End of April is a tricky time, as if it warms up quickly in the West even with an above-average snowpack, this blows out in a few weeks among the smaller watersheds and the bottom falls out flow-wise. Keeping an eye on the SNOTEL sites, which for the upper Salt drainage are currently reading 70% median SWE and 105% precip-to-date (https://wcc.sc.egov.usda.gov/reports...ort=Western+US
), which is neither great nor terrible...but checking daily the temps at these sites closer to your launch can give you an idea how much water is stored as well as how quickly its melting. In terms of the average flows, it is my understanding the historic hydrograph average has been weighted by many years of higher flow across the 80s, 90s, and 2000s that have become increasingly infrequent, so is not a fair assessment of what its like now...but perhaps some more local folks can give a better testimony of that.
Anecdotally I've been trying to get on the Salt for the last 5 years and had to bail on two permits both in April (early and late) because flow went well under 1200. This is a level at which it gets too boney for gear rafts though still remains runnable in a ducky and perhaps a canoe down to a few hundred CFS but of course YMMV. My fingers are crossed for late-March run this year