Watches & Warnings

The National Weather Service (NWS) issues statements on forecasted weather for the public and government agencies alike to make decisions about the weather. You can find the current forecast for the Memphis Area Here. NWS issues regular updates and increases update frequency dependent on severity of weather related hazards.

Difference Between a Watch and Warning

The NWS has several categories of watches and warnings:

  • The Outlook (Ready)
    • Risk of weather hazard in the next 7 days
    • Could pose a threat to life/property
    • Prepare a Plan of Action
  •  Watch (Set)
    • Risk of weather hazard in the near future
    • Could Pose a threat to life/property
    • Have a plan of action
  • Advisory (Go!)
    • Weather hazard is occuring or imminent
    • Could cause significant inconvenience
    • Use Cation
  • Warning (Go!)
    • Weather hazard is occuring or imminent
    • Poses a threat to life/property
    • Take Protective Action
Weather Outlook Example

NWS produces forecasts ahead of storms to inform the public of protentional threats. In these forecasts they use  a colorized scale for increasing severity:

  • Light Green - Thunderstorms - No Severe thunderstorms expected
    • The possibility for lightning/flooding exist with all thunderstorms
    • Winds up to 40 mph
    • Small hail possible
  • Green - Marginal Risk - Isolated severe thunderstorms
    • Limited in duration and/or coverage and/or intensity
    • Winds between 40 and 60 mph
    • Hail up to 1 inch
    • Low tornado risk
  • Yellow - Slight - Scattered severe storms possible
    • Short-lived and/or not widespread, isolated intense storms possible
    • One or two tornadoes
    • Reports of strong winds/wind damage
    • Hail around 1 inch, isolated reports of 2 inches
  • Orange - Enhanced - Numerous severe storms possible
    • More persistent and/or widespread a few intense
    • A few tornadoes
    • Several reports of wind damage
    • Damaging hail, 1 - 2 inches
  • Red - Moderate - Widespread severe storms likely
    • Long-lived, widespread and intense
    • Strong Tornadoes
    • Widespread wind damage
    • Destructive hail, 2+ inches
  • Purple - High - Widespread severe storms expected
    • Long-lived, very widespread and particularly in intense
    • Tornado Outbreak
    • Derecho
Understanding Severe Thunderstorm Risk Categories