textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Continued warm and dry conditions Friday.

- Windy conditions on Friday ahead of a cold front.

- Valley rain and mountain snow along a cold front Friday night into Saturday morning.

- Cooler and unsettled pattern next week with snow levels lowering to valley floors by the end of the week.

SHORT TERM /Through Sunday Night/

Issued 320 AM MST FRI NOV 13 2026 Strong southwest flow will continue considerably warmer than normal temperatures today, before a strong upper-level Pacific trough moves inland later today, driving a cold front eastward across the area. Windy conditions, with gusts 20-40 mph, will be expected this afternoon ahead of and along the frontal passage, with exposed areas in southeast OR and far southwest ID near NV border seeing gusts 35- 50 mph. The cold front will bring widespread precipitation throughout the area, with valleys seeing rain and higher terrain areas seeing snow showers tonight through Saturday morning. Snow levels will mostly linger in the 6000-8000 ft MSL range today, before gradually dropping into the 5000-7000 ft MSL range by early Saturday behind the frontal passage. As such, snow accumulations will continue to be limited to high mountain peaks. Precipitation will gradually taper off from west to east Saturday morning as the front pushes out of our area. Winds are expected to lower down to 5 to 15 mph for most areas by Saturday morning. Cooler temperatures will be expected Saturday behind the frontal passage.

A brief period of mostly dry conditions and temperatures 5 to 10 degrees above normal will be in store on Sunday, as our area stays under a dry but strong southwesterly flow ahead of another incoming Pacific trough. The dry break will be short lived, as precipitation chances return across eastern OR Sunday afternoon and evening, before spreading eastward into southwest ID late Sunday night. With snow levels mostly hanging in the 6000-7000 ft MSL range Sunday, light mountain snow showers and valley rain will be expected again with this second precipitation round.

LONG TERM /Monday through Friday/

Issued 320 AM MST FRI NOV 13 2026 Come Monday, the second Pacific upper trough digging into the northwest region will bring another cold front across the area. The system will bring a 50-70% chance of light precipitation Monday through Tuesday. Snow levels will drop down to 4000-6000 ft MSL by Tuesday, lowest across eastern Oregon. A brief dry period is expected early Wednesday morning before the next system moves in. This deep upper-level low will move overhead from mid to late week, bringing colder air than previous systems. Uncertainty remains over this system's exact pattern as it either digs across our area as an upper trough or dive down into the California coast as a closed upper low. For now, precipitation chances remain at 40-70% late Wednesday through Thursday, with temperatures favored to cool a few more degrees and snow levels around 3000-4500 feet. Come early Friday, our area is projected to be under a strong northerly flow as the upper low digs into the Desert Southwest region. Light remnant mountain snow showers are possible Friday, as snow levels are projected to drop down to valley floor levels by Friday.

AVIATION /12Z Friday through Saturday/

Issued 454 AM MST FRI NOV 13 2026 VFR and high clouds through most of today. A cold front will bring rain and high mountain snow in the evening through Saturday morning. Low VFR-MVFR in rain, IFR-LIFR and mountain obscuration in snow. Snow level: 6500-7500 ft MSL Fri night. Surface winds: E-S 5-15 kt overnight. Then, SE-SW 10-25 kt with gusts 25-45 kt from approaching cold front, strongest in south- central Oregon. Mountain wave activity possible Friday, particularly near/south of KTWF and the Owyhee Mountains. Winds aloft at 10kft MSL: southerly 25-40 kt. Areas of LLWS in Snake Plain from KONO to KTWF/KJER through early morning hours.

KBOI...VFR. Rain showers arrive this evening after Sat/00Z ahead of cold front. Rain intensity will increase between Sat/03Z-06Z, bringing a 45% chance of MVFR conditions during this window. Surface winds: SE 8-15 kt, increasing to SE 15-20 kt with gusts to 25-35 kt late this morning through evening. Winds will briefly shift to SW-W 5-15 kt with gusts 15-25 kt between Sat/03Z-06Z. Becoming variable up to 10 kt thereafter.

Weekend Outlook...Lingering MVFR-LIFR mountain showers over central ID Saturday morning, with isolated showers elsewhere. Snow levels: 6000-6500 ft MSL Sat/AM. Becoming drier with decreasing low and mid clouds late Saturday through early Sunday, then rain increasing across SE Oregon Sunday aftn/eve. Surface winds: On Saturday, SW-NW 5-15 kt with gusts 15-30 kt, strongest in the Magic Valley. On Sunday, E-S 5-15 kt with gusts 20-30 kt in portions of the Snake Plain and SE Oregon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.