539
FXUS65 KPIH 100825
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
225 AM MDT Fri May 10 2024

.SHORT TERM...Today and Saturday.
High pressure will continue building in from the west and ultimately
dominate the synoptic pattern into the weekend. That said, upper
level flow associated with the low pressure system to our south will
continue to filter remnant moisture into the southern extent of
Idaho. Furthermore, CAMs suggest chances for very isolated showers
across the southeast portion of Idaho and therefore we have
increased PoPs slightly from the Blend to around 15% to 20% across
the aforementioned area. Come Saturday, CAMs show a similar scenario
but with most activity further south into Utah as the low to our
south shifts eastward. High pressure will mean light winds over the
next couple of days, as well as ample sunshine and a warming trend,
with high temperatures reaching 5 to 10 degrees above climatological
norms on Saturday. However, widespread low temperatures this morning
will still run in the 30s and cooler, prompting another FROST
ADVISORY for the Lower and Upper Snake River Plain zones from 3 AM
to 9 AM. Portions of the Arco/Mud Lake region could just barely
reach frost criteria but the zone as a whole is borderline and
therefore will remain free of any headlines. Our agricultural zones
will not have to worry about frost or freeze for at least the next
week or so beginning Friday night/Saturday morning, as low
temperatures will generally span the 40s for these zones. Cropp

.LONG TERM...Sunday through next Friday.
Sunday continues to look like our warmest day under mostly clear
skies as temperatures warm by several more degrees into the upper
70s across the Snake Plain, eastern Magic Valley, and valleys
further south, with 40s and 50s in the mountains and highlands. As
early as Sunday afternoon though, models show weak moisture
signatures reaching the eastern highlands with the ridge breaking
down on Monday as a shortwave swings through the Pacific
Northwest. Along with widespread chances of precipitation early to
middle of next week, increased westerly 700mb winds will lead to
widespread breezy surface winds each afternoon. Deterministic
models depict drastically different scenarios Wednesday onward,
with the possibility that the pattern could remain unsettled
through the remainder of next week. 500mb ensemble clusters
highlight this well, showing varying degrees of both ridging and
troughing over SE Idaho during the latter half of next week. That
said, the National Blend maintains fairly stable and slightly
above normal temperatures throughout this timeframe. Cropp


&&

.AVIATION...VFR conditions forecast with light winds throughout
the period. FEW to SCT low and mid-level clouds will increase
this afternoon. There are slight chances of isolated rain showers
across extreme southeastern Idaho, but high resolution models
show them remaining south of KBYI and KPIH. Cropp


&&

.HYDROLOGY...Warming temps over the next several days are expected
to result in slight rises on several area rivers. Whatever
snowfall was realized recently at mid-slope is likely to melt off,
and temp profiles support some snowmelt at higher elevations as
well. So far, main flooding impacts still appear confined to the
Portneuf and Blackfoot rivers where FLOOD WARNINGS remain in
place, although the Big Lost River at Howell Ranch could approach
bankful early next week. Remember that flows are high, fast, and
cold on waterways across the region this time of year, as melting
mountain snow is still a significant contributor to these
waterways. People recreating on/near East Idaho rivers and streams
are urged to remain cautious, and keep children and pets away
from the water. 01


&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 9 AM MDT this morning for IDZ053-054.

&&

$$