Yeah, little in the way of progress toward a consensus 4-6 day outlook this evening.
Divergence point posted below (ECM on the left, GFSP right):
The focus region is the eastern third of the U.S/Canada and the westernmost N. Atlantic.
Look at the ridge/trough combination and the differences become clear; ECM makes less of the ridge and doesn't dig the trough as far south as GFSP.
GFS is close to GFSP (having increased the ridge strength since this morning) and UKMO close to ECM.
A stronger ridge leads to earlier phasing while also 'holding up' the progression of lows from the U.S. to the Atlantic.
So, who's got the better handle on the U.S. pattern at 4 days range, the American models or the European ones? I would be amazed if this wasn't sorted out by tomorrow evening. Each new set of runs will be edge-of-seat stuff.
The MJO update today shows that it has amplified beyond even the most vigorous of yesterday's model outlooks (GEFS still the only one even close. It's been miles ahead of ECMF with the accuracy) - as suspected given the GFS/GFSP trend. Yet the lack of response from ECM/UKMO places the idea of influence at such short range under question.
The ECM 12z op shows how that version of events can still set up a sliding lows/Scandi High situation in the longer term (by keeping the Azores High well to the west), with cold air still being drawn into the mix while we wait - but it's generally marginal for snow and trough development to the NW remains an issue, though weaker than we are seeing in the short term:
So concludes looking ahead for the time being. Focus is now shifting to short-term rain, wind and possibly snow.
Originally Posted by: Stormchaser