Forecast Details

Forecast trajectories for the Midwest U.S. area are summarized above. The 36-h duration backward trajectories begin at 21 UTC (4 pm EST) today and tomorrow at heights of 10 m, 500 m, 1000 m, and 1500 m above model ground level. The 18-h duration forward trajectories begin at 11 UTC (6 am EST) today and tomorrow at heights of 10 m, 500 m, 1000 m, and 1000 m above model ground level. The trajectories are computed using meteorological fields output from the NOAA National Centers for Environmental Prediction (NCEP) North American Mesoscale (NAM) forecast model. Model output from the latest 00, 06, 12, or 18 UTC NAM forecast are first used in the trajectory calculation, then, if necessary for the backward trajectories, short-term (up to 12 hours) NAM forecasts from previous run(s) are used. Details on the 40 km NAM gridded data used in these calculations are available HERE. Maps do not give the NAM model forecast initialization time if only short-term forecasts are used in the calculations. Trajectories in different states or provinces are shown in different colors. The trajectory endpoints are plotted on maps (gif) and displayed in text files (txt).

The trajectories originate at the following sites:

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