Ammon, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

986
FXUS65 KPIH 141708
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1108 AM MDT Wed May 14 2025

.KEY MESSAGES...

- Rain and high mountain snow will continue today with very cool
  and well below normal temperatures.

- Much cooler temperatures will continue through the end of the
  week, and especially for Sunday, with valley rain and high
  mountain snow showers continuing off and on Thursday and
  Friday before becoming more widespread into the weekend.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 153 AM MDT Wed May 14 2025

Early morning satellite imagery shows an area of low pressure
centered over southern Expecting a generally unpleasant day for
much of the daylight hours today with an upper low centered
over the area bringing widespread cloud cover and precipitation
to the region. Could even see some thunderstorms later this
afternoon and into the evening. Winds will be SW/W for most
local terminals in the 10-15 kt range, perhaps a touch higher
around KBYI, while KSUN will see their usual upvalley/downvalley
component although precip could throw a bit of a wrench in that
with any potential outflows. The biggest issue will gradually
lowering CIGs and trying to time out prolonged periods of
precip. MVFR reductions from CIGs certainly seem probable for
the first half of the day with things MAYBE improving during the
late afternoon and evening but BKN/OVC CIGs will still remain,
just may climb to 5kft feet or so. But as is usually the case
with a synoptic setup like this, confidence is lower than
desired. Idaho and this feature will lead to a rather raw mid-
May day across the area. Widespread clouds, precipitation and
well below normal temperatures are expected for the area today.
Temperatures this morning are in the 30s and 40s and they won`t
warm up all that much over the course of the day. We should be
able to climb into the 50s across the lower valleys with 40s
likely across the eastern highlands and higher terrain of the
central mountains, well below normal for this time of year. In
addition to the cold temps and cloud cover, anticipating
widespread precipiation for much of the day especially across
the Snake Plain and eastern highlands. Early morning radar
returns show the main focus area of precip currently is across
the central mountains but hi-res CAMs show this slipping south
throughout the morning and into the afternoon hours under the
cyclonic flow. Can`t rule out some isolated thunderstorms across
the region as well during the afternoon and evening hours. The
low will move slowly towards the east over the course of the day
allowing for slightly improved conditions by the time we get
into Thursday. Precip chances across the western half of the
forecast area look pretty low tomorrow but the eastern half
(Snake Plain towards the Montana Divide and Wyoming border) will
likely still see additional showers and thunderstorms during
the day tomorrow. Temperatures will be slightly warmer with
rising H5 heights as the low departs but still running well
below normal with 40s and 50s expected for most areas but a few
spots could briefly top 60.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 153 AM MDT Wed May 14 2025

Friday is a bit of a transition day as the atmosphere gears up
to send another potent low into our area for the weekend and
into early next week. It doesn`t look dry by any means but it
will be the driest day during the extended portion of the
forecast. Weak upper level impulses will move through the flow
aloft allowing for some orographically enhanced precip in the
central mountains and along the Montana Divide but the rest of
the area will likely remain dry, although continued mostly
cloudy to cloudy with temperatures continuing to run mainly in
the 50s to lower 60s. On Saturday, south to southwest flow ahead
of a potent low will allow temperatures to climb into the upper
50s to upper 60s with clouds increasing over the course of the
day. By the time we get into the afternoon and evening hours
though we`ll likely see showers and thunderstorms overspread the
region and this will continue for much of the day Sunday as
well. With the low moving close to the area on Sunday, high
temperatures will struggle to get out of the 40s for much of the
region with ample rainfall (and high elevation snow) expected.
This feature looks to move away early next week but models still
show at least weak trough over the area into early next week
which would support some continued cloud cover, cooler than
normal temperatures and at least some low-end precip chances.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1101 AM MDT Wed May 14 2025

Morning forecasts indicated a moderate risk of TSRA that
deserved mention in the TAFs for mid-afternoon through early
evening. SHRA has developed and will continue for most into the
late evening hours, then another round develops Thu morning.
Expect gusty and erratic wind during showers, although the main
wind should be southwest to west with gusts as high as 25KT.
Marginal VFR due mainly to CIG will continue in and out of
observations, and tonight should become more widespread for
KDIJ, KIDA, and KPIH. KBYI should bear a bigger brunt of VSBY
impacts this afternoon, along with stronger wind gusting up to
35 mph. However, conditions will quickly clear during the early
evening and by 15/01Z KBYI should be VFR. KDIJ risks some IFR
for CIG tonight, but right now keeping with only a SCT deck
below 1000ft AGL. Finally, KSUN will have no impact to CIG or
VSBY, but SHRA/TSRA will be around for the late afternoon into
mid-evening.

Expect a return to SHRA/TSRA for mid-day through evening on
Thu.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...McKaughan
LONG TERM...McKaughan
AVIATION...Messick