• Continental Polar
air masses form over large, high-latitude land masses, such as northern Canada or Siberia.
• cP air masses are cold
and extremely dry.
• Wintertime cooling
over these land areas cause the atmosphere to become very stable (even inversion).
• The combination of
dry and stable conditions ensure that few if any clouds form over a cP source region.
• Summer cP air masses
are similar to winter cP, but much less extreme and remain at higher latitudes.