Better Briefings, Safer Flights P&E WX WATCH L Tired of 50 page briefings? Q Want to save time and fuel? Q Have you ever had a lost flight plan? Q Do you use a flight planning app? Q Would you like to be notified when weather conditions change? www.1800wxbrief.com delivers the solutions you need! Register today and find out more about our free services. LOCKHEED MARTIN Q www.1800wxbrief.com m DUATS II meets Flight Service Delivering the Future TODAY Low-level jet (LLJ) L Direction of system movement isobars L Larko's Triangle LOW-LEVEL JET STREAMS often precede cold fronts (top), and the direction of a low-pres- sure system can sometimes be ballparked by looking at the orientation of the warmsector isobars (center). Tornadoes frequently appear in "Larko's Triangle" (above). THUNDERSTORM CELL MOVEMENT Ever seen a cold front pushing a line of thunderstorms ahead of it? It's a common phenomenon. And so is the movement of those storms, as they often travel along a southwest-to-northeast direction, moving parallel to the front's leading edge and heading toward the front's parent low. It's something to think about if you're planning a flight that might include a frontal crossing. Visit Us at AirVenture Oshkosh Hangar C 3115 108 | AOPA PILOT August 2015 Just don't try to time your crossing based on a guesstimate of gaps between cells. The art of predicting supercell thunderstorm behavior is an imperfect one, but forecasters sometimes use a formula to help anticipate a supercell complex's movement. It's called 30R75, meaning that the storm motion will be 30 degrees to the right of the mean mid-altitude winds, and at 75 percent of that wind's speed. Buthttp://www.1800wxbrief.com http://www.1800wxbrief.com http://www.1800wxbrief.com