Meso Exam 3 Flashcards
What characteristics are east of a dryline? West?
East: east wind,moist, cloudy. Warmer during night cooler during day
West: west wind,dry, clear, more vertical mixing. Warmer during day cooler at night
What air masses do drylines separate?
Maritime tropical and continental tropical
What synoptic feature aids in the development of a dryline?
Presence of a western US trough where dryline lies downstream of trough
How does a dryline move eastward?
Cap is overcome, lapse rate becomes dry adiabatic, and dry westerly momentum is mixed down.
What are sea breezes classified as and how deep are they?
Classified as density currents and are about 1/2 to 1 km deep
What are coastal fronts?
Areas of low level baroclinic zones separating warm ocean waters from cool land temps. Signature looks like CAD signature
What is the difference between single cells and multicell?
Single cells are short-lived and disorganized
Multicell are systematic and there is the triggering of new cells near the parent cell
What does a supercell have that the other cells do not?
Rotating updraft
What is the most important aspect in determining thunderstorm development?
Wind shear specifically 0-6 km shear
What are the 4 ways to keep a storm around and act to make them go multicellular?
1) Evacuation of precip from the updraft- don’t want precip to fall into the updraft
2) Storm rides the outflow(downward flank)- SRW are away from downdraft allowing to maintain updraft
3) Outflow that storm is riding produces low level convergence- creates chance to pop new cells along
4) Linear dynamic term- in presence of shear pushes flow more vertical allowing parcels to reach LFC faster
What are the stages of thunderstorm development?
Towering cumulus-all updraft
Mature- evident updraft and precip reaching ground
Dissipating- all downdraft with precip
Orphan anvil- hardly any precip reaching ground
Why is the density current faster with easterly shear?
Bc using U= V-(c+V) shows that U=10-19=-9 where 10 is ground relative wind and 19 is density current. Easterly wind shear along with weak U act to push the updraft over the current instead of pushing it upright like the westerly care
What is the horizontal temp advection term?
-d/dz(-V•delT)
What is the vertical advection of lapse rate term?
-w(d|^/dz)
What is the stretching term?
dw/dz(|^d-|^)
