Forecast of duration coincides with the periods used for estimating 10-hour timelag fuel moisture in the National Fire Danger Rating System. Periods will comprise the 24 hours from 1300 to 0500 for day one and 0500 to 1300 the next day. WIND Wind is perhaps the most important weather element to fire fighters. This is to allow forecasters to take into account diurnal variations in speed which frequently occur, resulting in smaller ranges. Speed values represent a one-minute average in miles an hour 20 feet above the ground in exposed areas.
Direction is expressed using eight compass points.
Wind gusts, which are rapid fluctuations in wind speed, are indicated in the forecast if greater than ten miles an hour over the sustained speed. Significant changes in surface wind during a forecast period will usually be highlighted in the synopsis or remarks section of a grouping of zones. Timing of these events is of utmost importance to firefighters, so officials may need to call the National Weather Service in critical situations and obtain a more precise prediction. In mountains, winds exhibit large variations over a small distances because of abrupt changes in terrain, creating slope and valley winds. These small scale winds will not be predicted in the routine fire weather forecast.