I think I've found the problem: my configuration setting of shortPoll 120 and longPoll 600 was exceeding my hourly and daily allowance of updates with my default (free) Tomorrow.io account. The allowance with a free Tomorrow.io account is 500/day, 25/hr, 3/sec. Now that I've changed to shortPoll 300 and longPoll 3600, I'm seeing no more errors. And updates of current weather ever 5 minutes and forecasts every hour are more than sufficient for my needs.
