Heat Persists in the South Central U.S. and Southwest; Heavy rains in the Desert Southwest and Central Plains

Sweltering heat remains across the South-Central Plains, Lower/Middle Mississippi Valley, and the Southwest this week with limited nighttime relief. Thunderstorms will bring heavy rainfall leading to localized flash flooding in portions of the Desert Southwest and central Plains. Isolated strong to severe thunderstorms are possible across portions of the central Plains into the Northeast. 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)

ZSE RSS Feed

Heat Persists in the South Central U.S. and Southwest; Heavy rains in the Desert Southwest and Central Plains

ZSE SIGMETs