{"id":3067,"date":"2015-03-20T19:47:35","date_gmt":"2015-03-20T19:47:35","guid":{"rendered":"http:\/\/ialert.com\/blog\/?p=3067"},"modified":"2026-06-11T23:09:58","modified_gmt":"2026-06-11T23:09:58","slug":"severe-weather-outlook","status":"publish","type":"post","link":"https:\/\/ialert.com\/blog\/weather-articles\/severe-weather-outlook\/","title":{"rendered":"Understanding National Weather Service “Severe Weather Outlook”"},"content":{"rendered":"
\"Example
Example SPC Day 1 Convective Outlook<\/figcaption><\/figure>\n

Severe weather outlooks, also commonly referred to as convective outlooks, are issued daily by the National Weather Service (NWS) Storm Prediction Center (SPC) in both text and graphic form.<\/p>\n

Severe Weather Outlook Periods<\/h2>\n

Convective outlooks are divided into four periods:<\/p>\n\n\n\n\n\n\n
Day 1<\/th>\nThe risk of severe weather today through early morning of the following day. Day 1 forecasts are issued five times
\ndaily: 06z (around midnight), 13z (around sunrise), 1630z (mid-morning), 20z (mid-afternoon), and 01z (early evening).<\/td>\n<\/tr>\n
Day 2<\/th>\nDay 2 continues from the end of Day 1 (tomorrow morning) for the next 24 hours. Issued twice daily: 07z (around
\nmidnight) and 1730z (around noon).<\/td>\n<\/tr>\n
Day 3<\/th>\nThe forecast for the subsequent 24 hours. Day 3 forecasts are issued daily by 0830z on standard time and 0730z on
\ndaylight time (after midnight).<\/td>\n<\/tr>\n
Days 4\u20138<\/th>\nA severe weather area depicted in the Day 4\u20138 period (issued at 10z, early morning) indicates a 30% or higher probability of severe
\nthunderstorms (a 30% chance that a severe thunderstorm will occur within 25 miles of any point).<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Severe Weather Outlook Risk Categories<\/h2>\n

The severe weather outlook graphics display up to six color categories reflecting an increasing likelihood and\/or severity of severe weather.<\/span><\/p>\n

\n

General Thunderstorms<\/h3>\n

The light green shading depicts a 10% or higher probability of non-severe or near-severe thunderstorms during the valid period.<\/p>\n<\/div>\n

\n

Severe Category 1 \u2013 Marginal (MRGL)<\/h3>\n

The dark green shading indicates a marginal risk of severe thunderstorms during the forecast period. This means a:<\/p>\n