National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KPIH 151006
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
406 AM MDT Mon Apr 15 2024

.SHORT TERM...Today and Tuesday.
Today will be breezy to windy with a chance of morning showers and
afternoon/early evening showers and thunderstorms. There remains
an upper level low over Nevada and Utah with breezy zonal flow
aloft directly to our west with an another upper level low over
northern British Columbia. Models continue to show moisture and
instability from the upper level low to our south bringing
morning showers today and afternoon showers and thunderstorms
mainly to southeastern Idaho. Our eastern areas along the Wyoming
border, have a 60 to 70 percent chance of thunderstorms this
afternoon into the early evening according to the HREF model.
Those chances drop to 30 to 50 percent eastward into the Snake
plain. Expect gusty winds of 30 to 45 mph with thunderstorms as
well as small hail. There is potential for hail up 1/2 inch, but
it is not that likely. Winds will be on the strong side (gusts of
40 to 50 mph) across our southwestern areas (Eastern Magic Valley,
Southern Highlands and Albion mountains as well as the Raft river
area, especially in the Yale/Idahome areas along I-84). These
areas are in a wind advisory. Some blowing dust is possible,
especially in areas that have been recently plowed. Tuesday expect
breezy to moderate wind conditions again as the low over British
Columbia drops over northern Idaho. Look for gusty winds of 30 to
50 mph, especially over the Shoshone, Arco Desert, and the Snake
plain. Some precipitation (high elevation snow) is likely in the
Island Park area starting in the evening, mainly after midnight on
Tuesday.
Wyatt

.LONG TERM...Wednesday through next Sunday. Low pressure will be
settling south of the US/Canada border through midweek. We are
starting to see more uncertainty creep back into this
forecast...as some trends and some of the ensemble clusters are
farther south that the previous couple of days. Perhaps not as far
south as several days ago...but definitely somewhere in between.
Wednesday begins that period of bigger uncertainty/spread in how
far south the low settles into our neck of the woods. The NAM
wants to push it as far south as the Utah border and isn`t shown
in any of the cluster forecasts. The GFS and ECMWF drops into
west-central Montana and into the central mountains/Idaho
Panhandle. That is hinted at in about 65% of the clusters, with
the rest of the clusters showing a more northward pattern. At the
moment, our Blend of Models is going with more wind...wet and
cooler conditions. That trend is going to occur no matter what
transpires. We have valley highs back down into the mid 40s to mid
50s. A mix of rain and snow is expected, with light accumulations
likely across the central mountains, eastern and southeast
highlands. Probability forecasts have a 40-70% chance of more than
1" of snow in the high country, and a 25-50% chance of more than
3" around Island Park. Agreement is back between the clusters and
models of a decreasing chance of showers even with another wave
dropping down west of the main low centered over south-central
Canada. We should continue to see improvement heading into next
week, although not necessarily shower-free any given day. The GFS
holds onto a lingering trough to our north longer than the ECMWF.
That would delay any warmup by about 24 hours. With cooler
temperatures through much of the upcoming week, that should help
slow down snowmelt/runoff especially at night.
Keyes

&&

.AVIATION...Look for light showers today for all TAF sites
outside of KSUN. With instability and moisture from an upper
level low to our south over southern Nevada and Utah, expect
afternoon showers and thunderstorms. Looking at the HREF model,
KDIJ has a 60 to 70 percent chance of thunderstorms on station and
KPIH and KIDA has a 50 to 60 percent chance of thunderstorms this
afternoon into early evening. Burley has a 20 to 30 percent
chance of thunderstorms and KSUN has a 10 to 20 percent chance of
thunderstorms. Expect VFR conditions outside of stronger showers
and thunderstorms on station. Winds will gust to 30 to 40 kts with
thunderstorms. Outside of thunderstorms winds will still be
breezy around 20 kts for all TAF sites expect KBYI. KBYI will have
even stronger winds this afternoon into the evening, with wind
gusts of 30 to 40 kts expected.
Wyatt

&&

.HYDROLOGY...
Water levels remain elevated on the Portneuf River in Pocatello and
Topaz where a river flood warning and a river flood advisory,
respectively, remain in place. The river forecast this morning has
not changed much from the previous forecast. The forecast is
still driven mainly from snowmelt from warmer temperatures from the
last couple of days. Rainfall today looks overall light and
should not contribute to additional flooding. Cooler temperatures
this week from cloud cover and a weak cold front will slow down
snow melt. Though the river forecast has the Portneuf river
dropping, the river still looks to remain in minor flood stage
through the week.
Wyatt

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from noon to 11 PM MDT Monday for IDZ055>057.

&&

$$