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Area forecast discussion 
National Weather Service Pendleton or
237 PM PDT Friday Aug 1 2014

Short term...tonight through Monday...the upper ridge over the
western U.S. Will generally remain in place through Sunday, though
it will slowly shift east. The upper level flow over the Pacific
northwest will remain south-southwesterly through tonight then
become more southwest to westerly Saturday afternoon into Sunday.
Weak disturbances imbedded within the upper flow will continue to
move across the region through Sunday. These disturbance will pull
pieces of subtropical moisture out of Nevada which will result in
isolated to scattered showers and thunderstorms over the area late
today through Saturday evening. Shear and energy may be sufficient
for stray strong storms across portions of central and northeast
Oregon Saturday afternoon and evening. Some drying from the west may
begin to work into the area Saturday evening, but the better drying
looks to occur on Sunday. Will indicate a dry slot around the
Columbia River gorge Saturday evening, while limiting showers/storms
on Sunday to central Oregon east to Grant County and northeast to
The Blues and wallowas. A system currently near the south end of
Baja California California looks to move north through California to southern
Idaho on Monday. This system could push some extra moisture into
south-central and southeast Oregon. Meanwhile west to northwest flow
looks to increase across Washington and north-central Oregon. Thus
expect any showers and thunderstorms Monday afternoon to be in
roughly the same locations as on Sunday, though these showers/storms
could be rather wet. 90

Long term...Monday night through Friday...wrap around moisture
associated with a middle/upper level low pressure system in eastern
Oregon and western Idaho will provide a chance of showers and a
slight chance of thunderstorms Monday evening in central and
northeast Oregon Monday evening. The low remains over the Oregon
portion of forecast area on Tuesday thus keeping a slight chance of
afternoon and evening showers and a slight chance of thunderstorms
Tuesday afternoon/evening in the mountains of central and northeast
Oregon. The southern Blue Mountains as well as the Elkhorn and
Wallowa Mountains will have a slight chance of showers overnight
Wednesday through Wednesday morning by virtue of the low still in
far eastern Oregon. Then Flat Ridge of high pressure takes control
across the Pacific northwest for dry and stable conditions Wednesday
afternoon through Friday night. Polan


Aviation...00z tafs...mfr conditions will prevail for the next 24
hours. Mostly scattered high cirrus with few-scattered middle level clouds with
base around 15000 feet above ground level through the period. Isolated to scattered
thunderstorms expected to develop in a few more hours over ridge
tops in central Oregon, the ochoco-John Day Highlands, the Blue
Mountains, the Elkhorn Mountains and the Wallowa Mountains. Mean
deep layer steering flow is out of the south so thunderstorms will
move northward through this afternoon and this evening. Will keep
-tsra for kbdn and krdm until 02z/02nd. Thunderstorms will end by
around sunset or 04z as the atmosphere stabilizes. Sustained winds
will remain below 15 kts. Winds will gust to 35 kts in the vicinity
of thunderstorms. There is some potential for strong or marginally
severe thunderstorms in central Oregon Saturday afternoon. However,
confidence is not high enough at this point to include small hail
and gusty winds of 30-40 kts in tafs for krdm and kbdn, but cannot
rule it out late Saturday afternoon at kbdn and krdm. Polan


Fire weather...warm and dry conditions continue under a ridge of high
pressure. Thunderstorms can be expected over the region this
afternoon and evening and again on Saturday. The best locations for
scattered thunderstorms is across central...north central and
northeast Oregon as well as the far southeastern Washington zones.
These locations are under a red flag warning in effect through
Saturday. Isolated thunderstorms are possible in the Columbia Basin
later this evening and on Saturday. Storms that develop will be a
mixture of wet and dry with precipitation ranging from a few
hundredths of an inch to around a quarter of an inch. Dmh


Preliminary point temps/pops...
PDT 66 98 65 98 / 20 20 20 10
alw 71 99 70 99 / 20 20 20 10
psc 65 101 65 101 / 20 20 20 10
ykm 65 97 64 96 / 20 20 20 10
hri 64 100 64 100 / 20 20 20 10
eln 61 98 60 99 / 20 20 20 10
rdm 56 93 51 94 / 30 30 30 20
lgd 59 93 59 93 / 30 30 30 20
gcd 63 96 59 96 / 30 30 30 30
dls 68 96 64 96 / 20 20 10 10


PDT watches/warnings/advisories... flag warning until 11 PM PDT Saturday
orz041-049-050-502-503-505>507-509>511. flag warning until 11 PM PDT Saturday waz030.


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