The boundary layer wind and relative humidity chart is produced twice daily from the 1200Z and 0000Z data cycles by the LFMII model. A typical chart is shown in figure 4-3-10. In the very near future, this product is expected to be produced by the NGM model. Four charts are produced in each cycle, for the 12-, 24-, 36-, and 48-hour forecasts. The chart background covers much of North America, as well as portions of the eastern Pacific, western Atlantic, and western Caribbean. The wind speed and direction are represented by standard wind barbs, with the tens unit of the direction plotted near the feathers. The LFM model calculates the winds for its boundary layer at 1,500 feet above the surface. Use of the NGM model will result in wind forecasts at approximately 986 feet above the surface, the boundary layer of the NGM. Relative humidity percent is plotted at the focus of each report except that no values are plotted for the far left side of the chart, which is not covered by the LFMIIs moisture grid. However, the NGMs grid C extends farther west and should correct that situation. The valid time, date, and chart identification are printed across the bottom of each chart, as well as in a cryptic ID block in the central Gulf of Mexico.

These charts are frequently used, with some adjustment, to forecast surface winds.

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