bluewave

It’s all about the way model biases have been evolving over the years. We went many years near the I-95 corridor when the long range models weren’t snowy enough beyond a few days. Which is the complete opposite of the model error pattern since 2018-2019 with the record breaking Pacific Jet. The January 1978 KU snowstorm was originally forecast to be a rainstorm the day before and we got a surprise 15” snowstorm on Long Island. Then in February 1983 the original forecast a few days out was for the heaviest snows to stay down near Philly. But instead the heaviest snows shifted north into NYC Metro as the models got under 60 hours. The January 1987 KU event was forecast to be snow quickly changing to rain but instead we got a surprise 6-12”. The December 1988 surprise Norlun wasn't even forecast at all and we got a narrow 6-12” band. The January 1996 blizzard was originally forecast to get suppressed to the south of NYC from 120 hrs out. But came north in the models only 24 hrs out. The late January 2000 snowstorm was forecast to be OTS and delivered record snows in the Carolinas and over 6” around NYC. The record January 2016 snowstorm was only forecast to be 6-12” the day before around NYC and turned out to be 20-30”. So model errors in good snowfall seasons tended to be underdone beyond 24 to 48 hours out. What the models have been doing since 18-19 is showing heavy snows beyond 72 to 120 hrs only to correct further north with the heavy snowfall axis. So the error has been for the storm tracks to verify warmer and further north than originally forecast. This model error pattern worked for us with colder storm tracks to our Southeast which dominated before 18-19. Since the long range forecasts could still afford to shift north changing suppression to a KU. These days the storm track is already too far north so any shift north under 60 hrs gives us to more rain. So cutters, huggers, and suppressed Southern Stream storm tracks have lead to the record low snowfall from Philly to Boston last 7 years. The big snowstorm has always been beyond 120 hrs out. So this has become the dominant model forecast storm track bias. The one good thing about repeating model biases is that I use them in real time to correct the long range model forecast biases leading to better forecasts than the models.

This is a new interesting study on how the oceans and land areas have warmed so rapidly in recent years. Ryan Katz-Rosene, PhD @ryankatzrosene · 20h Woah this is a fascinating new paper in Nature! It tries to figure out what caused the unprecedented marine heat wave seen in the North Atlantic in 2023 (which in turn caused extreme weather chaos and heatwaves, especially in Europe) They find that “the primary driver of the marine heatwave was record-breaking weak winds across much of the basin.” Weak Winds! You see, the winds were super weak, which in turn is linked in with an especially thin upper ocean level, which in turn can cause more rapid warming of that layer. Usually it’s 20-40 meters “thick”, but in 2023 it was only 10 meters thick. A secondary contributing factor was potentially the reduction in shipping fuels through the IMO’s low sulfur fuel policy. This allowed more solar energy to reach that already thin upper ocean layer. The weak winds could have been caused by the development of an El Niño that year, though prior research has shown how anthropogenic global warming is reducing the ability of winds to mix the upper ocean, causing it to gradually thin. As the lead authors note, “Marine heatwaves are expected to worsen as Earth continues to warm due to greenhouse gas emissions, with devastating impacts on marine ecosystemssuch as coral reefs and fisheries. This also means more intense hurricanes – and more intense land-based

Yeah, the clouds and showers will probably cap the high temperature potential unless the late month pattern can find a a way to dry out a bit.

Yes, when we have great winter patterns in place the snowstorms can often overperferform relative to longer range model forecasts. But since February 2022 most of the snowstorms have been in the long range only to disappear once the models catch onto how strong the Pacific Jet is under 120 hrs. So in effect these models aren’t well suited for such a fast Pacific Flow regime. Our only two colder and snowier months in the 2020s have been February 2021 and January 2022.

The deep red is the higher pressure than normal. This leads to easterly flow here once the back door drops south. The EPS is forecasting a stalled out front to be somewhere south of us mid-June. Once waves of low pressure start to ride east it will eventually lead to the rains coming back north into our area mid-June. But maybe we can sneak in a dry weekend for a change.

We are starting out with fog here today with showers across the area. Then we dry out tomorrow morning before more rain later in the day into the evening. So our first major 95° heat and first 90° east of NYC will have to wait. Longer range it looks like a back door pattern for next weekend with strong Canadian high pressure. Maybe the high will be strong enough to keep the stalled front and rains closer to DC and south. Would be nice to get a dry weekend with comfortable June temperatures. The strongest heat is forecast to stay to our West through mid-June.

My pointing out a particular repeating pattern over time with our storm tracks leading to less snow is more about pattern recognition on my part. I use it in real time to point out that the models have been too snowy beyond 5 days. This has lead to the famous modeled snowstorm always being a week a way. Which is due to the models underestimating the influence of the Pacific Jet longer range. Adding extra warmth to the system in multiple locations causes shifts in the storm tracks. So we need to acknowledge this as a forecast aid.

That ridge position in the means off the West Coast in January 2025 was able to build into the Rockies later in the month like you pointed out in 2022. But the Pacific Jet carving out a deeper Baja trough than we saw in 2022 was acting as a kicker. So the trough near the Northeast was a little too far east for a repeat of the late January 2022 blizzard. Too many competing marine heatwaves driving the pattern this past January to allow the pristine MJO 8 forcing pattern that we got back in 2022.

We’ll see if the pattern can dry out a bit after the 16th and maybe promote higher temperatures than we got the last few days.

The +PNA ridge worked out for us in January 2022 in that position just off the West Coast in conjunction with the solid MJO 8.

The EPO was only consistently negative in January. As the big swings in December and February lead to more neutral those months. Unfortunately, the big snowstorm in January got suppressed down to the Gulf Coast.

Rainy weekends theme continues with rainy periods possible on Saturday and Sunday. Hopefully, the Euro is too fast with the rain to return on Sunday. So we can at least get some drier conditions during the day.

The constant jet extensions led to wild fluctuations in the WPO,EPO, PNA, AO, and maybe even the NAO. This would have been a great winter before the big warming jump in 15-16. We need a significant relaxation of this jet in coming winters for at least a small rebound off the record low snowfall and cuttter regime of the last 7 years.

The -WPO blocking in the Bering Sea during February was overpowered by the very fast Pacific Jet and strong Southeast Ridge.

It could very well be a feedback process causing these big ridge expansions further north than we used to get back in the old days. These very strong ridges to the east of New England have been the norm. So the 500 mb ridges warm the waters below and the warmer waters could promote stronger 500mb ridges. Plus there could be remote teleconnections involved from marine heatwaves closer to the equator. Our first 90° Heat of the season is following a familiar theme. The mid 90s major heat missed our area to the north. So the record heat for June 5th was up in Maine and New Hampshire. This was the 2nd year in a row with record early June heat in those areas. Even closer to home, Danbury was 3° warmer than Newark in more over the top to the north fashion. So not sure what caused the comments that the temperature anomaly charts were showing too much red to our north. They turned out to be correct. Augusta Maine had a record high of 92° which was a +20. Newark at 90° was only a +12°. TEMPERATURE (F) YESTERDAY MAXIMUM 92R 2:21 PM 88 2024 72 20 88 TEMPERATURE (F) YESTERDAY MAXIMUM 90 428 PM 95 2021 78 12 81 RECORD EVENT REPORT NATIONAL WEATHER SERVICE GRAY ME 0409 AM EDT FRI JUN 06 2025 ...RECORD HIGH TEMPERATURE SET AT AUGUSTA... A RECORD HIGH TEMPERATURE OF 92 DEGREES WAS SET AT AUGUSTA YESTERDAY, JUNE 5TH. THIS BREAKS THE OLD RECORD OF 88 DEGREES SET IN 2024. Data for June 5, 2025 through June 5, 2025 Click column heading to sort ascending, click again to sort descending. NH ROCHESTER SKYHAVEN AP WBAN 96 ME FRYEBURG EASTERN SLOPES REGL AP WBAN 95 NH MANCHESTER AIRPORT WBAN 94 NH LEBANON MUNICIPAL AIRPORT WBAN 93 ME AUGUSTA STATE AIRPORT WBAN 92 Data for June 5, 2025 through June 5, 2025 Click column heading to sort ascending, click again to sort descending. NJ TETERBORO AIRPORT WBAN 93 CT DANBURY MUNICIPAL AP WBAN 93 NJ CALDWELL ESSEX COUNTY AP WBAN 91 NY PORT JERVIS COOP 90 NJ NEWARK LIBERTY INTL AP WBAN 90 NY MONTGOMERY ORANGE COUNTY AP WBAN 90

The exact reason that the warming is manifesting in these new stuck weather patterns that have become common in recent years may not be fully understood yet. But we can still use them as an aid to our long range winter and summer seasonal forecasts. Once a season begins and the same patterns emerge as recent years, then it helps gain confidence in the model forecasts going forward. So if the models show a big over the top warm up like today, then it’s a match for our new recent climo. This becomes useful in comparing it to what the longer range medium and and seasonals are showing.

A newer climate model that was first run back in 2013 is doing a pretty good job so far. It forecast the increase in summer ridging near the Pacific Northwest into the Rockies and another area to the east of New England. This has been the main summer pattern since 2018. It gives us these over the top warm ups. It has been a reliably warmer than normal summer pattern for us. As the only slightly cooler summer here was in 2023. Every other summer finished up warmer than average. But the increased onshore flow with a ridge east of New England holds down the big increase in 100° days that some of the older climate models were indicating. We need a strong 500mb positive height anomaly closer to the Great Lakes like from 2010 to 2013 to get a high number of 100° days from around NYC to the east. This is why JFK continues with the longest under 100° day streak on record. The Euro summer forecast is very similar to the general pattern since 2018 Similar to summer pattern since 2018 Resembling new climate model forecast made in 2013

They actually make it look like things are cooling. Since the more recent climate normals are the warmest on record. Our warmer summers patttern bagan back in 2010. So when we use more recent climate normals they appear cooler than the climate normals did over 20 years ago.

Yeah, it runs on the 5th of every month and this summer update was just released a few hours ago.

Latest Euro keeps the strongest heat this summer out West with a wetter pattern for us.

Tomorrow looks like a bigger Ambrose Jet day than today.

We were still a very solid +PDO SST signature through the winter of 16-17. Just look at that big cold pool south of the Aleutians and warm crescent along the West Coast. Then in 17-18 you could see the beginning of a shift with lingering warm pool near the Baja and cold pool still north of Hawaii. Still plenty of warmth up in the Bering Sea for a weaker +PDO than 16-17. But this is when the first hint of warming began to the east of Japan. Though not to the point of being overpowering yet which began in 18-19 flipping the PDO negative and preventing the El Niño from coupling in 18-19 and 19-20.

This one long range climate model initialized in 2013 did a great job forecasting the +PDO shift in 2014 that lasted through 2018. So we always have to evaluate on a case by case basis. Plus it’s tough to know when the model is just in repeater mode or actually seeing a shift until we see the verification. https://www.nature.com/articles/ncomms11718 The negative phase of the Interdecadal Pacific Oscillation (IPO), a dominant mode of multi-decadal variability of sea surface temperatures (SSTs) in the Pacific, contributed to the reduced rate of global surface temperature warming in the early 2000s. A proposed mechanism for IPO multidecadal variability indicates that the presence of decadal timescale upper ocean heat content in the off-equatorial western tropical Pacific can provide conditions for an interannual El Niño/Southern Oscillation event to trigger a transition of tropical Pacific SSTs to the opposite IPO phase. Here we show that a decadal prediction initialized in 2013 simulates predicted Niño3.4 SSTs that have qualitatively tracked the observations through 2015. The year three to seven average prediction (2015–2019) from the 2013 initial state shows a transition to the positive phase of the IPO from the previous negative phase and a resumption of larger rates of global warming over the 2013–2022 period consistent with a positive IPO phase.

Looks like the warmest readings today will be following the over the top pattern we have been getting since around 2018. Onshore flow for the south facing beaches. The warmest downslope flow in the Northeast will be found in Mass and NH. So the warmest departures and perhaps actual temperatures will be heading to our north today.