6 March snowfall

For the month of March, telemetry data indicate net snow accumulation of a paltry 2.7 cm. However, a detailed examination reveals a more interesting situation.

Telemetry shows only 2 snowfall events occurring at the summit during March. Establishing the magnitude of snowfall from telemetry data is sometimes tricky because: 1) telemetry data are only 4-hourly, 2) measurements by the 2 acoustic sensors often differ due spatial variability of accumulation, and 3) acoustic sensors sometimes yield noisy data during snowfall events. However, for the event on 6 March both acoustic sensors recorded 15-20 cm of accumulation, placing this event among the top 3 in the one-day snowfall rankings since 2000. More typically, snowfall events tend to occur over longer time periods.

The weather on 6 March contrasts sharply with that of other days last month. For example, the 4 AM and 8 AM 4-hourly mean values of temperature and humidity were the highest for both times during the month, suggesting cloud cover and moisture advection. Likewise, the temperature at noon was the lowest for any day of the month, humidity was the second highest, and 12 PM minima of both incoming and reflected solar irradiance were recorded.

Through the balance of March, lowering of the glacier surface was nearly linear, suggesting a near-constant, combined rate of ~7mm/day for settling, sublimation and melt.