Flows and forecasted flows:
Basin outlook reports:
Weather forecast for headwaters (Sunrise Park, in the White Mountains):
Snowpack at Sunrise Park:
You should hope for cold weather, and snow. If it heats up, not good. If it heats up and and rains, it will wipe it all out. A hot couple days in early Feb took things from 100% snowpack to 66%. Its stayed pretty cold since then and there is a bit of snow in the forecast.
If you do get a run on April 12 it will likely be in very low water range, but who really knows. I ran it last year in self-support duckies and kayaks on April 2, at around 380 cfs. Have a permit for April 4 this year and hoping for at least low-end flows for small rafts, but I'm not terribly confident.
Here's my extrapolated ranges from personal experience, buzz posts, ranger discussions. People have different thresholds and opinions which is fine.
1700+ good to go in a larger raft (15/16 footer)
1000+ low but good to go in smaller rafts (13 footer or less), more challenging in larger
600-1000+ very low, still doable in smaller rafts but leave the big coolers and dryboxes and bring the lightweight gear and food.
450-600 - doable but borderline for anything but a IK, kayak or tiny raft. Backpacking gear & food. Blackrock and Corkscrew getting ugly, consider lining.
250-450 - IK's, hardshells, tiny rafts only. Backpacking gear & food. Blackrock and especially Corkscrew are ugly.
At low flows, if your craft warrants it, putting in at "hoodoo" (end of day run) gets you past some of the shallowest rapids, which are above there. When in doubt go right on rapids above there.