Area Forecast Discussion

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Clear, warmer, and drier conditions persist through Sunday. - Breezy afternoon winds from Mountain Home through Western Magic Valley today.

- Significant warming begins Monday with temperatures peaking on Tuesday, followed by a slight cooling trend by mid-week as the ridge flattens.

SHORT TERM /Through Sunday Night/

Issued 316 AM MDT FRI JUN 12 2026 A robust Pacific high pressure ridge aloft will continue to build eastward into the Pacific Northwest today, replacing the cool trough. This setup will ensure entirely clear skies and dry conditions across our county warning area. A weak shortwave passage to the northeast will tighten the pressure gradient this afternoon bringing breezy westerly winds to the Snake River Plain from Mountain Home through the Western Magic Valley. Afternoon maximum temperatures today will climb a few degrees higher than Thursday, reaching right around normal seasonal benchmarks for mid-June. The ridge axis remains to the west of the forecast area through the weekend. Stable and warm conditions will hold level through Sunday. Light diurnal winds can be expected, mainly sticking to typical drainage paths in the mountain valleys and gentle western breezes along the Snake River Plain. Overnight lows will remain comfortable, dropping into the upper 40s to mid 50s in lower valley locations and the 30s across mountain basins.

LONG TERM /Monday through Friday/

Issued 316 AM MDT FRI JUN 12 2026 Ensemble guidance is in excellent agreement regarding a brief synoptic shift scheduled for early next week. The upper-level ridge is forecast to amplify substantially as it centers over the Great Basin and Pacific Northwest Monday and Tuesday. Daily high temperatures will trend upward by several degrees each afternoon with valley highs reaching the mid 90s by Tuesday afternoon. The high pressure ridge begins to flatten out slightly by Wednesday as a weak shortwave skims our northern periphery. This will lower temperatures to about 5 degrees above normal and could introduce a slight increase in breezy afternoon winds, but conditions will stay thoroughly dry with no precipitation expected through the entire long term period.

AVIATION /18Z Friday through Saturday/

Issued 1211 PM MDT FRI JUN 12 2026 VFR and mostly clear. Surface winds: variable up to 10 kt becoming NW 10-20 kt with gusts to 20-35 kt this afternoon through tonight. Winds aloft at 10kft MSL: W 15-25 kt.

KBOI...VFR and clear. Surface winds: WNW 5-10 kt, increasing to 8-15 kt with gusts to 20-25 kt in the afternoon.

Weekend Outlook...VFR and mostly clear, except a few afternoon mountain cumulus. Surface winds: NW-NE 10-20 kt with PM gusts to 20- 30 kt Saturday, then W-NW 5-15 kt with PM gusts around 20 kt Sunday.

BOI WATCHES / WARNINGS / ADVISORIES

ID...None.

OR...None.