901
FXUS65 KPIH 282020
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
220 PM MDT Tue May 28 2024

.SHORT TERM...Today through Wednesday Night.
Early afternoon satellite imagery shows a H5 shortwave trough
lifting out of the Great Basin with radar imagery showing strong
thunderstorms beginning to develop in and around the Magic Valley
and WRN CNTRL Mountains. This trough will be the main driver of
convection today which aided by 300-600 J/kg of SBCAPE, 20-40 kts
of 0-6km shear, and steep 8-10 degree 700-500 mb lapse rates, will
support the potential for strong downdrafts and dry microbursts,
supporting gusts in excess of 50 mph.

We have already seen a line of showers pass through the CNTRL
Mountains earlier today which with no lightning, was able to
produce 30-45 wind gusts, indicative of the convective environment
today. CAMS remain in reasonable agreement on taking these storms
currently in the Magic Valley NE and WRN CNTRL Mountains NE and
across the Snake River Plain through this evening. With the HRRR
model showing wind gust potential in that 50-60 mph range, this
lines up well with the HREF probability of sustained winds greater
than 30 kts sitting at 70-90% for the aforementioned area.

As these storms decrease in intensity after sunset, a cold front
will begin moving through SRN Idaho tonight into Wednesday which
will support strong synoptic winds during the daytime hours in
addition to keeping our isolated to scattered showers and storms
going through the night into tomorrow. As a result in the uptick
in daytime winds, have gone ahead with a WIND ADVISORY for the
ERN Magic Valley, Arco/Mud Lake Desert, and Upper Snake River
Plain which will be in effect from 6 AM to 9 PM for sustained
winds 25-35 mph with gusts up to 55 mph.

Given it is currently 83 degrees at the Pocatello Airport as of
155 PM, today will have marked the warmest day in 232 days or
since early October as many of our climate sites also see 80
degrees for the first time this year today. These above normal
temperatures will be short lived however as colder air settles in
midweek behind this cold front with highs about 10-20 degrees
colder in the 50s/60s for Wednesday. We are also monitoring the
potential for FROST ADVISORIES across portions of the Snake Plain
and ERN Magic Valley for Wednesday and Thursday nights given low
temperatures especially further north and west, hovering in the
low to mid 30s in the latest forecast each night. MacKay

.LONG TERM...Thursday through next Tuesday.
The long term will start very dry with temperatures well below
normal on Thursday with with highs mainly in the 40s and 50s
mountains and 60s valleys. Winds will be greatly diminished in the
Snake River Plain but still breezy. Generally expect 10 to 20 mph
sustained with gusts around 30 mph. Will see a warming trend
Friday into Saturday. Highs will be in the 60s and 70s Friday and
low elevations into the low 80s on Saturday. Strong zonal flow
aloft may bring at least a slight chance of showers and
thunderstorms Saturday night into Monday mainly in the central
mountains and Upper Snake Highlands. Highs Sunday through Tuesday
will be mainly 60s mountains and 70s low elevations so near or
slightly above normal. With the stronger zonal flow aloft expect
breezy conditions to continue Sunday through Tuesday with
continuing 10 to 20 mph sustained winds with gusts over 30 mph in
the Snake Plain. GK

&&

.AVIATION...For the 18Z TAFS through 18Z Wednesday.
An approaching cold front and upper level system will bring
showers and thunderstorms into southeast Idaho this afternoon and
tonight. For now have vicinity thunderstorms this afternoon and
evening at all sites and showers through tonight into Wednesday
morning as the system works east. Winds generally around 10 knots
overnight but very strong outflow gusts near any thunderstorm.
Winds will be much stronger Wednesday and expect sustained 20 to
30 knots at BYI, PIH, and IDA with higher gusts. So will have
impacts the next two days at all sites. GK

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 6 AM to 9 PM MDT Wednesday for IDZ051>055.

&&

$$