We will be getting the cold very soon. Winter arrived on the 15th. I already explained that. However, the heart of winter, also delayed a bit, will arrive on the 26th.

Another teleconnections overview:

The AO has started to tank. Yesterday the AO reached a neutral status for the first time in two months. The ensemble forecasts continue to bring it into the negatives at least for a day or two, before moderating out in February.
While the NAO and PNA are also helping the cause, their trend is not as huge as the 4SD shift of the AO from its record high level earlier this month. Now we have a shot at some true cold!

But wait!
Where's the snow? Yeah, that question is going to come up a lot. My first look at the the Jan 15 to Feb 1 pattern back in early January gave me confidence in a shift to winter finally. Storminess was also indicated, however details cannot be worked out that far in advance. Even 3 days in advance, things can change drastically. I would like to point out also that the above average storminess is verifying, only the details of it just didnt work out to our advantage. The various model forecasts back on Friday showed us that a huge storm was still in the making for the time period I gave earlier this month (23rd now shifted to 24th-25th). I suppose that when the internet explorer window loads the image of a massive sub 980 low striking Cape Cod during a winter that has been unsatisfactory to say the least, we tend to jump on board. A few wise meteorologists out there did not buy the apocolyptic solution shown by the GFS, because of the Euro's shift eastward. At this point, it appears that they will have been very wise in doing so. I should also include the recognition that the NWS gave the GFS on Friday and Saturday. While they were smart and stayed conservative as usual with the storm, Keene peaked with 50% POPs on the 5 day forecast. I think that reliance on single model solutions did in many pros and amateurs for the 19th storm and the 25th storm.

Im not going to 100% discount the 25th threat yet. It is 60-72 hours out and still has some potential, however Im 90/10 on this storm not happening here.

The cold story still holds. The northern stream low that may phase with the southern low, will deliver a reinforcing shot of cold air for late in the week. We may be looking at our coldest highs and lows so far this season in much of the northeast. The latest NWS forecast for Friday stops us at 8 degrees and drops us to -3 Friday Night. This along with increasing winds on the backside of the low bombing out to our east, will send windchills possibly to advisory level.

The NWS is going with the euro on a brief warm up on Saturday back to near 20 ahead of another northern storm that will eventually take us into the dead of winter again next week. In addition, the Euro brings a polar vortex into the Great Lakes region late next week.

This period should be drier than normal, and I like the current CPC 6-10 and 8-14 day outlooks for precipitation and temperature. Dry, however, does not mean nothing. And with cold in place, anything we get will be in the form of snow.

Here's some bullet points for the rest of January into February:

• High confidence in below normal temperatures through February 10th.


• Medium confidence in record breaking arctic cold February 1st through the 7th.


• Medium confidence in a significant winter precipitation event during the month of February.

As for late February (I may be getting in over my head, but oh well), whether cold continues into the second week of February will be determined by the state of the teleconnections. The current +PNA ridge in the west is allowing for cold air to be funnelled in from Canada. This ridge will likely break down as the jet stream sends more vortices southward into the Great Lakes region. For the first week of February, this will not affect us as troughiness continues to support temperatures well below average in the east. However, once the AO rises back from the negatives, a midwest ridge could develop, allowing for a brief continuation of cold before that ridge shifts eastward. The timing of that shift will be affected by the NAO, which will remain negative and support strong blocking through the 7th. Once the NAO becomes positive, the blocking weakens, allowing for a transient pattern to begin, shifting the midwest ridge into the east. So, in short, the temperature forecast for late February rides on the NAO.

As for storminess, the current state of the AO and PNA support ridging into the midwest states. This is too far east for a connection between the northern and southern jets over New England. Also, the ridge is acting as a blocking mechanism for disturbances riding the southern jet into the southwest. These two factors are what is limiting the storm potential on the 25th. We have the cold, phasing occurs too far east because the ridge to our west is pushing the southern storm eastward too quickly and energy for the southern storm is limited by the ridging, which would normally assist in recurving the storm northward. A change to a -AO and -NAO will help shift the entire operation westward, with blocking forming over Greenland and the ridge breaking down in the west. This will open up an opprotunity for storminess between January 28th and February 1st, before the -NAO blocking shifts eastward sending southern jet disturbances out to sea. The 2nd through the 8th will be a period of especially dry weather, with our only precipitation triggers as relatively dry fronts from the north. When the NAO does strengthen back later in February, 10th to the 20th, we have another shot at a stormy period as troughiness moves into the midwest and pushes a southern stream low into the OV eastward.
With the second storm, there will likely be precipitation type issues, so our best bet, and where my highest confidence lies is with the late Jan / early Feb threat.

More climate information later this evening.