• The low level jet is a high speed return of warm and moist air from the south or southeast; moisture source is the Gulf of Mexico
  • Most common and intense over the Plains states and Southeast states
  • The low level jet occurs in the warm sector of a developing mid-latitude cyclone in the Central and Eastern U.S.; occurs generally ahead of the cold front boundary
  • Intensity of low level jet is increased due to temperature gradient between cooler high elevations in the high plains compared to warmer East Great Plains at night. Can also intensify by the warm sector of a mid-latitude cyclone being east of the cold sector.
  • Low level jet adds heat, mass and momentum to developing thunderstorm and produces low level speed and directional shear (results in very high Helicity values)
  • Produces abundant WAA (warm air advection) that may break a weak to moderate cap. WAA produces broad synoptic scale uplift
  • Strongest low level jet winds are generally at the top of Planetary Boundary Layer due to less friction than at the surface
  • Advection may well be over 65 miles per hour
    [ Low Level Jet ]