Rain, Snow, H5 low nowhere to go

The GFS and ECMWF, before in disagreement with the GFS favoring a northwest / warmer solution and the ECMWF favoring the opposite, have switched places. The 12z Euro came in warmer, and west of the GFS. The 18z GFS has since then trended toward the Euro. The ECMWF is in its perfection range, where it is hard to be countered, and usually the GFS, if in disagreement, just matches up with it in the end. That may be the case here, except for the fact that neither models have been consistent. Continued flip-flopping may occur through the weekend. The storm is entering the NAM forecast range, with the 84hr forecast on the 18z run covering 06z Tuesday. In its longer range, the 18z has shifted south, and dug the trough deeper than the 12z. It matches up decently with the 18z GFS. The long range of the NAM isnt to be relied on however, and shouldnt be considered heavily until within 48 hours.

So, right now, it looks like precipitation may start as snow late Monday night, and begin to mix with rain through daybreak Tuesday, probably changing to all rain after 7am. There could be a period of freezing rain in there as well. And with the antecedent cold, some accretion is possible. Rain for most of Tuesday, ending as snow showers Tuesday Night. Snow through Tuesday afternoon (essentially occuring around midnight to 8am Tuesday) could accumulate to an inch or so mostly in the higher elevations.

Based upon icing potential combined with a sloppy snow accumulation, delay potential still exists Tuesday morning.

The GFS senarios have been very interesting for the past 5 or so model runs. It shows the H5 low holding tight over New York through the end of next week, becoming a very anomalous 300m-closed 5280m low. The surface low reflection is uncertain, however, with this set up, we would exposed to frequent snow showers through the end of next week. The placement of potential coastal development around Thanksgiving could lead to an increased threat of snow.