Area Forecast Discussion
Issued by NWS Boise, ID
FXUS65 KBOI 250334
Area Forecast Discussion
National Weather Service Boise ID
834 PM MST Fri Feb 24 2017
.DISCUSSION...Upper level trough remains entrenched over the
West this evening with cold unstable air aloft over the region.
Expect a cold night tonight with temperatures in the teens and
single digits in the snow covered areas and low 20s in non-snow
covered areas. With the cold unstable air aloft, expect isolated
snow showers to develop during the afternoon heating on Saturday,
mainly over the higher terrain. Next weather system arrives on
Sunday bringing snow showers to the region. Current forecast
reflects this well. No updates.
.AVIATION...Widespread VFR with isolated snow showers diminishing
this evening. Surface winds: Variable 10 kts or less. Winds aloft at
10k ft MSL: W 10-20 kts.
Weekend outlook...Mainly VFR on Saturday with isolated snow
showers. Deteriorating conditions Sunday as another moist weather
system spreads snow into the area.
SHORT TERM...Tonight through Saturday Night...A quiet period
expected. The low pressure system which resulted in significant
snowfall across the Magic Valley and areas south has moved further
northeast...taking its impacts with it. A few showers cannot be
completely ruled out over through Saturday night as an area of low
pressure moves southwest near the Pacific coastline. This system is
expected to have minimal impact over the forecast area. The next
influencing system will send an Alaskan low pressure system down the
Pacific coast, with moisture just beginning to reach into the
northern extremes of the forecast area late Saturday night.
LONG TERM...Sunday night through Friday...A trough will drop out of the
Gulf of Alaska Sunday into the beginning of next week bringing snow
across the region once more. Models have trended upwards in their
QPF amounts for this system and have taken this factor into account
in the updated forecast. Most of the new snowfall will focus over
the mountain areas, with most valley locations receiving little
accumulation. The West Central Mountains are looking to receive the
brunt of the impact. Southwesterly upper level flow out ahead of the
trough on Sunday as the trough digs in, will quickly turn westerly
and northwesterly by the beginning of the week, keeping the region 5
to 10 degrees below normal through the period. While the trough is
expected to move out of the region by Tuesday morning, the West
Central Mountains will stay under a wet northwesterly flow for daily
chances of snow showers through the end of the period.
PREV SHORT TERM...KB
PREV LONG TERM....AB/WH