Weather Map

[asterroc]

Anyone *cough*meredithanne42*cough* know what the yellow line with half-circles over west Texas means? I've never seen it before.



ETA: And while I'm at it, why does it make a difference if a cold front moves under warm air, or a warm front moves over cold air? They're the same except for the stationary ground under them, why does that affect them?

Comments

[sammka.livejournal.com]

Tornadoes!

(I just made that up)

[meredithanne42.livejournal.com]

I'm thinking it's probably a "dry line," but I will check.

[meredithanne42.livejournal.com]

Yep! It's a dry line. Read all about it here: http://www.stormtrack.org/library/forecast/dryline.htm

:)

[meredithanne42.livejournal.com]

Regarding the warm/cold fronts... I think the major difference is what happens to the air masses when they meet. A cold front, as you know, involves a cooler air mass approaching a warmer one--the colder air mass undercuts the warmer air mass, because of their density differences. With the warm air being displaced upwards, the resulting atmospheric condition tends to be unstable. High clouds can build, thunderstorms, a gradient that favors convective uplift, etc. Cold fronts also tend to move more quickly and are in general more intense, I guess simply because of what happens when warm air is displace upwards.