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NWS Marquette Aviation Forecast Program
Weather forecasting for aviation is an extremely challenging and important aspect of the NWS mission. Aviation weather forecasts are used in planning and executing over 100,000 flights in the United States every day. The tremendous impact of weather conditions on takeoff and landing operations requires that forecasts always be as specific and timely as possible. The primary duties of the aviation forecaster at NWS Marquette include: NWS Marquette issues Terminal Aerodrome Forecasts (TAFs). Terminal Aerodrome Forecasts Concept The NWS aviation terminal aerodrome forecast (TAF) is a concise statement of the expected meteorological conditions significant to aviation to impact an airport during the 24-hour forecast period. An airport is defined as the area within 5 statute miles of the center of an airport's runway complex. NWS Marquette issues TAFs for the Marquette Sawyer International Airport (SAW) and the Houghton County Memorial Airport (CMX). (The Marquette County Airport (MQT) TAF was discontinued when the airport moved to Sawyer.) The aviation forecaster at NWS Marquette maintains a watch of weather conditions at these locations and issues amended forecasts in addition to the scheduled TAFs when observed or expected conditions meet amendment criteria for the specified forecast elements and are expected to persist, or in the forecaster's judgment, the TAF is unrepresentative of current or expected weather. Format The necessary components of a TAF include a location identifier group, a date/time of forecast origin, a valid period date/time group, forecast group(s) for the forecast period, and an end of message designator (=), which trails the last forecast group. Content The forecast elements are entered into the body of the initial forecast period and then are followed by any succeeding time-divider (FM), forecast change (BECMG and TEMPO), and probability forecast (PROB30/PROB40) group(s). The order in which these forecast elements are encoded (if they are necessary) is as follows: wind, visibility, significant weather, cloud (or vertical visibility into a surface-based obscuration), and nonconvective low-level wind shear. An example of a scheduled TAF: ETTAA00 KMQT 241730 Examples of unscheduled TAFs: ETTAA00 KMQT 211125 AAA NOTE: This is the first amendment to the 211212 TAF issued at 1125Z ETTAA00 KMQT 162330 CCA NOTE: This TAF is the first correction to the 170024 forecast issued at 2330Z--the only way you can tell is from the date/time of forecast origin and the contraction CCA. NWS Marquette issues four scheduled SAW and CMX TAFs valid for 24 hours each day: between 2320-2340Z, 0520-0540Z, 1120- 1140Z, and 1720-1740Z valid 00Z-24Z, 06Z-06Z, 12Z-12Z and 18Z-18Z respectively. |