bluewave

February 11-12 will be the make of break moment for the entire winter so far around NYC Metro. That 0z OP Euro was similar to the multi day KU event at the same time around 2-11-94 with that gradient. So getting the gradient to settle just in the right spot will key here to getting a more memorable storm around NYC. It’s why we need these big KU events for normal to above normal seasonal snowfall. But we really have to take the next few storms first to see what the actual track will be. Since the exact wave spacing and gradient location left in the wake of the previous storms will determine whether we can get something really special or not. Just 30 miles can mean everything for a spot like NYC.

Classic case of hydroclimate volatility which makes accurate long range precipitation forecasting very challenging in the new climate. https://weatherwest.com/archives/43181 Hydroclimate volatility broadly refers to unusually rapid and/or high magnitude swings between unusually wet and dry conditions (or vice versa) relative to what is typical for a given location and season. Such rapid transitions can often generate hazards that are distinct from their constituent wet and dry extremes (e.g., floods and droughts), meaning that hydroclimate volatility can yield overall societal and ecological risks that are “greater than the sum of their parts.”

Yeah, they just exceeded that old record set back in 2022.

Today is a great example of how much of a change can occur with an ensemble mean from 360 hrs to 240hrs. The biggest change at day 10 is the much deeper trough digging into the West around Valentine’s Day. So any speculation based on the present 360 hr run is going to look different when it gets to 240 then 120 and 0 hrs. This is why you want to maximize opportunities closer in since you don’t know what the pattern is going to look like from day 10 and beyond. New run Old run

This is the first time we had a gradient pattern in the 2020s with the SE Ridge battling blocking over the top.

I agree. The risk with gradients is that we get mixed precipitation events when the systems really amped like the next few. Then if a system is too weak the confluence to the north can be too strong leading to suppression. What we want next week is a goldilocks scenario right in the middle.

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.