The Storm Prediction Center regularly issues convective outlooks, but few recognize the intricacies of this report. Convective outlooks predict the onset of severe weather across a number of different metrics. With this information, local weather stations can issue alerts surrounding severe weather, tornadoes, thunderstorms, and fires.
Convective outlooks are widely seen as reliable predictors of severe weather, but there remains much confusion among the public as to what these reports are saying. We’ll break down how to read a convective outlook as well as some ways more data can help keep these reports relevant as the climate changes.
What is a convective outlook?
A convective outlook is an advanced meteorological term that refers to the predicted severity and path of a storm. A convective outlook forecasts a combination of factors: the severity of the storm, the timing of the threat, and the expected path of the severe weather system. The convective outlook is expressed in four moments (Day 1, Day 2, Day 3, and Day 4-8) as well as colors and graphics.
The timeline for a convective outlook is as follows:
- Day 1: The risk of severe weather “today” through early “tomorrow morning”. The Day 1 forecast is issued five times during the day, starting at 06z (2AM EDT), 13z (9AM EDT), 1630z (12:30PM EDT), 20z (4PM EDT), and 01z (9PM EDT).
- Day 2: Predictably, Day 2 covers the 24 hours following Day 1 (tomorrow morning). Day 2 convective outlooks are issued twice daily starting at 07z (3AM EDT), followed by 1730z (1:30PM EDT).
- Day 3: Day 3 covers the 24 hours following Day 2. This convective outlook is issued by 0830z on standard time and 0730z on daylight time
- Day 4-8: The final convective outlook is issued at 10z daily (6AM EDT) in the days following Day 3, and indicates a 15% or 30% or higher probability that a severe thunderstorm will occur within 25 miles of any point.
These convective outlooks are issued using five specific categories indicating the severity of the storm. The categories range from marginal to high, as outlined in the convective outlook chart below:
These categories, along with the day timeline, can be a bit confusing. As the Storm Prediction Center summarizes, “The greater the threat (from Slight to High), the greater the risk for severe weather which could be either in a number of events or intensity or both.”
A convective outlook is seen as generally accurate. These forecasts use current trends in satellite and radar imagery, weather model output, pattern recognition, and expert forecasters to deliver predictions on the storm path and intensity. Tools like marine buoys are also playing an increasing role in informing convective outlooks.
How buoys help with convective outlooks
Convective outlooks cover thunderstorms, not hurricanes. As such, there are limits to how useful a marine buoy can be in providing data for a convective outlook.
However, convective outlooks do benefit from data collected by marine buoys off the coast. Moored networks of weather buoys that record and transmit weather and ocean data can host various interchangeable sensors. These sensors can provide new real-time data streams, collecting data on temperature, wind speed, and even wave height. Among other benefits, this capability unlocks new possibilities for convective outlooks and weather warnings.
Because weather fronts and storm systems often begin to form over water, these moored networks provide a consistent pulse on the sea state so communities can detect incoming storms and inform weather warnings. Additionally, communities can start to build robust historical data to be better prepared for natural disasters along the coast and further inland. Disaster planning can be achieved using data patterns, rather than guesswork.
Why do convective outlooks matter?
Convective outlooks are used by a host of industries and purposes. Pilots use convective outlooks to make sure their flight path is safe before taking off, as well as to re-route in the instance of a severe weather prediction.
For tornadoes, weather fronts, and other extreme weather events, a convective outlook is particularly important for evacuation or shelter-in-place orders. These forecasts are seen as highly reliable; but unfortunately, public education on convective outlooks is lacking. The categories used in the convective outlook chart are not intuitive, research shows.
“It’s been shown time and time again, however, that the general public doesn’t understand the categories. Is a slight risk or a marginal risk more significant? And why is moderate risk not in the middle? What’s an enhanced risk? Meteorologists know the system like the back of their hands. But the public does not,” reported the Washington Post.
Part of the problem is that a convective outlook was never meant to be used in public broadcasts. Its intended use as a tool for meteorologists was altered by federal law which governs the Storm Prediction Center as a public agency. There’s a big opportunity to make convective outlooks not only more advanced with marine buoy data, but also more intuitive and ready for public consumption.
Convective outlooks — also known as Storm Prediction Center forecasts — are accurate and vital to our disaster preparedness. The more data these important predictions have, the more accurate convective outlooks will be as changes to our climate cause more extreme events. The key to making these predictions useful lies in educating the public about what the convection outlook categories mean.