Well, still a ton of uncertainty about the evolution of the Pacific trough. In fact, all 4 of today’s GFS runs from 00z to 18z are markedly different from each other. Evan all four of todays GFS Ensemble suite of members show a lot of difference (below)….

This means very low uncertainty for sure! I think there is a continued signal, though, that Wednesday the 24th will indeed be a chase day… and most likely north of 40°N latitude (i.e. north of the KS-NEB line).
GFS 500mb:

GFS Surface:

Not shown, but the 18z GFS valid May 25/00z shows the storm system over the Northern Rockies…with nice 40-50kt west to west-southwest flow across much of the northern plains… even as far south as southern Kansas. I honestly do not know where to place today’s “GFS Deterministic” chase target dart… A compromise between the 12z and 00z run suggests northern KS into northern Nebraska… so I’ll shift today’s dart a little farther southeast I think
This is fun! I think…

Mike,
I have never been to the Dakotas…should be interesting! I’ll bring my passport too.
Comment by Stacie Hanes — May 18, 2006 @ 3:56 am