188
FXUS65 KBOI 282039
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
239 PM MDT Tue May 28 2024

.SHORT TERM...Tonight through Thursday night...Active weather
ramping up this afternoon and evening as a cold front approaches
the area. Warm southwest flow remains over the area, with
temperatures near 90F at Mountain Home this afternoon. Isolated
showers and thunderstorms have formed across southwest ID this
afternoon, keeping temperatures slightly cooler for portions of
southwest ID, but partial clearing this afternoon should help
temperatures rebound, and enhance instability for showers and
storms. Showers and storms will increase in coverage late this
afternoon into the evening hours. Morning sounding at BOI had a
nice inverted V sounding, with DCAPE of 1100 J/kg. DCAPE values
of 1200-1500 J/kg this afternoon will promote environment
capable of producing gusty winds up to 60 mph with any showers
or storms that form, along with areas of blowing dust. Forecast
storm motion is also 10-20kts, so heavy rain with ponding of
water possible, especially in the west central ID mountains.
Cold front moves through this evening bringing northwest winds
behind the front. Showers linger over the central ID mountains
into Wednesday morning, with temperatures cooling around 15-20
degrees compared to today. Breezy northwest winds continue
Wednesday and Thursday, especially during the afternoon.

.LONG TERM...Friday through Tuesday...Models continue to be in
relatively good agreement on the large-scale pattern through
Tuesday. The most notable differences can be found in the
progression of two troughs embedded in an otherwise zonal
westerly flow. The first trough passes through on Saturday, but
only amplifies after a majority of the moisture has already
moved east. Our area will see mostly cloudy skies and a 10-20%
chance of showers over the West Central Mountains Saturday
afternoon. The second trough passes on Monday/Tuesday and has a
decent gradient and moisture flow, but mostly to the north of
our area. This will allow a slightly higher 20-30% chance of
precipitation, but only over our northern zones including Baker
and Valley counties. The EFI isn`t flagging any majorly
anomalous weather over the long term, which reflects the overall
pattern well. Temps will be about normal on Friday and
Sunday/Monday after the first trough, but 5 degrees above normal
otherwise. Clusters after the long term period are confident
that a strong high will build, bringing very warm temperatures.

&&

.AVIATION...Scattered showers and thunderstorms this
afternoon/evening are capable of producing heavy rain, small
hail, and gusty outflow winds up to 50 kt. Conditions mainly
VFR with reductions to MVFR/IFR in heavier rain showers. A cold
front passage tonight into Wednesday morning will support
lingering showers over the W Central Mtns. The front will keep
winds gusty overnight through Wednesday. Surface winds: SW-W
5-15 kt, except gusty/erratic winds near thunderstorms.
Overnight W-NW 10-15 kt with gusts to 30 kt. 10k ft MSL winds:
SW 15-25 kt.

KBOI...20% chance of thunderstorms in the vicinity between
Tue/21z and Wed/00z, increasing to 50% until Wed/04z.
Development of storms will be mostly sporadic or terrain driven,
but may become more organized if a strong outflow develops.
While 50 kt outflow gusts are a possibility (5% chance), they
are most likely to be between 30- 40 kt. Winds SE around 12 kt
becoming NW 12 kt after 20z, except variable gusty winds near
thunderstorms. Overnight winds stay NW at 12-15 kt with gusts to
20-25 kt.

&&

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

&&

$$

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SHORT TERM...KA
LONG TERM....JM
AVIATION.....JM