Richland, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

699
FXUS66 KPDT 231058
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
258 AM PST Sat Nov 23 2024

.SHORT TERM...Today through Monday...Forecast area continues under a
moist southwest flow and a slow moving cold frontal boundary over
the eastern mountains. This is all due to the closed upper level low
pressure system off the coast which more or less stays there until.
it weakens and finally moves inland late Monday into Tuesday.

The frontal boundary will slowly continue moving east through the
morning and then exit into Idaho. Eastern mountains will continue to
see a steady precipitation through the morning then changing over to
showers in the afternoon. Snow levels are slowly lowering and will
be around 4000 feet through the day. Snow accumulations are expected
to remain low and below any advisory criteria. Tonight the showers
over the eastern mountains are expected to come to an end.

With the closed low remaining off the coast Sunday most of the
precipitation threat will be confined to the Cascade region and
areas westward. Then another shortwave coming out of the low will
move across the forecast area Sunday night and Monday bringing
another round of showers across the forecast area with snow levels
down around 3000 feet. Again, precipitation amounts are expected to
remain light so snow accumulations will remain below advisory
levels.



.LONG TERM...Tuesday through Saturday...Guidance continues to point
toward a benign, cold pattern for much of Thanksgiving week. After
an open low moves through the forecast area to start off the period,
north to northwesterly flow aloft prevails over the PacNW, making
for a relatively dry forecast, as the oncoming airmass lacks
moisture, but with cold temperatures that struggle to climb into the
40s by next weekend. Without the presence of high pressure and
subsidence aloft, light mountain precip remains possible, albeit
with limited PoPs (15-25%) given the lack of moisture advection.
Most guidance suggest that this upper-level flow won`t be amplified
enough to cause many precip concerns, but will have to keep an eye
on how the forecast evolves given that some deterministic guidance
(such as the GFS) do try to embed a shortwave into the prevailing
flow pattern towards the end of the period.

Light precip impacting primarily our high mountain zones is most
likely on Tuesday what with the low overhead, but QPF again looks to
be limited given the lack of sufficient moisture transport. Other
than that, beyond the colder temperatures coming in by Thanksgiving,
only other real concern would be valley and Basin fog, which can
form under these otherwise quiet patterns. Still opting to keep
mention out of the forecast, as the oncoming airmass is pretty dry
and the synoptic pattern doesn`t quite produce ridging, which is the
most ideal set-up for low elevation fog, but given how wet we`ve
been recently, could certainly see the atmosphere being primed
enough for some patchy early morning fog later in the week. Will pin
forecast confidence at the low end for now (20-30%) for fog chances.
Evans/74

&&

.AVIATION...12z TAFs...Variable conditions will once again prevail
early this morning as rain and low clouds slowly dissipate by
daybreak, with the biggest impacts occurring over PDT and ALW. By
the afternoon, drier conditions and higher cigs in the 5 to 10 kft
range will prevail, save for some scattered light showers that may
impact BDN and RDM between 21z and 00z (confidence 40-50%). Low
clouds and fog may persist a bit longer than what current TAFs call
for, as they sometimes do under a saturated environment such as this
one, but confidence is on the higher end (50-60%) that VFR
conditions will prevail across all sites by 00z this evening at the
absolute latest. Winds will remain light at less than 10 kts across
all sites. Evans/74


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  48  34  49  33 /  60  20  10  20
ALW  50  36  50  37 /  70  20  10  30
PSC  51  36  48  37 /  30  10  10  20
YKM  46  30  43  33 /  10  10  30  30
HRI  51  35  50  36 /  40  10  10  20
ELN  44  29  41  32 /  10  10  40  30
RDM  44  28  45  32 /  20  10  10  30
LGD  45  28  41  32 /  90  40  10  20
GCD  44  27  44  30 /  70  40  10  40
DLS  50  35  49  38 /  20  50  30  60

&&

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

$$

SHORT TERM...91
LONG TERM....74
AVIATION...74