bluewave

Warmest January SSTs on record east of Japan provided the fuel for the new all-time heaviest snowstorm there.

One of the least favorable winter patterns we have seen for Arctic sea ice thickness.

We have no idea how long this will continue past the 20th since this is more of a reflective event which is subject to reversal longer range.

We can trace it back to the wave break last week with the record low just east of Hudson Bay due to the enhanced temperature gradient after the +11°C January.

With gradient patterns we generally have to take it one storm at a time. Since each storm coming through the fast flow determines exactly where the gradient will be for the storm behind it. So I agree with the sentiment that any snowfall forecasts beyond around 5 days are very uncertain. Typically the snow to mix to rain occurs between I-78 to I-84. But it’s possible that after the 10th we can get a storm or two that comes in a little further south than over the next week or so. As for the longevity of this pattern it’s even more uncertain beyond the 20th. So just enjoy the active pattern for now.

Thanks. Moved in near the end of the summer back in 2023. Enjoying the much better radiational cooling than I had back on the LI South Shore. Not too far from the Sound so still get great sea breezes in the warm season.

I am definitely doing better here along on the CT Shoreline than I was back on the LI South Shore with these type of gradients. Picked up 3” earlier and still have 2” left on the colder surfaces. High of 43° here today.

We can trace the -AO development back to that big wave break with the record low east of Hudson Bay last week. It lead to a near record Scandinavian Ridge which will retrograde back toward Greenland. Hopefully, something happening near Hudson Bay can finally be of some benefit this winter. By Central Jersey I am referring to anything from the I-78 and south for posters in that area.

While this is still very much a La Niña base state, a -AO signal emerged over the last 3-4 days of runs for the mid-February 10th through 20th period. The AO has been very volatile in recent years with big swings to positive and negative over short periods. Hopefully, the gradient can sink far enough south over that period for Central NJ to cash in. But it’s still very uncertain where the gradient will settle. Short range features like how amplified the trough out West gets along with AO strength will probably have to wait a while. That being said, it’s uncertain how much beyond the 20th the -AO can last with the fast changes we have been seeing in recent years.

Definitely could be. Having the Southeast Ridge allows the WAA near 750 to 850mb to push the temperatures above freezing. This is what we are seeing forecast for the next several events through around the 10th. The models like the NAM actually do pretty good with this warm tongue once within around 48 hrs. Beyond February 10th things become more uncertain as to where the gradient will settle. A slightly weaker -AO than forecast could allow the Southeast Ridge to flex a bit more than the current long range forecasts indicate. A stronger -AO could suppress the Southeast Ridge a bit. Plus a wildcard may be how strong a vort diggs into the West.

That period may serve as a test of how far south we can get the gradient. Real battle setting up between the Southeast Ridge and -AO block over the top with its high pressure. Hopefully, we can eventually get the gradient far enough south so the areas closer to Central Jersey can cash in a bit. But with so much pattern volatility, we may not now how far south the gradient eventually drops this month until we get to within about 120 hrs of the event.

The period starting around the 12th could be our first shot at a coastal development.

3” here just to the east of HVN. It’s nice to be in Southern New England for these gradients. Also one of the thicker fogs over a fresh snowpack since I moved up here.

Yeah, my point was that it was more a blend of forcing influences across the tropics rather than one well defined MJO pattern like we have seen in recent winters. This goes back to my research with the very strong forcing which occurred near the Maritime Continent back in October. The past La Niña cases similarly saw weaker MJO 4-6 activity from December into January with +PNA and -EPO mismatch patterns for La Niña. The opposite was true with weaker MJO 5 October La Niña patterns and then stronger through the winter. So there has been a well defined inverse relationship with the October to winter patterns. We can see the blend of forcing across the tropics from January 1-20. So we didn’t get the coherent MJO 8 response and 30 inches of snow at Islip which occurred in January 2022. The late January forcing near the Maritime Continent was more the La Niña interseasonal forcing shift which occurs closer to the start of February. This is why the Southeast Ridge typically emerges during La Niña Februaries.

If the EPS 500 mb look verifies, then you would probably want to see more coupling than we have seen so far this season. This is why the -AO back in January faded pretty quickly. With coupling we would get more than a 5-7 day window where the gradient can finally sink to our south.

There was no real forcing in the 8-1-2 regions. It was mostly In the 4-5 regions. So the +PNA -EPO -AO Niña mismatch pattern was being driven by something else. But it’s possible that the background forcing in 4-5 may have lead to the unfavorable Pacific Jet response. Since Suffolk got 30 inches of snow with a legit MJO 8 back in January 2022. Notice how much more favorable the forcing was closer to and east of the Dateline in January 2022 than in 2025.

The stratosphere and troposphere have been decoupled this winter. So our fortunes will probably rise or fall on what happens closer to 500mb. Hopefully, the EPS ends up being more correct than the other guidance day 10 to 20.

The MJO hasn’t been driving the pattern this winter. This has been a combination of tropical forcing in multiple regions. So expectations based on past MJO events haven’t worked out.

You want the gradient to drop to our south. Otherwise it’s just a bunch of front end thumps changing to rain and 40s. The EPS had a better look beyond 10 days than the GEFS and GEPS. At least a ridge bridge like over the top the EPS is advertising beyond 10 days could introduce a BM track potential for maybe around 5 days. But the whole mid-February pattern will come down to the EPS scoring a win before the pattern begins relaxing later in the month.

The 5 day window would be the amount of time we could get the gradient to our south for more than just overrunning mixed precipitation events. You want the gradient to our south for a BM track. So when the pattern begins to relax we get a coastal development that takes a BM track. No guarantees yet since the GEFS and GEPS are weaker with the blocking. So we just have to let this play out and see if the Euro score a win with the much stronger blocking.

Hopefully, the EPS can score a win here in mid-February. The GEFS and GEPS aren’t as strong with the blocking. But the EPS verbatim is a very nice look. My guess is that if the EPS is correct we’ll probably get a 5 day window before the pattern relaxes later in February.

So far this has been a -1.2° winter across the area from December 1st through January 31st. Jan 2025 EWR…-1.4° NYC…-2.5° LGA….-2.0° JFK…..-0.2° HPN….-1.6° BDR….-1.3° ISP…...-1.5° AVG…..-1.5° Dec 2024 EWR….-0.1° NYC….-0.9° LGA…..-1.0° JFK…..+0.1° HPN….-1.6° BDR…..-1.3° ISP…….-0.6° AVG….-0.8° AVG through 1-31….-1.2°

1976-1977 was in a class by it self. The late 1970s was the last time the U.S had a top 10 coldest winter. The same for our area also. These days we need strong northerly flow to get closer to 0° like we saw in early February 2023. Back in the 70s to early 90s Canada and the Great Lakes we cold enough so NYC could get to -2° and Newark -8° on westerly flow.

Textbook La Niña progression heading into February. The -EPO ridge pulls back to the west allowing the Southeast Ridge to rebound. So February is in track for our first warmer than average temperature departure month this winter.

Combined effects from climate change. The warmth in the Great Lakes plus Hudson Bay were the result of the record warmth in Eastern Canada. So when you have a strong 500 mb low east of New England circulating air from these relatively milder regions the end result is that the cold over the Northeast gets muted. The colder departures to our south this month tracked from the region west of Hudson Bay which was colder. Plus the extent of Arctic air across the Northern Hemisphere was at a record low this winter. So if we had the amount of cold that was available in past decades, Canada and the Northeast would have been much colder.