Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus66 kpdt 211205 aac 
afdpdt

Area forecast discussion...updated
National Weather Service Pendleton or
505 am PDT Sat Oct 21 2017

Updated to add aviation discussion

Short term...today through Monday afternoon...a very progressive
pattern over the next several days beginning with a warm front
moving over the forecast area today, which will bring rain at times
to the interior Pacific northwest. Snow levels will be around 3500
feet in the Blue Mountains this morning and then rise rapidly this
afternoon to 5000 feet in The Blues. The warm front and attendant
rain will begin lifting northward tonight resulting in rain ending
this evening in central and north central Oregon and along the
southern foothills of the Oregon Blue Mountains. Rain should be
ending before daybreak Sunday in the lower Columbia Basin and the
Yakima Valley. A Flash Flood Watch is in effect for the Jolly
Mountain and Norse Peak fire burn areas as two to four inches of
rainfall is expected by Sunday morning. The warm front weakens
Sunday afternoon for decreasing pops in the eastern mountains and
then moves eastward into Idaho Sunday evening resulting in rain
ending early Sunday evening in the Blue Mountains. A ridge of high
pressure builds over the region late Sunday night through Monday for
dry conditions.

Strong winds aloft will mix down to the surface today and tonight in
central and north central Oregon, the Simcoe Highlands, the Grande
Ronde Valley and along the foothills of the Blue Mountains of Oregon
and Washington. A Wind Advisory is in effect for these areas. Polan

Long term...Monday night through Friday...an upper level ridge will
persist over Washington and or Monday night Tuesday with dry northwest flow.
Subsidence from the ridge will bring warm days...clear skies and
light winds. Monday night and Tuesday night light winds and clear
skies will provide good radiational cooling. Patchy late night and
early morning is possible in the Columbia Basin. A frontal system
will be moving through the area Wednesday with some rain for the
Cascades...foothills of The Blues...and the mountains of northeast
Oregon. Behind this system, the models are coming into agreement on
stronger northerly flow and cooler air spreading into the area from
the north as high pressure rebuilds offshore. Temperatures will be
above seasonal averages Tuesday and Wednesday and then cool to below
normal during the rest of the week. Coonfield

&&

Aviation...12z tafs...a warm front is approaching kdls this
morning. Cigs will lower through the day as overrunning occurs. MVFR
conditions are possible after 17z. Winds will increase after the
warm front passes when stronger Wilds aloft can mix to the
surface...particularly ridgetops. Winds will increase this afternoon
at krdm and kbdn. Winds will increase this evening at other taf
sites. Mountain wave winds are possible near kbdn and krdm between
15z and 22/09z and west of kykm between 22/03z and 22/12z. 76

&&

Preliminary point temps/pops...
PDT 59 53 67 47 / 100 70 40 10
alw 57 52 68 49 / 100 100 50 10
psc 57 53 69 46 / 90 60 10 10
ykm 53 46 65 41 / 100 70 10 10
hri 59 52 69 46 / 90 40 20 10
eln 49 43 60 40 / 100 90 10 10
rdm 59 46 63 40 / 90 20 20 10
lgd 48 44 56 42 / 100 90 70 30
gcd 51 47 57 44 / 100 50 40 20
dls 58 53 67 48 / 100 70 60 10

&&

PDT watches/warnings/advisories...
or...Wind Advisory from 5 PM this afternoon to 8 am PDT Sunday for
orz507-508-510-511.

Winter Weather Advisory from 8 am this morning to 11 PM PDT this
evening for orz050.

Winter Weather Advisory until 11 PM PDT this evening for orz502.

Winter Weather Advisory until 5 PM PDT this afternoon for orz503-
506.

Wind Advisory from 1 PM this afternoon to 11 PM PDT this evening
for orz049.

Washington...Wind Advisory from 5 PM this afternoon to 8 am PDT Sunday for
waz521.

Winter Weather Advisory until 11 PM PDT this evening for waz030.

Flash Flood Watch from 7 am PDT this morning through Sunday
morning for waz520.

Wind Advisory from 8 PM this evening to 1 PM PDT Sunday for
waz029.

National Weather Service Glossary of Abbreviations