Yes, we had a cold blast this week, but that’s only part of the transition to what I expect for the heart of the winter from mid-late January thru February.
You’re not going to go from record warmth in December to hard core winter without the proverbial two-steps forward, one-step backwards.
Unfortunately when a seismic pattern change is in the process of occurring, you’ll often get a big hiccup before we make it to the other side.
Sunday will be a case in point with yet another storm tracking to our west:
It’s every bit as grizzly as it looks! Temperatures in the 40s with rain (possibly heavy) to knock out much of the thin snow cover we’ve got now.
But mercifully, colder air rushes back in for Monday and gives us some lake effect snow:
This appears to be a relatively short duration effect, so it probably won’t be a major dump for the western ‘Dacks. But at least it will put some white back.
After the hurt…
Several days ago, many of the computer models were indicating the possibility of a significant snow event for Sunday night into Monday. But as I say, the demons always lie in the details! In this case, the storm will develop almost a day sooner than was expected and track to our west, instead of taking a track along the coast if the storm had developed later. Small detail on a hemispheric scale, big results in the actual weather.
Notwithstanding our lost “opportunity” and subsequent hurt this weekend, the long-advertised massive pattern change continues to evolve.
The ensembles are clustered around a massive tank into the negative phase of the Arctic Oscillation:
And, we have a good plunge into negative territory for the North Atlantic Oscillation:
I totally believe this will happen, because the weakening I expected to occur in the stratospheric Polar Vortex is occurring now. This phenomenon is a direct cause of the dramatic shift in the AO/NAO.
You can check out the analogs of what AO-/NAO- do for us in January:
The ECMWF ensembles are showing a pretty good pattern for mid-January with the Polar Vortex rooted over Hudson’s Bay and sub-tropical energy rotating around the base of the vortex:
Due to the massive changes happening to the stratospheric Polar Vortex, the operational models will continue having fits as to placement and timing of significant storm systems. I believe it’s more of a question as to WHEN we get that big snow instead of IF it will happen. This type of pattern will give us a cold and snowy weather regime if it sits there long enough.
El Niño?
Still here, but weakening…
The CFSv2 ensembles show the core of the warmest anomalies between 120W and 180W in February which resembles the “Modoki Niños” much more than the eastern-based Niños of 1982-83 and 1997-98:
“Modoki Niños” tend to pump up PNA+ ridging and promote cold and snowy weather in the eastern United States.
Bottom line:
The dominoes are falling into place and time is still on our side!
Remember this is a marathon, not a sprint. The turnaround from a December that averaged 12-14 degrees above normal to what we have now is amazing, but there is more road to travel before we get to where we want to be.
For the ilsnow nation,
Darrin
