865
FXUS65 KPIH 301951
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
151 PM MDT Tue Apr 30 2024

.SHORT TERM...Tonight and Wednesday
Afternoon satellite imagery shows gradually increasing clouds over
the region although there is still a lot of blue skies to be had
throughout eastern Idaho. Seeing breezy conditions again this
afternoon across the upper Snake and into the Arco Desert where a
Wind Advisory continues through 9PM tonight. Hi-res CAMs show the
potential for some showers into the evening and overnight, mainly
across the Montana Divide and into the eastern highlands.
Temperatures will be cold enough for much of this to fall as snow
showers. Impacts should be pretty limited however and only light
accumulations would be expected across the higher terrain.

As the calendar turns to May tomorrow, it won`t feel much like May.
Freeze warnings are out once again for the growing region. This
isn`t a "slam dunk" warning like yesterday though as there will be
more clouds to contend with tonight so it`s a bit more marginal.
Nevertheless, chose not to get cute with putting some zones under a
Frost Advisory and others with a Freeze Warning. Urban centers
around Burley, Pocatello and Idaho Falls may flirt with, or avoid,
freezing conditions but the more rural locations will likely get
there. Especially if cloud cover isn`t as pronounced as forecast. An
upper trough digging into the region tomorrow will bring us some
cooler, slightly active weather for Wednesday. After the cold start,
temps will only warm into the 40s for most locations, maybe a few
places reach 50. Additionally, models show some showers and
thunderstorms developing during the afternoon tomorrow. Highest PoPs
are forecast across the northern half of the region and into the
eastern highlands but everyone may get in on the action. Given the
cooler temperatures once again, some of this will be in the form of
snow, despite the fact that it is May. This includes the lower
valleys. Not expecting any issues with accumulations however given
marginal temps and warmer ground temps but don`t be shocked to see
some flakes fall tomorrow. Another freeze warning is likely going
to be needed into Thu AM before out overnight lows start to trend
upwards into the weekend. McKaughan

.LONG TERM...Thursday through next Tuesday
The next round of rain and snow showers shifts across the state
later Thursday into Friday. Clouds and showers will keep
temperatures running a few degrees BELOW AVERAGE. Precipitation
amounts don`t look too heavy, but heavier showers may produce
0.10-0.20" of moisture. Saturday should be mostly dry until later
in the day, as moisture shifts northward across eastern
Idaho...for the next round of showers. With the low still to the
west, the best chance will across the central mountains south into
the Magic Valley. Despite some increasing clouds, southerly flow
will drive temperatures up, with lower valley temperatures pushing
70. This is where things get a bit hectic. It will be back on the
cool side and showery heading into next week. However, we are
seeing some glaring differences on how the models and cluster
forecasts are handling the track of that low. The ECMWF wants to
drag the low almost on top of us, with a trailing developing on
the back side of it. The GFS develops split flow and takes the
main low to our south and east. The clusters have a
55(ECMWF)/45(GFS) split in their forecast Saturday, and
60(ECMWF)/40(GFS) split on Sunday into Monday...although the split
favoring the GFS is less pronounced vs the operational GFS. Keyes


&&

.AVIATION...
Breezy conditions will continue into Wednesday. Gusts of 20-35kts
are possible throughout the period. We will see occasional showers
especially Wednesday. We did include VCSH for this afternoon at
SUN, although the risk may end up being too far north to impact
the airport itself. We also included VCSH tonight for IDA and PIH,
but that is highly conditional. We may end with virga since the
airmass is really dry out there right now. At DIJ, we included a
mix of rain and snow showers since probabilities and potential
look a lot better there. For tomorrow, we will likely carry VCSH
until we get a better idea on timing. We may also have a low risk
of thunderstorms with tomorrow`s activity. Keyes

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Freeze Warning from 2 AM to 9 AM MDT Wednesday for IDZ051>055.

Wind Advisory until 9 PM MDT this evening for IDZ052-053.

&&

$$