bluewave

This looks like a super La Niña atmospheric response with the +55 SOI and strong +EPO -PNA SE Ridge pattern by later next week.

Getting some light ocean effect snow now in SW Suffolk and 26°.

Gusted close to 80 mph near Buffalo earlier today on the skyway bridge. https://operations.nysmesonet.org/~nbassill/live/index.php?stid=SKYWAY

That’s incorrect. The SE Ridge linking up with the -AO occurred before the shortwave entered the US. Notice the TPV is in the same location north of Montana. So it wasn’t caused by the TPV digging more. New run Old run

Gusting near 60 mph at JFK.

8.45 was above Irene and below Sandy. 1) 10.12 ft on 10/29/2012(2) 7.35 ft on 08/28/2011

Yeah, a slowing Gulf Stream warms the waters off the East Coast and cools the SSTs south of Greenland.

The much warmer Gulf Stream circulation to our east looks like the reason the SE Ridge is linking up with the -AO more often. The Pacific side is nearly identical to the colder storm track run from last Thursday. So that leaves the models underestimating the SE Ridge influence from 8-10 days out. New run Old run

Impressive squall line for late December.

Gusts in excess of 60 mph possible near the South Shore with the cold front as we get some deeper mixing this afternoon.

We needed one of the most positive December +PNA patterns on record in 2020 to overcome that south based block and produce the double digit snowstorm in NYC.

Yeah, this is also the first December with an AO reading of -4 or lower to link up with the SE Ridge. Decembers in -4 or lower daily AO composite 2010…2009…2000…1995…1978…1976…1968…1966…1963…1962…1950 https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.ao.index.b500101.current.ascii

High tide in Freeport came in above the Irene levels. https://water.weather.gov/ahps2/hydrograph.php?wfo=okx&gage=frpn6

Could be the strongest seiche on record for Lake Erie. Intense winds behind the cold front today will produce a SIGNIFICANT seiche event on Lake Erie which will rival the highest lake levels ever experienced. Sustained winds to at least 45 knots with frequent gusts over storm force in the central and eastern basin will push the lake level well above flood stage at Buffalo. Once the winds start ramping up this morning there will be a very rapid rise in the Lake Erie water level at the eastern end of the basin. Lake Erie water levels at Buffalo are expected to reach peak between 9 am today morning and 3 am Saturday morning, with the potential for lakeshore flooding continuing through Saturday. Peak lake levels exceeding 11 feet above low water datum at Buffalo are almost certain, with even the potential to exceed 12 feet looking quite likely. If this were to happen it would be near or even break the previous high lake level at Buffalo set back on 12/2/1985 of 12.08 feet above of low water datum. For historical perspective, peak winds for that event reached 66 mph, with this event we are looking at peak gusts at or exceeding these speeds. Only question is the actual level of the lake itself. The lake currently is at 2.5 feet above low water datum at Buffalo which is just under a foot above the long term monthly mean for December. The two most recent highest events at Buffalo were 11.12 feet on 11/15/2020 and 10.6 feet on 11/1/2019.

A record breaking 12 consecutive years with 55+ within 5 days of December 20th. Newark reached a high of 58° earlier. Many top 3 warmest daily temperature records set over this period. This has become the fastest warming period in December. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Ending Date Highest Max Temperature Dec 15 to Dec 25 Missing Count 2022-12-25 58 2 2021-12-25 65 0 2020-12-25 62 0 2019-12-25 57 0 2018-12-25 61 0 2017-12-25 57 0 2016-12-25 59 0 2015-12-25 71 0 2014-12-25 64 0 2013-12-25 71 0 2012-12-25 57 0 2011-12-25 62 0 12/15 68 in 2015 67 in 2008 63 in 2001 12/16 65 in 2021 65 in 1971 62 in 1982 12/17 66 in 2000 62 in 2021 60 in 1992+ 12/18 64 in 1937 61 in 2006 61 in 1984 12/19 60 in 1931 58 in 1967 57 in 2017+ 12/20 61 in 2002 61 in 1957 60 in 1999 12/21 64 in 2013 62 in 2011 61 in 2018+ 12/22 71 in 2013 65 in 1998 64 in 1949 12/23 67 in 1990 66 in 2015 63 in 1949+ 12/24 71 in 2015 64 in 1990 63 in 1996 12/25 69 in 1964 68 in 1982 64 in 2014

Major coastal flooding in Freeport with water rescues underway. https://water.weather.gov/ahps2/hydrograph.php?wfo=okx&gage=frpn6

Some gusts to around 55 mph with the downed trees. Norwalk Harbor N/A 54 N/A N/A SE44G55

It may have shaved 5-10° off of what the temperatures would have been on a NW flow instead.

I still remember the old wind chill chart before they revised them to less extreme values. https://www.adirondackdailyenterprise.com/opinion/columns/safety-on-the-roads-by-dave-werner/2016/12/wind-chill-values-revised-in-2001/

The 18z HRRR had ocean effect squalls for all of Long Island tomorrow afternoon but it’s still on its own.

Dropping from 55° to near 10° with 50-60 mph gusts will make it feel colder than if it started out in the low 30s before the cold front. The cool little feature which we almost never see with an Arctic front is a SW to WSW flow. The Euro has sound effect snow squalls in Southern Rhode Island. The mesos closer in will probably have a better handle on this. Wonder if those areas could get a surprise overperforming localized snow event?

The one piece of good news is that we didn’t have a 40” snowstorm like in 2020 before this storm. So while there will be heavy rains and flood potential in New England ski country tomorrow, the rapid runoff and landslide potential won’t be like 2020. But anything left will freeze like cement which isn’t the greatest.

NYC has finished every La Niña season in last 30 years with under 20” of seasonal snowfall following a December with under 3”. It must be due to the snowy La Niña seasons having a nice early frontloaded snowfall period. December snowfall doesn’t matter as much in El Niño’s like 14-15 or neutral years like 12-13. Those have traditionally had better backloaded periods. Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2021-2022 0.0 T 0.2 15.3 2.0 0.4 0.0 17.9 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2020-2021 0.0 0.0 10.5 2.1 26.0 T 0.0 38.6 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2017-2018 0.0 T 7.7 11.2 4.9 11.6 5.5 40.9 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2016-2017 0.0 T 3.2 7.9 9.4 9.7 0.0 30.2 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2011-2012 2.9 0.0 0.0 4.3 0.2 0.0 0.0 7.4 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2010-2011 0.0 T 20.1 36.0 4.8 1.0 T 61.9 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2008-2009 0.0 T 6.0 9.0 4.3 8.3 T 27.6 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2007-2008 0.0 T 2.9 T 9.0 T 0.0 11.9 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2005-2006 0.0 T 9.7 2.0 26.9 1.3 0.1 40.0 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2000-2001 T 0.0 13.4 8.3 9.5 3.8 0.0 35.0 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 1999-2000 0.0 0.0 T 9.5 5.2 0.4 1.2 16.3 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 1998-1999 0.0 0.0 2.0 4.5 1.7 4.5 0.0 12.7 Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 1995-1996 0.0 2.9 11.5 26.1 21.2 13.2 0.7 7

Continuation of the coldest temperatures staying to our west in recent years.

The block extending so far south has resulted in the forecast for record December low pressures north of the Lakes. Pressures around 970mb or lower have usually been associated with storm tracks very close to the coast. So it’s an impressive merger of a -3 to -4 -AO block and the SE Ridge. The colder storm track the Euro was showing last Thursday would have been closer to our old climo for +PNA -AO storm tracks. New December record low pressures possible Old forecast from last Thursday more traditional track New run much stronger SE Ridge over the record warm Gulf Stream