256
FXUS65 KPIH 191813
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1213 PM MDT Sun Jul 19 2026

.KEY MESSAGES...

- Drier air in place will not prevent dry thunderstorms today
  and Monday

- Monsoon moisture increases starting Monday evening

- Warmer temperatures through Monday will increase heat-related
  issues across the Magic Valley and South Hills

&&

.DISCUSSION...
Issued at 1254 AM MDT Sun Jul 19 2026

Drier air, at least at the surface, continues to lock in through
tomorrow. HOWEVER, there is still enough mid level moisture
along with hotter temperatures to kick off a few dry storms both
days. For today, we will see things developing from the Wood
River Valley through Gilmore Summit and Lone Pine, and along the
border through Island Park. A few storms are also expected
across higher elevations south of the Snake Plain. Tomorrow,
we are forecasting isolated dry storms in similar locations,
although we did expand that chance north from Soda Springs north
toward Driggs. Gusts over 35 mph are most likely with storms
farther north where the chance tops out at 70%. Down south, it
is on 10-30%. Stronger gusts tomorrow are lower, but NOT ZERO,
indicating even if we don`t get thunderstorms, virga is
certainly possible. Warmer temperatures continue to be an issue,
with highs today in the upper 80s to mid 90s, with a few spots
pushing 95-100. On Monday, we will be a few degrees warmer, with
valley highs 90-100 or topping just above 100. We are hitting
advisory/borderline warning thresholds, due to accumulating heat
impacts, across the Magic Valley and South Hills/Albion
Mountains. We did issue a HEAT ADVISORY for tomorrow. We are
also potentially hitting thresholds for the Arco Desert, but for
now left that area.

Starting Monday and through the rest of the week, the ridge
resets back to the northwest, pulling in deeper and more
persistent monsoon moisture. Expect more daily shower and
thunderstorm chances across the board, along with a general
"cooling" trends back through 90s and into the 80s. By the end
of next weekend, we may be seeing a similar scenario we are
expecting in the next 24-36 hours, as a system to our north
breaks down the ridge and attempts to bring drier air in the
state.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1155 AM MDT Sun Jul 19 2026

VFR conditions expected through the period with generally mostly
sunny skies and light winds. There remains a chance, albeit low,
for an isolated shower or storm to develop near KSUN or in the
higher terrain around KPIH, KIDA and KBYI which could cause some
gusty and erratic winds around these terminals with any outflow
boundaries. Probabilities remain too low to include any mention
of this in the forecast but will continue to monitor
nevertheless. Similar conditions appear likely for Monday across
eastern Idaho.

&&

.FIRE WEATHER...
Issued at 1254 AM MDT Sun Jul 19 2026

Drier surface will remain in place through Monday, HOWEVER, we
are still seeing enough moisture around for isolated dry storms
later today and again Monday afternoon and evening. Expect
development today across the central mountains extending from
around the Wood River Valley (422) through Gilmore Summit (476).
That batch of storms eventually extends along the Montana border
in Zone 411. The other area we are watching is Zone 413 and 427
south of the Snake Plain. There is potential for strong outflow
winds over 35 mph, especially farther north where the chance is
up to 70%. Down south, the potential only tops out around 30%.
Outside of storms, gusts up to 25 mph in some spots is
forecasts. The same areas are forecast to see isolated dry
storms, although we might see a few more storms developing north
from Soda Springs to Driggs. The chance for stronger outflow
winds is lower, but still NOT ZERO. The other concern may be
heat-related issues for crews as more valley locations are
seeing highs today in the mid to upper 90s, and even higher with
some locations top out just above 100 tomorrow.

Monsoon moisture increases again starting tomorrow evening and
continues through the rest of the week. This will basically be a
repeat of this past week where we see daily shower and
thunderstorm chances, and afternoon temperatures highly
dependent on the amount of cloud cover on any given day.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from noon to 8 PM MDT Monday for IDZ051-055>057.

&&

$$

DISCUSSION...Keyes
AVIATION...McKaughan
FIRE WEATHER...Keyes