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On site weather observations are necessary for issuance of a spot weather forecast. Minimum requirements for a weather observation include the dry bulb temperature, the relative humidity, and the surface wind speed and direction. If those elements are unavailable, and the forecaster feels that will negatively impact the forecast, he/she may decline to fulfill a formal spot forecast request. All wind measurements are assumed to be at eye level using a hand held wind instrument. If wind measurements are taken from a tower, this should be noted and relayed to the forecaster. Please use the Spot Forecast Request Form as guidance for information to supply to the fire weather forecaster. For very large fires (involving thousands of acres), observations should be obtained, if possible from several points around the fire. This will enable the forecaster to better gauge the effects of the fire on local weather patterns. For prescribed burns, a weather observation from the site should be taken and sent to the forecaster about two hours before ignition. Location of the fire site must also be included with the spot forecast. Latitude and longitude along with a nearby major feature (topographic, town, etc.) is best. The fire weather user requesting the spot forecast should also provide the following information: Location, Size of burn, Elevation, and Fuel (vegetation) type (e.g. is it a stand of dense pines or perhaps a grassy field?) The National Weather Service forecaster should ask what weather elements are desired and most important to the burn. The forecaster should also inquire about the time period for the spot forecast. The first 12 hours of the burn time should have the most detail in it. Remember to provide a phone number or fax number in order for the spot forecast information to reach the proper location.
If weather conditions develop that were not forecasted and threaten the success of the operations at the fire, the forecaster should be notified immediately. Furthermore, any feedback concerning the accuracy of the spot weather forecast (both positive and negative) will assist the forecaster in subsequent forecasts for the same or similar location. |