The GFS has been consistent in showing a major early season shot of cold air reaching the region in the beginning of October. A shortwave will be moving through southern Manitoba Sunday evening (9/28) as high pressure builds in over the Atlantic, and western US. The PNA isnt going to budge much from its +2.6 SD status at the moment and the AO and NAO are both projected to become negative within the next three days. The shortwave in Canada will reach the Great Lakes region Monday evening (9/29), and continue to deepen, eventually closing off at 546dm by Wednesday morning (10/1). The low deepens to 534dm in northern NY by Thursday morning (10/2). The 850mb 0C isotherm drops south of DCA, and the 850mb temperatures drop to -4C at KEEN. This is all according to the 12z run of the GFS, but hasnt strayed much from what the last few days has shown - which is light precipitation (.1" / 6hr) during a period of below freezing temperatures at KEEN - snow? Unlikely since this forecast is still 9 days down the road, but something fun to keep an eye on.
|posted by Sam Lillo @ 9/23/2008 12:13:00 PM
