221
FXUS65 KPIH 072020
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
220 PM MDT Sun Jul 7 2024

.SHORT TERM...Tonight and Monday. We will continue with dry
conditions across central and eastern Idaho. Northeast winds will
slowly diminish into this evening. The current LAKE WIND ADVISORY
for American Falls expires at 3pm, but some guidance shows enough
wind lasting through 5-7pm that we MIGHT have to extend the
headline. It likely will be a last minute decision if we do that.
We should see a few afternoon cumulus clouds, especially up north
closer to Montana and the Divide, but we are not expecting
anything other than that. Temperatures will jump several degrees
Monday, but that is only the beginning of a long duration
excessive heat event. Keyes

.LONG TERM...Tuesday through next Saturday.
The heat will be here by Tuesday, but we will be hottest from
Wednesday through Saturday. Highs will stay in the 90s for most of
the eastern Magic Valley and Snake Plain on Tuesday. However, once
we get to Wednesday these areas will have a 50 to 70 percent chance
(per the NBM) for highs to reach or exceed 100 degrees. The upper
Snake Plain is where the 50 percent chance will be as the NBM
continues to advertise highs of generally 95 to 100 degrees in this
area while both the ECMWF and GFS ensembles show highs in Idaho
Falls reaching and exceeding 100 degrees beginning on Wednesday.
Temperatures in most of our population centers will stay in the 60
to 65 degree range overnight. All of this to say, both our highs and
lows will be running about 10 to 15 degrees above normal for mid
July. And some of us will be approaching record highs and record
high lows through this stretch. As such, we`ve issued an Excessive
Heat Watch for Wednesday through Saturday. It`s no surprise that it
will be quite dry through the week, too, with minimum relative
humidities in the upper single digits to mid teens. Winds gusts on
Wednesday will be around 20 to 25 mph through the eastern Magic
Valley and Snake Plain with the potential for some stronger gusts
around 30 mph out across Craters of the Moon and the rest of the
Arco Desert/Mud Lake areas on Thursday and Friday, so we will see
near-critical, if not hitting critical, fire weather conditions, too.
AMM

&&

.AVIATION...VFR conditions continue throughout today and into Monday as high
pressure keeps any rain or storms well out of our area. We may see a
few afternoon cumulus clouds pop up around 7000 ft, but that`s about
it. Winds are much lighter at all sites today with gusts of only 15
to 20 kts. Winds become light and variable overnight and through
Monday morning. Of note, as temperatures continue to increase, be
aware of increased density altitudes each afternoon, especially at
BYI, PIH, and IDA.
AMM

&&

.FIRE WEATHER...Dry and warmer conditions will continue throughout
the week. Temperatures will climb to well above average later this
week, which will lead to potential heat stress issues for any
crews outside for longer periods of time. This will also lead to
some very low humidity in the afternoon along with poor to very
poor overnight recovery for the mountains. It does look like we
may see some afternoon cumulus at times. Our Blend of Models
through midweek are trying to show some type of dry thunderstorm
potential, most areas under 10% except around Monida Pass, Island
Park and Driggs where it is 10-20%. While it is something to
watch, that is likely WAY OVERDONE...and reality is somewhere
closer to zero or 5% at best. A new wrench thrown into the mix is
the increasing potential for afternoon gusty winds, as we may end
up sitting on the north end of the ridge...and the combination
of afternoon heating and any passing wave to the north helping to
stir things up. Lastly, it still looks like by Friday, more
likely the weekend, we get enough monsoon moisture wrapping around
the ridge to begin worrying about dry thunderstorm potential.
Keyes


&&

.PIH WATCHES/WARNINGS/ADVISORIES...

Lake Wind Advisory Until 3PM MDT For IDZ054.
Excessive Heat Watch Wednesday Through Saturday For
IDZ051>053-055>059-061>062-065-067>068-070-075

&&

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