Key Parameters


  • Sea level pressure: frontal trough and associated low pressure system and post-frontal anticyclone.
  • Advection of equivalent potential temperature (EPT) and humidity convergence at 850 hPa: maximum values of both variables at the leading edge of the cold surface front.
  • Thermal front parameter (TFP): maximum value of thermal front parameter in the frontal zone.
  • Cyclonic vorticity advection at 500 hPa: maximum values ahead of the trough.
  • Isotachs and streamlines at 250 hPa: maximum wind associated with the jet stream at high levels. Jet streak orientation is mostly parallel to the CF cloud band

Sea level pressure

06 February 2014/00:00 UTC. GOES 13 IR 10.7 image; magenta: sea level pressure

Advection of equivalent potential temperature and humidity convergence at 850 hPa

06 February 2014/00:00 UTC. GOES 13 IR 10.7 image; magenta: Equivalent Potential Temperature at 850 hPa, yellow: humidity convergence at 850 hPa (gr/kg day), green vector (arrows): wind at 850 hPa.

Thermal Front Parameter

06 February 2014/00:00 UTC. GOES 13 IR 10.7 image; green: equivalent thickness, blue: TFP.

Cyclonic vorticity advection at 500 hPa

06 February 2014/00:00 UTC. GOES 13 IR 10.7 image; cyan: geopotential height of 500 hPa, green: positive vorticity advection at 500 hPa, blue: negative vorticity advection at 500 hPa.

Isotachs and streamlines at 250 hPa

06 February 2014/00:00 UTC. GOES 13 IR 10.7 image; green: streamlines at 250 hPa, yellow: isotachs at 250 hPa.