Malta, Idaho Weather Forecast Discussion

043
FXUS65 KPIH 271720
AFDPIH
Area Forecast Discussion
National Weather Service Pocatello ID
1120 AM MDT Sat Sep 27 2025
.KEY MESSAGES...
- Some locations warming to 80 or more degrees today, maybe for
  the last time this year.
- Showers and thunderstorms develop Sunday afternoon in the
  south, spread northward Monday morning and continue through
  Wednesday.
- Afternoon temperatures turning much cooler, down 10 to 15 deg
  F from today`s highs by Tuesday.
&&
.SHORT TERM /THROUGH SUNDAY/...
Issued at 110 AM MDT Sat
Sep 27 2025
Summer`s last gasp, perhaps, occurring today as temperatures
warm up in the sunny skies behind the previous Thu low. This is
a temporary upper level ridge with light wind at the surface
and moderate wind aloft. Late tonight, clouds start to move in
from a low coming in from the west. With southerly flow ahead of
the low, the clouds will be moving in from the south on Sun.
Showers and a slight chance of thunderstorms is possible, then a
greater coverage for Mon. The low is still off the west coast,
moving slower than previous thinking. That has reduced
precipitation amounts quite a bit for everywhere but the central
Idaho mountains, with moderate amounts not developing in the
remainder of the forecast area until Mon night.
Afternoon temperatures under the sunny skies have one last
opportunity this year to eclipse 80 deg F for the eastern Magic
Valley and lower Snake River plain. Clouds start a cool down of
up to 2 deg from Sat to Sun, then 2 to 8 deg F from Sun to Mon.
The cloud cover overnight on Sun night and Mon night allow
temperatures to remain mild; in the 40s for the Snake River
plain and above freezing even at Stanley in the mountains.
Wind will return to being light under this brief spate of high
pressure, but the approaching trough keeps the upper level winds
around the 15KT threshold, so by Sun afternoon wind of this
strength should be reaching the surface, with gusts into the
20+KT range.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 110 AM MDT Sat
Sep 27 2025
The upper level low of the near term period lingers through Tue,
then only about 20-25 percent of the solutions keep low pressure
over the forecast area on Wed and Thu. The rest bring in
positive height anomalies and southwest flow which should help
keep temperatures warm. What happens with precipitation is a
little less confident. It is an opportune set up for shortwave
impulses exiting the base of the trough and moving through
southern Idaho. Model output has a less than normal chance of
precipitation for Wed and Thu. On Fri, most solutions have some
sort of low amplitude wave finally leaving the coast and quickly
moving through the northern Rockies. About 23 percent of the
solutions represent a cluster with a stronger trough that could
bring a more vigorous storm into southern Idaho. At this point
the risk of precipitation pushes into the high chance and likely
categories for the forecast area.
Continued cloud cover is offset by the southwesterly flow, so
only Tue and Fri appear to have afternoon temperatures near
normal. High temperatures for Wed and Thu are 5 to 10 deg F
above normal. The continued cloud cover is keeping overnight
lows mild with apparently little chance of Frost until Fri
night, just beyond the end of this forecast.
Winds to not appear to be driven by any strong cold front until
perhaps Fri, just stronger in the afternoon. The front or low expected
Fri could have sustained wind near Wind Advisory criteria.
&&
.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1117 AM MDT Sat Sep 27 2025
Will be continued VFR with mainly light winds and clear skies
this afternoon into tonight. Will likely see an increase in mid
and high level clouds early Sunday morning through the day. For
now kept any vicinity showers out of area but moisture will be
on the increase and showers more likely after 18Z time frame on
Sunday.
&&
.FIRE WEATHER...
Issued at 110 AM MDT Sat Sep 27 2025
The last warm day for a while will be due to cloudless skies.
Late tonight clouds from a low at the Pacific NW coast will push
in clouds in the southerly flow ahead of this low into south
Idaho. By afternoon, there could be some light shower and
isolated thunderstorm activity, primarily in the ID-UT border
region. The showers and thunderstorms will push to the ID-MT
border by Mon morning, with showers and thunderstorms continuing
to be at a likely/chance risk, respectively, through Tue night.
Humidity will lower to the upper teens in the lower elevations
today, but it may be the last day for a while for this to occur.
Overnight the moisture developing the clouds will also be felt
at the surface with very high humidity for each afternoon Sun
through at least Wed.
Wind, outside of thunderstorms, should remain light today and
light to moderate on Sun.
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Messick
LONG TERM...Messick
AVIATION...GK
FIRE WEATHER...Messick

NWS PIH Office Area Forecast Discussion