Inspired by Tygart Media Storm Tracker — Storm Updates: Idaho–Utah Marginal, Dakotas Flood Slight — Thursday, September 17, 2026 — https://tygartmedia.com/storm-updates-september-17-2026-idaho-utah-marginal-dakotas-flood-slight/.
What changed since the morning companion: the 2000 UTC SPC Day 1 outlook, issued 2:47 p.m. CDT, made no change from the midday package. Headline stays isolated severe wind and hail over parts of Idaho and Utah plus a small High Plains pocket. No Slight. No tornado probabilities. Ohio Valley is off today’s map. No convective watch is valid; Watch 669 stays expired. New product this afternoon is Mesoscale Discussion 2304, issued 2:46 p.m. CDT for southern and central Idaho — peak hail 1.00–1.75 inches, peak gust 55–70 mph, 20 percent watch probability, tagged watch unlikely. Offices on that MD: Pocatello, Missoula, Boise. By late afternoon the live MD list was empty; treat 2304 as the latest issued discussion, not a standing watch. WPC Day 1 excessive rainfall still holds two Slight corridors. The organized ticket is the high-end Slight across much of South Dakota, now expanded east toward Sioux Falls into southwestern Minnesota and northwest Iowa, and west-southwest to the Cheyenne region east of the Laramie Range. The second Slight is leftover Southwest terrain: New Mexico and eastern Arizona into the San Juans and western Colorado. Wednesday’s Arizona Moderate is aftermath. Today’s 1200 UTC-forward LSR page is still empty for tornado, hail, and wind. Overnight tickets remain Emery and Carbon County, Utah quarter-size hail; Ohio trees, wires, barn sheet metal, and a silo; Mesa downed lines; Camden County, Missouri hail and limbs.
Owner / Principal
Do not open a national surge. Keep three thin envelopes. Envelope A — Dakotas water: extraction, air movers, dehumidifiers, liners, Category 3 PPE, after-hours commercial access from the Wyoming Front Range across western and central South Dakota into southwest Minnesota and northwest Iowa tonight into Friday morning. That is still today’s organized ticket. Envelope B — southern and central Idaho under MD 2304: one hail-and-gust on-call through evening for Boise, Pocatello, and the eastern Snake River Plain. A 20 percent watch tag is not a CAT. Envelope C — Wasatch Front and leftover Southwest terrain: isolated hail on-call if a warning verifies near Salt Lake, Provo, or Orem; leftover extract capacity on New Mexico and eastern Arizona washes that already took water Wednesday. Cash last night’s verified files first — Huntington and East Carbon hail, Darke and Miami and Preble County trees, Mesa lines. Overtime waits for a warning or a measured LSR this window, not the Marginal contour that lists Salt Lake City.
GM / Ops
Four boards. Board 1 — live flood: Rapid City into the Badlands centroid, Sioux Falls expansion, Cheyenne east of the Laramie Range, southwest Minnesota, northwest Iowa. Extractors stay staged; do not strip standing dry jobs in quiet ZIPs to chase a wash that has not flooded. Board 2 — MD 2304: one tarp/hail crew on-call per branch under Pocatello, Boise, and the eastern Snake. Coverage is one or two cells, not a line. Board 3 — Wasatch and High Plains gust overlay: isolated on-call only if a warning posts; cloud cover is the limiter on the High Plains. Board 4 — leftover: Ohio trees-on-wires in Versailles, Piqua, West Alexandria, and southeast of Mansfield; Emery/Carbon hail; Mesa lines; Sacramento and San Juan burn-scar runoff. Do not send one crew to a Cheyenne gust and a Rapid City wash without checking which county has a product now. Ohio warnings are expired. The trees are still on the lines.
Project Manager
New water on the Dakotas corridor: exterior set if it is safe, water line on the elevation, interior moisture map, then extract. Photograph wash, slab, dock, and interior as separate frames. Do not drive flooded Front Range or Badlands crossings. Occupied houses: contents up, plastic on remaining dry stock, habitability note before demo talk. Vacant shops: dry-in and power confirmation before air movers park. Idaho or Utah hail, if it verifies: daylight roof and siding only — shoot the plane, the soft metals, and auto glass in remaining light. Ohio leftover: finish last night’s tree-on-structure map; do not restart it as a new storm because the Intermountain Marginal is out. Southwest leftover water is still on the mold clock. Do not open walls until source and category are written.
Estimator
Keep the files split. Water file: WPC Slight on the Dakotas plus leftover Arizona–New Mexico terrain — extraction and drying from measured moisture, not from 2–4 inch discussion language. Category 1 holds only if you can show clean stormwater; wash, street, and agricultural mix is the fight. Wind file: isolated High Plains and Snake River gusts only if they verify; Ohio overnight trees, wires, barn sheet metal, and the Preble County silo stay on last night’s cycle. Hail file: Huntington, East Carbon, and Sunnyside 1.00 inch plus any MD 2304 stones that actually hit. Do not price a full roof from a phone photo. Leave ordinance and matching for the supplement. Do not fold an empty tropical outlook or a watch-unlikely MD into a CAT file.
Technician
Meter and category before any wall is opened. Treat wash, street, and ranch-adjacent water as Category 2 until the PM writes otherwise; sewage or livestock mix is Category 3 until proven. PPE is not optional in a basement or slab that took overland water. Confirm electrical safety on outage blocks before plugging equipment; generator stays outside and downwind. Photograph silt lines and debris on the first pass. If the PM has not released demo, leave the wall closed. Do not chase the entire Marginal envelope for a 60 mph rumor. Turn around on High Plains and Southwest washes. The ticket is after the water drops. Burn-scar runoff in the Sacramentos and San Juans is a life-safety hold, not a first-hour extract.
Business Development
Call damage and standing accounts, not the outlook. Commercial managers from Rapid City through Sioux Falls and the Cheyenne Front Range get a one-line flood heads-up — slabs, docks, after-hours access — only if a warning is live or water is already inside. Idaho commercial is hail and gust after a warning under MD 2304, not a blast across Boise and Pocatello on Marginal language. Wasatch commercial is a hail call after a warning, not a Salt Lake neighborhood blast. Ohio leftover trees and Mesa lines are claim-follow-up, not a new CAT blast. Do not send “we are in your neighborhood” copy across quiet ZIPs that have not taken water. Do not pitch. Do not name clients.
Commercial vs Residential
The afternoon split is organized Dakotas water versus isolated Intermountain hail, plus leftover Ohio wind. Warehouse and light industrial on the South Dakota and Sioux Falls corridor take dock and slab water, after-hours access, and tenant notification; roof work on those buildings is gusty outflow if it verifies, not the rainfall itself. Single-family from Rapid City through southwest Minnesota takes contents, possible ALE if sleeping rooms or power fail, and a 24–48 hour mold clock if cells stall overnight. Idaho and Utah residential, if discrete cells fire, is hail on roof, siding, and auto glass — commercial plant language is not in MD 2304. High Plains commercial is thin wind. Ohio residential is leftover tree-on-structure and wires; that is a separate staffing problem from this afternoon’s West. Do not mix a Rapid City extract crew with a Boise hail crew without checking which county still has a product.
Close
Full weather pulse, pulse table, and official source list remain on the Tygart Media afternoon desk: Storm Updates: Idaho–Utah Marginal, Dakotas Flood Slight — Thursday, September 17, 2026. Morning operator companion stays up: Storm Pulse for Operators — Thursday morning. For water protocol depth, see Storm Water Intrusion: Extraction, Drying, and Mitigation Protocol. For hail and wind scope standards, see Wind and Hail Damage: Scope Development, Insurance Claims, and Repair Standards.
Informational operator brief only — not an official NWS warning. Verify every county and ZIP with weather.gov and local emergency management before rolling. Turn around, don’t drown.