Fronts extend not only in the horizontal direction, but in the vertical as well. Therefore, when referring to the frontal surface (or frontal zone), we referring to both the horizontal and vertical components of the front.
ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/af/frnts/home.rxm... ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/af/frnts/home.rxml
(WW2010) - Introduces polar and tropical air masses, the most common types of fronts plus a detailed description about advection. ... Clashing air masses in the middle latitudes spark interesting weather events and the boundaries separating these air masses are known as fronts. This module examines fronts,
ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/af/home.rxml
Many fronts cause weather events such as rain, thunderstorms, gusty winds, and tornadoes. At a cold front passes there may there may be dramatic thunderstorms. At a warm front there may be low stratus clouds.  Usually the skies clear once the front has passed.
www.windows.ucar.edu/tour/link=/earth/Atmosphere/front.... www.windows.ucar.edu/tour/link=/earth/Atmosphere/front.html
Weather front - Wikipedia, the free encyclopedia
A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena. In surface weather analyses, fronts are depicted using vari...
en.wikipedia.org/wiki/Weather_front
Cold front - Wikipedia, the free encyclopedia
A cold front is defined as the leading edge of a cooler and drier mass of air, replacing (at ground level) a warmer mass of air. The cooler, denser air wedges under the less dense warmer air, liftin...
en.wikipedia.org/wiki/Cold_front
Company of Heroes: Tales of Valor ... Company of Heroes ... Company of Heroes: Opposing Fronts...
www.companyofheroesgame.com/
Fronts can be several hundred kilometres in width. The air behind a cold front is cooler than the air in front of it. If a warm front passed overhead when you were standing outside, then you would feel the air cooling down.
www.ecn.ac.uk/Education/cold_fronts.htm www.ecn.ac.uk/Education/cold_fronts.htm
So you want to learn about Fronts. ... Daily variations in the weather are caused by the influence of different air masses. The front is the point where these different air masses meet. Fronts can either be Warm, Cold, or Occluded.
www.ecn.ac.uk/Education/fronts.htm www.ecn.ac.uk/Education/fronts.htm
Such zones of contrast are marked by lines on the surface weather map called fronts. ... Stationary fronts are found where the cold and warm air masses are moving parallel to the front (not moving with respect to one another) or if the cold and warm air masses are meeting directly with comparable wind speeds.
tornado.sfsu.edu/geosciences/classes/m356/Fronts.html tornado.sfsu.edu/geosciences/classes/m356/Fronts.html