Snowpack Telemetry Discrepancy

Yesterday I was up in Commonwealth Basin looking for a location to take some friends snow caving. The data for Alpental says around 100 ", Snoqualmie low 90's. I probed in many areas, open clearings, and it's only about 60 inches. What up? Is it that way everywhere?

I can attest that the HS (Height of snow) displayed on the NWAC Alpental and Snoqualmie Pass sites are correct. We compare the automated HS to a manual measurement at least once a day. Were you probing in flat areas near the creek that might have been subjected to flooding in January?