet will continue over mainly Oregon
overnight with increasingly west to northwest flow over Washington
as weak weather system moves through southern Canada. West to
northwest wind 10-20kts will persist through 06z at kdls and kpdt
and 10 kts and less at other tafs sites. 93


Fire weather...the red flag warnings for wind and low relative
humidity for portions of the Columbia Basin...eastern Columbia River
gorge...and north central and central Oregon remain in effect. Rh's
and winds are similar to yesterday...I.E. 8 to 15 percent and 10-15
miles per hour for most of the region. Winds may be less than yesterday but
will still bring the possibility of rapid fire spread in some areas
where winds will increase to around 10-20 miles per hour this afternoon and
evening. The warning for the Hanford district and the Yakima Valley
is in effect through Sunday morning. Northerly winds will increase
there tonight and gusts to 30-35 miles per hour are possible...mainly along
Rattlesnake Ridge. The fire weather concerns will shift to the
thunderstorm potential during the work week. The threat of
thunderstorms will be a slight chance for our far southern zones Monday-
Wednesday but the threat increases farther north with isolated-scattered
thunderstorms possible Thursday and Friday. The short- and long-
term discussions will provide more details. Wister


Preliminary point temps/pops...
PDT 65 97 64 98 / 0 0 0 0
alw 71 96 69 97 / 0 0 0 0
psc 68 100 66 102 / 0 0 0 0
ykm 68 99 67 97 / 0 0 0 0
hri 66 100 65 101 / 0 0 0 0
eln 65 98 63 99 / 0 0 0 0
rdm 56 94 58 97 / 0 0 0 10
lgd 58 91 57 91 / 0 0 0 10
gcd 59 96 57 99 / 10 0 0 10
dls 69 101 69 102 / 0 0 0 0


PDT watches/warnings/advisories... flag warning until 8 PM PDT this evening for orz610-639>641. flag warning until 8 PM PDT this evening for waz639.

Red flag warning until 9 am PDT Sunday for waz675.


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