Conda, Idaho Weather Forecast Discussion

110
FXUS65 KPIH 290443
AFDPIH
Area Forecast Discussion
National Weather Service Pocatello ID
1043 PM MDT Sun Sep 28 2025
.KEY MESSAGES...
- Unsettled conditions have begun with showers and
  thunderstorms across the south and east of East Idaho.
- Increasing risk of showers and thunderstorms across the
  entire forecast area on Monday, peaking on Tuesday.
- Much cooler temperatures for Tuesday.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 156 PM MDT Sun Sep 28 2025
Satellite imagery shows upper low over the desert southwest opening
up allowing moisture to shift north across East Idaho. A few light
showers have been ongoing today and further development expected
this afternoon and evening. Winds aloft fairly light so a few storms
may be efficient and able to produce locally heavy downpours.
Portions of the eastern highlands have been upgraded to a MARGINAL
RISK for Excessive Rainfall for the remainder of today. A few
showers may continue into the overnight hours, otherwise most of the
region expected to be on a brief break with dry conditions. Further
upstream, amplified Pacific trough off coast projected to spin next
shortwave feature into Idaho early Monday. Showers and thunderstorms
expected to redevelop across the western zones during the afternoon.
Rainfall could become moderate to heavy at times associated with
this feature, and MARGINAL RISK for Excessive Rainfall remains in
place. Heaviest rainfall across the central mountains could be
exacerbated by embedded thunderstorm activity, and recent burn scars
remain a concern. NBM probability of reach 0.50" of QPF for the
Monday evening hours ranges from 15-40% within the vicinity of the
Wapiti scar. Those probabilities have trended slightly upward from
previous runs. A Flood Watch may be necessary if projections
continue current trend. Models shift the heaviest precipitation east
across the remainder of the forecast area for during the day
Tuesday, and the MARGINAL RISK for Excessive Rainfall shifts
eastward accordingly. Temperatures likely to be coolest on Tuesday,
with widespread daytime highs dropping into the 60s for most
areas.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 156 PM MDT Sun Sep 28 2025
Southwest flow aloft continues with upper low churning off
Seattle/Vancouver coast. Ensembles begin to shift the low inland
Wednesday, opening it up and ejecting a weak shortwave across the
region. Showers and a few thunderstorms remain possible Wednesday,
but the main trough passage appears to be Thursday to Friday. There
are significant differences in how the ensemble clusters portray
passage of the trough. NBM blend brings the greatest precipitation
chances Friday, but spread the chances out from Thursday night into
Saturday. Breezy conditions accompany another cooldown, this time
lasting into the weekend with deterministic NBM reaching only into
the 50s for lower elevations both Saturday and Sunday. It is worth
nothing that there is roughly a 15 degree spread between low-end and
high-end temperatures, so not a lot of confidence yet. That said,
the late week frontal system does look more robust and amplified
than the previous features ejecting across the region.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1043 PM MDT Sun Sep 28 2025
Models have trended a bit drier on potential VCSH overnight, and
we have pulled mention from KBYI and KPIH. Confidence remains
low on afternoon shower and thunderstorm potential Monday as
well, although KSUN and KBYI seem to have the best chance as our
next system approaches from the west, so have added PROB30s
there. Overall, expect a VFR day Monday before clouds thicken
and lower and rain with embedded thunder moves in from the west
Monday night.
&&
.FIRE WEATHER...
Issued at 156 PM MDT Sun Sep 28 2025
Southern zones will have showers and thunderstorms this evening
mainly isolated to scattered coverage. An upper level trof will
move east Monday and expect more widespread showers and
thunderstorms Monday and Tuesday. Will have drier conditions
Wednesday with a slight chance in 475, 476 and 422. Will see a
more widespread chance Thursday and Friday with the next Pacific
system. Temperatures will cool off significantly Friday through
next weekend. Will see highs in the 40s mountains and 50s
valleys possibly at the end of the weekend. So main impact is
expected to be wetter conditions this week and a significant
cool down late week through next weekend.
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...DMH
LONG TERM...DMH
AVIATION...01
FIRE WEATHER...GK

NWS PIH Office Area Forecast Discussion