Virginia, Idaho Weather Forecast Discussion

537
FXUS65 KPIH 262250
AFDPIH
Area Forecast Discussion
National Weather Service Pocatello ID
450 PM MDT Fri Sep 26 2025
.KEY MESSAGES...
- Mild and dry for Saturday, but pattern begins to shift Sunday
  with isolated to scattered showers and thunderstorms across
  the south.
- Deeper moisture arrives early in the week for more widespread
  precipitation Monday and Tuesday.
- Temperatures expected to remain cool through the week starting
  Monday.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 204 PM MDT Fri Sep 26 2025
Quiet pattern continues for one more day. Satellite imagery shows
northwest flow over East Idaho with band of thin high clouds
drifting across the region, and a few CU across the southeast
corner. Gusty winds in place across East Idaho behind the shortwave
from earlier today, which should ease off during the evening.
Transitory ridge in place for Saturday as flow aloft gradually
transitions to southwest. Temperatures Saturday warm up a few
degrees above today`s highs, staying above normal. Deeper moisture
associated with low over the desert southwest/southern California
starts to rotate slowly north through the Great Basin, but should
remain south of the region throughout the day Saturday. Will likely
see cloud cover increase from the south overnight Saturday
night.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 204 PM MDT Fri Sep 26 2025
Pattern begins to shift in earnest on Sunday as low over the south
opens and ejects northeast through the Great Basin ahead of incoming
Pacific trough. Sunday remains warm, but we begin to see the
reintroduction of showers and thunderstorms to the forecast, mainly
across the southern and eastern highlands, creeping a little into
the Snake Plain interstate corridors. Coverage remains isolated to
scattered across the south, and precipitation amounts average less
than 0.10 for most locations, though a few storms could produce
heavier amounts. By Monday, precipitation becomes more widespread
and continues through Tuesday night. Temperatures begin to fall with
the onset of the rainfall, and should remain below normal into
midweek. As far as precipitation amounts go, there is still quite a
bit of spread in the ensemble probabilities for any particular 24 hr
period. Differences between each low-end and high-end probability
exceed 0.50" for almost all locations, and over an inch for many
higher elevation zones. Much of this appears to be due to ensemble
differences with respect to the depth of the low. Midweek brings a
break in the precipitation as main leading shortwave finally shifts
east of the region, allowing for drier flow aloft. GFS and ECMWF
hold a closed low off the Seattle/Vancouver coast, but this solution
is only held by about 40% of the ensemble clusters. The rest
indicate a more broad open southwest flow across the PacNW. NBM
Blend begins to shift toward a drier period to round out the work
week, trending toward isolated showers over mainly higher
elevations. Temperatures remain below normal with highs generally in
the 60s, though the high-end estimates put 70s back on the table for
lower elevations by Thursday and Friday. All that to say that the
variability in the models is not inspiring confidence in the late
week forecast, not a rare thing to say in Autumn!
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 450 PM MDT Fri Sep 26 2025
Breezy winds will start to decrease around 02z/8pm this evening.
Thereafter, no hazards are expected for aviation under clear
skies with light winds. Clouds will begin to increase again from
the south Saturday night ahead of our next storm system.
&&
.FIRE WEATHER...
Issued at 204 PM MDT Fri Sep 26 2025
Conditions will remain dry for a few more days before the pattern
changes as we move into next week. Until then, expect continued dry
weather with afternoon RHs in the 15-25 percent range this afternoon
and again on Saturday. Moisture returns with isolated to scattered
precip chances during the day on Sunday with more widespread
precipitation expected Monday through Wednesday next week. In
addition to the precipitation, temperatures look to run on the cool
side of normal for much of next week. This should keep fire weather
concerns low.
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...DMH
LONG TERM...DMH
AVIATION...01
FIRE WEATHER...McKaughan

NWS PIH Office Area Forecast Discussion