Quick question for those calibrating large-basin inflows… I’m updating PMF for a 1950s embankment dam and need reliable, basin-scale snowpack and soil moisture inputs to tighten spillway overtopping risk estimates — any strong opinions on SNODAS vs SMAP vs NWM v3 forcings for a 1,800 km² Colorado headwaters basin feeding HEC-HMS? If you have a workflow for merging USGS gages with MRMS QPE to bound uncertainty, I can swap our Jan 2024 back-analysis in return.
For a CO headwaters basin, I’d lean SNODAS for SWE and NWM v3 reanalysis for met forcing, with SMAP only as a soil-moisture sanity check (https://nsidc.org/data/snodas). Concrete step: basin-average SNODAS SWE, bias it to nearby SNOTEL, set HMS initial snow/soil states, then “merge USGS gages” by mass-balance scaling the first 24 h of inflow; watch wind-scoured ridges where SNODAS underestimates. Would you consider seeding HMS soils with NWM Noah-MP states if SMAP looks noisy right after storms?