Area Forecast Discussion
Issued by NWS Pendleton, OR

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FXUS66 KPDT 250519
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
919 PM PST Fri Feb 24 2017

Updated aviation discussion

.SHORT TERM...Tonight and Saturday...The upper level low off the
Oregon coast continues to move southward. Regional radars show a few
showers from the Cascades westward but rest of the forecast area has
seen showers come to an end this evening. As the low continues to
drop southward the forecast area will be under a dry northerly flow
with just a few lingering showers near the Oregon Cascades. There
could be enough instability in this north flow for a few showers to
develop over the eastern Oregon mountains Saturday afternoon
otherwise the forecast area will remain dry.

.AVIATION...06Z TAFs. VFR conditions will prevail for the next 24
hours. Winds will be less than 10 knots through the period.  Wister

&&

.PREV DISCUSSION... /issued 315 PM PST Fri Feb 24 2017/

SHORT TERM...Tonight through Monday. Upper low moving south
along the coast today. Satellite showing weak instability over
the area with cumulus development over the mountains and scattered
snow showers. Circulation around the low also producing some
light snow over the Cascades. This will continue through the
evening then diminish overnight as the low moves south and the
instability decreases. Skies will be mostly cloudy with some
gradual clearing later tonight. Temperatures will be cold with
teens and 20s. Upper ridge over the area Saturday with partly
cloudy skies and light winds. An upper level trough will start
moving into the Pacific northwest Saturday night. Clouds will be
increasing with light snow developing toward morning. The trough
will be over the area Sunday with snow likely. The lower elevations
may mix with rain during the afternoon with temperatures in the
30s. As the trough slowly exits the region Monday the snow will
taper off to showers although cold northwest flow will continue
the snow a bit longer over the northeast Oregon mountains. At this
point total snow accumulations for the mid and higher elevations
are expected to be 3-8 inches. Accumulations for the Columbia
basin will be more dependent on temperatures Sunday however expect
1-2 inches possible.  94

LONG TERM...Monday night through Friday. Medium-range models are in
general agreement through the extended period but are trending more
toward a westerly flow late in the week compared to the upper level
ridge in the previous runs.  The forecast area will be under a NW
flow aloft Mon night and Tues bringing scattered snow showers
(snow/rain mix in the lowest elevations). This will be followed by
westerly flow the remainder of the period.  Any precipitation Tues
night through Fri will be scattered snow showers along the
Cascades...mainly WA...and the northern Blue Mtns and Wallowas. A
strong westerly flow aloft combined with tight surface pressure
gradients will bring windy conditions in many areas Wed-Fri.  Models
are hinting at the potential for strong winds on Fri when the upper
level jet positioned over northern Washington begins to slide south.
A slight warming trend is forecast in the long term period with
daytime temperatures increasing in the 40s to lower 50s and
overnight lows in the mid 20s to mid 30s late in the work week.
Wister



&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  27  42  26  36 /   0   0  20  60
ALW  30  42  28  37 /   0   0  20  60
PSC  24  45  28  40 /   0   0  20  60
YKM  20  41  24  37 /  10   0  30  60
HRI  26  44  27  40 /   0   0  20  60
ELN  14  37  22  33 /  10   0  30  70
RDM  18  38  21  36 /  10  10  10  60
LGD  21  35  23  33 /  10  10  20  70
GCD  23  36  18  33 /  10  10  10  60
DLS  27  44  29  39 /  10   0  30  70

&&

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

$$

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