Area Forecast Discussion Issued by NWS Pendleton, OR
000
FXUS66 KPDT 072243
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
243 PM PST Sun Mar 7 2021
Updated aviation discussion
.SHORT TERM...TONIGHT THROUGH TUESDAY...An upper level trough off
the coast will continue to influence the regional weather by
inducing periods of showery weather. At the heart of the trough is a
closed low pressure currently off the coast of Canada. This low will
slowly drop southward and be along the Oregon coast by Tuesday. In
doing so it will send some occasional impulses across the forecast
area under a southwest flow aloft. It will also increase shallow
Spring time instability helping enhance shower activity during the
afternoons. Snow levels will range from 2000 to 3000 feet but
occasional dip lower in the overnight periods. However, the showery
nature of the precipitation means that snow accumulations will be
spotty and will quickly melt.
One of those impulses will arrive early Monday and spread some
light showery precipitation mainly across central and eastern
Oregon. Some of this could be snow showers producing some light
accumulations which is expected to melt quickly once the sun is up.
This will be followed by increasing shallow instability midday and
afternoon producing more convective showers. These showers will
begin to decrease around sunset with most ending by midnight with
possible exception of far eastern mountains. Showers will then
return on Tuesday midday and afternoon as the heating of the day
induces the shallow instability which in turn develops into
showers. These showers to will begin to fade out around and after
sunset Tuesday.
.LONG TERM...WEDNESDAY THROUGH SUNDAY...The upper level low off the
Oregon Coast will eventually drop down into California on Wednesday.
This will push the upper level trough across the region for one last
day of cool showery weather. The trough will exit to the east on
Thursday with just a few lingering showers over the eastern
mountains. Meanwhile, an upper level ridge will build into and over
the region Thursday through Saturday for a stretch of warmer and dry
weather. A high degree of model uncertainty begins going into next
weekend. The GFS wants to begin breaking down the ridge and have the
next upper level trough arriving late Saturday into Sunday with
possible precipitation. However, the ECMWF wants to hold the ridge
in position over the region through Saturday and then just flatten
the ridge on Sunday but stay dry. Opted to keep a dry forecast
through Saturday and then introduce just a slight chance of showers
on Sunday.
&&
.AVIATION...00Z TAFs...VFR conditions will continue for all location
with the possible exception of BDN and RDM where some rain/snow
showers will become possible Monday locally reducing VSBYs and CIGS
to possible MVFR to IFR briefly. 10-20kts winds will drop to less 10
kts after sunset.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 34 44 31 51 / 10 30 10 20
ALW 35 47 33 53 / 10 30 10 20
PSC 36 50 33 55 / 0 10 0 10
YKM 31 49 29 51 / 0 10 10 10
HRI 35 49 31 55 / 10 20 10 10
ELN 28 47 28 46 / 0 10 10 20
RDM 27 46 25 48 / 20 20 20 20
LGD 30 40 26 42 / 20 50 20 20
GCD 31 44 27 44 / 20 40 20 20
DLS 35 49 34 51 / 0 20 20 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
SHORT TERM...91
LONG TERM....91
AVIATION...91