National Weather Service United States Department of Commerce

Severe Storms and Heavy Rainfall From the Plains to the Carolinas

Isolated strong to severe thunderstorms are possible Thursday afternoon across the central and southern High Plains as well Virginia into the eastern Carolinas. Stronger storms may produce heavy to excessive rainfall leading to isolated instances of flash flooding. Heavy rain will also be possible for parts of the Lower Mississippi Valley. Read More >

NWR Coverage

 

 


Iowa Map

 

Coverage Map Notes

The coverage statistics and maps are calculated using a computer model and station data assuming ideal conditions. Coverage may be 5 to 10 percent below the computer predicted coverage for the following reasons:

  • The computer model is sensitive to antenna performance. Antenna performance is a function of local conditions, causing signals to be stronger signal level in some directions than others.
  • Placement of NWR antennas is dictated by the tower owner, which may result in a less than ideal set up.
  • The antenna may be affected by nearby structures or bodies of water.
  • In some special instances, the antenna may have been intentionally adjusted to be "directional" and provide better coverage to a specific area to the detriment of other areas.
  • Because of variations in local site conditions, the performance of an individual transmitter and antenna may be less than predicted or expected.
  • Seasonal environmental conditions, such as icing or heavy rain, affect performance of a transmitter station and its various components, particularly those subject to continuous weather exposure.
  • The coverage maps are shown in a single color format, which relates to an estimated signal level.
    • White: Signal level of greater than 18dBuV: Reliable coverage