textproduct: Boise

LONG TERM...Sunday through Thursday

Upper-level ridging continues into early next week, with the ridge axis shifting west enough to cause more northerly flow aloft. Clusters and ensembles keep ridging in place at least through Tuesday afternoon, after which the ridge will weaken but still persist. The pattern change comes in Wednesday into Thursday, when an upper-level shortwave trough moves over the region. Precipitation amounts and trough intensity vary substantially across models, however, the solutions agree on providing *some* relief against this inversion. Snow chances also return to the higher elevations with this system around 30% on Thursday.

AVIATION

Widespread IFR-LIFR in the Snake Plain, with fog chances existing for all sites. Localized improvement of conditions possible before sunset, with rapidly worsening of conditions back to LIFR around sunset. Confidence in timing of clearing and coverage will remain low. Otherwise VFR conditions under clear skies. Surface winds: Variable up to 10 kt. Winds aloft at 10kft MSL: N 15-30 kt.

KBOI...IFR-VLIFR conditions to persist. Minor improvement to IFR conditions before sunset, with LIFR conditions returning overnight. Earliest improvement to MVFR-VFR conditions looks to be Friday afternoon, however chances are still 30% for IFR conditions during that period. Surface winds: light and variable.

Weekend Outlook...Valley fog and stratus continues over the weekend with VFR above the inversion. Light surface winds.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Air Stagnation Advisory until 5 AM MST Monday IDZ011>014-016-028-033. Dense Fog Advisory until 1 PM MST Friday IDZ012-014-016-033. OR...Air Stagnation Advisory until 5 AM MST /4 AM PST/ Monday ORZ061>064. Dense Fog Advisory until 1 PM MST /noon PST/ Friday ORZ064.