424 
FXUS65 KBOI 230848
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
248 AM MDT Thu Aug 23 2018

.SHORT TERM...Today through Friday...As the persistent upper level
low that has dominated our weather for the past few days finally 
moves away to the east, it will be replaced by brief upper level 
ridging today. This will bring dry conditions but little if any 
relief from air quality issues. The next trough moves onshore 
Thursday night, and upper level flow will be out of the 
southwest. This will likely bring more smoke into the region. the
trough will push a cold front through early Friday. As the 
initial trough axis passes through on Friday, upper flow will 
become westerly, and models indicate it could bring a rapid 
decrease in smoke during the day Friday. Smoke should decrease 
from northwest to southeast during the day and into the evening.

.LONG TERM...Friday night through Wednesday...An upper level 
trough is still on track to impact the coming weekend. Cooler 
temperatures and increased chances of precipitation will be the 
major impacts. Model agreement stays relatively the same with some
minor differences in timing and placement. The ECMWF is much less
excited about precipitation chances than yesterdays run and 
lingers the trough over the area a bit longer. The GFS still wants
to pull precipitation all the way down through our CWA into 
northern Nevada and pushes the trough axis out by late Tuesday. 
With that being said, did adjust PoP's slightly farther south by 
blending in some of the GFS's solution in with the ECMWF. 
Temperatures are still forecast to drop below normal for the 
period with Monday and Tuesday staying in the mid-upper 70's for 
valley locations. After Wednesday, the forecast stays dry, but 
models become out of phase leaving little confidence.

&&

.AVIATION...Reduced visibility with areas of MVFR and local IFR 
due to wildfire smoke. Surface winds, west-northwest 5-10kts. 
Winds aloft to 10k feet MSL, westerly 20-25kts.

&&

.AIR STAGNATION...
Air Quality Advisories are still in effect for most of the area. 
Please read AQABOI for more details. No significant decrease of
smoke is indicated by models today, but there is some hope of 
clearing from the northwest during the day Friday. This would be
the result of air from over the Pacific Ocean being drawn into 
the area. It will not eliminate all the smoke, but should bring a 
noticeable improvement Friday and certainly by Friday night.

&&

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

&&

$$

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SHORT TERM...SP
LONG TERM....JC
AVIATION.....JC