038 
FXUS66 KPDT 060608
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1008 PM PST Fri Feb 5 2021

.SHORT TERM...Strong northwest flow aloft into the region
overnight into Saturday. Upper ridge remains offshore with a 
short wave and jet approaching southern BC and the Pacific 
northwest this evening. This system will move through later 
tonight and Sat. Main impacts will be wind. Expect winds aloft to 
mix down. Models have been fairly consistent with this scenario. 
Many locations will have westerly winds 20-40 mph. Some gusts to
45 mph likely. Precipitation will be limited to snow over the 
Cascades and Blues for the most part with good upslope flow. 
Otherwise partly to mostly cloudy skies. Sunday into Monday will 
be the start of a significant cooling trend as a large cold low 
pressure system moves into southern Canada and the northern tier
of states. Tue-Fri next week look very cold as 850mb temps fall to
-10 to -15C.  94

.AVIATION...06Z TAFS. Main impacts for the Taf sites will be wind.
Westerly winds will increase to 20-35kt Sat. Cloud cover will be
sct-bkn 040-080. Precipitation will be mainly over the mountains. 

PREV DISCUSSION... /issued 205 PM PST Fri Feb 5 2021/ 

SHORT TERM...Tonight through Sunday...An upper level ridge will
continue to be over the eastern Pacific through this weekend 
while positioning the region under a strong northwest flow aloft. 
Shortwave that brought breezy conditions and moderate snow 
accumulations across the mountains has exit the region this 
afternoon, leaving light upslope snow showers to continue in 
portions of the WA Cascades and in the northern Blues. Breezy 
winds have continued across the OR Blue Mountain foothills, the 
Gorge, and the Kittitas valley this afternoon and are expected to
continue through tonight. Otherwise, winds have been 5 to 15 mph 
everywhere else this afternoon.

Another shortwave will pass over the region tomorrow with another
round of snow showers across the mountains. The moisture plume
associated with this shortwave is weaker than this mornings, so
snow accumulations of 3-6" can be expected in the WA Cascades and
the Blues with higher amounts near the crests; 1-3" of snow 
accumulations are possible in the passes. Shortwave passage will
also be associated with a low level jet that will see gusty winds
mix down into the lower elevations late Saturday morning through
the early evening. Wind advisories have been issued for the
Columbia Basin/Gorge, the Blue Mountain foothills, and the
Kittitas valley for tomorrow. While the Yakima valley will also 
see breezy winds develop tomorrow, they are not expected to reach 
advisory level criteria. As shortwave exits the region overnight 
Saturday, snow showers will become light across the mountains 
while winds gradually decrease.

Sunday, northwesterly flow aloft will continue to produce upslope
snow showers into the Cascades and the Blues with light
accumulations expected through the day. Surface pressure 
gradients east of the Cascades will slowly relax Sunday behind 
the shortwave passage, however, locally breezy conditions in the
lower elevations will persist into the overnight hours. 
Lawhorn/82

LONG TERM...Monday through Friday...A large are of low pressure was 
located south of Hudson Bay and this was the predominant feature on 
the map.  Northwesterly flow around this low will mainly bring dry 
weather to the Pacific Northwest, though a weak short wave and 
upslope flow will bring some mountain snow on Monday.  The low over 
Canada drops a bit further South by Thursday and a backdoor cold 
front will move through Wednesday in Thursday.  Temperatures will be 
much colder Thursday and Friday, the coldest they have been all 
winter.  Some guidance suggests many locations will not get above 
freezing Thursday and Friday, though it is still February and these 
temperatures are not all that cold for February they will be at 
least 10 degrees below normal.  Overnight lows will be in the teens 
and 20s.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  36  53  36  45 /   0  10  10  20 
ALW  38  53  36  46 /  10  10  10  30 
PSC  38  55  36  50 /   0   0   0  10 
YKM  31  54  31  48 /   0  10  10  10 
HRI  39  56  36  50 /   0   0   0  10 
ELN  33  49  31  43 /  10  20  10  10 
RDM  25  49  27  45 /   0   0   0   0 
LGD  30  44  31  39 /  10  30  30  30 
GCD  25  46  29  42 /  10  10  10  10 
DLS  38  52  37  47 /  10  20  20  20 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from 10 AM to 7 PM PST Saturday for ORZ041-044-507-
     508.

WA...Wind Advisory from 10 AM to 7 PM PST Saturday for WAZ024-026-028-
     029.

&&

$$

SHORT TERM...94