bluewave

The historic +13.3 departure in December 2015 marked the shift to much warmer winters. This January is only the 5th winter month out of the last 20 with below normal temperatures. The coldest departure month was December 2017 at only -2.5. NYC Jan 22….-1.4 Dec 21….+4.7 Feb 21….-1.1 Jan 21….+2.2 Dec 20…+1.7 Feb 20…+4.8 Jan 20….+6.5 Dec 19….+0.8 Feb 19….+0.9 Jan 19….-0.1 Dec 18…+2.6 Feb 18…+6.7 Jan 18….-0.9 Dec 17…..-2.5 Feb 17…..+6.3 Jan 17….+5.4 Dec 16….+0.8 Feb 16….+2.4 Jan 16….+1.9 Dec 15….+13.3

The EPS is great for general 500 mb teleconnections days 5 to 15. But the OP and EPS doesn’t have great skill with coastal storm tracks beyond 3-5 days. It does seem to have a slightly better long range track record with cutters like we had on Monday. Maybe the future 3-5 KM convection allowing resolution upgrade on the OP and EPS will extend the range of coastal storm track prediction.

The rule this season has been needing more than one model showing the event. The GFS was the overamped model on January 3rd initially showing the heavy totals near ACY in our area. But the mesos showed the confluence over our area and us missing the storm. This event it was the Euros turn to show several overamped runs before it backed off and joined the other models. It would be great to have the old days back like February 2013 and January 1996 when amped up Euro run was all we needed for a KU without any other models on board. But these days we need multiple globals on board beyond 72 hrs and then have the mesos hone in on the finer details like banding locations.

My guess is there have been several factors contributing to the record snowfall since 02-03. Much stronger blocking patterns both in the North Atlantic and North Pacific. Warming winters allow the atmosphere to hold more water vapor. Record SSTs also provide more moisture for snowstorms. The last 20 years will stand against any historic 20 year period for snowfall. But the one caveat is that older eras before the 1980s measured snowfall differently. They measured after snowstorms which allowed the snows to compact. So those older totals would be higher if they used the modern methods. https://news.ucar.edu/14009/snowfall-measurement-flaky-history

We can get a KU without NYC reaching 10”. But the lowest rank of cat 1 usually requires widespread accumulations over 10” somewhere in the NE corridor. Most KUs also produce numerous 10” + totals in our area. Sometimes the 10”+ zones are east of NYC like Nemo in Feb 2013. With Stella in March 2017, the jackpot was NW of NYC. So the normal or better snowfall winters in NYC need storms that can reach these levels somewhere in our area.

The bar was lower for normal snowfall in the 1980s since the 1951-1980 30 year normal was around 24.7” in NYC. So NYC had around 5 seasons in the 1980s with close to normal snowfall. We had 1KU in February 83…1 KU in April 82…2 KUs a few days apart in January 87. The 2nd event did much better in Central NJ to Eastern Long Island. There was another KU in February 87 that favored Central NJ. Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Nov Dec Jan Feb Mar Apr Season 1980-1981 T 2.8 8.0 T 8.6 0.0 19.4 1981-1982 0.0 2.1 11.8 0.4 0.7 9.6 24.6 1982-1983 0.0 3.0 1.9 21.5 T 0.8 27.2 1983-1984 T 1.6 11.7 0.2 11.9 0.0 25.4 1984-1985 T 5.5 8.4 10.0 0.2 T 24.1 1985-1986 T 0.9 2.2 9.9 T T 13.0 1986-1987 T 0.6 13.6 7.0 1.9 0.0 23.1 1987-1988 1.1 2.6 13.9 1.5 T 0.0 19.1 1988-1989 0.0 0.3 5.0 0.3 2.5 0.0 8.1 1989-1990 4.7 1.4 1.8 1.8 3.1 0.6 13.4

I sure hope so. NYC is going to need at least 1 KU event before the season is over to reach normal snowfall. This is the first season with the new higher 29.8” normal seasonal snowfall in NYC. Every season since 09-10 needed at least 1 KU event in the region to make it to at least normal snowfall. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 1 to Apr 30 KU Storms 2022-04-30 6.8 0 2021-04-30 38.6 2 2020-04-30 4.8 0 2019-04-30 20.5 0 2018-04-30 40.9 4 2017-04-30 30.2 2 2016-04-30 32.8 1 2015-04-30 50.3 2 2014-04-30 57.4 3 2013-04-30 26.1 2 2012-04-30 7.4 0 2011-04-30 61.9 3 2010-04-30 51.4 3

While it has gotten much colder than December, we still have the overpowering Pacific Jet. So we have had several events get suppressed. The cutter was our most intense storm but the lack of -AO and -NAO hurt us. We generally need the northern branch to back off when there are STJ disturbances. So places to our south like ACY already have reached their normal snowfall for the entire season. At least we are close to average for January so far which is a big win coming off December.

Models seem to lock in cutter tracks like yesterday earlier than coastal storm tracks. Especially like the OP runs did over the ensembles such as the GEFS which were way too suppressed and cold. My guess is that the complexity created by the thermal contrast between the Eastern US and Gulf Stream is just too hard for the longer range runs to resolve.So it’s no surprise that the mesos like the NAM often take the lead with coastals like we saw in January 2016. But they only go out 84 hrs so we need to be patient until the storm track gets within their better range under 36-48 hrs.

The GFS hasn’t been doing so great recently with storm tracks either like we saw with it being overamped on January 3rd.

I believe Nemo in February 2013 was the last high profile snowstorm that only the Euro showed to work out. But that was before the series of upgrades and the January 2015 and 2016 misses. So now we need more than just one model showing any given solution to have enough confidence in an event from more than 72 hrs out.

We really need enough spacing between this very crowded vort pattern to make something work for us.

I believe they stopped doing upgrades on the NAM back in 2017. They are working on some type of FV3 replacement. In the mean time, the Canadians are continuing to improve the RGEM which seems to be getting better. So maybe the RGEM will become the go to meso with 84 hrs once the NAM stops running. Not a big fan of having to learn all the new biases of a FV3 CAM model.

We definitely want something like that since the Euro is gong in the opposite direction from what we want to see at the start of February.

This will be the storm that tells us how effective the recent Euro upgrade was. Before the upgrades around 2015, the Euro would often be the first model to lock onto southern stream systems. The GFS and CMC were always too flat and slow to catch on. The next thing to watch will be the mesos. In the old days, we had something called the EE rule. The ETA which is now the NAM agreeing with the Euro was always a great sign.

4th highest January 24 hr temperature rise on record at Newark. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=NJ_ASOS&zstation=EWR&hours=24&month=jan&dir=warm&_r=t&dpi=100&_fmt=png

Coldest January so far for NYC in 4 years. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Mean Avg Temperature Jan 1 to Jan 16 Missing Count 2022-01-16 32.3 0 2021-01-16 37.7 0 2020-01-16 42.6 0 2019-01-16 35.3 0 2018-01-16 26.5 0 2017-01-16 35.9 0 2016-01-16 35.9 0 2015-01-16 29.1 0 2014-01-16 32.0 0 2013-01-16 38.7 0 2012-01-16 36.3 0 2011-01-16 31.2 0 2010-01-16 29.7 0 Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Jan Click column heading to sort ascending, click again to sort descending. Year Mean Avg Temperature Missing Count 2022 32.3 15 2021 34.8 0 2020 39.1 0 2019 32.5 0 2018 31.7 0 2017 38.0 0 2016 34.5 0 2015 29.9 0 2014 28.6 0 2013 35.1 0 2012 37.3 0 2011 29.7 0 2010 32.5 0

Gusts close to 70mph on the Long Island South Shore.

Yeah, the NAM gets the 925mb jet near 75 KT while the strong squall line is crossing the area. The record for January at OKX is very close to those levels. But the balloon launch will probably miss it since the peak winds will be before 12z. So it’s no surprise that the NAM has wind gusts in the 60-70 mph range from near NYC South Shore across Long Island. Some spots especially further east could even see higher gusts than that.

The low of 6° at Newark is the coldest in 3 years. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Ending Date Lowest Min Temperature Oct 1 to Apr 30 Missing Count 2022-04-30 6 105 2021-04-30 16 0 2020-04-30 12 0 2019-04-30 2 0 2018-04-30 4 0 2017-04-30 12 0 2016-04-30 0 0 2015-04-30 1 0 2014-04-30 3 0 2013-04-30 11 0 2012-04-30 12 0 2011-04-30 5 0 2010-04-30 14 0

It’s great that you start these storm threads. We need a dedicated thread for storms since the January thread can become unreadable when when too many topics are crammed into just one thread. We have an active storm discussion on which type of weather elements can be expected with each event. Once a model consensus begins to show a storm threat, it’s great to have a thread whether it’s snow, rain, mix, high winds,flooding, thunderstorms…etc.

This is going to be one of the most intense cutters that we have seen during the month of January as per the extreme LLJ wind speeds.

That’s it. A more north based -PNA with some ridging lingering near California is always preferable. It’s the deep trough digging toward the Baja that’s not what we ever want to see. Models seem to agree on the ridge pull back closer to the Aleutians. But the critical depth of the -PNA in early February will probably have to wait for later runs. As you mentioned, the AO is even less certain long range for the models. This could be related to the potential for wave breaks to pop up in the short term.

Sometimes a 15 day ensemble teleconnection forecast will do better than an operational run for a snowstorm from 5 days. But you need to check which 500 mb parameters the ensemble is showing compared to past snowstorms. It’s easier to nail a KU event from weeks out when we get a verified SSW event in progress that results in strong blocking near Greenland. We got this last winter ahead of the SSW in January and also in February 2018 for the epic March. The historic January KU pattern in 2016 became more obvious when the KB block built back across the pole early in the month.

While the long range 500 mb anomaly charts can identify patterns favorable for snow, it’s always better to wait until we get to within the 5 day window before getting overly invested in any individual snowfall opportunity.