000
FXUS65 KPIH 182002
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
202 PM MDT Thu Apr 18 2024

.SHORT TERM...Tonight and Friday
Afternoon satellite imagery shows mostly clear skies in places
across eastern Idaho this afternoon. Temperatures remain chilly
for mid April however with many spots still in the 40s despite all
the sunshine. Not expecting much in the way of impactful weather
over the next 36 hours. Hi-res CAMs show a very, very low
potential of maybe a snow shower or two across the central
mountains but the better chances appear north of the CWA.
Probability is too low to even mention in the forecast (less than
10%). Expecting another chilly night although probably not as cold
as what we saw this morning. Everyone should drop below freezing
but probably mid to upper 20s in the lower valleys tonight as
opposed to upper teens and lower 20s like we saw today. Friday
looks like another pleasant, precip-free day although we may see a
bit more clouds during the afternoon hours but still generally
partly cloudy. Daytime highs will remain on the cooler side of
normal, by a few degrees, but we should be able to climb into the
mid to upper 50s in the lower valleys with mid 40s to low 50s in
the high country. McKaughan

.LONG TERM...Sat through next Thu night
This period can be broken into two pieces: Over the weekend, a
close upper level low will move across the Canada-US border,
bringing perhaps some light showers to the border region and
northern half of the eastern highlands, and breezy to windy
conditions to the ridges and Snake River plain/ eastern Magic
Valley through Mon night. The second part starts Tue with a
coastal low changing the upper level flow to SWly and pushing some
moisture into the Great Basin that gives a threat to the entire
forecast area during this second half. The flow is anchored by a
slow moving low off the British Columbia coast. Expect light to
moderate amounts of precipitation, mainly in mountainous zones,
but occasionally raining in the Snake River plain/eastern Magic
Valley. There is also enough instability for afternoon and evening
thunderstorms.

Temperatures will get above seasonal normals on Sat, warm some
more on Sun, then with the increasing cloudiness start to cool
Mon. This will be offset in future days by the SWly airflow so
that temperatures at the lower elevations will stay in the 60s for
highs, and around 40 deg F for lows during the more rainy period.
Snow will also develop, although daytime melting will occur as
high as 10000ft elevation.

The weekend low has enough energy to generate some wind on Sun-Mon,
and may need a Wind Advisory in the lower elevations. Also expect
windy conditions on Wed afternoon/Thu afternoon with the approach
of that British Columbia low as it moves onshore. Messick


&&

.AVIATION...
Low pressure has moved on and taken the stratus with it, so do not
expect any issues for CIG or VSBY for a while, at least at the
five airdromes. A weak feature moving through the mean WNWly flow
is expected to generate light showers across the northern tier
around the ID-MT border, but little else. Moderate to strong WNWly
flow will product some breezy to windy conditions, but little
else through the weekend. Only CIG tonight will be at northern-
most KIDA, and only briefly at cirriform altitudes. See no
significant impacts at any airdrome until the middle of the work
week next week. Messick

&&

.HYDROLOGY...
Water levels on the Portneuf river continue to run high, just
below moderate flood stage for the Portneuf river in Pocatello.
The river forecast for the Portneuf river in Pocatello shows the
river running above flood stage for the foreseeable future. At
Topaz, levels remain and are forecast to remain very near minor
flood stage for the rest of the week. McKaughan

&&

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

$$