Check a Japan itinerary [{date, prefecture}] against JMA warnings/advisories in effect now. Per stop: matched_advisory (with severity), no_match_in_checked_sources (NOT a statement of no impact) or unknown (data missing, or date not today/tomorrow JST). Returns checked sources and areas, unchecked areas, issued_at, retrieved_at, and current JMA typhoon/volcano bulletins (listed, not matched). No forecast. Retrying with the same payment is not charged; use receipt_id with get_receipt.