Area Forecast Discussion
Issued by NWS Pocatello, ID

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FXUS65 KPIH 200315

Area Forecast Discussion
National Weather Service Pocatello ID
915 PM MDT THU MAY 19 2016

.UPDATE...Surface cold front has shifted through east Idaho this
evening. Convection behind the front has decreased in intensity
while shifting east toward the WY border though a few stronger
cells may still impact the Bear Lake area before 06z. Second batch
of weaker convection over northern Nevada this evening ahead of
next shortwave rotating around upper low painted into southern
half of east Idaho between 09z and 12z. Northeasterly down-valley
surface gradient enhanced by surface low deepening over northern
UT could help to enhance this band by sunrise. Instability minimal
so have left thunder out of grids overnight but would not be
surprised with a few lightning strikes. Have made grid adjustments
based on satellite and radar trends, and adjusted overnight temps
and evening winds with surface observations. DMH


.PREV DISCUSSION... /issued 121 PM MDT THU MAY 19 2016/

SHORT TERM...Today through Sunday. An upper level low is
currently centered over Washington state. This low will bring
unsettled weather across the area through the period. A cold
front associated with this low has just started to cross our
western border. Scattered showers and isolated thunderstorms are
out ahead of this front. As this front moves through look for
widespread showers and scattered thunderstorms. Expect .2 to .5
inch of rain today with locally higher amounts particularly across
higher elevation for the Southeast highlands. Look for breezy to
moderate winds of gust near 25 to 35 mph ahead of the front as
well as behind the front. Storm outflows along the frontal
boundary could reach 40 to 50 mph. Also look for small to moderate
hail with these thunderstorms.

Friday models are showing good precipitation chances with another
2 to .5 inch of rain across much of our Eastern and Southern
areas. This rain spreads North and Westward across our area as a
strong jet core moves over our Southeast areas. A wind advisory
may be needed Friday afternoon into Friday evening for our
Southern and Eastern highlands with wind gusts approaching 35 to
40 mph. The upper level low will move over Northern Idaho Saturday
in Sunday. Expect Scattered to Numerous Showers and Isolated
afternoon thunderstorms Saturday and Sunday. Daytime temperatures
will run 5 to 10 degrees below normal through the period. TW

LONG TERM...Monday through Thursday. Disturbed weather pattern will
bring a chance for showers across our area each afternoon next week.
European forecast model takes the trough responsible for this
activity east of our area by Thursday and builds high pressure in
thereafter. Various other weather solutions are noted by GFS and
CNC which involve the progression of a new upper low from the
northwest. Temperatures will not vary much during this period with
mid 60s for highs throughout the Snake River Plain and 50s in the
mountains. NP/TW

AVIATION...Approaching frontal boundary to bring showers and
thunderstorms to all Taf sites this afternoon and into early
evening. Ahead of this front, increased southwesterly winds are
noted at PIH and IDA which will decrease gradually as the front
nears. Expect overcast skies at 3500 to 5000 feet becoming broken
overnight. MVFR cigs are possible during heavier showers on
station. Then before daybreak and into the early morning expect
more isolated to scattered rain showers to reappear from the south
and continue through the day. Ceilings could potentially reduce to
MVFR status early tomorrow morning for all TAF sites. NP/TW


.PIH Watches/Warnings/Advisories...

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