The NOAA Storm Prediction Center's latest Day 1 convective outlook places a slight severe risk across portions of the central Plains and Carolinas, with marginal areas extending into the Midwest and Southeast, where model guidance highlights modest instability, upper-60s dewpoints, and sufficient shear for isolated supercells amid a weakening frontal boundary. Tornado probabilities remain low (typically 2–5%) relative to damaging winds and large hail, consistent with August climatology showing reduced frequency outside peak spring patterns. Recent active severe weather across the Mid-Atlantic and Plains has kept trader attention elevated, though today's setup favors linear storm modes over discrete rotation. Updated SPC outlooks, NWS radar trends, and short-term HRRR model runs through evening will drive any shifts in implied probabilities for affected cities.
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 21?

Chicago, IL
51%

Houston, TX
50%

San Antonio, TX
50%

Dallas, TX
50%

Austin, TX
50%

Fort Worth, TX
50%

Columbus, OH
50%

Charlotte, NC
50%

Indianapolis, IN
50%

Denver, CO
50%

Nashville, TN
50%

Oklahoma City, OK
50%

Memphis, TN
50%

Louisville, KY
50%

Atlanta, GA
50%

Kansas City, MO
50%

Omaha, NE
50%

Minneapolis, MN
50%

Wichita, KS
50%

New Orleans, LA
50%

Tampa, FL
50%

St. Louis, MO
50%

Birmingham, AL
50%

Des Moines, IA
50%

Little Rock, AR
50%
$0.00 Vol.

Chicago, IL
51%

Houston, TX
50%

San Antonio, TX
50%

Dallas, TX
50%

Austin, TX
50%

Fort Worth, TX
50%

Columbus, OH
50%

Charlotte, NC
50%

Indianapolis, IN
50%

Denver, CO
50%

Nashville, TN
50%

Oklahoma City, OK
50%

Memphis, TN
50%

Louisville, KY
50%

Atlanta, GA
50%

Kansas City, MO
50%

Omaha, NE
50%

Minneapolis, MN
50%

Wichita, KS
50%

New Orleans, LA
50%

Tampa, FL
50%

St. Louis, MO
50%

Birmingham, AL
50%

Des Moines, IA
50%

Little Rock, AR
50%
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.
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 21, 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.
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...The NOAA Storm Prediction Center's latest Day 1 convective outlook places a slight severe risk across portions of the central Plains and Carolinas, with marginal areas extending into the Midwest and Southeast, where model guidance highlights modest instability, upper-60s dewpoints, and sufficient shear for isolated supercells amid a weakening frontal boundary. Tornado probabilities remain low (typically 2–5%) relative to damaging winds and large hail, consistent with August climatology showing reduced frequency outside peak spring patterns. Recent active severe weather across the Mid-Atlantic and Plains has kept trader attention elevated, though today's setup favors linear storm modes over discrete rotation. Updated SPC outlooks, NWS radar trends, and short-term HRRR model runs through evening will drive any shifts in implied probabilities for affected cities.
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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