Eta 24 hour forecast cross-section of divergence and omega (shaded) valid at 1/6/05 12 UTC.

Slide Links:

Speaker Notes:

The large-scale lift associated with the QPF was generated largely as a result of persistent upper-level divergence in the right entrance region of the jet maxima over northeast New England, and convergence along a sloping frontal zone across the northern mid-Atlantic region. This slide shows a cross-section of divergence and omega, taken across the northern mid-Atlantic region at 12 UTC on the 6th. Note the pronounced maxima of mid-level upward vertical motion associated with the couplet of convergence (associated with the sloping frontal zone) between 700 and 500 mb, and divergence (associated with the jet entrance region) between 400 and 300 mb.