Free training on Florida convective weather for general aviation pilots. Built on National Weather Service methodology and NTSB accident reports, and taught on a live map you can go and use afterwards.
Reading a Skew-T, and a route cross-section from Falcon Field to Winter Haven. Three and a half minutes.
Watch the sounding class How it actually kills you What your cockpit is not showing you Open the mapFlorida has more thunderstorms than anywhere else in the United States, and most of them are built by the same machine on the same schedule: two sea breezes, one from each coast, marching inland until they collide. Where they meet, the air has nowhere left to go but up.
That collision produces a fine line on weather radar — a thin arc of clear-air return, roughly parallel to the coast, typically 5 to 20 dBZ. It appears before any cumulus does. It is the earliest observable signal in the entire sequence, and it tells you where the storms will form and roughly when.
Here is the problem. Every radar product in a normal general aviation cockpit filters that signal out before you ever see it. Not by accident, and not because anyone is hiding it. It is below the broadcast floor.
| Product | Floor | Fine line visible? |
|---|---|---|
| FIS-B / ADS-B datalink weather | 20 dBZ | Never. Not broadcast at all. |
| ATC en-route NEXRAD mosaic | 30 dBZ | No |
| Typical satellite datalink | 10 dBZ | No |
| Raw Level II, clear-air mode | −32 dBZ | Yes, clearly |
And the FAA's own Aviation Weather Handbook teaches pilots to discard exactly this class of return. Chapter 15 calls it "angels", attributes it to bats, birds and insects, and files it under non-meteorological. The phrase "fine line" does not appear anywhere in the handbook.
So a pilot flying with the free in-cockpit weather the FAA promotes cannot see a sea-breeze front, ever, and has never been told that. This site can show it, because it reads raw Level II from a single radar site rather than the filtered mosaic.
And the floor is only the first of three. The second is worse, because it is the one where the display is confidently wrong: the NTSB found that the age indicator on datalink radar shows the age of the mosaic, not of the weather, and that the real data can be 15 to 20 minutes older than the number you are reading. All three gaps, with the sources →
The Skew-T log-P diagram, what its axes mean, and why it is skewed at all. Then the route cross-section: the same physics laid on its side and stretched along a flight. Available now →
Two coasts, one peninsula, and a collision that runs on a clock. Where the line forms, what moves it, and why the same setup puts storms over Orlando one day and Tampa the next. Taught with a live convergence field, not a diagram. In production.
How to recognise a boundary on raw radar an hour before the first cell, and what to do about it when the aircraft you are sitting in cannot display it. In production.
Real flights, real decisions, from the public record. Fifteen verified cases and the six mechanisms behind them →
Briefed weather held no thunderstorms. Convection built during the mission. He discontinued and turned back, which was right, and met the edge of a 55 dBZ core on the way home.
Radar track shows him flying parallel to a band, passing between two weather areas, then turning back into it. The gap closed.
Central Florida, 3 PM, September. Multiple briefings, delayed departure, twice warned by ATC. Updrafts pushed the aircraft beyond its own climb performance. He pulled the parachute.
Each case is drawn from the published NTSB final report and is used the way the NTSB intends its reports to be used: to change what the next pilot does. The focus is on the decisions and the information available at the time. There are no wreckage photographs here and there will not be.
Not for navigation, and not a substitute for a briefing. This is training material built by a private pilot, not an instructor, an examiner or a meteorologist. Everything on the map is a model forecast or a public data feed, presented with its limits stated. Get a real briefing before you fly.