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
859
FXUS66 KPDT 232159
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
256 PM PDT Thu Mar 23 2017

.SHORT TERM...Tonight through Saturday Night...A mid/upper level
ridge of high pressure continues moving eastward. The western flank
of the ridge is now over the forecast area thus allowing flow aloft
to back to southwest, which will allow transport of moisture ahead
of a cold front now approaching the coast. Clouds will increase
tonight with cloud bases lowering. Rain preceding the cold front
will move into central and north central Oregon, the eastern
COlumbia Gorge, the east slopes of the Washington Cascades and the
Kittitas valley this evening. Snow levels tonight will be 3000-4000
feet along the east slopes of the Washington Cascades and 4000-5000
feet along the east slopes of the Oregon Cascades as well as in the
eastern mountains of Oregon and the Blue Mountains of SE Washington.
The cold front will begin its march through the forecast Friday
morning in the western sections of the CWA. The cold front will then
move across the eastern sections of the forecast area Friday
afternoon. As such widespread rain will occur with the front. The
foothills of the northern Blue Mountains are likely to get 0.30-
0.50 inches of rain by frontal passage late in the afternoon.
Friday night the mid/upper level trough moves east and reaches the
Cascades and then moves across the region on Saturday providing some
dynamic lift combined with orographic lift over the mountains for
rain and snow showers likely in the Blue Mountains and the Wallowa
Mountains with snow levels 3500-4000 feet. Saturday night a
mid/upper level ridge of high pressure moves over the interior
Pacific Northwest for dry conditions.  Polan

.LONG TERM...Sunday through Thursday...Two major weather systems
will impact the forecast area during the extended. The first will
arrive on Sunday and linger into Monday. This system comes off the
Pacific Ocean in a westerly flow as an upper level trough but then
develops a closed low that dives into California and eventually the
Desert Southwest. This will weaken the system as it moves inland but
still the system will spread precipitation across the forecast area
with snow levels 3500 to 5000 feet.

The next system arrives on Wednesday as another upper level trough
pushes a cold front through the region. Snow levels will begin
around 5000 feet and then lower to around 4000 feet on Thursday as
precipitation turns to showers and decreases.

&&

.AVIATION...00Z TAFs...VFR conditions will prevail over the
next 24 hours but expecting a weather system will move in tonight
with increasing clouds and showers from the west. This may result in
brief periods of MVFR in lower CIGS and visibility late night and
early Friday.


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  40  53  39  54 /  60  90  40  20
ALW  43  53  42  56 /  60  90  40  30
PSC  43  55  41  59 /  50  80  10  10
YKM  41  57  36  59 /  50  60  10  10
HRI  41  55  40  57 /  60  80  10  10
ELN  36  50  33  52 /  70  70  10  10
RDM  39  54  33  52 /  60  50  10  10
LGD  39  52  37  54 /  50  80  60  40
GCD  39  52  35  54 /  60  80  50  40
DLS  43  55  41  57 /  60  80  10  20

&&

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

$$

99/91/91



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