Area Forecast Discussion
Issued by NWS Pocatello, ID

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FXUS65 KPIH 171842
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1242 PM MDT WED AUG 17 2016

.SHORT TERM...Tonight through Sunday...Scattered showers and thunderstorms
expected across the Central Mountains and Southern Highlands for
this evening with improving conditions after 10 pm MDT, though an
isolated shower or thunderstorm cannot be ruled out overnight.
Wind gusts up to 20 mph possible with light rainfall amounts of
less than 0.10 inches in individual cells. Small hail is also
possible. It is likely that another round of shower and
thunderstorm activity will occur on Thursday and will probably
begin earlier in the day compared to today. Therefore, expect
thunderstorms in the morning for those along the Divide, Island
Park, and in the northern Snake Plain. This activity will push
southwards through the day.

A cold front will be progressing southwards through SE Idaho on Friday,
decreasing temperatures 5 to 10 degrees in its wake. High
temperatures Friday are expected to be in the low to mid 80s
across the Snake River Plain with lower temperatures elsewhere. A
gradual warming trend is expected over the weekend with
temperatures back into the upper 80s to low 90s by Sunday. Behind
the front, expect wind speeds to increase upwards of 15 to 25 mph
with higher gusts to 35 mph at times. Northerly winds will
increase at first along the Divide and in the Central Mountains
early Friday and continue to push southwards during the day. Only
isolated showers are forecast with the actual passage of this
front.

.LONG TERM...Monday through Wednesday...Approaching upper trough
expected early next week though amplitude of this wave differs a
bit between global forecast models. GFS model currently shows the
wave to be relatively strong and thus brings SE Idaho strong 15 to
20 mph afternoon winds Monday and Tuesday afternoons. Hints of
precipitation are noted Monday through Wednesday across the
Southern and Eastern Highland locations as well. With the ECMWF
solution, precipitation is noted Monday afternoon only, in these
same locations, and winds closer to 10 to 15 mph are noted with
weaker amplified trough. A weak, broad trough to the west may
bring isolated showers to the region late week. NP/Hedges

&&
.AVIATION...Disorganized, orographically forced convection is
expected today while stubborn upper troughing remains over Nevada.
Will keep VCTS mention in TAFs, and wouldn`t be surprised if
terminals are occasionally impacted by strong outflow winds. Smoke
from the increasing number of wildfires may also pose a challenge to
visibility at the sites, though we are expecting things to remain
predominantly VFR. Showers/isolated thunderstorms could linger
through the overnight hours into tomorrow morning.  Hinsberger

&&

.FIRE WEATHER...Concern today will be thunderstorm coverage.
Continuing with isolated to widely scattered wording. Convection is
already underway along our southern and eastern borders as of noon
today. Models all suggest disorganized pulse convection, mainly
developing over the mountains. The 17Z HRRR favors convection over
the Central Mountains this afternoon, but is slow in picking up on
current convective trends. Storms will likely generate strong
outflow winds. Forecast tomorrow is even less certain as to where
thunderstorms will initiate. GFS favors the Central Mountains, and
the NAM favors the Southeastern Highlands. A cold front is expected
to enter the area Thursday night into Friday, shifting winds
northeasterly. Wind gusts will generally be 20 to 25 mph for fire
weather zones 410 and 411, but Red Flag potential will be assuaged
by the higher humidity. The 12Z GFS solution, however, shows less
influence of the cold front over Idaho and pushes the system further
into Wyoming. Dry and stable weather should prevail over the weekend
into early next week. Hinsberger

&&
.PIH Watches/Warnings/Advisories...
None.
&&

$$



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