Typical Environment for
Frontal Squall Line
qAt the
surface, ahead of the front, winds from the south-southeast transport warm,
moist air into the line of thunderstorms. The front provides the lift to trigger
the squall line.
qIn the
upper troposphere, a trough is located west of the squall line. Winds east of the
squall line aloft are typically southwesterly or southerly. West of the squall
line the winds are more westerly.