textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Elevated fire weather in hot and windy conditions Thursday in the high desert. - Cold front passage Friday with strong 25 to 40 mph wind gusts, sharply cooling temperatures, and a 20% of precipitation to the north and west.

- Cooler conditions this weekend through early next week, with a slight chance of showers Sunday/Monday.

SHORT TERM /Through Saturday Night/

Issued 242 AM MDT THU SEP 24 2026 Today will be mostly sunny with hot afternoon temperatures. Maximum temperatures today will reach the low 90s in lower elevations, mid 80s in much of SE Oregon, and low 80s in mountain valleys. Ahead of a cold front, winds increase this afternoon. Wind gusts in SE Oregon and parts of the Snake Plain rise to 20-30 mph. Hot temperatures and dry conditions alongside the breezy gusts will support elevated fire weather this afternoon. Winds remain gusty through the night, strengthening along ridgetops as upper-level wind increases ahead of the approaching trough and cold front. The cold front moves through SE Oregon Friday morning, and through SW Idaho in the afternoon. The strongest frontal winds will last roughly from 9AM/8AM MDT/PDT through 9PM/8PM, with wind gusts up to 35-40 mph possible across the region. A thin band of showers follows the front, but remains very limited to the northern portions of our area near the Blue Mountains in Oregon and northern Adams, Washington, and Valley counties in Idaho. Southwesterly surface winds behind the front allow wind gusts up to 35 mph to continue in the Snake Plain Friday night through Saturday morning. Temperatures cool from about 15 degrees above normal Thursday, down to about 5-10 degrees below normal on Saturday. Oregon sees most of that cooling on Friday given the earlier frontal passage, while most of Idaho cools about 10 degrees Friday and 10 degrees Saturday.

LONG TERM /Sunday through Thursday/

Issued 242 AM MDT THU SEP 24 2026 Slightly below normal to near normal temperatures persist t. Sunday will warm a few degrees compared to Saturday, as our area gets a brief period of southwesterly return flow ahead of the next system. Consensus is still good on another cold front, weaker than that of Friday, crossing over our area come late Sunday. This front will bring west/northwest winds and keep the cool conditions in place. This trough should keep the tropical moisture from activity in the eastern Pacific south and east of our area. Though, just enough of that tropical moisture reaches the area to support a 15-30% chance of showers primarily across higher terrain of southwest Idaho. Shortwave ridging behind this trough will for dry conditions and a warming trend into mid-week next week.

AVIATION /12Z Thursday through Friday/

Issued 515 AM MDT THU SEP 24 2026 VFR. LLWS in the Treasure Valley this morning with a 25kt wind speed difference, direction at 2kft AGL is still SE. Surface winds: SE 5-15 kt this morning, becoming S-SE 10-15 kt with gusts 20-25 kt this afternoon. Winds aloft at 10kft MSL: SW 15-25 kt.

KBOI...VFR. LLWS in the area near 25 kts 0-2 km through Thu/15z. Surface winds: SE 5-15 kt throughout the period, with gusts up to 22 kt developing later this morning.

Weekend Outlook...Cold front passage Friday with gusty winds across the area. Rain band along the front passes north KBNO/KBKE/KMYL, but light rain and virga is possible Friday morning and afternoon. Saturday will be partly cloudy and Sunday mostly cloudy as another system and scattered showers move through the area. Surface winds: W-SW 15-20 kt with gusts to 30 kt Friday, NW 5-15 kt Saturday, and NW 10-20 kt Sunday.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.