Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Pendleton or
947 PM PST Thursday Mar 6 2014
Updated aviation discussion
Short term...update...winds have decreased across the region with
some locally breezy to windy locations. Winds will continue to
gradually decrease overnight as a surface low in north central
Washington moves east into Montana. Thus allowed the wind advisories
to expire at 7 PM. Precipitation has decreased across the area with some
slop over showers continuing along the Cascade crest and over
Wallowa County. Showers have largely ended in The Blues as of 830
PM. Expect slop over showers to continue through the night along
the Cascade crest, especially in Washington. Also a weak trailing
wave currently moving onshore should reinvigorate showers over the
northern half of the Blue Mountains overnight. Overall precipitation
coverage forecasts on track and only made minor adjustments. Snow
levels are around 4000 feet over south central Washington, 4500 feet
over central Oregon and around 5000 feet over northeast Oregon.
These snow levels will generally hold through the night, though they
should lower to near 4500 feet over northeast Oregon. The colder
temperatures associated with these lower snow levels will end snow melt and
precipitation run off at and above these elevations. Thus do not expect
much in the way of additional run off into the rivers and streams
flowing out of the mountains. At the same there remains a fair
amount of water moving down the area rivers and streams. Thus will
continue most current flood watches and the advisory in Kittitas
Long term...previous discussion...ec/GFS in agreement on a couple
of shortwave troughs moving through the area Sunday night and
Monday. Snow levels will remain quite high on Sunday night and
Monday...so travel impacts from the precipitation should be minimal.
Precipitation diminishes on Monday night and it turns generally dry
for Tuesday and Wednesday with a high pressure ridge over the area.
Ec model brings another shortwave trough for Wednesday night and
early Thursday and have slightly increased probability of precipitation for that period
although confidence is quite low since the Middle Range models are at
odds. Breezy to windy conditions are likely early in the period with
the frontal passage on Sunday night and Monday.
Aviation...06z tafs...VFR conditions expected through this period.
Ceilings between 5000 and 8000 feet above ground level early this period expected at
times at kdls, kalw and kpdt. Expect few-scattered clouds during the day
Friday at all sites. Winds have decreased at most sites except kpsc.
Generally winds are expected to run 5 to 15 kts through the period.
Winds could increase for a while during the first 6 hours or so at
kpdt and kalw. Kpsc winds should fall in line with other locations
by or shortly after 12 UTC. 90
Preliminary point temps/pops...
PDT 40 58 39 64 / 30 0 0 0
alw 43 59 41 62 / 40 0 0 0
psc 43 62 40 66 / 20 0 0 0
ykm 34 59 34 62 / 10 0 0 10
hri 42 62 40 66 / 20 0 0 0
eln 36 55 34 58 / 20 0 0 10
rdm 30 59 34 63 / 20 0 0 10
lgd 36 53 35 57 / 50 10 0 0
gcd 34 56 36 58 / 40 0 0 0
dls 40 60 37 63 / 30 0 0 10
or...Flood Watch through Friday morning orz049-050-502-503-507.
Washington...Flood Watch through Friday morning waz026-027-029-030-520-521.
Friday : green
Saturday : green
Sunday : green
Green: none or limited need for watches, warnings, or advisories.
Yellow: a few watches, warnings, or advisories possible or in effect.
Red: numerous watches, warnings, or advisories possible or in effect.
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