textproduct: Boise

KEY MESSAGES

- Weak system with light rain showers exiting east this evening, then clearing and cooler, except patchy valley fog forming overnight and early Tuesday.

- Mostly sunny and spring-like Tuesday.

- Strong cold front late Wednesday. Snow levels lowering to 3500-4500ft with 3 to 6 inches of snow above 6000ft.

- Windy Thursday, especially in south-central Idaho Thursday afternoon.

- Pattern change to colder and showery likely early next week.

AVIATION /00Z Tuesday through Wednesday/

Issued 513 PM MST MON MAR 2 2026

Convection will continue to diminish this evening. Areas of MVFR to LIFR developing in low stratus and fog late tonight, from KBNO-KONO-KJER and southward. Pockets of stratus/fog also possible for KMYL and Weiser Basin. Surface winds: W-NW 5-15 kt, becoming light and variable overnight. Winds aloft at 10kft MSL: N-NE 5-15 kt, becoming variable 5-10 kt after Tue/12Z.

KBOI...VFR this evening. Scattered convection will decrease after sunset. MVFR-IFR mist/fog will begin to develop after Tue/06Z. Then, LIFR chances increase to 50% after Tue/09Z. Current TAF includes IFR conditions, but may be updated to include LIFR once confidence grows. Surface winds: NW 5-10 kt, becoming light and variable overnight.

SHORT TERM /Through Wednesday Night/

Issued 212 PM MST MON MAR 2 2026

Current system has proved even weaker than models predicted with less pcpn and only light winds. At 2 PM MST the wettest area was near the ID/UT border, well east of the supporting upper low in southeast OR. The upper low will move eastward across our southern zones this evening with only scattered light rain showers. We note that a couple lightning strikes have already occurred in southwest Idaho so we are continuing isolated thunderstorms in the southwest Highlands and near Glenns Ferry until early evening. Today's light rain will leave the lower levels moist, favorable for patchy valley fog overnight and early Tuesday morning when temps are coolest. Later Tuesday an upper ridge will come inland from the Pacific and raise temps to the lower 60s in the southern valleys and upper 40s through 50s elsewhere, normal for mid-April. The next trough will approach from the Gulf of Alaska on Wednesday, bringing rain showers and a cold front late Wednesday and Wednesday night. That system will be stronger, colder, and wetter that the current one. Total pcpn through Wednesday night should be .25 to .50 inch, with snow level staying above 6000 feet until near the end of pcpn.

LONG TERM /Thursday through Monday/

Issued 212 PM MST MON MAR 2 2026

Following the cold front Wednesday evening, Thursday will see gusty winds, colder temperatures, and a chance of showers in high elevation areas. Gusts on Thursday will reach 30 to 45 mph in the Snake Plain and highlands. Temps cool down to a few degrees below normal for this time of year. High pressure builds in the north Pacific, leading to a warming trend through the weekend. During this same time, northwest flow aloft persists leading to a 40% chance of precipitation each day in the mountains. Temperatures by Sunday reach 5-10 degrees above normal. Friday, wind gusts 25 to 35 mph are possible in the same areas as Thursday, but over the weekend winds are reduced to 5 to 15 mph. Minimal mountain snow or valley rain accumulation is expected over the duration of this milder weather.

Sunday is currently forecast to be the warmest day in the long \term,although precipitation chances and cloud cover begin to increase as a strong pressure gradient develops north of the Pacific High. This pressure gradient will support strong moisture flux through the Pacific and Interior Northwest, including our area. Currently, precipitation is most likely in northern areas, but run-to-run trends have carried the precipitation farther south and model solutions past the long term forecast continue to carry it south. A colder and wetter start to next week seems likely.

BOI WATCHES/WARNINGS/ADVISORIES

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