Confidence is highest from Friday morning through Sunday evening, when summit weather on Mauna Kea is at its most hazardous. Dense snow, icing, and severe southwest wind should stack up to around 15 inches at the summit before conditions back off early next week. After that, snowfall becomes much less certain, with a quieter Monday and Tuesday followed by another chance for intermittent summit snow from midweek into next weekend.
Friday through Sunday evening brings the main storm cycle, and guidance is clustered best in that period on timing and wind while snowfall intensity and snow levels wobble more. Expect repeated snow and icing bursts at the summit as a kona storm drives strong south to southwest flow across the Big Island. Most guidance keeps temperatures between 31 and 35 °F with snow levels roughly 13,300 to 14,200 feet when precipitation is active, so Mauna Kea spends part of the event close to the rain-snow line. Snow quality will be poor by ski standards, with SLRs mostly 3 to 7, meaning very bad to dense snow rather than anything fluffy. Around 15 inches is a solid working expectation through Sunday evening, and summit gusts in the 60 to 80 mph range should remain the bigger story for anyone watching access or surface conditions. The summit access road remains a major limitation.
Late Sunday night through Tuesday looks like the clearest downshift in the forecast. Confidence is still fairly good on the easing trend itself because guidance converges on weaker wind and much less organized precipitation once the weekend storm lifts away. Gusts should fall back into the 20 to 40 mph range by Monday and Tuesday, with temperatures still hovering near freezing to the mid 30s. Monday appears mostly dry, and Tuesday only hints at a stray summit shower. Even if a brief shower clips the summit, snow levels stay close enough to summit height that any fresh accumulation would still be wet, dense, and limited.
From Tuesday night into next weekend, the pattern turns unsettled again but confidence drops notably after Tuesday. This is the point where guidance diverges clearly on timing, intensity, snow levels, and wind impacts. The wetter camp keeps intermittent summit snow going for days, while the drier side breaks it into shorter, weaker waves with long lulls in between. The common signal is for at least some additional precipitation around the Big Island summits, snow levels often near 12,800 to 13,500 feet when it is snowing, and winds that stay well below the weekend’s damaging levels. The conservative read is for several more inches of dense snow from midweek into next weekend, with roughly a foot possible if the wetter scenario verifies. Ratios only improve modestly toward 7 to 9 later in the period, so even the extended setup still favors heavy, wind-affected snow.
Forecast Totals (Fri Mar 13 – Sun Mar 15)
- Mauna Kea – 13″-17″