Area Forecast Discussion
Issued by NWS Pendleton, OR

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
300
FXUS66 KPDT 190517 AAA
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1010 PM PDT Fri Oct 18 2019

updated the aviation discussion

.UPDATE...A weather system will move across the region through
tomorrow spreading clouds and showers to the area. Minor changes
were done to overnight temps. The chance of pcpn is expected to
increase toward morning as a stronger part of the system pushes
through the region. Pressure gradients tighten resulting in breezy
to windy conditions tomorrow and a wind advisory is in effect across
the gorge and north central Oregon. Meanwhile snow levels will
fall and winter storm warnings are in effect later tonight and
tomorrow for the blue mountains above 5k feet with winter weather
advisories for portions of the wallowa region above 4500 ft.

.AVIATION...A weather system will approach the area with increasing
rain chances into Saturday. lcl mvfr conditions could develop at taf
site kdls through the period especially in showers and then at most
other taf sites after 10z. Meanwhile the winds will increase and
sustained winds between 15 to 30 mph with gusts nearing 40 to 45 mph
can be expected at times after 15z.

&&

.PREV DISCUSSION... /issued 440 PM PDT Fri Oct 18 2019/

SHORT TERM...This afternoon through Sunday night. Moist, unstable
northwest flow will result in upslope showers along the Cascades
with scattered showers over the eastern mountains through this
evening. Snow levels fluctuating around 5000 ft. An outside shot
for rain shower out in the basin, but will likely stay dry with
the with the westerly flow off the Cascades. Localized breezy
winds in the basin this afternoon will die off after sundown. A
stronger short-wave digs southeast across the PacNW late tonight
through tomorrow night. Rain and mountain snow likely in all areas
between midnight and tomorrow afternoon. Significant upslope flow
will bring hefty amounts of QPF for the Cascades, the Blue
Mountains, and the Wallowas--between 0.50 inch to 1.0 inch of
liquid precipitation. Snow levels will lower during the day and
will fall to near 4000 feet by tomorrow night. Precipitation will
taper off after the frontal passage, therefore the heaviest snow
accumulations will be in the higher elevations. Currently a winter
storm warning for northern Blues and winter weather advisory for
Wallowa county is in effect for late tonight through late Saturday
night.

Winds tomorrow will be another concern. Strong winds aloft and a
tightening pressure gradient behind a surface cold front will
result in breezy to windy conditions across much of the region,
especially over northern OR. For areas along the WA/OR border,
particularly from Mosier to Milton-Freewater, sustained winds of
25-30 gusting to 45 mph are likely. A wind advisory is in effect
tomorrow for the eastern Columbia Gorge and for a good portion of
north-central OR.

The system departs late tomorrow night but moist, northwest flow
continues in its wake with mountain snow showers expected through
Sunday night with a chance of rain showers in the basin. One to
two inches of new snow possible for elevations above 4000 feet.

LONG TERM...Monday through Friday.  Northwest flow will prevail
over the area through much of the period as a ridge of high pressure
remains offshore. Several rounds of moisture will move through in the
flow, producing mainly mountain showers Monday and Tuesday.  A
shortwave will be dropping south through Idaho on Wednesday,
clipping the northeast corner of Oregon with a few showers and
bringing in some cooler air. The ridge is expected to move inland
Thursday and Friday with dry conditions and seasonal temperatures. 93

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  46  54  39  56 /  70  90  30  30
ALW  48  54  42  57 /  60  90  60  40
PSC  50  59  43  58 /  80  70  20  30
YKM  42  57  36  55 /  90  50  10  40
HRI  48  58  42  59 /  80  70  20  30
ELN  40  52  35  51 /  80  60  20  50
RDM  41  50  33  56 /  80  80  40  30
LGD  41  46  36  46 /  70 100  50  40
GCD  42  46  34  49 /  90 100  50  40
DLS  47  54  44  56 /  90  80  40  50

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from 11 AM to 8 PM PDT Saturday for ORZ041-044-508-
     510.

     Winter Storm Warning from midnight tonight to 4 AM PDT Sunday
     for ORZ502.

     Winter Weather Advisory from midnight tonight to 4 AM PDT Sunday
     for ORZ050.

WA...Wind Advisory from 11 AM to 8 PM PDT Saturday for WAZ024.

     Winter Storm Warning from midnight tonight to 4 AM PDT Sunday
     for WAZ030.

&&

$$

97/97/



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.