338
FXUS65 KBOI 012045
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
245 PM MDT Wed May 1 2024

.SHORT TERM...Tonight through Friday night...A weak shortwave
is continuing to move southeastward across central Idaho,
sustaining scattered showers primarily over the West Central and
Boise Mountains. Additionally, weak showers have cropped up in
Baker County and the Lower Treasure Valley. Snow levels are
hovering around 3500 feet, leading to predominantly snowy
conditions in mountainous regions, while lower valleys may
experience a mix of rain and snow. However, snow accumulation is
expected to be minimal, with most areas receiving between 0.1
to 0.3. In the Treasure Valley, showers will likely yield
little to no rainfall until early evening. There`s a slight
possibility of lightning strikes, particularly in the central
Idaho mountains. Shower activity will wane as the evening
progresses and the low pressure system shifts over Utah.

In the Western Magic Valley, gusts of up to 40 MPH have been
observed, anticipated to persist through the evening before
tapering off post-sunset.

Overnight, there will be a brief respite before another low-
pressure system traverses the forecast area on Thursday. The
brunt of precipitation is forecasted to remain south and west of
the Western Snake River Plain, initially affecting Southeast
Oregon and later moving into the Southwest Highlands on Thursday
afternoon. This region has a 30% chance of receiving over 0.10
of rainfall. Furthermore, scattered showers and isolated
thunderstorms are expected to develop over the central Idaho
Mountains Thursday afternoon due to increased instability and
dynamics associated with the approaching low center.

Friday will bring warm and dry conditions as a weak ridge
builds over the area ahead of the next upper-level low.
Temperatures are forecasted to rise above normal with heightened
southerly flow aloft.

.LONG TERM...Saturday through Wednesday...A deep upper low will
move into the Pacific Northwest on Saturday. Ahead of the low,
southwest flow will bring mild temperatures to much of the area,
with lower valley highs in the upper 60s to mid 70s. However,
southeast Oregon will be closer to the low center and
significantly cooler. Warm temperatures will be aided by gusty
southeasterly winds, with gusts up to 40 mph in the Snake Basin.
Precipitation will move into southeast Oregon by Saturday
morning, then push into southwest Idaho Saturday afternoon and
evening. A band of moderate to heavy precipitation may develop
along a cold front as the low moves east. Snow levels will be
high initially, then fall to 3500-6000 feet as the low center
moves overhead. The lowest snow levels will develop where the
low center and core of cold air aloft moves across. The coldest
air looks to arrive mainly behind the cold front on Sunday, with
significant snow accumulations limited to the mountains.
However, light snow accumulations are possible above 3500 feet.

Sunday will be cool and showery as the low tracks across our area.
Highs will be 10-15 degrees below normal, and gusty northwest winds
will make it feel even colder. The pattern will remain active into
early next week as a large upper level trough develops across the
northern US, with shortwave troughs rotating through our area under
northwesterly flow aloft. This will bring periodic chances of rain
and snow with fluctuating snow levels, but at times dropping as low
as 3000-3500 feet. Each day will bring a 20-60% chance of
precipitation, with the highest chances Monday and Wednesday.
Precipitation amounts with each system look to be light.
Temperatures will remain 5-10 degrees below normal. Each passing
system will bring periods of gusty winds, particularly in the Magic
Valley.

&&

.AVIATION...Mainly VFR. Scattered rain/snow showers and
isolated thunderstorms, mainly north of a KBKE-KBOI-KSUN line, will
taper off this evening. Snow showers obscuring mountains and
producing brief MVFR/IFR conditions. Snow levels 3500-4500 ft MSL.
Additional rain and snow will move into SE Oregon overnight, with
isolated to scattered rain and snow showers moving into SW Idaho on
Thursday. Surface winds: W-NW 5-15 kt, with gusts to 30 kt through
Thurs/03z near KTWF/KJER/KGNG, becoming variable less than 10 kt
overnight. NW winds 5-15 kt redeveloping by Thursday afternoon.
Winds aloft at 10kft MSL: SW-NW 15-25 kt.

KBOI...VFR with scattered to broken clouds 4000-9000 ft AGL.
Isolated showers will taper off by early evening. Snow levels around
4000 ft. A 20% chance of showers will redevelop on Thursday. Surface
winds generally NW 5-15 kt with gusts to around 20 kt through 03Z,
becoming SE 5-10 kt overnight, then back to NW by 21Z Thursday.

&&

.CLIMATE...April 2024 brought unusual weather to Boise,
featuring significant precipitation and snowfall. From January
1st through April 30th, 2024, Boise amassed a total
precipitation of 8.87 inches, marking it as the 6th wettest year
on record for that period. A total of 2.37 inches of rain made
April the 9th wettest on record. On April 4th, Boise set a new
daily rainfall record with 1.09 inches, followed by another
record-breaking day on April 5th, with 1.05 inches of rainfall.
This occurrence is noteworthy as it`s only the second time in
Boise`s history that the city experienced 1 inch or more of
rainfall on consecutive days. Additionally, April 5th saw Boise
hit a high temperature of 39 degrees Fahrenheit, the coldest
April high since 1936. On the same day, 2.1 inches of snowfall
shattered the daily snowfall record, marking the first instance
of such significant April snowfall since 1969. This also made
April 2024 tied for the 12th snowiest on Record.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

$$

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SHORT TERM...JDS
LONG TERM....ST
AVIATION.....ST
CLIMATE......JDS