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fxus65 kpih 212003 
afdpih

Area forecast discussion
National Weather Service Pocatello Idaho
203 PM MDT Mon Oct 21 2019

Short term...tonight through Wednesday. Northwest flow pattern
remains in place through the short term with several embedded
shortwaves crossing east Idaho. A few light showers remain
possible through the night in favored upslope areas of the central
mountains and eastern Highlands along the Wyoming border. Snow
levels are generally fluctuating between 5000-6000 ft especially
in the eastern Highlands. Quantitative precipitation forecast amounts remain quite low for this
first feature so snow amounts overnight are generally an inch or
below even at higher elevations. Breezy winds continue through the
snake plain this evening with some decrease overnight with loss
of most mixing. Second shortwave drives across the region Tuesday.
Winds ramp back up in the snake plain, and guidance is suggesting
that winds could reach low end advisory criteria in the 25-30 mph
range. Held winds just shy of that for now, but an increase in
forecast speeds may be necessary if the weak uptick trend in
guidance values holds another run. Precipitation spreads across
the region once again as well, again favoring higher elevation
upslope regions in the northwest flow:
central mountains, and most of the eastern Highlands including the
Island Park area. Quantitative precipitation forecast values still are not very impressive so
expect snow amounts in the 1-2 inch range for the higher
elevations, and generally a dusting up to an inch for communities
like Stanley, Island park, and Driggs/Victor. Remnants of this
shortwave feature linger Tuesday night into Wednesday, but the
bulk of the moisture drives southeast, so only lingering
orographically induced showers are expected with very light
accumulations. Locally breezy winds should continue into
Wednesday, but overall should be much less than Tuesday. Dmh

Long term...Wednesday night through Monday. A ridge of high
pressure is still expected to develop over the Great Basin into
Thursday night, giving way to another shortwave pushing through
the pacnw Friday into Friday night. This feature induces more of a
zonal flow across the region, which will have the potential to
push winds back into breezy or even windy status by Saturday as
the upper trough begins to deepen across Idaho. Expect
precipitation to become more widespread across east Idaho for the
weekend. There is quite a bit of variability among operational and
ensemble members, but the general trend is for wetter and
increasingly cooler conditions for the weekend. Dmh



&&

Aviation...gusty winds continue across eastern Idaho today, and
will through the next 24 hours due to strong flow aloft. We should
remain VFR during most of the period. We will see another surge
later tonight and potentially Tuesday afternoon. For now, we have
vcsh for sun, pih and Ida at various times to handle this...but not
going to MVFR/IFR for now. Just not enough confidence to do that
right now. We did drop dij to MVFR/IFR overnight and tomorrow
morning as it appears there is much better chance of snow occurring
directly at the Airport. Keyes



&&

Pih watches/warnings/advisories...

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