0530 wx. at 6350′ in Carnelian Bay: 34.2° / 31.8° dew point / 91% RH / mostly clear skies

Backcountry obs.:

Light snow showers transitioned to rain up to 9000′ before ending late Sat (3/22) and temps since then have remained warm, even at higher elevation areas. Sun (3/23) high temps peaked in the mid 40s up to 9600′ and haven’t fallen below freezing since. Sensors this morning (3/24) show above freezing temps across the central Sierra, even up to 11,000′.

The abrupt transition from cold to warm hasn’t allowed a melt-freeze cycle resulting in wet, sticky snow with plentiful free water in the upper snowpack. Skiing has turned abruptly wet and sloppy with wet snow instabilities widespread in the backcountry. The next few days will get even warmer with highs well into the 50s by midweek, before cooler, unsettled weather returns toward the latter half of the week.

Weather and forecast thoughts:

The next few days will be unseasonably warm with late spring high temps reaching the 50s and lows falling into the mid-upper 30s the next few nights (3/24-26). Sunshine will prevail as well, further baking surface snow on solar aspects. Be on the lookout for sloppy skiing and loose/wet avalanche problems, especially in the late morning and afternoon as the snowpack adjusts to rapid warming, possibly becoming isothermal.

The big heat up does have an expiration date. Looking ahead, models show the spike in temps being short-lived, followed by a generally cool and unsettled pattern returning by the end of the week and continuing into the first week in April.

Rain and snow shower chances enter the picture on Thurs (3/27) and continue off and on through the first half of next weekend. Most of the energy with these systems will head north into the PacNW, but the Sierra will see a return to freezing temps and some modest snow accumulations in the backcountry.

By Sunday (3/30) a more significant wave could bring more significant snows and colder temps, potentially resetting the snowpack. The pattern for the first week of April continues the trend of cold and unsettled as a large, upper level trough centered over the NE Pacific begins moving into CA, bringing chances for more potent storms to keep winter going for a little longer.