Area Forecast Discussion
Issued by NWS Boise, ID

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FXUS65 KBOI 210303

Area Forecast Discussion
National Weather Service Boise ID
903 PM MDT Fri Apr 20 2018

.DISCUSSION...Clear skies associated with an upper ridge will
shift east on Saturday as an upper trough passes by to our north.
The trough will bring some clouds into the area, mainly across the
north. The trough will be accompanied by a weak dry cold front,
which will bring a return to breezy northwest winds in the
afternoon. Temperatures will be slightly cooler across the north
due to the front. No updates.


.AVIATION...VFR under mostly clear skies. Surface winds:
Northwest 5-15kt this evening becoming light after sunset,
becoming NW 10-20kt with higher gusts on Saturday afternoon. Winds
aloft near 10 kft MSL: westerly 15-25kt.

Sunday outlook...VFR. Northwest surface winds 10-20kt during
Sunday afternoon, light winds overnight. Isolated showers over the
higher terrain Sunday afternoon/evening.


SHORT TERM...Tonight through Sunday...Gusty winds remain across
the Treasure Valley and into the Western Magic Valley this
afternoon. Otherwise, high pressure is bringing warm and dry
conditions, which will last into Sunday. A developing trough will
move through the area beginning Sunday afternoon. Models do show
some instability with this shower development, so opted to include
some thunderstorm wording for impacted areas. Temperatures will
remain warm, generally around 5 degrees above normal.

LONG TERM...Sunday night through Wednesday...Lingering showers are
expected Sunday night, mainly across the higher terrain, as a quick
moving shortwave trough moves east. Upon its exit, an upper level
ridge will build quickly in its stead, for sunny and warm
conditions. Maximum temperatures will increase to about 10-15
degrees above normal across the region by Wednesday.

Wednesday evening through Saturday morning...Sunny skies and light
winds aloft as a ridge is temporarily in control until Friday
morning. Models (the most current runs) agree that the ridge will
gradually exit eastward as the next low approaches from the
southwest and treks northeastward across the CWA (the GFS is more
progressive). Expect widespread cloudiness and precipitation to
spread across the area starting late Friday afternoon and continue
on into the overnight, sustained by an upper level disturbance.
A slight chance of thunderstorms returns Friday afternoon
starting in southeastern oregon and migrating eastward. Temperatures
expected to be around 10 degrees above normal will be an
additional contributing factor towards the intensity of the late
afternoon convection.





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