bluewave

I would just watch the winds behind the storm since these westerly flow events since last winter seem to be over performing. The high temperatures usually go a few degrees above on these strong westerly flow days. This leads to the low lapse rates being steeper than forecast. Then the winds end up beating guidance. So we could see advisory level winds develop and even a few spots especially east could get close to high wind warning criteria.

Yes since it’s the only station showing a high temperature decline especially on sunny days.

Maybe a sting jet-like feature to watch for on Friday with some 50-60+ wind gusts as the lapse rates really steepen behind the storm especially the northern and eastern sections of the region.

It wasn’t as much. But we need to see the 30 years prior to and after the ASOS getting put under the trees in 1995 for the full 60 year trend to emerge. Since 1995 was the year that NYC changed how they measure temperatures. This is why NYC is the only site with a decline in 90 days since the 1960s. If NYC didn’t have the ASOS in the shade, then their current 15 year October average would be closer to LGA and not the artificially low 59.3°. That mid century period was a warm in October. Which declined later in the century. But the recent 15 year period is the warmest on record. Average October temperatures 1941-1970 EWR…57.4° NYC…58.7° LGA…58.8° 1961-1990 EWR….57.2° NYC….57.5° LGA….57.4° 2010-2024 EWR…59.6° NYC…59.3° LGA….60.9°

The fall temperature pattern across the CONUS and or Canada will usually carry over into winter in some way especially when there is a significant temperature departure in either direction. Sometimes it can be an extreme in either October or November that shows up during the winter either in Canada or the CONUS. A great example of this was the 4th coldest October across the CONUS before the cold and snowy 09-10 winter across the CONUS. Then the record cold and snow in November 2014 especially in the Great Lakes into the East which preceded the cold in January and February of 2015. Then the fall cold in 2018 up in Canada which came before the all-time coldest reading at Rockford, Illinois late in January 2019. Same goes for all the recent record fall warmth prior to the record number of +10 winter departures at spots in the CONUS. We saw this as recently as last winter with the 4th warmest December across the CONUS and stations out West getting near +10 in December following one of our warmest falls across the CONUS. This fall to winter warmth pattern also emerged in other recent years. Plus the really cold winters in our colder climate era of the 1970s like 76-77 began with record cold as early as late August through the fall into the winter. So the relationship isn’t always an even one to one. But when we are seeing extremes of warmth or cold during the fall, then it usually follows in some way during the winter.

This period would be much warmer if it wasn’t for the tree growth. You can see how NYC is the only station which the high temperature has declined especially on the sunny days in October and other fully leafed out months. So in reality like all out other stations the actual high temperature if measured the old way prior to 1995 would have seen a steep rise instead of a slight decline. When we look at period since 1961 covering the 30 years prior to moving the ASOS under the trees in 1995 and the 30 years following we can see what is happening. Notice the lows aren’t affected only the highs especially on the sunny days when the shade effect is greatest.

This was why I pointed out the big Pacific Jet extension a few days ago. Models typically underestimate the warmth following one of these. The CONUS is on track for another very warm fall. This impressive fall warmth has been the norm over the last decade since the big shift warmer with the 2015-2016 super El Niño. Our last colder fall was back in 2014 and occurred just prior to the big temperature jump. Early signs that fall it was going to be a cold and snowy winter in the East. Plus the record snowfall in South Carolina in early November. https://www.weather.gov/cae/november2014climatesummary.html PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE COLUMBIA SC 1000 PM EDT FRI DEC 5 2014 ...NOVEMBER 2014 CLIMATE SUMMARY... ...EARLIEST SNOWFALL ON RECORD AT COLUMBIA... ...SOME PARTS OF THE MIDLANDS RECEIVED UP TO 6 INCHES OF SNOW ON THE 1ST... ...2ND COLDEST NOVEMBER ON RECORD AT AUGUSTA... ...11TH COLDEST NOVEMBER ON RECORD AT COLUMBIA... ...17TH WETTEST NOVEMBER ON RECORD AT COLUMBIA... ...SEVERAL TEMPERATURE RECORDS EITHER BROKEN OR TIED AT AUGUSTA AND COLUMBIA... ...EL NINO WATCH CONTINUES WITH A WEAK EL NINO EXPECTED TO DEVELOP... THE THEME FOR THE MONTH OF NOVEMBER WAS COLD AND WET...EVEN WHITE. THE MONTH STARTED OFF IN A BIG WAY WITH EARLIEST AND LARGEST SNOW EVENT ON RECORD FOR NOVEMBER. PRIOR TO THIS EVENT...THE EARLIEST SNOWFALL RECORDED IN COLUMBIA OCCURRED ON NOVEMBER 9TH, 1913. ALTHOUGH THE AREA THAT RECEIVED THE GREATEST SNOW AMOUNTS WAS SMALL...AMOUNTS BETWEEN 4 AND 6 INCHES ARE EXTREMELY UNUSUAL. MORE ABOUT THIS EVENT IS BELOW IN THE NOVEMBER EVENTS SECTION. A PERSISTENT MID/UPPER LEVEL TROUGH LINGERED ALONG THE EAST COAST INTO THE SOUTHEAST FOR MUCH OF THE MONTH. THIS PRODUCED RECORD COLD TEMPERATURES DURING THE MONTH AND AT TIMES A STORM TRACK BRINGING WEATHER SYSTEMS OUT OF THE Gulf of America AND TRACKING THEM NORTHEAST ALONG THE CAROLINA COAST. THIS WAS QUITE A CONTRAST TO THE WARM AND DRY MONTH OF OCTOBER. THE AVERAGE TEMPERATURE AT AUGUSTA REGIONAL BUSH FIELD WAS 49.2 DEGREES OR 6.0 DEGREES BELOW THE NORMAL OF 55.2 DEGREES. THE AVERAGE TEMPERATURE AT COLUMBIA METRO AIRPORT WAS 50.5 DEGREES OR 4.3 DEGREES BELOW THE NORMAL OF 54.8 DEGREES. EVENTS FOR NOVEMBER 2014: NOVEMBER 1ST...A VERY STRONG UPPER LEVEL WEATHER SYSTEM MOVED FROM NORTHWEST TO SOUTHEAST ACROSS THE STATE DURING THE EARLY MORNING HOURS OF SATURDAY THE 1ST. VERY COLD AIR ALOFT WAS ASSOCIATED WITH THIS SYSTEM...YET TEMPERATURES AT THE SURFACE AT THE ONSET WERE WELL ABOVE FREEZING. AS THE SYSTEM MOVED ACROSS THE AREA...THE INTENSE NATURE OF THE PRECIPITATION WAS ABLE TO COOL THE LOWER LEVELS OF THE ATMOSPHERE DOWN TO NEAR OR JUST BELOW FREEZING. A CHANGEOVER FROM RAIN TO SNOW OCCURRED FROM THE UPSTATE AREA THEN EVENTUALLY TO THE CENTRAL MIDLANDS AND NORTHERN CSRA. THE SNOW CAME DOWN HEAVY AT TIMES...ESPECIALLY ACROSS WESTERN LEXINGTON COUNTY. SNOWFALL RATES OF 1 TO 2 INCHES PER HOUR WERE NOT UNCOMMON. THE AREAS THAT RECEIVED THE MOST SNOW WERE LOCATED FROM WESTERN LEXINGTON COUNTY INTO SALUDA COUNTY...EDGEFIELD COUNTY AND EXTREME NW AIKEN COUNTY. SNOW WAS REPORTED AS FAR WEST AND SOUTH AS LINCOLN COUNTY GA...MCCORMICK COUNTY SC...THE AUGUSTA METRO AREA...BARNWELL COUNTY SC...BAMBERG COUNTY SC...ORANGEBURG COUNTY SC AND EVEN DORCHESTER COUNTY SC. MANY AREAS REPORTED TREES DOWN DUE TO THE HEAVY WET SNOW AND MANY TREES STILL HOLDING MANY OF THEIR LEAVES. IN LEXINGTON COUNTY THE HEAVIEST SNOWFALL AMOUNTS RANGED FROM 2 TO 6 INCHES WITH THE HEAVIEST SNOWFALL AROUND THE TOWN OF GILBERT WHERE UP TO 6 INCHES FELL. THE HEAVY SNOW BROUGHT DOWN TREES AND POWERLINES...EVEN CLOSING A PORTION OF I-26. IN SALUDA COUNTY SNOWFALL AMOUNTS AVERAGED BETWEEN 1 AND 2 INCHES. THE EMERGENCY MANAGER REPORTED 40 TO 50 TREES DOWN ACROSS THE COUNTY. IN NEWBERRY COUNTY...AIKEN COUNTY AND EDGEFIELD COUNTY...SNOWFALL AMOUNTS WERE UP TO 1 INCH IN PLACES. HERE ARE SOME SNOWFALL AMOUNTS FROM COCORAHS OBSERVERS: SC-LX-93 GILBERT 1.0 SE.............4.3 INCHES SC-LX-22 LEXINGTON 5.9 SW...........4.2 INCHES SC-LX-39 GILBERT 1.2 SSW............3.5 INCHES SC-LX-69 LEXINGTON 3.0 WSW..........3.0 INCHES SC-LX-26 LEXINGTON 3.4 SSE..........1.5 INCHES SC-LX-43 LEXINGTON 1.2 SSW..........1.5 INCHES HERE ARE SOME SNOWFALL AMOUNTS FROM OUR NWS COOPERATIVE OBSERVERS: BATESBURG (BATS1)...................3.5 INCHES PELION 4 NW (PLNS1).................3.0 INCHES CEDAR CREEK (BLYS1).................1.0 INCHES JOHNSTON 4 SW (JOHS1)...............0.8 INCHES NEWBERRY (NWYS1)....................0.5 INCHES HERE ARE SOME SNOWFALL AMOUNTS VIA EM/PUBLIC/SOCIAL MEDIA: GILBERT.............................6.0 INCHES RED BANK............................4.5 INCHES I-26 MILEMARKER 47..................4.5 INCHES SUMMIT..............................4.0 INCHES SALUDA..............................2.0 INCHES PELION..............................2.0 INCHES LEXINGTON...........................1-2 INCHES ...HISTORICAL NOVEMBER SNOW INFORMATION FOR COLUMBIA... PRIOR TO THIS EVENT THE EARLIEST SNOWFALL ON RECORD FOR COLUMBIA WAS A TRACE OF SNOW THAT FELL ON NOVEMBER 9TH, 1913. THE RECORD SNOWFALL FOR NOVEMBER OCCURRED BACK ON NOVEMBER 28TH, 1912 WHEN 1 INCH OF SNOW WAS OBSERVED. NOVEMBER 19TH...COLD CANADIAN HIGH PRESSURE SETTLED IN ACROSS THE REGION AND PRODUCED THE LOWEST TEMPERATURES OF THE SEASON. MANY LOCATIONS FELL INTO THE TEENS. HERE ARE SOME OF THE MORNING LOW TEMPERATURES: 8 E FORT JACKSON...................14 DEGREES 2 ESE SALUDA.......................14 DEGREES CEDAR CREEK NWS COOP (BLYS1).......14 DEGREES 8 SE NEW ELLENTON..................14 DEGREES LANDFILL (RCWINDS).................14 DEGREES BEAR CREEK (RCWINDS)...............14 DEGREES GADSDEN (RCWINDS)..................14 DEGREES 1 NW BLYTHEWOOD....................15 DEGREES 1 SSE WAYNESBORO GA................15 DEGREES 3 SSE RIDGEWAY.....................15 DEGREES 4 NW PELION NWS COOP (PLNS1).......15 DEGREES 2 E CANE SAVANNAH..................15 DEGREES 9 WNW JEFFERSON....................15 DEGREES EASTOVER (RCWINDS).................15 DEGREES

The Central Park ASOS has become covered the dense tree growth since 1995 so we can’t use data prior to that for comparison. Since the highs there have been artificially suppressed. The temperatures in our climate division only saw a gentle increase from 1885 to 1980. Since 1981 we have been rapidly warming at +1.1° per decade. So those earlier climate eras were much colder than the Octobers in recent years have been. From 1895 to 1980 the climate division average of stations was 54.4° during October. During the last decade with all the October record warmth the average has been 58.1°. So October is getting closer to a 60° month.

The Greenland block frequently linked up with the Southeast ridge last winter when it actually counted on the days which .20 or greater of precipitation fell. This is why the snowfall totals were so low from Philly to Boston. The average temperature from Philly to NYC was in the low 40s on the 11 days in the composite below. Way too warm of a storm track for decent snows along the I-95 corridor. The winter average was cooler at close to 35° around NYC. But it only arrived following the storms cutting to our west and closely hugging the I-78 to I-84 corridors. 11 day storm composite from Philly to Boston on the 11 days of heaviest precipitation over .20 with strong Greenland block linkage with the Southeast ridge

What it is feels like is a bit deceptive since October is one of the fastest warming months of the year. So we have been normalizing how warm it has been getting since it only takes a small + departure to rank in the top 15 warmest Octobers. Sussex NJ is currently ranked 8th warmest October through the 28th. White Plains is 12th warmest and Islip is 7th warmest. It would probably make more sense to use an earlier climate era like 1961-1990 or 1951-2000 as a base period so rankings and departures will actually match up. Instead of updating the normals every 10 years in a rapidly warming climate. This frequent updating leads to the false sense that it isn’t warming as fast as it really is and making the departures less relevant unless they are very high. Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Oct Click column heading to sort ascending, click again to sort descending. 1 2017 61.9 0 2 2021 61.2 0 3 2007 61.1 0 4 1990 60.9 0 5 1971 59.7 0 6 2023 58.8 0 7 2025 58.6 3 8 1995 58.5 0 9 2024 58.4 0 10 1963 58.3 0 11 2019 57.9 0 - 2013 57.9 0 - 2012 57.9 0

Most stations on track to finish October warmer than average as this is another month with Canada being so warm that areas to our north will finish warmer again relative to the means. POU…..+0.7 FWN….+1.3 PHL…..+1.7 SMQ….+0.3 NBW….+1.5 EWR….+1.7 NYC…..+0.5 LGA……+0.1 JFK……+1.1 HPN…..+2.2 BDR….-0.3 ISP……+2.4

Yes that’s true. All the models except the NAM were too surpassed with the system so the snowfall forecasts from the globals were way too low. We really had an epic run of benchmark storm tracks from 93-94 all the way up to 17-18. Both under -PDO and +PDO regimes. The -PDOs were defined by the cold ring off the West Coast. With the +PDOs by the warm ring. So the Pacific Jet was much weaker during the best seasons for benchmark storm tracks during that era. Since 2018-2019 we have need a new type of -PDO defined more by the warm pool to the east of Japan and south of the Aleutians. This combined with the cold over Siberia leads to a faster Pacific Jet and these three prime storm tracks over the last seven winters leading to the record low snowfall. The last reprieve for us was during January 2022 when a solid MJO 8 lead to a weakening of the Pacific Jet and the snowy benchmark pattern from ACY to ISP and BOS. It was the last time we had both a cold and really snowy month. But it was bookmarked by a very warm December and a milder February and March with little to no snow. I am really hoping we can find some periods in this coming winter and others where we can see at least a brief return to benchmark tracks. But the overall pattern since 2018-2019 has been working against that.

Most storms over the last seven years have been falling into the cutter, I-78 to I-84 hugger and suppressed Southern stream. Strong benchmark storm tracks have been missing. This very strong Northern stream of the Pacific Jet has been leading to these groupings. One group of storms gets suppressed to the south as kicker lows in the fast Pacific flow come into Western North America. This was the case last winter with the big Gulf snowstorm which went OTS to our south instead of coming up the coast. The second group is the Great Lakes cutter like we got in mid-February during the -5 SD Greenland block. The jet was so strong and the SSTs to our east so warm that it forced a Southeast ridge rather then getting a benchmark track. Instead Toronto got the historic snows. Enough room between the shortwaves so one system can really amplify and cut to our west like later this week. That was originally forecast to be a coastal storm. Then the third track is the hugger which can produce some lighter snow events like we got last February. But there was still too much Southeast ridging for NYC Metro so the heaviest totals were to our NW. Plus the there are often too many shortwaves in the fast Pacific flow leading to poor wavelength spacing. It would be great in the coming winters if we can at least see a few very deep benchmark tracks. But the last time we were able to pull this off was in January 2022 and February 2021.

The starting point is when the climate began to warm more rapidly along with the oceans. So one of the predictions made years ago was that we would see an increase in the strongest of hurricanes but not necessarily the total number of storms. Has to do with dueling influences as the oceans reach all time record warmth. Stability can limit the total numbers but lead to the storms that do form being more intense. First, we have seen a record concentration in Cat 5 hurricanes in the last decade due to the warmest SSTs ever observed in the Atlantic and other basins. Second, uneven warming of these basins also lead to stability issues at varying points in the season such as what used to be thought of as the peak from late August into early September. So recently we have seen an early burst of activity followed by a late August into early September lull and followed by unusually late season development. When we get these very warm SSTs at the higher latitudes during mid-summer it has lead to stability issues in the tropics. But later in the session these stability issues have been resolving leading to this record late season activity.

The WPAC to the east of Japan is different from the EPAC since the Kuroshio Current like the Gulf Stream waters are certainly warm enough to cause a feedback process. But the wam blob off the West Coast during the 2010s was the result of the forced pattern emanating in the subtropical or tropical WPAC . So once the fall pattern in 2019 shifted the warm blob easily disappeared. This is why 19-20 wasn’t a repeat of 13-14 like some were speculating about that fall. So more remotely forced. The WPAC warm pool is much more stable and longer lasting since both the forcing and SST feedback are at play for pattern maintenance. This is why the Aleutian ridge and Southeast ridge have become such dominant features over the years.

We probably have to factor the summer drought stress during peak heating into the equation. This was the 4th driest and warmest summer here. Last year the summer was much wetter before the dry conditions last fall. Time Series Summary for NEW HAVEN TWEED AP, CT - Jun through Aug Click column heading to sort ascending, click again to sort descending. 1 1966 4.15 0 2 2022 4.29 0 3 2017 4.76 3 4 2025 4.99 0 Time Series Summary for NEW HAVEN TWEED AP, CT Click column heading to sort ascending, click again to sort descending. 1 2022 75.4 0 2 2024 75.2 0 3 2020 74.9 2 4 2025 74.5 0 5 2010 74.3 0

It’s very challenging to guess ahead of time how vibrant the foliage will be during any given year. Not really noticing colors quite a vivid up here compared to years past here and back on Long Island. The best fall color that I can remember back on Long Island was actually the late very vibrant foliage back in 2007. Went to a friends house in Mt. Sinai for Thanksgiving that year and the colors were gorgeous for that late in the season.

I get it that people on here are eager to see some type of shift with the SST and atmospheric state in the WPAC. But what we we are seeing now is only a reduction from very high summer levels to a still very warm level. It’s primarily a result of the recurving typhoons and unusually strong +WPO for October. Plus the subsurface is still plenty warm. So like after the cooling last winter, it didn’t take long for the surface to warm back up in the following months since the subsurface has so much stored heat energy. This is why the PDO has been fluxuaring between deeply negative states and levels and readings which aren’t as negative. But the orientation of the entire sea and atmospheric state results in the -PDO persisting at varying levels. Even with the decline from the extremely warm surface levels to still very warm, this October has produced one of the strongest East Asian to North Pacific Jets on record for the month of October. So it’s really the gradient between Siberia and the entirety of the Western and Central Pacific Ocean SST warmth.

Snowfall season starting at the higher elevations with some still great fall foliage even in the more northerly spots that are just past the peak.

Even with the +PNA -EPO pattern during January, the coldest departures were displaced further south toward the Mid-Atlantic and Southeast since Canada was so warm.

No it wasn’t prior to 2018-2019. Maybe since you live west of I-95 you are unfamiliar with the coastal areas. We had numerous events prior to 2018-2019 which were all or mostly snow. That mid-October storm track would have been mostly rain or mixed near the coastal plain during the winter. Too many storms to count prior to 2018-2019 which were the opposite.

It’s coming near the tail end of a -NAO period which began around the 15th. Not really sure how to define a classic -NAO since there have been many versions over the years with blocking near Greenland. It’s just that during the 2020s we are finding more ways for higher latitude blocking to merge with the subtropical ridge especially at storm time.

I am using the term early season to describe the activity prior to what is considered the late August into early September traditional peak we used to get more often. Erin went Cat 5 on August 16th which is early in the season for Cat 5 development. The record SSTs are why we haven’t had any really low ACE seasons since 2013 and 2014. This lead some to speculate that the AMO was going to shift colder back then. But instead the Atlantic SSTs reached all warmth over the last decade with the historic run of Cat 4-5 systems.

Yeah, that was an amazing late season snowfall pattern. Islip had 36.5” of snow from 3-7-18 to 4-2-18. But Islip has only had a total of 27.6” during 22-23, 23-24, and 24-25 combined.

Noticing the continuing pattern with these cool downs. The coldest departures will be found more to the south closer to where you live as Canada remains very warm relative to their means. Then we are already seeing a big PAC Jet extension in early November forecasts so expect the temperatures to warm up during the 2nd week of November.