Weather Service Report

FXUS65 KPIH 230756

Area Forecast Discussion
National Weather Service Pocatello ID
156 AM MDT Thu Sep 23 2021

An upper level trough continues its progression across southeast 
Idaho this morning, with a cold front moving through and slight 
chances for precipitation lingering to sunrise. Showers began 
developing in western Idaho with a few thunderstorms Wednesday 
evening, but that convective activity quickly dissipated as storms
began progressing across the Snake River Plain under greater 
stability. Isolated light rain showers are possible for eastern 
Idaho this morning, with chances quickly dissipating past sunrise 
with some lingering rain showers along the Wyoming border. High 
temperatures behind this cold front are cooler by about 10 
degrees, with highs in the upper 60s and low 70s for Thursday. Dry
and warmer conditions are expected through the weekend, as an 
upper level ridge begins to envelop the region. Saturday sees a 
small shortwave trough work through the area, with slightly breezy
conditions that afternoon and evening. Highs generally remain 
seasonable, with temperatures warming up to be in the upper 70s 
and low 80s to round out the week. CM

Continued upper level ridge development across southeast Idaho
will keep precipitation out of the area until at least next
Tuesday, with an upper level trough expected to work through our
region. For Sunday, another small shortwave troughs looks to
bring gusts around 20kts. Winds continue to be slightly elevated 
through the period and increase associated with the upper level 
trough passage, bringing breezy conditions for both Tuesday 
and Wednesday. The trough brings with it widespread precipitation
chances, along with cooler temperatures. Cold northwest flow 
allows for some high level snow possible above 9000ft in the 
forecast for both Tuesday night and lesser chance Wednesday 
night. Accumulation wise, light to modern bouts of precipitation 
are expected with highest totals in the Central Mountains. 
Temperatures Sunday will be in the 70s and 80s, but cool 
progressively through midweek with Wednesday being the coldest day 
with highs about 10-15 degrees cooler in the 60s. Long range 
models are beginning to indicate another upper level ridge moving
back into our area for Thursday and beyond, with greater 
uncertainty this far out amongst ensemble members. CM


VFR conditions remain the predominant group for Thursday, with
light passing rain showers working across southeast Idaho this
morning. These showers dissipate quickly after sunrise, with KDIJ
seeing some possible lingering showers along the Wyoming border.
Clouds move out of the area during the daytime hours, with some
lingering clouds at KDIJ and KSUN. KSUN looks be the only one to 
have a lingering ceiling which lowers throughout the day to 
around 5000ft into the evening hours, before widespread clearing 
Thursday night into Friday. Winds look to remain quiet, with 
possible elevated afternoon gusts at KPIH and KBYI up to 
15-20kts. CM


High pressure will begin to build back over the region today keeping 
our weather dry through the weekend. Temperatures today will be a 
tad cooler in the wake of a weak cold front keeping minimum RHs 
elevated today. As the high continues to build and temperatures 
warm, RHs may approach critical levels Saturday through Monday but 
sub 15% readings shouldn't be very widespread. Winds may become a 
tad breezy over the weekend perhaps in the 15-20 mph range but given 
the marginal RHs, Red Flag concerns will be low but will be 
something to monitor over the next few days. Weather pattern looks 
to change Tuesday and especially Wednesday next week with cooler, 
wetter weather seeming increasingly likely for much of the area.




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Western Regional Climate Center,