Area Forecast Discussion
Issued by NWS Pocatello, ID
FXUS65 KPIH 240949
Area Forecast Discussion
National Weather Service Pocatello ID
349 AM MDT Mon Apr 24 2017
.SHORT TERM...Today through Wednesday night.
Expect a wet pattern through the next several days. Looking at
the current water vapor imagery there is a continuous stream of
moisture across the Eastern Pacific moving into our area with a
jet max over Western Oregon. Showers are beginning this morning
with the first surge of precipitation starting to move over our
area. Expect .20 to .40 of precipitation with locally higher
amounts particularly over our Eastern areas today into tomorrow
morning. The snow level will be around 6500 feet to 7000 feet.
Expect 2 to 4 inches of snow with locally higher amounts through
Tuesday morning. Also, expect isolated afternoon thunderstorm this
afternoon. Look for breezy to moderate winds by this afternoon
and continuing through most of the evening. Expect lingering
precipitation over the Eastern highlands Tuesday afternoon before
the next big surge of moisture moves over the area on Wednesday.
Precipitation and snow amounts could be slightly higher Wednesday
than today`s system with snow levels dropping to around 6000 feet.
.LONG TERM...Thursday through Monday.
Colder air is pouring into the region on Thursday. Because this
is such a large system, moisture will extend all the way from
Nebraska to the Pacific Northwest coast. So, we`ll have showers
around for Thursday and Friday, possibly into Saturday and Sunday
as well. Snow levels will fall considerably, and either rain/snow
mix or all snow will be possible even down to valley floors.
However, these will be showers and not widespread precipitation so
amounts will vary considerably and probably not much will stick
on the valley floors. Expect a strong diurnal component to the
showers with coverage best during the afternoon. There may even be
enough instability for some thunder Thursday afternoon. Do expect
somewhat drier weather over the area by Saturday. But the models
continue to show some moisture flowing in from the northwest. So,
the coverage may be much less but there still may be a threat for
showers for Saturday and beyond.
.AVIATION...As of 3:10 AM MDT...We kick off our 12Z TAF period with
VCSH, but generally VFR, at all terminals. Conditions only go
downhill from there rest of the day, with areas of steadier and more
widespread precip likely overspreading SE ID west to east between
14Z and 16Z, cont until after sunset. During periods of steadiest
precip today, solid MVFR with occasional IFR conditions will be poss
at all terminals, with CIGS dropping as low as 900 to 2,000 feet
with precip/BR, and VSBYS dropping to 3-5 miles at times. Greatest
risk for these conditions will gen exist from 14Z to 23Z at KSUN and
KBYI, 15Z to 03Z at KPIH/KIDA, and 16Z to 12Z at KDIJ. Model
guidance at KDIJ suggests both BR and precip changing to snow Mon
night will keep a moderate threat of IFR conditions going all night.
Strong gusty winds expected to display a non-diurnal trend today,
with strongest winds of 15+ kts with gusts of 25+ kts likely after
dark this eve, esp at the Snake Plain terminals KBYI/KPIH/KIDA. At
this time, believe sfc winds will be high enough relative to winds
off the deck to fall short of LLWS criteria.