textproduct: Boise

LONG TERM...Saturday through Wednesday

Stable conditions (thanks to this ridge staying well past it's welcome) will continue through at least the middle of next week. Expect more of the same under this pattern...warm mid slopes and ridgetops with cold valley temperatures and stagnant conditions with valley fog through next Tuesday. By the middle of next week, models still hint at an incoming shortwave trough bringing precipitation and colder air with breezy winds, which would hopefully be enough to scour out this inversion. Uncertainty remains in the strength of this trough, but agreement is high in the ridge breaking down by the end of next week.

AVIATION

VFR in the Magic Valley and near KBNO, elsewhere MVFR-LIFR conditions and mountain obscuration in areas of fog/low stratus through the early afternoon, mainly in sheltered mountain-valleys and lower basins. Surface winds: Variable up to 8 kt. Winds aloft at 10kft MSL: NW 5-20 kt.

KBOI...Mainly VFR by the afternoon. Fog in the vicinity this morning with brief MVFR conditions in mist over the terminal. Low confidence (<20% chance) in IFR-LIFR conditions over the terminal from fog between 12Z-16Z. Surface winds: light and variable.

AIR STAGNATION

High pressure will remain in the area through next week, bringing a persistent surface inversion. This stable air will trap pollutants and valley fog in the area thanks to low mixing heights less than 1000 feet and transport winds generally less than 10 mph. This stable layer is anticipated to remain in place until the middle of next week with no significant pattern shift until next Wednesday-Thursday.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Air Stagnation Advisory until 5 AM MST Monday IDZ011>014-016-028-033. Dense Fog Advisory until noon MST today IDZ012. OR...Air Stagnation Advisory until 5 AM MST /4 AM PST/ Monday ORZ061>064. Dense Fog Advisory until noon MST /11 AM PST/ today ORZ064.