The Intermountain West and central High Plains — Marginal, and only that

ACTIVE · September 17, 2026 · NO. 0917

THE RISK WINDOW

Marginal only. Day 1 carries Intermountain West hail and wind with central High Plains gusts; Day 2 is Marginal over the northern Intermountain West, the central Plains and Missouri Valley and the Carolinas-Georgia Piedmont. The level held and the corridor shifted west — tornado is not emphasised.

THE RECORD

51 turning points on record since Jun 9 — the 8 most recent shown.

Sep 16easing → active

Sep 15active → easing

Sep 13▽ slipped down the board

Sep 12▽ eased

Sep 11↑ firmed

Sep 8easing → active

Aug 28active → easing

Aug 27↑ firmed

WHO IT TOUCHES

Aviationa holiday-weekend flight bank into Tokyo, a flooded Southwest hub pair today, and an easy day everywhere else