Assertion: cold front | /r/CapableOf | mark the boundary
Facets:
value: often
type: TEMPORAL
Source sentences:
text: Cold fronts, marked by a chain of blue triangles pointing in the direction of movement (toward the warmer air), often mark the boundary between a maritime-Tropical (mT) and an advancing continental-Polar (cP) air mass or perhaps the boundary between a cP air mass and an advancing continental-Arctic (cA) air mass (the coldest of the cold).