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