000
FXUS65 KPIH 180329
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
929 PM MDT Wed Apr 17 2024

.UPDATE...

Convergence band precipitation seems to have stalled from around
Craters to just east of Pocatello this evening. Updated forecast
based on radar trends which do show the precipitation gradually
weakening. Think that trend will continue although it may not
fully dissipate until later into the overnight hours.

13

&&

.PREV DISCUSSION... /issued 201 PM MDT Wed Apr 17 2024/

SHORT TERM...Tonight and Thursday
We continue to see snow showers across the upper Snake and into the
upper Snake Highlands up towards Island Park this afternoon as a
persistent band of light precipitation remains in place. Regional
webcams don`t show much in the way of any impacts on roadways but
some light accumulations on grassy surfaces has been observed. As
we progress through the afternoon and evening, enhanced lift aloft
will abate and this should shut down the precip. Temps overnight
will remain on the cooler side of normal with most locations in the
20s, teens in the high country. Tomorrow looks dry although it`ll
remain on the cooler side of average as high pressure slowly starts
to take control of the weather once again. This will lead to warming
temps in the extended. McKaughan

LONG TERM...Fri through next Wed night
Very little precipitation under the west northwest air flow of
moderate or stronger speed. At the end of this period the upper
level flow shifts to zonal, then southerly, in the last 48 hours.
This keeps the precipitation light with few locations even
reaching the chance threshold (25%) and thus does allow more
sunshine and warmer temperatures, but the afternoon highs will be
slow to warm. Fri is a day with Snake River plain temperatures
reaching the upper 50s, then for Sat-Mon temperatures should warm
into the 60s at that same elevation. Finally Tue and Wed should
reach the 70s.

A shortwave trough with very low amplitude moves through Fri
night/Sat that increases the surface wind. On Mon and Tue the air
flow becomes more zonal, aiding the warm up while the westerly wind
is expected to be at least windy, possibly very windy with the need
for a Wind Advisory. Messick

AVIATION...
SHSN continue to linger in the two farthest north terminals, KIDA
and KDIJ. The VSBY has lowered at KDIJ to below field approach
minimums, and at KIDA to IFR. This should show improvement by
early evening according to consistent 12Z guidance and later. Wind
should also be decreasing in the mid- to late afternoon. A
northerly component should develop at every airdrome except KBYI;
the farther south will shift to east as the wind in the Snake
River plain and eastern Magic Valley becomes downslope. CIGs
should dissipate during the late overnight hours, the farther
north the later. For Thu, CIGs may re-develop at KSUN and KDIJ,
but stay VFR. Messick

HYDROLOGY...
Water levels on the Portneuf river continue to run high, just
above 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.
&&

$$