bluewave

It was a very impressive first half of November for early record snow and cold. You can see the beginning of the -EPO relaxation with the North American snow extent peaking. We’ll have to see how the record +IOD interacts with the MJO and El Niño. Even weak El Niño patterns like we have now are usually back-loaded winters with mild Decembers. The one exception to that is getting a -NAO. But we have been in a mild December +NAO streak since 2011. Daily EPO 2019 10 23 -43.21 2019 10 24 -36.14 2019 10 25 -49.33 2019 10 26 -193.78 2019 10 27 -286.38 2019 10 28 -273.06 2019 10 29 -225.04 2019 10 30 -191.46 2019 10 31 -179.78 2019 11 01 -191.50 2019 11 02 -233.94 2019 11 03 -260.13 2019 11 04 -268.09 2019 11 05 -261.25 2019 11 06 -237.61 2019 11 07 -181.25 2019 11 08 -150.84 2019 11 09 -175.85 2019 11 10 -217.23 2019 11 11 -197.04 2019 11 12 -92.56 2019 11 13 -67.49 2019 11 14 -10.10 2019 11 15 42.49

Looks like the Arctic air mass that dominated the first half of November will be replaced by more of a Pacific one. So any cold we get should be much less intense. Probably have to wait for the next big -EPO drop to see Arctic air again.

It works out to a -5.7 departure for the first 16 days of the month. About 3 to 4 weeks early early for those temperatures which are average for December 1st.

Suffolk is living up to its snowy 2010’s reputation.

Some of the models were showing this snow on Long Island. Islip now has 2 days with reported snow by November 17th. This was the 2nd coldest start to November for Islip behind 1976. 17 Nov 7:56 am 34 28 79 23 NNE 17 4.00 Lt Snow BKN031,OVC039 Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 1 to Nov 16 Missing Count 1 1976-11-16 40.6 0 2 2019-11-16 41.5 0

While we have seen record cold during recent Novembers, this year Is showing us something more impressive.

Rare to see the relative humidity drop under 10% at White Plains. This looks like the lowest relative humidity of the 2010’s. White Plains FAIR 39 -15 9 NE14 https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=157&network=NY_ASOS&station=HPN&year=2019&var=min_rh&dir=below&thres=10&dpi=100&_fmt=png

Relative humidity down to 13% now in NYC. This has to be a new record for NE flow in November. Central Park FAIR 40 -7 13 NE14G23

Today could be one of the driest days that we have seen this time of year on a NE wind. The relative humidity is already down to 30% with dewpoints falling to near 0. The NWS even put out a special statement. This is essentially an Arctic backdoor with the temperatures modifying due to the NE flow. But the dryness remains. East Hampton FAIR 32 5 32 NE12G21 Willimantic FAIR 27 -1 30 N8 There will be an enhanced risk of fire spread today with gusty winds and low relative humidity. Winds will be out of the north to northeast at 10 to 20 mph with gusts mainly between 20 and 30 mph. Relative humidity is expected to lower to around 15 to 25 percent.

It may not make much of a difference for us if the AMO goes more negative in the future. The waters of the NW Atlantic have seen some of fastest rates of increase. Perhaps a combination of the upward global SST trend and the slowing AMOC. So we get the persistent cool pool south of Greenland and warm SST’s off the East Coast. This effect could mute any influence on our weather of a more -AMO. The 1980’s were a much colder SST and global climate era. http://www.realclimate.org/index.php/archives/2016/05/amoc-slowdown-connecting-the-dots/

I am not sure that Manhattan was ever the greatest spot to radiate at night. It is a narrow island surrounded by water. So NYC probably always needed strong cold air advection to set record lows. I found this UHI study that was published 11 years ago with data through 2002. It found that UHI was already strongly established by around 1900. In addition, the UHI effect isn’t really that much stronger in Central Park than it was back then. They have a bunch of charts and graphs. http://www.theurbanclimatologist.com/uploads/4/4/2/5/44250401/gaffinetal2008nycuhiandtemptrends.pdf

The record colder minimums are really driving the departures this month in NYC. min temp departure....-6.9...max....-4.0.....avg....-5.5

We were more competitive with the late 1880’s on the number of freezes for NYC. This year tied the record of 5 days for the first 2 weeks of November. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Min Temperature <= 32 Nov 1 to Nov 14 Missing Count 1 2019-11-14 5 0 - 1976-11-14 5 0 - 1933-11-14 5 0 - 1886-11-14 5 0 - 1879-11-14 5 0 - 1871-11-14 5 0 2 2004-11-14 4 0 - 1951-11-14 4 0 - 1926-11-14 4 0 - 1875-11-14 4 0 - 1873-11-14 4 0 - 1869-11-14 4 0

The cold came later last November. It was the 4th coldest 14th-24th on record for NYC. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 14 to Nov 24 Missing Count 1 1880-11-24 30.7 0 2 1873-11-24 34.3 0 3 1882-11-24 35.9 0 4 2018-11-24 36.8 0 5 1933-11-24 37.3 0

This was the 14th coldest first 2 weeks of November in NYC. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 1 to Nov 14 Missing Count 1 1873-11-14 40.4 0 2 1869-11-14 41.2 0 3 1875-11-14 41.8 0 4 1871-11-14 42.0 0 5 1976-11-14 42.3 0 - 1887-11-14 42.3 0 6 1878-11-14 42.4 0 7 1894-11-14 42.8 0 8 1933-11-14 43.2 0 9 1921-11-14 43.9 0 10 1962-11-14 44.1 0 11 1939-11-14 44.3 0 12 1917-11-14 44.5 0 13 1905-11-14 44.7 0 14 2019-11-14 44.8 0

Looks like this weekend may be our last shot at an Arctic air mass for a while. The EPS shifts the coldest air over to Asia as the Aleutian low intensifies and the -EPO relaxes. So any below normal temperatures should be more Pacific origin rather than Arctic. Maybe this Arctic relaxation will translate into a wetter pattern for us.

Cold and dry is the big story this month with the strong -EPO suppression. It’s a flip from the warm and wet in October and the warm and dry in September.

Beautiful sea smoke display today at Pensacola Beach. Record low of 29 at Pensacola going over the warm Gulf.

Yeah, November is our only month during the 2010’s with more record lows than highs. I used Newark since NYC would have had many more record highs if the thermometer was still on the castle instead of under the trees after the move around 1996. Newark ...daily record highs....daily record lows Jan....5...4 Feb....6...4 Mar...5...3 Apr...4....0 May..5...1 Jun...7...0 Jul...10...0 Aug...1....0 Sep...8....1 Oct...5....1 Nov..2....7 Dec..6....0 total...64...21

Yeah, more coastal flooding and beach erosion looks possible for that part of the coast. Not what they wanted to see following Dorian in September and Florence last year.

The most impressive feature in the forecasts going forward will be the pressure gradient along the East Coast. This could be one of the tightest pressure gradients of 2019. The Euro generates hurricane force wind gusts off the Carolinas this weekend.

I know that we have become accustomed to warning level snows by November 15th. But 8 out of 10 years during the 2010’s with at least a T of snow by November 15th is very impressive. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 15 to Nov 15 Missing Count 2019-11-15 T 3 2018-11-15 6.4 0 2017-11-15 T 0 2016-11-15 0.0 0 2015-11-15 0.0 0 2014-11-15 T 0 2013-11-15 T 0 2012-11-15 6.2 0 2011-11-15 5.2 0 2010-11-15 T 0

2 record lows in a row for NYC. It’s also is the 2nd earliest 23 degree reading on record. This is one of the few times that NYC has ever had 3 record lows in any single November. NYC recorded 2 record lows recently in 2017. NYC daily record lows 11/1 30 in 1885 30 in 1869 32 in 1925 11/2 30 in 1887 31 in 1965 31 in 1875 11/3 28 in 1875 30 in 1879 31 in 1912 11/4 25 in 1879 29 in 1951 30 in 1891 11/5 23 in 1879 29 in 1933 29 in 1878 11/6 27 in 1879 29 in 1871 30 in 1953+ 11/7 29 in 1930 30 in 1931 31 in 2012+ 11/8 29 in 2019 29 in 1886 30 in 1992+ 11/9 24 in 1976 27 in 2019 28 in 1971 11/10 25 in 2017 27 in 1914 29 in 2004+ 11/11 24 in 2017 28 in 1933 28 in 1926+ 11/12 25 in 2019 26 in 1926 27 in 1920 11/13 23 in 2019 24 in 1986 26 in 1911+

ISP was the only airport out of EWR-LGA-JFK- BDR to get above a trace of snow. https://twitter.com/iembot_okx?ref_src=twsrc^google|twcamp^serp|twgr^author ISLIP NY Nov 12 Climate: Hi: 58 Lo: 33 Precip: 0.19 Snow: 0.1

Gorgeous sunset right now.