text: Chapter 7
  WEATHER ANALYSIS
  7-38. The BFSB USAF combat weather team and the S-2 section work closely during much of the
  analysis process. The weather team analyzes the weather’s direct effects and its effects on terrain and other
  aspects of the environment that integrates climate, forecasts, and current weather data with terrain analysis
  and with the overall analysis of the environment. The weather team describes in detail how the weather
  will affect each equipment system and subsystem.
  7-39. Terrain and weather aspects of the environment are inseparable. During terrain analysis, the
  analyst determines how the weather will affect terrain. In this substep, the analyst also evaluates how the
  weather will directly affect operations.
  7-40. The Integrated Meteorological System (IMETS) produces the Integrated Weather Effects
  Decision Aid (IWEDA). The IWEDA shows the LRSU how the weather will affect current and planned
  operations. IMETS forecasts wind turbulence, surface temperatures, cloud ceilings, humidity, visibility,
  and ice.
  Military Aspects of Weather
  7-41. The military aspects of weather are visibility, wind, precipitation, cloud cover, temperature, and
  humidity.
  Visibility is the greatest distance from which prominent objects can be seen and identified by the
  unaided, normal eye.
  Wind of sufficient speed from any direction can blow dust, smoke, sand, or precipitation, reducing
  the combat effectiveness of a force.
  Precipitation is any moisture that falls from a cloud in frozen or liquid form. Rain, snow, hail,
  drizzle, sleet, and freezing rain are examples.
  Cloud Cover affects ground operations by limiting illumination. It can also reduce the thermal
  signature of targets.
  Temperature extremes can reduce effectiveness of troops and equipment.
  Humidity is the amount of water vapor suspended in the atmosphere.
  Additional Weather Considerations
  Thermal Crossover
  7-42. Temperature of targets and objects on the ground is important for the use of thermal sights and
  forward-looking infrared (FLIR). Thermal crossover, which is an additional weather consideration, is a
  natural phenomenon that normally occurs twice daily when temperature conditions reduce thermal contrast
  between adjacent objects.
  Direct and Indirect Effects
  7-43. Weather has both direct and indirect effects on military operations. The following are examples of
  direct effects and indirect effects on military operations:
  • Temperature inversion can increase the risk of contamination by chemical agents.
  • Low visibility, such as that caused by fog, obviously affects the observation capabilities of both
  friendly and threat forces.
  • Hot, dry weather might force friendly and threat forces to consider water sources key terrain.