- Will Chicago, IL face tornado risk on August 28?<1¢
- Will Houston, TX face tornado risk on August 28?<1¢
- Will San Antonio, TX face tornado risk on August 28?<1¢
- Will Dallas, TX face tornado risk on August 28?<1¢
- Will Austin, TX face tornado risk on August 28?<1¢
- Will Fort Worth, TX face tornado risk on August 28?<1¢
- Will Columbus, OH face tornado risk on August 28?<1¢
- Will Charlotte, NC face tornado risk on August 28?<1¢
- Will Indianapolis, IN face tornado risk on August 28?<1¢
- Will Denver, CO face tornado risk on August 28?<1¢
- Will Nashville, TN face tornado risk on August 28?<1¢
- Will Oklahoma City, OK face tornado risk on August 28?<1¢
This market will resolve to "Yes" for each listed city that falls within a tornado probability area rated ≥2% in the NOAA Storm Prediction Center Day 1 Convective Outlook on August 28, 2026. Otherwise, this market will resolve to "No". The SPC Day 1 Convective Outlook assigns tornado probability percentages (2%, 5%, 10%, etc.) to geographic areas across the US. If a city's coordinates fall inside any area rated 2% or higher, that city resolves "Yes". If a city is outside all tornado probability areas, or only within areas rated below 2%, that city resolves "No". The SPC outlook is published as machine-readable geographic data (GeoJSON) at spc.noaa.gov. Each city's coordinates and the polygon boundaries are publicly verifiable. Borderline cases can be independently confirmed using the polygon data (excluding the hatched SIGN overlay, which is not a probability rating) and the city's listed coordinates. The point-in-polygon test is performed on unprojected WGS84 (EPSG:4326) coordinates, which is the native coordinate system of the SPC GeoJSON data. Resolution is based on the scheduled 01:00 UTC Day 1 Convective Outlook update issued on the following UTC calendar day. The SPC Day 1 outlook covers a 24-hour period from 12:00 UTC to 12:00 UTC the following day. Subsequent revisions published after that scheduled update will not be considered. If the SPC outlook is not published or is unavailable, the market remains open until data is available. The resolution source for this market is the NOAA Storm Prediction Center at spc.noaa.gov.
SPC convective outlooks for August 28, 2026, showed marginal severe thunderstorm risk across parts of the central/northern Plains, Great Basin, northern Rockies, Mid-Atlantic, and Carolinas, driven by modest CAPE, weak deep-layer shear, and outflow boundaries, yet explicitly forecast no tornado risk areas. NOAA’s Storm Prediction Center Day 1 and Day 2 products highlighted 5% wind and hail probabilities in those zones while listing zero tornado probabilities, reflecting limited low-level shear and instability unfavorable for rotation. Actual reports confirmed isolated severe wind and hail but no significant tornadoes tied to the day’s activity. Traders monitoring resolution criteria—confirmed tornado touchdowns within specific city boundaries—would weigh these official zero-probability maps and post-event verification data against any late-model shifts or localized reports. Updated SPC summaries and NWS damage surveys remain the key near-term inputs.