Ohio State University’s Twister page for CAPE The Traffic Flow Management (TFM) page is intended to keep air traffic control advised of any high-confidence, strong convection (echo tops above 25,000 feet, radar reflectivity of 40 dBz or higher) with coverage areas that could influence traffic routing. Together with the SPC’s outlooks, the ECFP can give you a good idea if trouble is in the works for that weekend trip. The Extended Convective Forecast Plot (ECFP) shows forecast areas for the next 72 hours, along with three levels of probability: 40 to 59 percent 60 to 79 percent and more than 80 percent. This lets you see where storms are expected to pop up, as well as where they’re forecast to move. The National Convective Weather Forecast (NCWF) plots show the current day’s observed and forecast areas of storms at five-minute intervals. ( Here you can find several interesting renditions of future convection. The Aviation Weather Center’s convection pages The probabilities are 10, 40, or 70 percent. The SPC’s Thunderstorm Outlooks cover probabilities for four- or eight-hour predictive time frames.
The SPC dwells on the likelihood of severe thunderstorms (those with 75-mph/65-knot winds, hail greater than two inches in diameter, or tornadoes capable of lifting cars off the ground) but they also cover “general” thunderstorms, which are bad enough by themselves. Some outlook maps go out four to eight days in the future-but as you might suspect, long-range accuracy is less reliable. The Day One (today) and Day Two (tomorrow) outlooks are pretty accurate. ( You say you’re planning on flying tomorrow or the day after that? Then check out the SPC’s Convective Outlooks.