SPC convective outlooks for August 28, 2026, placed no tornado risk areas across the contiguous U.S., reflecting limited low-level shear and weak instability gradients that favored primarily damaging winds and marginal hail rather than organized supercells capable of tornadogenesis. National Weather Service confirmation of two weak tornadoes (EF-0 and EF-1) in Michigan’s Lake County late that evening represented isolated events within a broader marginal severe risk zone extending from the northern Plains through the Great Basin and Mid-Atlantic, where high-based storms and straight-line winds dominated. Model guidance consistently showed insufficient curved hodographs or CAPE-shear overlap for higher tornado probabilities, aligning trader consensus around limited or no major city impacts. Updated local storm reports and NWS verification data will determine final resolution thresholds.
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 August 28?
Chicago, IL
<1%
Houston, TX
<1%
San Antonio, TX
<1%
Dallas, TX
<1%
Austin, TX
<1%
Fort Worth, TX
<1%
Columbus, OH
<1%
Charlotte, NC
<1%
Indianapolis, IN
<1%
Denver, CO
<1%
Nashville, TN
<1%
Oklahoma City, OK
<1%
Memphis, TN
<1%
Louisville, KY
<1%
Atlanta, GA
<1%
Kansas City, MO
<1%
Omaha, NE
<1%
Minneapolis, MN
<1%
Wichita, KS
<1%
New Orleans, LA
<1%
Tampa, FL
<1%
St. Louis, MO
<1%
Birmingham, AL
<1%
Des Moines, IA
<1%
Little Rock, AR
<1%
$8,524 Vol.
Chicago, IL
<1%
Houston, TX
<1%
San Antonio, TX
<1%
Dallas, TX
<1%
Austin, TX
<1%
Fort Worth, TX
<1%
Columbus, OH
<1%
Charlotte, NC
<1%
Indianapolis, IN
<1%
Denver, CO
<1%
Nashville, TN
<1%
Oklahoma City, OK
<1%
Memphis, TN
<1%
Louisville, KY
<1%
Atlanta, GA
<1%
Kansas City, MO
<1%
Omaha, NE
<1%
Minneapolis, MN
<1%
Wichita, KS
<1%
New Orleans, LA
<1%
Tampa, FL
<1%
St. Louis, MO
<1%
Birmingham, AL
<1%
Des Moines, IA
<1%
Little Rock, AR
<1%
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 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.
This market uses coordinates 41.8781, -87.6298 for Chicago, IL.
Market Opened: Aug 28, 2026, 8:13 AM ET
Resolution Source
https://www.spc.noaa.gov/products/outlook/day1otlk.htmlResolver
0x65070BE91...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 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.
This market uses coordinates 41.8781, -87.6298 for Chicago, IL.
Resolution Source
https://www.spc.noaa.gov/products/outlook/day1otlk.htmlResolver
0x65070BE91...SPC convective outlooks for August 28, 2026, placed no tornado risk areas across the contiguous U.S., reflecting limited low-level shear and weak instability gradients that favored primarily damaging winds and marginal hail rather than organized supercells capable of tornadogenesis. National Weather Service confirmation of two weak tornadoes (EF-0 and EF-1) in Michigan’s Lake County late that evening represented isolated events within a broader marginal severe risk zone extending from the northern Plains through the Great Basin and Mid-Atlantic, where high-based storms and straight-line winds dominated. Model guidance consistently showed insufficient curved hodographs or CAPE-shear overlap for higher tornado probabilities, aligning trader consensus around limited or no major city impacts. Updated local storm reports and NWS verification data will determine final resolution thresholds.
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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