Chris: Clarify shear from low to NE?

[Recurve]

As in, Chris is being sheared by a low/trough to the northeast, as I gather from forecasts (like Derek's last) in the analysis forum and other posts.

So that means winds blowing from the southwest toward the ULL (correct?), meaning the shear setup is lower-level trades (from the east or northeast) at the level of the convection, and upper winds blowing across where the high-altitude core circulation would need to be developing, the top of the chimney has winds blowing toward the northeast, though the convection wenty south (literally) on satellite?

Starting this discussion because with a dying Chris, it seem like a good time to better understand the shear, ULL low winds and so on.

[KFDM Meteorologist]

The shear is coming from the N/NE. Example last night the thunderstorms were moving S/SW.

[Recurve]

OK, I did get that wrong, probably cause I'm thinking the low was farther west. So it was the upper-level winds on the west side of the low blowing from n/ne to s/sw. These winds were/are at the level of the convection, while the LLC is down where just the trades are (and are slower than the winds from the trough/low).

Thanks for the correction.

[Aslkahuna]

Important thing to remember about shear. Shear is a vector quantity meaning that it has both speed and direction. While we most often discuss directional shear with relation to hurricanes, speed shear can also be a negative factor if the winds increase dramatically with height but with little direction change then the tops will blow out in one direction and the convective chimney will not form. If they decrease sharply with height the LLCC can run out ahead of the convection.

Steve