Heman, Idaho Weather Forecast Discussion

110
FXUS65 KPIH 201930
AFDPIH
Area Forecast Discussion
National Weather Service Pocatello ID
130 PM MDT Sat Sep 20 2025
.KEY MESSAGES...
- Showers and thunderstorms increasing through tomorrow
- Some storms may produce gusty winds and moderate to heavy
  rainfall
- Cooler temperature Monday before warming back up next week
&&
.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 130 PM MDT Sat Sep 20 2025
Shower and thunderstorm chances jump up through tomorrow night,
with the highest potential late tonight through tomorrow
afternoon. The best chance of rain and thunderstorms will
generally be along and south of the Snake Plain tonight,
although a few showers are expected across the Magic Valley into
the Sawtooths and Wood River region. Rainfall for the most part
will be light, but the South Hills and Albion Mountains could
see 0.25-0.40" of rain with heavier storms through this evening.
The chance of more than that amount is less than 10%. Light to
moderate rain spreads northeast through tomorrow morning, with
the best chance of rain currently over the southeast highlands
where amounts around 0.25" are expected. There is a 10-30%
chance of exceeding that much, and 5-10% chance of more than
0.50". The heaviest rain will be tomorrow afternoon and evening,
where portions of the central mountains could see 0.30-0.60" of
rain. Probability forecasts are very low, but NOT ZERO for
seeing over 0.75 in that 12 hour period. By sunrise Monday, the
bulk of the showers will be along and east of I-15. Of note,
don`t be surprised if tonight and tomorrow night...we see
thunderstorms after dark. The chance of gusts over 35 mph across
the South Hills and Albion Mountains is 10% or less. For
tomorrow, there is a 30-50% chance where stronger storms
develop...with the possibility of gusts hitting 45-55 mph.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 130 PM MDT Sat Sep 20 2025
Showers and storms persist through Monday evening over the
eastern half of our area. It does appear that as the winds
switch to a northerly direction, a convergence band develops and
impacts the northern half of the Snake Plain and into the
eastern highlands. Rainfall amounts look lighter, but we still
could see some localized moderate rainfall rates and
accumulation. Monday will be much cooler with northerly flow and
cooler air briefly spilling into eastern Idaho. Highs may barely
push 70 in some spots. Dry weather returns for the middle part
of next week. We are still looking to see if a low cutting
through the ridge ends up far enough north for a chance of
showers and thunderstorms...especially along the Utah border.
The Blend of Models is trending drier although not necessarily
indicating there is NO CHANCE. Both the GFS and ECMWF do
indicate we could see some clouds and at least a slight chance
of rain and thunder. We shall see what happens in a few days.
&&
.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1121 AM MDT Sat Sep 20 2025
Generally clear skies most areas early today, giving way to SCT-BKN
cover above 7kft. Light convection expected generally across the
southern highlands this afternoon, but close enough to maintain VCTS
for BYI and PIH through the evening. Remainder of terminals should
remain dry. Better chances for a line of showers shifting northeast
across East Idaho overnight through early Sunday for all sites
except SUN. Afternoon thunderstorms expected Sunday for all
sites.
&&
.FIRE WEATHER...
Issued at 130 PM MDT Sat Sep 20 2025
A few showers and thunderstorms will be possible this afternoon and
evening for Zones 413 and 427, with a very low but non-zero chance
that something shifts out into the Snake Plain. Slower moving storms
may be capable of producing a wetting rain. After sunset tonight, a
more broad area of showers is expected to develop across Zones 427,
425, and 413, shifting northeast into 410 and the southern portions
of 411 into Sunday morning. This area of showers will have a better
chance of producing a wetting rain, especially across 413 overnight
and Sunday morning. By afternoon, showers and thunderstorms increase
in coverage across the region. Scattered to numerous showers and
isolated to scattered thunderstorms are forecast for the afternoon
and evening. Wetting rain chances have risen to 45-70% for all
higher elevation zones outside the Snake Plain for the 12-hr period
from noon to midnight Sunday. Coupled with the increased daytime
humidity for Sunday, critical fire conditions are NOT expected. The
thunderstorm coverage decreases after sunset, but showers and
isolated thunderstorms continue, shifting focus to the eastern half
of the region overnight into Monday. Drier air mass shifts into
place for late Monday through the rest of the week as a ridge of
high pressure builds into the western states. There is still quite a
bit of uncertainty as to how the next system will move in, and the
model blends have shifted that potential off until next weekend for
now.
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Keyes
LONG TERM...Keyes
AVIATION...DMH
FIRE WEATHER...DMH

NWS PIH Office Area Forecast Discussion