Storm Prediction Center Day 4-8 Severe Weather Outlook Page (2024)

FAQs

What does the severe weather outlook chart depict? ›

Description: This product depicts the area where the forecaster expects convection or severe convection to occur during the first 24-hour period. The product denotes the areas that have a marginal, slight, enhanced, moderate, or high risk of severe thunderstorms during the period.

Marginal Risk (of severe thunderstorms) An area of severe storms of either limited organization and longevity, or very low coverage and marginal intensity. Specifically, 2% probability or greater tornado probability OR. 2% probability or greater for severe hail (≥1" / ≥2.4cm) OR.

The SPC further defines significant severe thunderstorms as any storm that produce one or more of the following elements: A tornado that produces EF2 or greater damage. Wind speeds of 75 mph (65 knots) or greater. Hail 2 inch in diameter or larger.

Public Severe Weather Outlooks

The Public Severe Weather Outlooks (PWO) are issued when a potentially significant or widespread tornado outbreak is expected.

Those levels from 1 to 5 respectively are MARGINAL, SLIGHT, ENHANCED, MODERATE, and HIGH. An area under a MARGINAL risk for severe weather will feature a threat of isolated severe weather.

On May 20, 2013, an extremely powerful tornado destroyed a huge part of Moore, Oklahoma. Eleven years later, it remains the most recent tornado to be rated EF5, the strongest possible rating on the Enhanced Fujita Scale. The 11-year gap is the longest since official U.S. records began in 1950.

The "Low" category contains probability values ranging from less than 2% to 20% (EF2-EF5 tornadoes), less than 5% to 20% (all other probabilities), "Moderate" from 30% to 60%, and "High" from 70% to greater than 95%.

A level 4 out of 5 risk is considered a moderate risk. It's shaded in red. A moderate risk is rare and is only seen a couple of times a year. Widespread severe weather is likely with long-lived, intense thunderstorms. Strong tornadoes, widespread wind damage and large hail are possible depending on the situation.

Tropical Depression - wind speed less than 39 mphS: Tropical Storm - wind speed between 39 mph and 73 mph H: Hurricane - wind speed between 74 mph and 110 mph M: Major Hurricane - wind speed greater than 110 mph The cone on the map indicates the potential path of the storm, and it indicates the uncertainty of where the ...

MDT – Moderate risk – this level corresponds to 30-45% probability of organized severe weather occurring in a 40 km radius from a location. Additionally, 15% or higher probability of extremely severe weather is expected. Organized severe weather is expected, moderate intensity and coverage.

What is the pink weather alert? ›

Severe thunderstorm watch (SVA; pink box or blue box in NWS documents, typically yellow box in other media) – Conditions are favorable for the development of severe thunderstorms in and close to the watch area.

The outlooks issued are for Day 1, Day 2, and Days 3–8. The Day 1 product is issued at 4:00 a.m. Central Time and is updated at 1700Z, and is valid from 1200Z to 1200Z the following day. The Day 2 outlook is issued at 1000Z and is updated at 2000Z for the forecast period of 1200Z to 1200Z the following day.

MRGL (dark green) - Marginal risk - An area of severe storms of either limited organization and longevity, or very low coverage and marginal intensity. SLGT (yellow) - Slight risk - An area of organized severe storms, which is not widespread in coverage with varying levels of intensity.

Learn all about thunderstorms, tornadoes, hail, lightning, floods, damaging winds and severe winter weather.

Lightning can travel 10 to 12 miles from a thunderstorm. This is often farther than the sound of thunder travels. That means that if you can hear thunder you are close enough to a storm to be in danger of being struck by lightning.

Weather Depiction Charts provide a graphical overview of the weather, making the information accessible "at-a-glance". This enables many public users of the data to get a general overview of weather patterns on any given day.

a prediction about how something (as the weather) will develop.

A warm front is shown with a red line and red semi-circles and a cold front with a blue line and blue triangles. The way in which the semi-circles or triangles point shows the direction in which the front is moving.

The weather map, also known as a synoptic chart, is a simplified depiction of the Earth's surface weather patterns that shows the positions and motions of the various systems. Weather charts are very useful in learning about a region's weather conditions. They also can help in knowing about the climate of an area.