Elgin, Oregon Weather Forecast Discussion

774
FXUS66 KPDT 300538 AAB
AFDPDT
Area Forecast Discussion...UPDATED
National Weather Service Pendleton OR
1038 PM PDT Mon Sep 29 2025
.DISCUSSION...
.AVIATION...
Probability for VFR conditions is high (95%) for all the the area
late this evening and through the overnight based on HREF fields,
with one caveat, where slightly lower, but barely counting as
MVFR conditional visibility in rain showers seems evident in the
LAMP MOS guidance after about 21 UTC Tuesday - 00 UTC Wednesday.
Winds are mainly light and predominately from the south with some
locations veering early Tuesday morning but returning to the south
in the afternoon. Model fields do show an uptick in gusts getting
mixed to the surface layer to around 18-23 knots near the RDM and
BDN terminals from around 17z to 00z Wednesday. Russell/71
&&
.PREV DISCUSSION... /issued 439 PM PDT Mon Sep 29 2025/
AVIATION...
/00Z TAFs/
Light rain showers will overspread southern WA and northeast OR
through this evening, generally peaking in coverage before 06z.
Showers will linger into the early morning hours, especially in
the lower basins and into the northern Blue Mountains with
generally dry weather through early Tuesday afternoon. Prevailing
VFR conditions will persist with cloud bases generally 5-10 kft
AGL, although tempo reductions in visibility and ceilings just
under 5000 ft will be possible within rain (MVFR ceilings are not
anticipated at forecast terminals). After the lull Tuesday
morning, the next round of rain showers will move across the
Cascades during the afternoon and evening hours. /MJ
PREV DISCUSSION... /issued 100 PM PDT Mon Sep 29 2025/
DISCUSSION...Latest radar imagery currently shows a band of showers
enveloping western WA and OR, slowly moving east. These showers stem
from a deep low centered off the Gulf of Alaska, which will slowly
meander its way toward the PacNW over the course of the week. In the
meantime, this low will circulate a pair of cold fronts through the
region and make for rounds of beneficial wetting rains across our
Probability for VFR conditions is high (95%) for all the the area
late this evening and through the overnight based on HREF fields,
with one caveat, the RDM and BND terminals where conditional
visibility with rain showers seems evident in the LAMP MOS
guidance after about 00 UTC Wednesday. Winds are mainly light and
predominately from the south with some locations veering early
Tuesday morning. Model fields do show and uptick in gusts getting
mixed to the surface layer to around 18-23 knots near the RDM and
BDN terminals from around 17z to 00z Wednesday. mountain zones,
with light rain expected to occur across the Basin and adjacent
valleys.
The first front is currently bearing down on us, with showers
expected to envelop much of the forecast area by around 3 to 5 PM.
Isolated thunderstorms are possible across central OR and the
eastern mountains this evening, mainly around the Strawberries, but
am a bit skeptical in how aggressive the HREF is in depicting storms
in these areas given the cloud cover and relatively cool air mass
overhead. Should any storms develop, they will primarily be
orographically driven in nature. Will gauge forecast confidence in
storms for these areas at around 20-25%. Scattered showers will
occur elsewhere across the lower elevations this evening.
We`ll see a break in the rain before round two arrives Tuesday night
into Wednesday. Guidance currently suggests that this round won`t be
quite as wet as the showers expected tonight, especially for the
eastern mountains, but could still prove to bring wetting rains for
our mountains. NBM probabilistic guidance currently depicts a high
(>80%) chance for wetting rains for the Cascades and eastern
mountains once these rounds of rain are over with, about 40-70% for
our more elevated valleys such as central Oregon, foothills of the
Blues, and Yakima/Kittitas Valleys, and only about 30% for the lower
Columbia Basin. Even if the Basin is largely spared from heavier
rains, this week`s rain should still wet down ongoing activity
across the Cascades and central Oregon, and hopefully start the home
stretch of this year`s wildfire season.
Models put the trough axis associated with this Alaskan low over our
forecast area around Friday, making for periodic chances of rain
across our mountains after Wednesday with dry conditions elsewhere,
before dry weather prevails area-wide on Saturday under a transitory
ridge. Long-range ensembles appear to depict another northwesterly
low arriving early next week, which should further contribute toward
the closure of this wildfire season. Evans/74
AVIATION...18z TAFs (Previous Discussion)...A cold front moving
through the region will provide for chances of rain showers across
all sites, mainly late this afternoon through the evening.
Conditions may briefly deteriorate to MVFR under showers
(confidence 30-40%), with isolated thunderstorms possible (chance
15-20%) for BDN and RDM. Rain chances are largely expected to end
for all sites after midnight tonight. Winds could become gusty as
this front initially moves through, but are otherwise expected to
be light at 8-12 kts out of the W/SW. Ovc cigs will give way to
sct-bkn mid-level clouds overnight. Evans/74
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT  50  74  52  69 /  60  20  50  40
ALW  55  74  55  69 /  60  30  50  50
PSC  51  75  51  71 /  40  10  40  30
YKM  45  71  48  69 /  50  20  60  30
HRI  50  74  52  71 /  50  10  40  40
ELN  42  68  43  65 /  60  20  60  30
RDM  37  68  43  66 /  60  30  60  40
LGD  49  72  48  68 /  80  30  40  50
GCD  46  71  47  68 /  70  10  40  30
DLS  50  73  52  70 /  70  50  80  50
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
SHORT TERM...76
LONG TERM....76
AVIATION...71

NWS PDT Office Area Forecast Discussion