Cool air aloft has moved into the area bringing scattered showers this afternoon, with a more active weather pattern expected to continue through Presidents Day as multiple systems approach from the Pacific.
Current Conditions: Afternoon Instability
Enough daytime instability has developed for scattered showers this afternoon over the central Idaho mountains and Treasure Valley. These showers will continue through this evening before tapering off around sunset, leading to clear and cool conditions tonight.
Temperatures will drop significantly overnight, with teens and single-digit readings possible in the west-central Idaho and Boise mountains, while other areas see temperatures in the 20s and 30s. This represents a dramatic change from the recent record-breaking warmth.
Tuesday Into Wednesday: Next System Approaches
Tuesday will generally be dry during the day with increasing clouds in the afternoon as the next system off the California coast approaches. Showers will develop during the evening hours, continuing into Wednesday evening before tapering off during the night.
Snow levels with this system will be around 3,000 to 4,500 feet, bringing snow accumulations of 1 to 2 inches in valleys above 4,500 feet and 2 to 4 inches over mountain peaks.
Mountain Snow Conditions for Ski Areas
Brundage mountain has recieved over 15" of snow from this past storm with Tamarack Resort over 11" and Bogus Basin more than 4"! The approaching systems will provide beneficial snowfall for ski areas, particularly those at higher elevations. With snow levels at 3,000 to 4,500 feet, most ski areas will receive fresh snow accumulations ranging from 1 to 4 inches depending on elevation.
This represents a welcome change from the recent dry pattern and will help improve base conditions that were impacted by the extended warm, dry period.
Extended Outlook: Active Pattern Continues
A shortwave trough will continue pushing east Thursday, allowing for lingering showers near the Nevada border and higher terrain in southwest Idaho. Weak ridging will take over Friday, bringing elevated temperatures and dry conditions for a brief respite.
The active pattern will continue through the weekend as a long-wave trough extends down from western Canada. This will keep the region oriented in southwest flow with a significant moisture tap from the Pacific Ocean, maintaining high precipitation chances of 40 to 70% through Monday.
Presidents Day Weekend: Unsettled Weather
The upper-level trough off the west coast will deepen into a closed low by early next week. Most weather models and ensemble solutions favor continued southwest flow aloft, which would keep snow levels elevated above valley floors and continue the trend of above-normal temperatures.
However, a few outlier solutions show this low moving onshore more quickly, which would bring cooler air into the region. This storm track could bring snow down to valley floors, although confidence in this potential remains low.
Long-Range Pattern: Continued Activity
The Climate Prediction Center's 8 to 14-day outlook favors this unsettled pattern continuing through the middle of the month, with a 30 to 40% chance of above-normal precipitation and a 40 to 50% chance of below-normal temperatures over the region.
This represents a significant shift from the persistent ridge pattern that dominated much of the winter, bringing more typical February weather with regular precipitation chances and more variable temperatures.
Temperature Transition
The dramatic shift from record-breaking warmth to more seasonal temperatures illustrates the significant pattern change now underway. While temperatures will remain generally above normal due to the southwest flow pattern, they will be much closer to typical February values than the exceptional warmth experienced recently.
Daily Forecast:
Tonight: Increasing clouds, with a low around 31. East wind around 5 mph becoming calm after midnight.
Tuesday: Mostly cloudy, with a high near 51. Southeast wind 5 to 10 mph.
Tuesday Night: A 30% chance of showers after 11 p.m. Mostly cloudy, with a low around 35. East wind 5 to 9 mph becoming light after midnight.
Wednesday: A 30% chance of showers, mainly before 11 a.m. Cloudy, with a high near 49. Calm wind becoming west northwest around 5 mph in the afternoon.
Wednesday Night: Mostly cloudy, with a low around 34.
Thursday: Mostly sunny, with a high near 50.
Thursday Night: Partly cloudy, with a low around 30.
Friday: Mostly sunny, with a high near 51.
Friday Night: Mostly cloudy, with a low around 34.
Saturday: A 30% chance of rain. Cloudy, with a high near 50.
Saturday Night: A 50% chance of rain. Cloudy, with a low around 33.
Sunday: A 40% chance of rain. Cloudy, with a high near 46.
Sunday Night: A chance of rain and snow. Mostly cloudy, with a low around 30. Chance of precipitation is 30%.
Monday: A chance of rain and snow. Mostly cloudy, with a high near 46.
