545
FXUS65 KPIH 071125
AFDPIH
Area Forecast Discussion
National Weather Service Pocatello ID
525 AM MDT Mon Jul 7 2025
.KEY MESSAGES...
- Hot weather for the first half of the week.
- Cold front arrives Wednesday bringing cooler weather for late
week.
- Potential red flag conditions for wind and humidity Wednesday.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 149 AM MDT Mon Jul 7 2025
Ridge of high pressure will amplify over Central and East Idaho
on Monday. This will produce dry and hot conditions for Monday
and Tuesday. Many of the lower elevations will see highs in the
upper 80s to around 90 today. On Tuesday, these same areas will
see highs in the low to mid 90s. Looking at dry conditions
today. Although on Tuesday, a weak shortwave trough will work
through the greater ridge. Models are showing some isolated dry
thunderstorms across the high country Tuesday afternoon. The
better chances are across the central mountains where the ridge
is not as strong. Some virga bombs are possible Tuesday
afternoon, with gusty outflow winds likely in and around
thunderstorms.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 149 AM MDT Mon Jul 7 2025
As a H5 ridge axis shifts east on Wednesday, a Pacific trough
will move onshore to the PacNW and track east into southeast
Idaho. This trough will support an uptick in winds for Wednesday
and Thursday and a 5-15% chance of virga/showers and wet/dry
thunderstorms Wednesday through Friday, supported additionally
by a secondary reinforcing trough passing north through Montana
Thursday into Friday. Given a good deal of dry air to overcome
at the surface and the isolated nature of any showers and
convection, our latest forecast keeps conditions mostly dry with
this trough passage with best chances remaining confined to the
mountains. Gusty winds will however be possible associated with
any activity given a very dry airmass at the surface remaining
conducive for gusty outflow winds. Winds on Wednesday and
Thursday will peak synoptically each afternoon around 15-30 mph
with gusts to around 25-45 mph. Behind a mostly dry cold frontal
passage late Wednesday into early Thursday, temperatures will
drop about 5-10 degrees for Thursday and Friday as isolated
showers and storms shift further north and east associated with
that secondary trough passing through Montana. Following this
series of troughs to finish out the work week, ensemble model
guidance continues to support the resurgence of high pressure
over southeast Idaho, allowing for warming temperatures and dry
conditions back for the weekend into early next week.
&&
.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 525 AM MDT Mon Jul 7 2025
Predominant VFR and dry conditions will prevail across
southeast Idaho for Monday under the increasing influence of
high pressure. Skies will remain mostly clear into Tuesday
morning, with winds peaking around 10-15 kts with gusts to
20-25 kts in the afternoon, following typical diurnal patterns.
&&
.FIRE WEATHER...
Issued at 149 AM MDT Mon Jul 7 2025
Under the increasing influence of high pressure early this
week, conditions will remain hot and dry as temperatures see a
warming trend with lighter winds and mostly clear skies. The
warmest temperatures are expected Monday through Wednesday, with
highs reaching the upper 80s to upper 90s in the valleys. Given
a very dry airmass in place, afternoon humidities will drop to
the teens/20s each afternoon, dropping even further for Tuesday
and Wednesday to the single digits and teens. Increased fire
weather concerns are expected for Wednesday as high confidence
supports a Pacific trough and mostly dry cold front building in
late Wednesday into Thursday, bringing the return of breezy
winds and isolated wet and dry showers and thunderstorms. Due to
a combination of elevated winds and low relative humidity, near
critical to critical fire weather conditions are expected on
Wednesday. Wind gusts look to peak around 25-45 mph both
Wednesday and Thursday. As a result, we will likely be
coordinating with regional partners for any fire weather
headlines midweek, particularly Wednesday. As that trough and
front passes east on Thursday, a secondary reinforcing trough
passing through Montana through Friday will help bring
temperatures down and support a slight increase in RHs, albeit
still supporting elevated fire weather conditions Thursday. With
that secondary trough departing east on Friday, isolated
showers and storms will shift to being along the Wyoming border
region, with hot and dry conditions building back in for the
weekend into early next week.
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...13
LONG TERM...MacKay
AVIATION...MacKay
FIRE WEATHER...MacKay
