Meridian, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

194
FXUS65 KBOI 201548
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
948 AM MDT Fri Jun 20 2025

.DISCUSSION...Showers have been isolated and limited to the far
north near McCall this morning. The showers are expected to
expand in coverage this afternoon as an upper low approaches
from the west. In addition to the showers, isolated
thunderstorms will develop from Baker County into central Idaho,
accompanied by gusty winds and small hail. A cold front moves
through today, resulting in gusty winds this afternoon -
especially in s-central Idaho where a Wind Advisory is in
effect. Temperatures will be 10 to 15 degrees below normal. No
updates.

&&

.AVIATION...VFR. Cold front near KMSO-KBOI at 18Z will move to
KSMN-KEKO by 21/00Z. Showers along and behind the front north
of KBOI locally obscuring mountains. Isolated thunderstorms in
the central ID mountains until 21/06Z. Surface winds: W-NW
increasing to 15-25 kt with gusts 30-40kt along and behind the
cold front. Winds aloft at 10kft MSL: W-SW near 30kt.

KBOI...VFR. 30-40% chance of rain showers after 18z, greatest
chance from 21/00Z to 21/03Z. Less than 10% chance of
thunderstorm. Surface wind NW 13-23kt from 20/18Z to 21/06Z.

KMYL...VFR. Periods of MVFR and mountain obscuration in showers
and thunderstorms. Greatest chance of showers (60-75%) and
greatest chance of thunderstorms (15-25%) from 21/00z to 21/03Z.
Surface winds: SW 10-15kt with gusts to 20 kt, from 20/18Z to
21/02Z, then variable less than 6kt.

WEEKEND OUTLOOK...VFR. Numerous showers/isolated thunderstorms
obscuring mountains in Baker County/OR and ID north of the Snake
Basin. Areas of MVFR in clouds and pcpn. Snow as low as 6000
feet MSL late Saturday night through Sunday morning.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Sunday night...A significant pattern
shift will continue today with the passage of a cold front,
bringing cooler temperatures, breezy conditions, and increasing
chances for showers and isolated thunderstorms.

Showers are expected to develop by early afternoon,
particularly across the higher terrain of southeast Oregon and
the mountains of southwest Idaho. Additional activity will form
along the cold front as it progresses west to east across
southwest Idaho later today. Light rain is possible across the
Snake River Plainparticularly from Ontario to Mountain
Homewhere chances are near 40%. Behind the front, daytime
heating may support convective showers, though the best dynamics
and instability for thunderstorm development will remain
confined to Baker County and the West Central Mountains of
Idaho. The strongest storms today may produce gusty winds and
small hail.

A tightening pressure gradient ahead of the front will bring
increasing winds to south-central Idaho this afternoon. ECMWF
Extreme Forecast Index (EFI) highlights the potential for
significantly stronger winds across this region, especially from
Mountain Home through the Western Magic Valley. Most guidance
supports wind gusts of 4050 mph, prompting a Wind Advisory for
the Western Magic Valley and southern Twin Falls County.

Temperatures will fall sharply behind the front, with southeast
Oregon expected to cool by 1520 degrees compared to Thursdays
highs and southwest Idaho by about 15 degrees.

The upper-level low will move directly over the region on
Saturday, maintaining cool, breezy, and showery conditions.
Gusty winds will persist, especially across the Snake River
Plain from Mountain Home through the Western Magic Valley,
though likely not as strong as today. Afternoon showers are
expected, particularly across the higher terrain, with some of
the stronger cells capable of producing small hail or graupel.
Valley highs will struggle to reach the mid 60s, making Saturday
the coolest day since mid-May.

The low will remain over the region into Sunday morning,
centered near our northern zones before gradually shifting east
into Montana and Wyoming Sunday afternoon. This will keep
showers in the forecast through much of the day. Snow levels
will drop to around 6500 feet MSL across northern zones Sunday
morning, with the potential for snow to fall as low as 6000
feet. However, accumulating snow will be limited to elevations
above 7000 feet, where up to 3 inches is possibleparticularly
across Valley County. Temperatures will warm slightly Sunday
afternoon but remain at least 15 degrees below normal.

LONG TERM...Monday through Friday...A broad and weak troughing
pattern is on tap for Monday and Tuesday. While shortwaves of
varying degree can be seen on individual model guidance,
intensity, timing, and placement is all over the place. PoPs may
become raised as event draws closer with better model
agreement. Temperatures will be 5-10 degrees cooler than normal
Monday and near normal Tuesday. As the troughing moves east of
the area on Wednesday, weak ridging will be quite temporary
going into Thursday. A rapid pattern change back into longwave
troughing, emanating from British Colombia, appears evident
Thursday and Friday. Weak cold frontal passage, nowhere near as
strong as this weekend, will temporarily lull our high temps
from rising. High temps will increase to be 5-10 degrees higher
than normal Wed/Thu/Fri.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory until 9 PM MDT this evening IDZ016-030.
OR...None.

&&

$$

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DISCUSSION...BW
AVIATION.....LC
SHORT TERM...JDS
LONG TERM....CH