Summary (tl;dr)

Idaho is experiencing a rare late-June weather event with winter storm warnings in its high elevations, bringing significant snowfall while simultaneously facing wildfire risks in lower areas.

Essential Background

Historically, late June in Idaho marks the acceleration of wildfire risk in dry, lower elevations as fuels dry out and thunderstorms become more frequent. However, the current situation presents a dramatic contrast, as a robust low-pressure system is bringing unseasonably cold temperatures and snow to mountainous regions, a phenomenon that occurs only once every few years.

The Full Story

A strong low-pressure system has moved into Idaho, ushering in a cold front that is generating winter storm warnings for high-elevation areas, primarily above 6,000 to 6,500 feet, across central and eastern parts of the state. Heavy, wet snow accumulations of 4 to 16 inches are expected, with some peaks in Lemhi County and the Anaconda Pintler Mountains potentially receiving up to 24 inches. These warnings are in effect from Saturday evening through Monday morning. Simultaneously, lower elevations in central and southern Idaho, including the Sawtooth Range and the Boise area, are under Red Flag Warnings due to increased wildfire risk from dry thunderstorms and gusty winds. This unusual weather pattern extends beyond Idaho, affecting mountainous regions of Montana and Wyoming as well.

Why It Matters

This rare late-season winter storm in June is a significant concern for travelers and those in backcountry areas. Officials are advising against non-essential travel in high elevations due to hazardous winter driving conditions, including slick roads and potential tree falls caused by heavy, wet snow. Backcountry users also face a heightened risk of hypothermia due to cold and wet conditions. The simultaneous issuance of both winter storm warnings and Red Flag Warnings underscores the volatile and rapidly changing weather patterns across the Western United States, highlighting the contrasting dangers of unseasonal snow and early-season wildfires.

Geographic Location

• Western Lemhi County, Idaho, United States (Winter Storm Warning for heavy snow)
• Central Idaho High Country, Idaho, United States (up to 12 inches of snow)
• Lemhi County peaks, Idaho, United States (up to 12 inches of snow)
• Bitterroot Range (Idaho portion), Idaho, United States (heavy wet snow)
• Northern Clark County, Idaho, United States (Winter Weather Advisory)
• Fremont County, Idaho, United States (Winter Weather Advisory)
• Sawtooth Range, Idaho, United States (Red Flag Warning)
• Northern Sawtooth National Forest, Idaho, United States (Red Flag Warning)
• Boise, Ada County, Idaho, United States (Red Flag Warning)
• Highway 28, Idaho, United States (winter alerts)
• Lemhi Pass, Idaho, United States (winter alerts)
• Lost Trail Pass, Idaho, United States (winter alerts)