bluewave

Active convective pattern next few weeks. So it doesn’t look like the late June heat will be able to be matched through the reliable forecast period. But a generally warmer pattern with plenty of convection opportunities. Through July 14th July 14-21

We keep setting new records by significant margins with that WPAC warm pool driving this pattern.

SMQ set their all-time highest dew point temperature of 83° back in June. They just came in 2nd with a dew point of 81 yesterday. So a record amount of atmospheric moisture around the world leading to the numerous extreme flooding events. The SPC HREF has a 2”-3”+ max potential with the better storm coverage for later today.

The models have better coverage of the storms tomorrow.

Dewpoints getting close to 80° here on the CT Shoreline. New Haven PTSUNNY 85 78 80 S8G21 29.97F HX 96

Argentina was the place to go recently to avoid all the record heat around the world.

22-23 was a little lower for snowfall around NYC than 01-02. But 01-02 remains a little warmer. If the 01-02 snowfall and temperature departures occurred again in this much warmer climate, then NYC would probably finish up with only around 1” or less of snow and a winter average temperature close to 43.0°. Time Series Summary for NY CITY CENTRAL PARK, NY - Oct through Sep Top 10 lowest snowfall seasons Click column heading to sort ascending, click again to sort descending. 1 2022-2023 2.3 0 2 1972-1973 2.8 0 3 2001-2002 3.5 0 4 1918-1919 3.8 0 5 2019-2020 4.8 0 6 1931-1932 5.3 0 7 1997-1998 5.5 0 8 2011-2012 7.4 0 9 2023-2024 7.5 0 10 1988-1989 8.1 0 - 1877-1878 8.1 0 Time Series Summary for NY CITY CENTRAL PARK, NY Top 10 Warmest Winters Click column heading to sort ascending, click again to sort descending. 1 2001-2002 41.5 0 2 2022-2023 41.0 0 - 2015-2016 41.0 0 3 2023-2024 40.6 0 4 2011-2012 40.5 0 5 1931-1932 40.1 0 6 1997-1998 39.6 0 7 2016-2017 39.3 0 8 2019-2020 39.2 0 9 1990-1991 39.1 0 10 1998-1999 38.6 0

These 75°+ dewpoints have become the new normal for us over the last decade. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=yes&q=161&network=NY_ASOS&zstation=12N&var=max_dwpf&dir=aoa&thres=75&month=all&year=2025&_r=t&dpi=100&_fmt=js https://mesonet.agron.iastate.edu/plotting/auto/?_wait=yes&q=161&network=NY_ASOS&zstation=12N&var=max_dwpf&dir=aoa&thres=75&month=all&year=2025&_r=t&dpi=100&_fmt=js

Third warmest June on record right behind the last two years.

Most of my posts are based on what has already happened over the last 30 to 60 years around NYC Metro. The last 7 seasons with well below normal snowfall are just a small microcosm of this greater pattern with our snowfall over this much longer period. The same way the 09-10 to 17-18 period was. During the colder climate era from the early 1960s to early 1990s my area would get many snowfall seasons near the middle of the range with very few well above or well below seasons. As our climate began to really warm since the mid 90s, the snowfall around NYC has shifted to an all or nothing type of pattern. Very few seasons near the middle of the range anymore with nearly all seasons now well below or well above. Since the mid 90s we have become exclusively reliant on KU benchmark snowstorms to reach average to above average snowfall. So from 09-10 to 17-18 we had a record number of these storms. We were in a transition phase when we began to see extreme winter warmth starting with the +13 December 2015. This carried over into 17-18 with our first 80° winter warmth in February 2018. But the storm tracks still remained cold. So we were getting warm and snowy winters. Things began to shift again in 18-19 with the storm tracks becoming warmer to match the general warmth which began in December 2015. So the storm tracks still warming lagged the general winter warming which began in 15-16. The 7 year period since 18-19 has featured the warmest 7 year winter storm track and lowest snowfall totals. So now we are getting consistently warmer background winter patterns and storm tracks. While this past winter was the first since 15-16 to feature near to slightly below average temperatures, the storm tracks remained warm like they have since 18-19. While the NYC average winter temperature was near 35°, the average temperature on the days that .25 or more of precipitation fell was 41°. So smother well below normal snowfall season. From the early 60s to 90s we had multiple ways to get closer to average snowfall. So we didn’t have to exclusively rely on benchmark KU events. The colder pattern allowed for hugger tracks which dumped heavier snow amounts before mixing to rain. Plus their we’re frequent clipper tracks to our south which have been missing in recent years. So fewer options to get to average snowfall. These days it’s all Great Lakes cutter tracks which are all rain. The hugger tracks are too warm to deliver the heavier snows which got us to normal snowfall in the colder climate. These days the benchmark tracks have been replaced by cutters, huggers, and suppressed Southern Stream storm tracks. Looking forward we have a few options. While the winter warming absent a major volcanic event will continue, it’s uncertain whether we will see at least an intermittent return to benchmark storm tracks again. Scenario #1 is that we shifted into a permanently lower snowfall regime in 18-19 and the low snowfall seasons will become the new normal. Maybe an odd snowy season now and then in the mix. Scenario #2 is a temporary shift to more benchmark tracks and closer to average snowfall later in the 2020s into the early 2030s. But winters would still likely stay warmer even though the storm tracks shifted to colder. We would eventually see another period of declining winter snowfall into the 2030s as the winter warming and warmer storm tracks reduce the snows again. Scenario #3 would be a major volcanic eruption not seen for hundreds or thousands of years. Temporary return to colder and snowier winters. Very uncertain since a reliable long range volcanic forecast still doesn’t exist yet.

The sea breeze fronts will probably be the focus for convection along with the remnant moisture from Chantal. Some areas might not see much rain next few days. While others could get a quick 2-3”+. Kind of like Florida where you can drive a few miles between sunny and thunderstorms.

The 12z Euro has a Miami summer pattern here form the next 10 days. Many days with 75+ dew points and thunderstorms. So the spots that get the best training will probably have flooding concerns.

The treetops look like they are at a similar height to the anemometer. So they could also be serving as a barrier in front of the equipment to lessen the winds. The trees were much lower in 1974 when the record 78 mph gust occurred. That was the strongest Nor’easter of the early 1970s. The winds were very loud in Long Beach with extensive coastal flooding. My elementary school in the LB West End still had water in the street from the tidal surge when the ocean met the bay in spots earlier that day. Plenty of sand and big puddles in the streets around my school. It was a really cool school bus ride that morning seeing all the sand and water still on West Park ave.

I already gave the JMA credit for seeing the record TNH pattern for the 13-14 winter.

To be fair, our really warm winters like 22-23 and 23-24 weren’t forecast to be that warm. The seasonal models had a pretty extensive cold bias for both those winters. The seasonal forecasts for years like 15-16, 16-17, and 19-20 were also much cooler than the record warmth which verified. I believe from memory that the 01-02 and 11-12 seasonal model forecasts missed the warmth also. So most of the time as the winters have been warming these seasonal forecasts have been too cold. Last October I was pointing out the colder La Niña mismatch potential that some of the seasonal models could have been missing. So I wasn’t surprised at the colder pattern last January than some of the seasonals had many months in advance.

The one particular month shows the greater bias of being too cold in the Northeast which is the same as the collection of all the months averaged out we have been discussing. Seasonal models beyond a month out are usually a crapshoot even when looking at the 500mb forecasts and not taking into account the general temperature biases for said patterns. The last time one of these seasonal models had a great winter forecast in October and verified close to having a great actual winter was the JMA winter 13-14 forecast with the wall of Pacific blocking which verified.

You are using an example of the CanSIPS missing the 500mb forecast from multiple months out. My observation is based on the months when the 500mb forecast is reasonably close. The updated January 2025 forecast which came out on January 1st was too cold in the Great Lakes and Northeast even though the 500mb forecast did better once we got closer in.

Thanks. I have kept a running tally of past model forecasts and where their errors or biases have been. I use them in the various threads for my forecast discussions. While AI models on their own haven’t been very good with real world use compared to the numerical models, they may have some promise if they could figure out how to incorporate AI to bias correct the numerical models in real time. I think the ECMWF is trying to do this. But the computer power involved in that is pretty demanding.

Yeah, these forecast soundings are really loaded with tropical moisture. Also weak steering flow could lead to stalling and training convection. Somebody could see some very heavy rains in a short time period.

Models having inherent biases have nothing to do with cherry picking. They are a function of the way the models work. The CanSIPS is well known for showing too much cold where the troughs are forecast especially in the East. One of the few parts of the country that can verify colder than these seasonal forecasts is the Rockies and Upper Plains. But that doesn’t do the posters living in the I-95 corridor any good. Plus the forecasts beyond one month are a crap shoot anyway. So don’t get too attached to what any of the seasonal models are showing now for next winter. The CanSIPS and other models don’t have a ton of skill forecasting the 500mb pattern more than 30 days out. So we have to wait until the 1st of each month for the monthly forecast. Then adjust the temperatures warmer in the spots where a trough is indicated for models like the CanSIPS. With the exception of Western areas which can sometimes verify colder. But usually not the East. The one model truism over the years is that the Southeast Ridge or general 500 mb heights in the East verify higher than forecast. This is why the heavy snows which were indicated as far south as NY Metro last February got pushed up into Canada from Toronto to Montreal. So understanding these model biases is essential if you want to have a better handle on the medium to long range and seasonal forecasts.

Just look at all the new mesonet sites that have multiple elevation temperature observations. Temperatures most times decline with elevation from 2m to 10m and 30m to over 100m at some sites. The exceptions are during radiational cooling inversions and strong winter WAA when the higher levels warm more than the surface and we get fog.

Higher dew points and more clouds with onshore flow mean more rain chances. So your area usually sees at least 30-40 days reaching 90° each season. But the chances of going 20 straight days reaching 90° like in 1988 when it was much drier without interruption are very low. But the overall 90° day counts in NJ are much higher than the 1980s and 1990s. Just no really long extended heatwaves. So a bunch of shorter heatwaves giving you more total 90° days than you used to get.

No problem. We need some levity in here after what has happened since 2018-2019. My only comment on the CanSIPS is that temperatures never match the forecasted 500 mb pattern. Just look at the one month forecast for June to see what I am talking about. The 500mb forecast for June wasn’t bad. But the cold pool to the south was way overdone. So this has also been happening with the La Niña winters showing so much cold to the north around the Great Lakes, Northeast, and Canada. If that Southeast Ridge verifies like it’s showing for the winter, there will be much less cold to the north and the warmth to the south will be much more expansive. 500 mb pattern forecast not bad Cold pool to the south never verified

We have been fortunate from Philly to Boston that it hasn’t happened yet. But it has come close at Philly. They managed to narrowly miss a complete shutout twice with 0.3” in 19-20 and 22-23. So they avoided the T from 72-73. NYC also has avoided a complete shutout with their lowest season out of the last 7 coming in at 2.3” in 22-23. Boston was able to stay over 5” with their low season coming in at 9.8” in 23-24. People would really start to say it’s never going to snow again if Philly had a T or their first 0.0”. With a T to 0.9” in NYC and under 5.0” at Boston. Thankfully we are yet to see a snowfall season this low from Philly to Boston.

Great Lakes cutters, I-95 to I84 huggers, and suppressed Southern Stream storm tracks have been dominant since the 2018-2019 winter. This is what we have had with the much stronger Pacific Jet. With the Great Lakes Cutter track the fast Pacific flow carves out a trough out West and pumps the Southeast Ridge with an I-95 rainstorm. The hugger track has wave spacing issues due to too many short waves in the fast Pacific flow. So we get the brief light to sometimes moderate snows changing to rain. Then there is the suppressed Southern Stream low due to the fast Pacific flow having a kicker trough coming into the West Coast. This doesn’t allow the Gulf low like the one last winter which gave record snows to the Gulf Coast to turn the corner and come up the coast. Then sometimes the lows come far enough north for DC to get snows but not areas further north. So the fast Pacific flow effectively turns off the benchmark snowstorm track. I hope we can see at least a small relaxation of this pattern in the coming years even if we still stay warm. Would take a warm and snowy La Niña winter like 16-17 and a weaker Pacific Jet in a second if I could get it. Wouldn’t mind a 60° day before of after some of the blizzards that season. Now we just get the 60° days without the great snows.