High Wind in Idaho, January 30, 2018

Area Forecast Discussion
National Weather Service Pocatello ID
206 PM MST Tue Jan 30 2018

.SHORT TERM...Tonight through Friday. Cold front still trying to
sag across East Idaho this afternoon. Southerly winds still across
portions of the Snake Plain have maintained temperatures WELL
above normal and WELL into record territory. Actual high for PIH
this afternoon already at least 57, with former record of 51. Not
the only record expected. Temps have stayed warm all day, even in
higher elevation basins like Stanley. This has kept whatever
meager precipitation we've seen out of this system wet for the
most part. QPF amounts have remained extremely light. Have kept
chance PoP in higher elevations in favored northwest flow terrain,
but mid-level clearing marching into the system behind the
shortwave may prevent even that. Still, with northwest flow and
the last few systems holding on to stratus in these same regions,
it's hard to argue the possibility. Confidence is low, but high
that if it happens, QPF will remain minimal. So, winds remain the
biggest concern in the short term. Advisory remains a lock for the
Upper Snake region with several mesonet sites gusting over 40mph.
Will let that headline continue as planned through the evening,
and have nudged early evening winds upwards slightly to better fit
current areas where winds are strongest. Rest of forecast may as
well be stamped with a great big DITTO as series of shortwaves
slides along Divide in this persistent northwest flow regime.
Wednesday appears to be coldest day of the week, and still above
normal. Any precipitation associated with the shortwaves look to
be confined to the same northwest flow favored areas, and snow
levels likely to stay elevated. Strongest shortwave, at least per
models, appears to be late Wednesday night through mid-day
Thursday, which may have a better shot at introducing some well-
needed moisture to southern highlands. If it goes the way that the
last month has gone, this will likely be another event with high
confidence of not very much. DMH

.LONG TERM...Friday night through next Tuesday. Stop us if you've
heard this before: northwest flow holds over eastern Idaho into next
week. Persistent light precipitation remains focused over the
highlands from Island Park south toward Palisades. We will see the
occasional "wave" come over the ridge and push the chance of rain
and snow farther south in the mountains and Snake Plain. Timing any
of those remains a problem although it looks like we MIGHT on
Saturday, as the GFS and ECMWF show that. Speaking of the GFS, it
still wants to show the pattern shifting west a bit and MAYBE allow
a little cooler air into the Upper Snake Highlands late in the
weekend or early next week. We tried to show that trend ever so
slightly but didn't want to jump in the deep end head first right
now. Expect ABOVE AVERAGE temperatures to continue and also see some
wind especially when one of these "waves" crosses the state. Keyes

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.AVIATION...As expected, issues with lower ceilings or visibility
haven't materialized. There is a lot of dry air near the surface and
any precipitation isn't reaching the ground at our TAF sites, as
well as not allowing lower clouds to develop. Winds are definitely
breezy out there and that should continue through mid evening. With
the lighter winds at KSUN, wind shear should continue to persist
until winds just off the ground die down. It's certainly possible
that we see stronger west wind sneak across the airport on occasion
this afternoon, as this does happen on occasion in this scenario.
The only site that has VCSH is KDIJ as they could benefit from
upslope in the surrounding mountains. Even, there we keep conditions
VFR. These trends should persist into Wednesday, although winds will
be not as strong. Keyes

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.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 8 PM MST this evening for IDZ020.

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