EML's -- packets of  desert air that originate in the inter-mountain west -- are often invoked to explain severe weather as far away from the Rockies as New England.  For several months I have been puzzling how such dry (heavy, dense) air could maintain its coherence and altitude while passing the two thousand miles from ABQ to BDL.  To put the question in the least technical way possible:  Why wouldn't it fall down?  Looking at SKEW-T's I see that such parcels of air are fairly common in the Ea