National Weather Service Storm Prediction Center outlooks for September 7, 2026, placed a slight risk of severe thunderstorms across parts of North Dakota and southeast South Dakota into northeast Nebraska, with 2% tornado probabilities centered on cities including Bismarck, Minot, Mitchell, and Huron. Forecasters cited a fast-moving shortwave trough, dryline sharpening, and sufficient low-level veering with effective SRH of 200-300 m²/s² supporting supercell potential amid modest instability. Actual reports later confirmed brief tornadoes near Strawberry Lake, ND, and Spencer, NE, while marginal wind and hail threats extended into the central Gulf Coast. Post-event verification and final local storm reports from NWS offices will determine which specific cities aligned with verified tornado risk for market resolution.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedWhich cities face tornado risk on September 7?
$6,772 Vol.
Chicago, IL
No
Houston, TX
No
San Antonio, TX
No
Dallas, TX
No
Austin, TX
No
Fort Worth, TX
No
Columbus, OH
No
Charlotte, NC
No
Indianapolis, IN
No
Denver, CO
No
Nashville, TN
No
Oklahoma City, OK
No
Memphis, TN
No
Louisville, KY
No
Atlanta, GA
No
Kansas City, MO
No
Omaha, NE
No
Minneapolis, MN
No
Wichita, KS
No
New Orleans, LA
No
Tampa, FL
No
St. Louis, MO
No
Birmingham, AL
No
Des Moines, IA
No
Little Rock, AR
No
$6,772 Vol.
Chicago, IL
No
Houston, TX
No
San Antonio, TX
No
Dallas, TX
No
Austin, TX
No
Fort Worth, TX
No
Columbus, OH
No
Charlotte, NC
No
Indianapolis, IN
No
Denver, CO
No
Nashville, TN
No
Oklahoma City, OK
No
Memphis, TN
No
Louisville, KY
No
Atlanta, GA
No
Kansas City, MO
No
Omaha, NE
No
Minneapolis, MN
No
Wichita, KS
No
New Orleans, LA
No
Tampa, FL
No
St. Louis, MO
No
Birmingham, AL
No
Des Moines, IA
No
Little Rock, AR
No
The SPC Day 1 Convective Outlook assigns tornado probability percentages (2%, 5%, 10%, etc.) to geographic areas across the US. If the 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 Day 1 Convective Outlook has not been published by the time the market closes, this market will resolve to "No".
The resolution source for this market is the NOAA Storm Prediction Center at spc.noaa.gov.
This market uses coordinates 41.8781, -87.6298 for Chicago, IL.
Market Opened: Sep 7, 2026, 8:13 AM ET
Resolution Source
https://www.spc.noaa.gov/products/outlook/day1otlk.htmlResolver
0x65070BE91...Outcome proposed: No
No dispute
Final outcome: No
The SPC Day 1 Convective Outlook assigns tornado probability percentages (2%, 5%, 10%, etc.) to geographic areas across the US. If the 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 Day 1 Convective Outlook has not been published by the time the market closes, this market will resolve to "No".
The resolution source for this market is the NOAA Storm Prediction Center at spc.noaa.gov.
This market uses coordinates 41.8781, -87.6298 for Chicago, IL.
Resolution Source
https://www.spc.noaa.gov/products/outlook/day1otlk.htmlResolver
0x65070BE91...Outcome proposed: No
No dispute
Final outcome: No
National Weather Service Storm Prediction Center outlooks for September 7, 2026, placed a slight risk of severe thunderstorms across parts of North Dakota and southeast South Dakota into northeast Nebraska, with 2% tornado probabilities centered on cities including Bismarck, Minot, Mitchell, and Huron. Forecasters cited a fast-moving shortwave trough, dryline sharpening, and sufficient low-level veering with effective SRH of 200-300 m²/s² supporting supercell potential amid modest instability. Actual reports later confirmed brief tornadoes near Strawberry Lake, ND, and Spencer, NE, while marginal wind and hail threats extended into the central Gulf Coast. Post-event verification and final local storm reports from NWS offices will determine which specific cities aligned with verified tornado risk for market resolution.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated

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