bluewave

The warmer ending to January pushed the local 7 station average up to 30.7° or a -1.8° departure. The last time all 7 stations finished below 30° in January was back in 2014. The most recent January that all 7 stations finished under 26° was back in 2004. Other Januaries averaging under 26° were 1994, 1982, 1981, and 1977. So while we have had a few slightly colder Januaries since the 15-16 super El Niño like 2022 and 2018, the coldest January temperatures and departures have been missing the area. EWR…31.1°…..-1.7° NYC...30.9°….-2.8° LGA….32.0°….-2.4° JFK….32.7°….-0.2° HPN…28.0°….-1.9° BDR…29.9°….-1.5° ISP…..30.1°……-1.8° AVG…30.7°…..-1.8°

There was a 95 inches of snow report from New Haven for the 1779-1780 season. https://www.nps.gov/morr/learn/historyculture/hard-winter-news.htm ALL REPORTS INDICATE THAT THE WINTER OF 1779-80 IS THE WORST WINTER EVER KNOWN IN THE NORTHEAST UNITED STATES David M. Ludlum in his book Early American Winter 1604-1820, in the chapter on “The Hard Winter of 1779-80” writes that it was “the most hard difficult winter….that ever was known by any person living. There has been only one winter in recorded American history during which the waters surrounding New York City have frozen over and remained closed to all navigation for weeks at a time…the Hard Winter of 1780.” According to Ludlum, January 1780 rated as the most persistently cold calendar month in the history of the eastern United States, and “The severity of the 1780 season reached all parts of the colonies. Reports from Maine southward along the seaboard to Georgia, and from Detroit down through the interior waterways to New Orleans, all chronicled tales of deep snow, and widespread suffering.” Ludlum believed that his research definitely showed that the season of 1779-80 in the eastern United States well deserved the name given to it by the people that experienced its effects….The Hard Winter. EYEWITNESS ACCOUNTS SUPPORT THIS BELIEF William Smith (a loyalist living in New York City) records in his diary that on January 16, 1780, people were walking across the frozen Hudson River from New York to Paulus Hook (today Jersey City) New Jersey. A Hessian soldier, Johann Dohla recorded in his diary on January 30, "The North (Hudson) and East rivers are frozen solid. The ice was checked and found to be eighteen feet thick. All ships were frozen in, and it was possible to cross over the North (Hudson) River on foot, riding or driving, without fear." Later, (on February 22) Dohla wrote "Today the North River ice began to break, after having been frozen for nearly seven weeks." A German officer, Major Baurmeister wrote, "The severe winter covered the North River with ice early in January; even where the current of the river is swiftest, the ice was eleven feet thick, in spire of the fact that it is 1800 yards wide between Fort George (today Battery Park, New York City) and Powles Hook." February 1780 seems to have been even colder: On February 10, William Smith mentions in his diary that a few days earlier a "24 Pounder" (that is, a cannon that fired a solid ball weighing 24 pounds - the entire cannon weighed three tons) was rolled across the Hudson River to Paulus Hook (today part of Jersey City, New Jersey.) Smith goes on to say that even a heavy load as this it made no impression on the ice. On the night of February 10th, Smith heard that four to five hundred British cavalry rode their horses across the river. MANY ACCOUNTS MENTION UNPRECEDENTED CONDITIONS A teacher in Yale College (New Haven, Connecticut) recorded approximately twenty days with snowfall, and a total of 95 inches of snow that winter. People walked across the Sound from Stanford, Connecticut to Long Island. Others walked from Rhode Island mainland to Block Island. Chesapeake Bay and the York River in Virginia froze over for the first time since Europeans settled there. Many people mentioned in letters that they could not remember a winter as bad.

Imagine how many posts the January 1780 thread would have had if online weather forums were around in those days.

Similar pattern to December when the cold departures got smaller during the last week of the month. EWR…-1.8 NYC….-2.9 LGA…..-2.4 JFK…..-0.2 HPN….-1.9 BDR….-1.5 ISP……-1.8 AVG….-1.8

I was discussing the +PNA mismatch La Niña potential for December into January back in the La Niña thread during October. The very robust MJO 5 this October I pointed out back in October thread preceded La Niña winters like 2020-2021 and 2017-2018. But at the time I was also highlighted that there were other things about this event that didn’t match past analogs. While we got the -EPO+PNA, and -AO, the Pacific Jet didn’t relax like it did during earlier mismatch La Niña Decembers into January. So we got the lowest snowfall for this type of pattern compared to previous years. The clue I picked up on back in October was the change in tropical forcing from the 22-23 La Niña indicating that the warm MJO phases would be inactive this winter so far. And that has been the case with the recent patterns not matching the typical MJO phase composites. For some reason stronger MJO 5 October activity during La Ninas since 2010 have preceded weaker MJO 5s from December into January. And the La Nina’s with weaker MJO 5s in October followed with stronger MJO 5 into the early and mid winter. Click on top right arrow to read post

Today was a great example of how much models like the Euro have been struggling with all the westerly flow in January. The EPS had a 11 day run of NYC not getting above 32° which was much too cold from the 6th to the 16th. Then had lows near 0° last week around NYC which were around 10° too cold. Same today with the Euro having a high at JFK of 46° which was 9° too cool for the 55° high. This is why the monthly average temperatures came in several degrees above the forecasts from earlier in the month. They should develop a way for AI to fix this cold bias.

2004 was the last time that JFK had a top 10 coldest January. There have been 5 top 10 warmest Januaries since 2002. The last below 0° reading at JFK was January 1985. Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Jan Click column heading to sort ascending, click again to sort descending. 1 1977 21.9 0 2 2004 24.6 0 3 1968 25.6 0 4 1994 26.3 0 5 1981 26.5 0 6 1982 26.7 0 - 1970 26.7 0 7 2003 27.6 0 - 1961 27.6 0 8 1971 27.9 0 9 1976 28.0 0 10 1957 28.2 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Jan Click column heading to sort ascending, click again to sort descending. 1 1985 -2 0 2 1982 -1 0 - 1977 -1 0 3 1994 0 0 - 1968 0 0 4 2004 1 0 5 1976 2 0 6 2019 3 0 - 2014 3 0 - 1957 3 0 7 2018 4 0 - 2000 4 0 - 1997 4 0 - 1988 4 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Jan Click column heading to sort ascending, click again to sort descending. 1 2023 41.8 0 2 1950 40.5 0 3 1998 39.6 0 4 1990 39.4 0 5 2006 39.1 0 6 2002 38.9 0 7 2020 38.7 0 8 2017 38.6 0 9 1949 38.1 0 10 1975 37.9 0

Yeah, JFK is up to 55° now. So they won’t be able to finish January below 32° like they did back in 2022. The last really cold January at JFK was in 2004. I can remember Reynolds Channel at the Long Beach bridge nearly frozen all the way across. Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Jan Click column heading to sort ascending, click again to sort descending. 2025 32.2 3 2024 36.0 0 2023 41.8 0 2022 30.3 0 2021 34.8 0 2020 38.7 0 2019 32.4 0 2018 30.2 0 2017 38.6 0 2016 34.6 0 2015 30.7 0 2014 28.6 0 2013 35.0 0 2012 37.2 0 2011 29.1 0 2010 32.1 0 2009 28.7 0 2008 35.3 0 2007 37.3 0 2006 39.1 0 2005 30.5 0 2004 24.6 0

Would be great to know exactly what the trigger was for the rapid acceleration in global temperatures back in 2023. Since it occurred much sooner than past El Niños that were much stronger and has lingered beyond anything in the past into a La Niña. It may very well be that we have just have experienced some type of nonlinear or threshold event on a global scale.

Westerly flow downsloping winds were much colder in the 1970s than today. Canada was significantly colder back then than they were this month. Plus much of the Great Lakes were frozen over that winter. Not to mention a much larger cold pool across the entire Northern Hemisphere. So the broader source region and geographic extent of the cold is very important. Notice that NYC didn’t get below 10° this month with the westerly flow. From the 1970s to early 1990s NYC could get to -2° with westerly flow. These days NYC needs northerly flow to get down closer to 0° like they did in February 2023 when they reached 3°. It’s no coincidence that February 2016 and January 2004 Arctic outbreaks near 0° around NYC were northerly flow events. This is why I posted early on that the Euro and EPS were way too cold this month here. Remember when the Euro had near 0° around NYC this month. The GFS had upper single digits which was closer to reality. The world was a much colder place in January 1977. So the -EPO +PNA -AO pattern like this month had a tremendous Northern Hemisphere cold pool to work with. That wasn’t the case this time around when the world just experienced its warmest January on record. So these teleconnections were much warmer this month.

What theory are you talking about? The planet has warmed tremendously since the 1970s. So even a roughly similar 500 mb pattern won’t be as cold.

These were some of the strongest westerlies since Janaury 1977. So this used to be a much colder pattern. Janaury 1977 was nearly 10° colder on average around the area than this month was. But at least we can brag that we got some version of the Jan 77 analog to repeat in a much warmer fashion.

Tomorrow looks like the kind of westerly flow day that high temperatures and winds can beat expectations with the very steep lapse rates and deep mixed layer. A 45-50 day for temps and wind gusts. This has been the strongest westerly flow January of the 2020s.

It’s been the storm tracks since 18-19 which have been main the issue. The much faster Northern Stream of the Pacific Jet has resulted in the predominant cutter, hugger, and suppressed Southern Stream storm tracks. The KU BM track has been missing much of this time with a brief appearance during 20-21 areawide and more localized in January 22. But January 22 was a little too far east so areas further west missed out. This is why we had some of the lowest snowfall totals on record for a La Niña December into January with a +PNA, -EPO, and -AO pattern this year so far. The faster Northern Stream of the Pacific Jet didn’t relax like it did during past La Niña years with strong +PNAs and -AOs. Now that the 500 mb vortex is relaxing east of New England the Southeast Ridge is returning. So we will lose the suppressed storm track risk and substitute it for a hugger or cutter blend risk of warmer potential at the coast. At best maybe we could put together a smaller or maybe moderate event at some point in February. But it’s not looking like a BM KU which is necessary to get us above 20” is on the horizon. La Nina’s are usually frontloaded by nature. So many times the highest seasonal events would have occurred by February 1st. The big question now is if we will be able to go over 10” on the season. Still too early to tell if that will be the case before the season ends. But it’s not a bad thing to keep some hope going for such an occurrence. Last February actually had a much better storm track pattern for snow than anything we have seen this year so far. Record breaking STJ pattern in mid-February since it was an El Niño which are backloaded by nature. But that was only a one week window and many areas missed that great event in Central NJ. But some areas did very well with a +5 departure. Much better than the -2 to -3 this month. So it comes down to storm tracks since it’s usually cold enough to snow this time of year even during winter months that average closer to 40°. It’s just if you want a 50” season near NYC the winter average needs to be near 32° with great BM KU storm tracks. But this hasn’t happened since 13-14 and 14-15. So this month I would be more concerned with trying to get a better storm track rather than whether we get a +1 departure or something closer to +2 or +3. Since either way it will be cold enough to snow. The most important temperatures are on storm day with the right storm track. March is a different story as we need both good storm tracks and cold enough temperatures for snow. Since even an average March in the low around NYC 40s can be marginal for snow. We had a great run of colder Marches from 2010 to 2018 with cold and great storm tracks. But the Marches in the 2020s so far have featured both too warm to snow and unfavorable stoem tracks. Even with the great -AO in March 2022. So we are going to need a return to KU MB storm tracks next 3-4 years in order to avoid the lowest 10 running means for snowfall that we have ever seen. Absent a big shift, the current 5 year mean near 14” in NYC and surrounding sites will become a 10 year average which has never happened before. Same goes for several coastal sites. The BM KU tracks need to return in a big way in order to avoid the first decade average well under 20”. We don’t have the colder climate of the past which would give us over 20” with frequent small to moderate events which was common before the 90s. Several years didn’t need KUs to get above 20”. All our average to above average seasons since the 90s have required KU events with a 10” or 12” max somewhere between EWR and Eastern Long Island.

It’s why areas most east of the Hudson this month couldn’t come anywhere close the lows from early February 2023 with that impressive northerly flow which avoided the Great Lakes.

High winds plus the record January cloud cover coming off the lakes both worked in tandem to warm the minimum departures. So it’s no surprise that the brief radiational cooling around the 22nd occurred during a relaxation of the flow over the Lakes in conjunction with the snow cover. It’s also true that the stronger winds across the Great Lakes picked up clouds and downsloped into JFK adding enough warmth so JFK only dropped to 13° which was a little warmer than the 12 in December. This was only the 3rd such occurrence of the January minimum not exceeding the December minimum at JFK in 24 years. So this January can make for an interesting study of the highly anomalous temperature pattern in the Northeast relative to areas further south. Northern Maine going +5 with West Virginia at -10 never occurred before in modern times during January. Add in the warmest year on record in Canada and latest freeze-up on Hudson Bay along with record Great Lakes warmth to start the season. And we can’t forget the near record 500 mb vortex east of New England for any January acting has a huge gyre causing the flow to travel down from the Hudson Bay and across the Great Lakes. The rapidly warming climate especially since mid 2023 continues to set records. Monthly Lowest Min Temperature for New York-Kennedy Airport Area, NY (ThreadEx) Click column heading to sort ascending, click again to sort descending. 2024-2025 12 13 12 2023-2024 25 18 18 2022-2023 7 29 7 2021-2022 24 9 9 2020-2021 18 15 15 2019-2020 17 19 17 2018-2019 24 3 3 2017-2018 9 4 4 2016-2017 19 13 13 2015-2016 34 12 12 2014-2015 26 8 8 2013-2014 20 3 3 2012-2013 28 12 12 2011-2012 21 13 13 2010-2011 19 6 6 2009-2010 16 14 14 2008-2009 14 7 7 2007-2008 20 14 14 2006-2007 19 9 9 2005-2006 15 14 14 2004-2005 12 6 6 2003-2004 21 1 1 2002-2003 18 7 7 2001-2002 21 22 21 2000-2001 14 15 14

The ridge emerges in the Southern Plains first than expands eastward over time through the Southeast and eventually Mid-Atlantic and Northeast.

Yeah, the much warmer minimum temperature departures than the maximums across the Northeast this month were very obvious.

Those charts don’t go back that far since they are more geared for modern departures. If we use the 1871-1900 January means for NYC, then this month so far is +0.3° rather than the -3.5° of 1991-2020. But even getting an average January vs the older climo is an accomplishment these days. The last really cold January in NYC was back in 2004. That was the 11th coldest January on record. So even using the 1871-1900 means it was still -5.2°.

You can see how the small cold departure over the area back in December disappears as we go back to the earlier climate normal periods.

The storm track pattern is shifting back to the Great Lakes now that the Southeast Ridge is making a comeback. So warmer storm tracks are now the risk rather than suppression. At least we can use the rainfall which is preferable to a dry suppression pattern.

They began to use 30 year departures as the basis for the climate normals when we were in more of a stable climate regime prior to 1980. This was in the era before the rapid climate warming took off from the 1980s especially into the 2020s. In those days the departures were more aligned with the top 10 coldest and warmest months. So a -3 month now is close to normal for earlier period. No chance any more of a top 10 or even top 20 cold month with such a departure. But a +2 to +3 month can be top 10 or top 15 warmest with ease. This is why portions of the Northeast have had over 50 top 10 warmest months since 2010 to only 1 top 10 coldest. The global temperature monitoring sites use an earlier baseline like 1850 to 1900 and don’t have this issue.

Read my original post that you quoted. The modification west of the Great Lakes is probably more related to the warmth adjacent to that region in Canada. Plus the modification in areas like Minnesota and Wisconsin is obviously less than that experienced here in the Northeast from the maps I posted. So your characterization of the maps is incorrect.

We had several factors in play. Warmest year on record in Canada. With the secondary effects of delaying the freeze-up on Hudson Bay and the Great Lakes. So this lead to the surface temperature departures modifying much more than the 850 mb temperature departures near and to the east of the Great Lakes with the dominant westerly flow. So the core of the cold departures at the surface was significantly smaller than at 850mb.

January 1985 was the last time that I got to experience wind chills close to -30° on the Long Beach Boardwalk. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=46&network=NY_ASOS&zstation=JFK&var=wcht&month=jan&_r=t&dpi=100&_fmt=png