478
FXUS65 KPIH 192005
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
205 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. More
  widespread storms Monday evening through Wednesday.

- Warmer temperatures through Monday will increase heat-related
  issues across the Magic Valley, Snake River Plain, and South
  Hills. Many low elevations around 100 degrees.

&&

.DISCUSSION...
Issued at 138 PM MDT Sun Jul 19 2026

Isolated high elevation thunderstorms this evening mostly in the
central mountains and southern hills. Have heat advisories in
effect Monday in several areas with many high temperatures
expected to be near 100. Humidity a little elevated as well.
MOnsoonal flow elevates with a much better chance for showers
and thunderstorms Tuesday and Wednesday across the entirety of
southeast Idaho. Will see cooler but still very warm high
temperatures with the expected cloud cover. Coverage will
decrease Thursday through next Sunday but still have at least
isolated coverage in the grids with temperatures rising once
again. Some areas will likely see wetting rains Tuesday and
Wednesday but most areas will likely not see extensive rainfall.
Could see some breezier conditions by next weekend, but very low
confidence that far out.

&&

.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>059.

&&

$$

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