National Weather Service United States Department of Commerce

Heavy Rainfall Continues from the Southwest to the Plains; Severe Thunderstorms in the Southern Plains

Pacific tropical moisture wrapping into a storm will continue a multi-day heavy rainfall event this week that will impact the Southwest into the Plains. Scattered severe thunderstorms capable of mainly severe wind gusts appear possible across portions of the southern Plains this afternoon into tonight. There is also a risk of isolated severe winds gusts and tornadoes in Kansas into Nebraska. Read More >

 

 

 


Text of all SIGMETs Around Contiguous Western US

None Found
Description of Convective and Non-Convective SIGMETs

SIGMETs are Inflight Weather Advisories for Significant Meteorological hazards. A SIGMET is "widespread" in that it covers an area of at least 3,000 square miles. Note that the particular hazard may be present in only a small portion of the area at any particular time. SIGMETS are issued for:
  • Severe Icing (not associated with thunderstorms -- otherwise, it is a Convective SIGMET)
  • Severe Turbulence (similarly, only if not associated with thunderstorms)
  • Duststorms and sandstorms lowering visibility to less than three miles
  • Volcanic Ash

Convective SIGMETs are issued for severe convective activity, which implies severe turbulence, severe icing, and low-level wind shear. Specifically:
  • Embedded thunderstorms
  • A line of thunderstorms
  • Thunderstorms with heavy precipitation affecting 40%+ of an area at least 3,000 square miles
  • Surface winds 50+ knots due to severe thunderstorm
  • Hail 3/4+ inches in diameter
  • Tornadoes


Map of SIGMETs (including International)