774
FXUS65 KPIH 132036
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
236 PM MDT Sun Jul 13 2025

.KEY MESSAGES...

- Warm and dry conditions will continue through Monday

- Critical fire weather conditions expected Monday

- Isolated dry thunderstorms Monday increase in coverage Tuesday

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 236 PM MDT Sun Jul 13 2025

Most of East Idaho will continue to see dry and warm conditions into
Monday. A weak feature pushing across the region today may be enough
to help fire a thunderstorm or two from the Central Mountains along
the Divide late this afternoon into the evening, roughly Copper
Basin to Island Park. Confidence is VERY low, but satellite shows a
few early afternoon build-ups already starting in the Copper Basin
region. Any storm that does develop in this region will have the
potential for gusty outflows around 40 mph, and activity should
diminish after sunset. Monday looks a little more complex around
East Idaho with another round of generally isolated thunderstorms
mainly across the northeast quarter of the forecast area from INL
north and east to the Montana and Wyoming state lines. Another weak
secondary area will be possible along the Utah border generally
across the highlands south of Burley. These storms will have better
for potential for gusty winds with potential 50+ mph especially
across the northeast. Once again storms will be generally dry. Have
nudged up the PoP and Thunder risk across these areas above the
drier NBM solution. Outside the thunderstorms, winds will be gustier
in general as well, with gusts 30-35 mph across the Magic Valley,
Raft River/Southern Highlands and up through the INL region.
Temperatures remain warm through the short term, with afternoon
highs in the low to mid 90s.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 236 PM MDT Sun Jul 13 2025

A compact mid/upper-level low diving southeast out of British
Columbia will continue to slide southeast across the ID Panhandle
and Western MT Tuesday and Tuesday night. Ahead of this low, breezy
and warm conditions will persist Tuesday, as it looks like the
surface cold front will largely hang up near the Divide until
Tuesday evening. Increased cloud cover and moisture may shave a
couple of degrees off of high temps in some areas, but aside from
northern portions of the Central Mountains east along the MT border,
high temps will be very similar to those forecast for Monday. Shower
and thunderstorm chances increase Tuesday afternoon and evening with
stronger dynamics ahead of the low and as the front eventually
slides through, although the better precip potential overall still
remains north and east of the forecast area across MT and WY. This
upper low will continue its trek east across MT and WY on Wednesday
as it continues to open up and become more progressive. Most of the
shower/thunderstorm chances will shift east of the area as well,
although low chances (10-20%) will linger along the MT Divide and
Island Park region. Temperatures cool 5-10 degrees in most locations
in the post-frontal airmass, knocking Wednesday afternoon highs back
near to slightly below normal. This cool down will be short-lived
however, as temps already begin to rebound starting Thursday under
increasingly zonal flow aloft. Ensemble means and cluster analysis
data are in good agreement showing this transition back to westerly
flow late week into the weekend, leading to warm and mostly dry
conditions, as any monsoon moisture looks to remain to our south
while any upper troughs embedded in stronger flow aloft remain to
our north. So aside from an isolated afternoon/evening mountain
shower or storm (<20% chance), precipitation appears absent late
week into the weekend. We do start to see increasing spread in the
ensemble clusters by the latter half of next weekend, with about 40%
of the membership showing a shortwave trough grazing us to the north
(suggesting slightly cooler but breezy conditions), another 40%
maintaining the zonal flow, and the remaining 15-20% showing
stronger ridging developing over the Four Corners (which would give
hope for a little monsoon moisture to make it farther north).
Nonetheless, up until then the next week looks a lot like July
-- hot, mainly dry, with some occasional thunderstorm chances.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1135 AM MDT Sun Jul 13 2025

VFR conditions will persist through the period as a ridge of
high pressure aloft continues to dominate. A weak disturbance
rotating around the periphery of this ridge may generate a few
isolated (10-20% chance) showers or thunderstorms this
afternoon and evening over portions of the Central Mountains and
along the MT Divide, but these are expected to remain
north/northeast of all terminals. Winds will increase diurnally
this afternoon, with gusts up to 20 kts at KPIH, KIDA, and KBYI,
before subsiding around sunset this evening.

&&

.FIRE WEATHER...
Issued at 236 PM MDT Sun Jul 13 2025

A few thunderstorms will still be possible this afternoon mainly
across zones 476 and 411 along the Divide, with potential outflows
around 40 mph. Otherwise dry conditions will persist into early
Monday for the remainder of the region. More of the region
could see isolated thunderstorms on Monday, including portions
of the Southern Sawtooth and the northern half of Zone 410. The
storms Monday will be stronger, with a greater than 50% chance
of exceeding 35 mph and potential for over 50 mph. Outside of
thunderstorms, winds will be gusty, and humidities will be low.
The best chance for the combination of winds and low humidity
reaching critical thresholds will be across zones 425 and 427,
but may APPROACH CRITICAL across zones 410 and portions of 413
as well. A Fire Weather Watch is already in effect for 425 and
427, and will likely be upgraded to a Red Flag Warning tonight.
A system drops through Montana on Tuesday, increasing the threat
for thunderstorms across the region, but also increasing the
daytime humidity slightly. Winds are expected to remain
elevated, and more Red Flag Warnings may be necessary depending
on thunderstorm coverage and/or winds and RH. Surface cold front
drops through by Tuesday night, allowing for a temporary slight
reprieve in the hot dry pattern. Brief cooling trend for
Wednesday transitions toward a return toward warmer and drier
conditions, though a few thunderstorms may still be possible
later in the week.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Monday afternoon through Monday
evening for IDZ425-427.

&&

$$

SHORT TERM...DMH
LONG TERM...KB
AVIATION...KB
FIRE WEATHER...DMH