textproduct: Boise

LONG TERM...Friday through Tuesday

A ridge builds in from the west as a closed low moves over southern California, this will allow for a mostly zonal flow to keep temps moderated through Monday at about 5-10 degrees above normal. During this period, mixing heights have a daily maximum of around 2-3 kft MSL, lowest on Friday and Saturday. This could allow a weak inversion to develop, while supporting morning fog. A broad trough moves in from Alaska Monday evening, bringing a 20-40% chance of precipitation to the north and cooling temperatures down to normal on Tuesday. Models seem less confident in the precipitation than previous runs, but the trough is consistent so a cooldown is likely.

AVIATION

LIFR-IFR in fog hanging on for longer than expected. Some improvement is still expected this afternoon as ceilings and visibilities have continued to slowly climb. With a similar environment tonight/tomorrow morning fog/stratus is likely again, with widespread reductions back to LIFR-IFR. Surface winds: light and variable. Winds aloft at 10kft MSL: S 5-15kt.

KBOI...Low clouds bringing IFR-MVFR conditions are still expected to clear this afternoon as ceilings slowly climb. A period of MVFR-VFR this afternoon won't last too long before fog/stratus is favored to form again tonight through the morning. Surface winds: light and variable.

AIR STAGNATION

Forecasts keep conditions borderline in regards to a prolonged stagnant air mass setting up. Mixing heights of 1800-2500 feet AGL and light winds are expected through Friday. The weekend will see a low-amplitude ridge which will keep dry and stable conditions in place. Expect fog and stratus to be in play through at least Wednesday with a system on Thursday possibly breaking it up, especially in the Snake Plain which gets into easterly winds.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None. OR...None.