National Weather Service Definitions

  • Hazardous Weather Outlook: Issued by the local National Weather Service office daily at 7 a.m. Usually covers a large portion of southeast Texas. Outlines the reasons for the potential for severe weather, the area that could be affected and the time that severe weather is anticipated.
  • Severe Thunderstorm Watch: Issued by the Storm Prediction Center in Norman, OK. Usually covers a large area (such as all or a portion of southeast Texas) and lasts for 6 to 8 hours. A Severe Thunderstorm Watch means that conditions are favorable for severe thunderstorms that may produce large hail, damaging wind, dangerous lightning, or possibly tornadoes.
  • Severe Thunderstorm Warning: Issued by the local National Weather Service office. Usually covers a small area (one or a few counties) and has a short duration of 30 minutes to an hour. A Severe Thunderstorm Warning means that a severe thunderstorm has been detected by radar, or reports of severe weather have been received by the National Weather Service in the area covered by the warning. The warnings are broadcast over NOAA Weather Radio and are usually scrolled on local television stations. The warnings are also relayed to local emergency management and public safety officials who can activate emergency procedures to help protect the public. If a warning is issued for your area, take action immediately!
  • Severe Weather Statement: Follow-up information on a warning.
  • Flood Watch: Means that conditions in the watch area will be favorable for flooding during the specified period. Usually heavy rainfall is expected following a long period of wet weather.
  • Flash Flood Warning: Flash flooding is reported or is imminent in the counties specified in the warning. Take immediate precautions.
  • Urban and Small Stream Flood Advisory: Flooding of streets, low-lying areas like underpasses and storm drains, and small streams is expected. Caution should be taken while traveling.
  • Flash Flood Statement: Follow-up information on a Flood Watch or a Flash Flood warning.
  • River Flood Outlook: Indicates potential for flooding along rivers and streams.