Mineral King to Mt. Whitney

The weather is the whole story this trip. An active winter pattern is hammering the southern Sierra right now — 90% precip chance today with light snow likely at your trailhead elevation, dropping to 20°F tonight with continued snow showers and WNW winds at 10-15 mph. Sunday doesn't clear: still 31°F high, 59% precip chance, 15 mph WNW winds. This isn't a passing afternoon storm. You're looking at two full days of accumulating snow on a route that already has 37 inches of depth on the ground. Navigation above treeline will be genuinely difficult, and wind-driven snow at those temps with that wind speed puts you in the 0°F to -10°F wind chill range on exposed ridgelines. Monday improves — only 22% precip, mostly clear Monday night — but you'll spend Saturday and Sunday digging in.

The route from Mineral King to Whitney crosses serious high country, and fresh snow on top of an already deep late-season snowpack means postholing, obscured trail markers, and potentially unstable cornices on any ridgeline features. Avalanche data is unavailable for this zone, so there's no forecast to lean on — but new snow loading on steep aspects in the Great Western Divide and upper Kern drainage is a real consideration with this storm cycle. Treat steep avalanche-path runouts with the same respect you would in winter. If you're on route during or immediately after Sunday's snowfall, stay off steep lee aspects above 9,000 feet until the new snow settles.

Stream crossings are not a problem. All five gauges in the broader region are running 87-118% of median with stable to slightly rising trends — well below the threshold where crossings get technical. The Kern River tributaries and crossings on the high route may tick up slightly as snowmelt resumes Monday with improving temperatures, but you won't hit anything dangerous at current levels. No fires within 50 miles, air quality is clean.

If you go today, get your miles in fast before the storm fully locks in this afternoon. Camp low Saturday night — below 10,000 feet if possible — and hunker down. Sunday's your weather day; don't try to push over major passes on Sunday with 15 mph winds and active snowfall. Use the 13.5 hours of daylight on Monday aggressively once conditions clear. Plan your high-elevation crossings for Monday morning when the new snow has had a night to settle and before afternoon melt softens the surface. Bring an extra layer you don't plan to use — the 17°F overnight Sunday is the coldest point and you'll feel it.