Pasco, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

117
FXUS66 KPDT 090552
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1052 PM PDT Tue Jul 8 2025

.AVIATION...06Z TAFs...A pair of weather systems will track over
the region through Wednesday, inducing periods of breezy to windy
conditions for all TAF sites. Isolated high-based showers and
thunderstorms across south-central Washington and northeast Oregon
have a very low (<30% chance) of impacting DLS/YKM/PSC/ALW/PDT
through 09Z Wednesday. Plunkett/86

&&

.PREV DISCUSSION... /issued 141 PM PDT Tue Jul 8 2025/

.SHORT TERM...Tonight through Thursday...Satellite imagery this
afternoon shows mostly clear conditions across the region, though
cumulus fields are beginning to develop along the higher terrain
of central and eastern OR.

Upper level ridging over the PacNW will begin to break down later
this evening as a developing trough offshore begins to move
inland. However, the influence of the upper ridge will continue to
be felt across the region today, as high temperatures across the
Columbia Basin increase into the lower 100s, with widespread mid
to upper 90s elsewhere. Ahead of the trough, southwest flow has
developed across the PacNW, leading to increasing instability
across central and eastern OR this afternoon. Isolated to widely
scattered thunderstorms (15-20% chance) developing in these areas
throughout the afternoon and evening will be able to tap into that
instability, but also tap into the strong low to mid level lapse
rates. All that said, shear aloft doesn`t look to favor
maintaining storms, so gusty outflow winds from a collapsing
updraft are expected. Thunderstorm activity is expected to wane
tonight, however, an HREF member or two do depict a few storms
developing and moving along the Blue Mountain foothills tonight,
but confidence is very low (10%) in these storms developing.
Otherwise, breezy winds will begin to develop through the Cascade
Gaps as the cross Cascade pressure gradient tightens.

Wednesday, the upper trough and a dry cold front will move across
the PacNW bringing two fire weather concerns: strong winds and
another round of isolated thunderstorms. Persistent instability
across eastern OR in tandem with some divergence aloft will allow
for isolated thunderstorms (~15% chance) to develop across
southern and eastern portions of Grant county into southern Union
and Wallowa counties tomorrow afternoon and evening. As for winds,
the cold front passage tomorrow afternoon will result in
sustained winds of 25-35 mph with gusts up to 45 mph developing
through the eastern Gorge and Kittitas valley, with sustained
winds 20-30 mph and gusts up to 40 mph across the Columbia Basin
and portions of north central OR. Winds will generally be 15-25
mph with gusts 25-35 mph elsewhere in the lower elevations. The
cold front boundary will also produce cooler temperatures tomorrow
into Thursday, which will help increase afternoon RHs above
critical thresholds tomorrow. That said, the strength of the winds
tomorrow will overcome the impacts from higher RHs, necessitating
the need of a Red Flag Warning for the Columbia Basin tomorrow
afternoon and evening.

By Thursday afternoon the upper trough will have moved east of the
region, leaving behind a cooler airmass with locally breezy
conditions through the Cascade Gaps. By the evening hours, a
transient upper level ridge will slide across the PacNW, with a
more broad upper ridge beginning to develop in the northeast
Pacific. Lawhorn/82

&&

.LONG TERM...Friday through Tuesday...Ensemble cluster guidance
in great agreement through the extended forecast that upper level
riding will build over the northeast Pacific, with the PacNW
coming under the influence of the upper ridge (confidence 60-70%).
Flow aloft will waver from a weak zonal flow into northwest flow
aloft early next week. Temperatures will be increasing Friday into
the weekend, with a slight cool off into early next week with
northwest flow developing. Breezy winds will develop through the
Cascade gaps each day as well, but as flow aloft turns more
northwesterly, the Kittitas Valley and gaps through the WA
Cascades will see breezy to locally gusty conditions (50-70%).
Otherwise, mod-high confidence (60-80%) that the upper ridge will
suppress storm activity across the region through early next week.
Lawhorn/82

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  64  91  59  86 /  20   0   0   0
ALW  68  92  63  85 /  20   0   0   0
PSC  64  95  60  89 /  20   0  10   0
YKM  62  89  58  87 /  20   0  10   0
HRI  66  93  61  89 /  20   0   0   0
ELN  64  82  57  82 /  10  10  10   0
RDM  52  86  51  83 /  20   0   0   0
LGD  61  87  57  81 /  20  10  10   0
GCD  56  89  54  84 /  20  20  20   0
DLS  65  84  61  84 /  20   0  10   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning from 11 AM to 10 PM PDT Wednesday for ORZ691.

  Red Flag Warning from 2 PM to 11 PM PDT Wednesday for ORZ698.

WA...Red Flag Warning from 11 AM to 10 PM PDT Wednesday for WAZ691.

&&

$$

SHORT TERM...82
LONG TERM....82
AVIATION...86