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
FXUS66 KPDT 260959

Area Forecast Discussion
National Weather Service Pendleton OR
300 AM PDT Sun Mar 26 2017

.SHORT TERM...Today through Tuesday...An upper level trough has
moved into Idaho tonight and a brief transitory ridge is over the
region early this morning. This is leading to the current dry
conditions. This will not last long as a system is approaching the
Pacific Northwest coast. The warm front of this system will cross
the Cascades later this morning and bring a chance of showers to the
Cascades and Central Oregon in the morning and a chance of showers
across the area in the afternoon. The cold front will arrive Sunday
evening and showers will be likely before starting to taper off late
in the evening with just a slight chance of showers in the Columbia
Basin and North Central Oregon overnight. Precipitation will be
mainly rain with snow levels rising from around 4500 feet this
morning to around 5500-6000 feet this evening before dropping down
to 3500 to 4000 feet behind the front by tomorrow morning.
Precipitation amounts will be around a tenth of an inch in the
Columbia Basin, up to a quarter of an inch in the rest of the lower
elevations and up to a half inch in the mountains. Snow amounts in
the mountains will be up to 3 inches in the higher mountain passes.
On Monday as the front departs, the associated trough will cross the
area. Instability with the front will keep a chance of rain and snow
showers in the mountains in the afternoon and a slight chance of
rain showers in the lower elevations. Snow levels will remain around
3500-4000 feet and precipitation amounts will be less than a tenth
of an inch. Monday night and Tuesday a ridge will be over the area
for mainly dry conditions. Another system  will be trying to cross
the Cascades, but a chance of light rain and showers will be
confined to the Cascades Crest region. Temperatures will be in the
mid 40s to mid 50s today then warm Monday and Tuesday to the mid to
upper 50s in the Columbia Basin and in the mid 40s to mid 50s
elsewhere. Perry

.LONG TERM...Tuesday night through Sunday night...The latest GFS
model run is more in line now with the ECMWF and Canadian models for
the extended period...especially this coming mid week. The main
concern during the extended period will be a couple of weather
systems bringing more rain to the CWA. While these will mostly be
just spring time rain events with little hazardous impacts it may
cause rivers and streams to rise again. However at this time rivers
are not expected to reach flood stage anymore. There are a few that
will be at bankfull which will be covered with river statements.
Tuesday night and Wednesday a weather system will move into the
region with a period of rain followed by mainly mountain rain
showers behind the system by Wednesday afternoon, caused by upslope.
Snow levels will be quite high so there will be no concern with
winter weather at this time. Conditions will dry out by Friday and
then it will stay mostly dry until next Sunday night. However that
far out the models do not agree well with each other anymore, and
therefore only made minor changes to the previous forecast until the
forecast becomes more certain. It may be breezy at times...
especially on the ridge tops and open grassy terrain. Temperatures
will be near normal through the extended period. 88


.AVIATION...12Z TAFs...VFR conditions are expected through this
morning, but then another weather system will move into the region
this afternoon possibly causing periods of MVFR and possibly IFR due
to low CIGs and reduced visibility in rain/showers. Conditions will
improve after 06Z tonight, but there might be some patchy fog due to
some clearing skies and abundant low level moisture with light
winds. Wind will become locally breezy this afternoon though with
speeds of mostly 10-20 kts. 88


PDT  52  39  55  38 /  60  80  40  10
ALW  55  42  57  43 /  60  70  40  20
PSC  54  41  59  41 /  60  60  20  10
YKM  53  37  61  38 /  70  60  20  10
HRI  53  40  57  39 /  60  60  20  10
ELN  46  34  51  36 /  70  60  20  10
RDM  53  34  52  31 /  70  70  30  10
LGD  54  38  53  35 /  50  80  60  20
GCD  54  38  53  33 /  60  90  50  10
DLS  52  41  56  43 /  80  70  20  10




83/88/88 is the U.S. government's official web portal to all federal, state and local government web resources and services.