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Area forecast discussion...updated 
National Weather Service Pendleton or
1030 am PDT Wednesday Jul 23 2014

Updated aviation discussion

Short term...large upper level low is moving into the Pacific
northwest today. Frontal boundary has moved onshore and is producing
showers and thunderstorms with heavy rain over western Washington
and western Oregon. The front will move across the forecast area
today with showers and thunderstorms. Expect areas of heavy rain
over the Cascades and east slopes. Vorticity center and jet moving around
the upper low may result in some strong storms this afternoon into
the evening with hail and wind. Westerly winds will be increasing
later today. As the low moves off to the northeast tonight
precipitation will diminish. Breezy west winds will continue. 94


Aviation...18z tafs...expect another day of convective weather for
all taf sites. Thunderstorms will be possible as early as 21z at
kykm...kdls...krdm and kbdn. Strong wind shear and moderate
instability could also cause a few storms to become strong to
severe. Taf sites will be breezy with winds 10-20 kts gusting 20-30
kts. Conditions should begin to improve after 03z as clouds become
more scattered and precipitation moves north of the area. Thursday
will be dry but breezy with scattered clouds. 82


Previous disc... /issued 437 am PDT Wednesday Jul 23 2014/

Short through Friday night...lightning strikes have
decreased over the past 3 hours. Infrared satellite indicates that the
colder cloud tops have moved north of the County Warning Area. However models
indicate that another wave will rotate around an offshore upper
level low into eastern Oregon and Washington this afternoon. This
will keep moist unstable over the area. Expect thunderstorms to
redevelop this morning...particularly over central Oregon and
Washington...then spread east in the afternoon. The low will move
into northwestern Washington this evening...with diminishing
precipitation through the night. Winds will become breezy to windy
this afternoon as higher winds aloft mix to the surface. A dry
westerly flow aloft Thursday will bring mostly sunny skies...cooler
temperatures and breezy conditions. Westerly flow continues into
Friday with another sunny day. Temperatures will be warmer with less
wind. 76

Long term...Saturday through Tuesday night...west flow will shift
to the southwest Saturday as a Four Corners high strengthens. Flow
will quickly shift to be southerly...and monsoonal moisture from the
south will make its way to the forecast area. Models don't put out
to much quantitative precipitation forecast with this have only gone with a slight
chance of thunderstorms. Right now the slight chance thunder is
over central Oregon on Monday and will spread to northeast Oregon as
well Tuesday Onward. Temperatures will be fairly hot with highs in
the middle 90s to lower 100s starting Sunday and continuing through the
extended. Weber


Preliminary point temps/pops...
PDT 81 53 79 51 / 40 30 10 0
alw 84 57 78 57 / 40 30 10 0
psc 85 59 82 54 / 30 30 10 0
ykm 77 53 78 54 / 50 30 10 10
hri 83 56 80 53 / 30 20 10 0
eln 74 51 74 52 / 60 30 10 10
rdm 73 38 74 39 / 40 20 0 10
lgd 82 50 72 45 / 40 30 10 0
gcd 81 49 75 48 / 30 20 0 0
dls 73 57 77 56 / 70 30 10 10


PDT watches/warnings/advisories... flag warning until 11 PM PDT this evening

Red flag warning until 5 PM PDT this afternoon orz509-511. flag warning until 11 PM PDT this evening


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