bluewave

Yeah, December has been the toughest month of the entire year to sustain a -NAO pattern since 2011. The only time was in 2020. So we always have to wait and see if these long range -NAO forecasts get weaker the closer in time we get.

It mostly looks like a cold and dry pattern after Wednesday as we get our first freeze by next weekend. This is one of the strongest -EPO patterns on record coming up for this time of year. Maybe we can catch a stray streamer from the Great Lakes for some flurries. EPS starting to show Greenland Blocking near the end of the month.

Way too much -EPO suppression of the southern stream. Notice how the 0z OP Euro went back to the ensemble mean as expected. The hugger on Wednesday suppresses the SE Ridge.

Too bad none of these overamped day 7-10 OP runs have had any ensemble support. The 12z OP Euro is the latest example today. The other day it was the GFS and GEM. That’s why ensemble means are the way to go beyond the 120 hr forecast. The record -EPO looks too progressive for a big wrapped up benchmark track. But maybe even the coast can get a few mood flakes as the waves scoot by to our east as colder air gets drawn further east. Overamped OP run Ensemble mean more progressive weaker wave with maybe some mood flakes

LGA had their greatest snowstorm only a few weeks after their latest first freeze in January 2016. Frost/Freeze Summary for LAGUARDIA AIRPORT, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length 2015 03-29 (2015) 27 01-04 (2016) 15 280 2001 03-28 (2001) 31 12-23 (2001) 32 269 1998 03-22 (1998) 31 12-22 (1998) 24 274 2021 04-02 (2021) 29 12-19 (2021) 31 260 2011 03-29 (2011) 32 12-11 (2011) 31 256 1948 04-10 (1948) 32 12-11 (1948) 32 244 Maximum 2-Day Total Snowfall for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date Missing Days 1 28.2 2016-01-24 0 2 27.9 2016-01-23 0 3 25.4 2006-02-12 0 4 23.8 1996-01-08 0 5 23.3 2006-02-13 0 6 22.8 1947-12-27 0 7 22.2 1947-12-26 0 8 22.0 1983-02-12 0

We would probably be talking close to 6” of snow this week in NYC with this record -EPO block if we had the high pressure in New England like during mid-November 2018. https://www.weather.gov/okx/November15162018_Snow

While it looks like Islip will eventually get their first freeze by next weekend, this will be one of the latest on record. Frost/Freeze Summary for ISLIP-LI MACARTHUR AP, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length 1984 04-10 (1984) 30 11-15 (1984) 29 218 2016 04-10 (2016) 32 11-14 (2016) 32 217 1994 04-23 (1994) 32 11-12 (1994) 32 202 1981 04-22 (1981) 32 11-12 (1981) 31 203 1977 04-11 (1977) 32 11-12 (1977) 32 214

This was the warmest November 1-12 on record across the area by several degrees. Time Series Summary for Poughkeepsie Area, NY (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 1 to Nov 12 Missing Count 1 2022-11-12 56.2 2 2 1975-11-12 55.6 0 3 1938-11-12 54.0 0 4 2015-11-12 53.1 0 5 1935-11-12 52.7 0 Time Series Summary for WESTCHESTER CO AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 1 to Nov 12 Missing Count 1 2022-11-12 58.4 0 2 1975-11-12 55.8 0 3 1994-11-12 55.0 1 4 2015-11-12 54.7 0 5 2020-11-12 53.0 0 Time Series Summary for SUSSEX AIRPORT, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 1 to Nov 12 Missing Count 1 2022-11-12 58.3 2 2 2015-11-12 51.8 0 3 2020-11-12 50.7 0 4 2014-11-12 47.9 0 5 2008-11-12 47.6 0 Time Series Summary for New Brunswick Area, NJ (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 1 to Nov 12 Missing Count 1 2022-11-12 58.3 0 2 1975-11-12 57.8 0 3 1935-11-12 56.7 0 4 1950-11-12 56.3 0 5 1948-11-12 55.9 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 1 to Nov 12 Missing Count 1 2022-11-12 62.2 0 2 1975-11-12 60.2 0 3 2015-11-12 58.2 0 4 1994-11-12 57.1 0 5 1974-11-12 56.8 0 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 12 Missing Count 1 2022-11-12 59.2 0 2 1975-11-12 56.8 0 3 1977-11-12 55.4 0 4 2015-11-12 55.0 0 5 1974-11-12 54.6 0 Time Series Summary for NEW HAVEN TWEED AP, CT Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 1 to Nov 12 Missing Count 1 2022-11-12 59.1 0 2 1975-11-12 55.9 0 3 2020-11-12 52.7 0 4 2015-11-12 52.5 0 5 1948-11-12 52.3 1

The record high so far of 72° at Islip is the 6th day this month and a new high for November. Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Nov Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Max Temperature >= 70 Missing Count 1 2022 6 18 2 1975 4 0 3 2020 3 0 - 1990 3 0 - 1974 3 0 4 2017 2 0 - 2015 2 0 - 1982 2 0

Not really caused by Nicole. But Nicole is helping to pull the trough further east. The record EPO block is related to the EA and Pacific pattern.

The first 12 days of November are running +10 to +15 for high temperatures across the entire region.This is in par with December 2015 type extremes. But it won’t have the longevity for the entire month.

Today should be our last record warm 70s for a while as the record 5SD EPO block cools things down from mid to late November.

Newark tied the all-time highest November dewpoint of 68° Friday evening. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=155&network=NJ_ASOS&zstation=EWR&var=max_dwpf&threshold=100&hour=12&sdate=0101&edate=1231&month=nov&_r=t&dpi=100&_fmt=png

More record heat next few days. The models have 70s right out onto Long Island on Saturday with a warm offshore flow. The record high of 67 at Islip looks easy to beat. Islip Area, NYPeriod of record: 1963-09-05 through 2022-11-10 11/11 68 in 2020 66 in 1970 65 in 1974 11/12 67 in 2014 66 in 2021 66 in 2020+

Yeah, we are going to need the record -EPO for parts of Long Island like Islip to get their first freeze. Islip is already in the top 5 latest without a freeze. So a continuation of needing record blocking just to get some colder temperatures around here. Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Ending Date Lowest Min Temperature Sep 1 to Nov 9 Missing Count 2022-11-09 36 0 Frost/Freeze Summary for ISLIP-LI MACARTHUR AP, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length 1984 04-10 (1984) 30 11-15 (1984) 29 218 2016 04-10 (2016) 32 11-14 (2016) 32 217 1994 04-23 (1994) 32 11-12 (1994) 32 202 1981 04-22 (1981) 32 11-12 (1981) 31 203 1977 04-11 (1977) 32 11-12 (1977) 32 214 2005 04-17 (2005) 30 11-11 (2005) 30 207 2017 03-30 (2017) 32 11-10 (2017) 26 224

We should probably develop our own custom teleconnection indices based on how anomalous the raw 500mb height anomalies are. I like using the NAEFS site for finding record minimums and maximums. Plus we can also use how many meters above and below the 500 mb heights are. The forecast for next week is showing up as a 5 sigma block near Alaska which would be a record for this time of year.

Right. They post the daily values but don’t issue forecasts anymore. So we have to go by extrapolating from the 500 mb heights or looking at the vendors custom forecast indices.

Don, where did you find those raw forecast EPO values? The EPO site stopped posting the official forecast numbers like they do with the other teleconnection indices. I was using the NAEFS 500 mb forecast heights which will be the highest since 1979 for the dates coming up. Old ESRL/PSD forecast site discontinued

Record -EPO blocking setting up for next week. So a much colder pattern with the first freeze of the season for many in the forecast. These -EPO patterns are usually fairly progressive. So the GFS looks overamped compared to the Euro and GEM. But the chance exists for the first flakes of the season for interior zones.

https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=155&network=NJ_ASOS&zstation=EWR&var=max_dwpf&threshold=100&hour=12&sdate=0101&edate=1231&month=nov&_r=t&dpi=100&_fmt=png

You know a tropical system is going by to our west from Friday into early Saturday when the dewpoints approach the all-time November high of 68° at places like Newark.

This morning wasn’t that cold compared to the means. The 38° low at Newark was only a -3. But dropping from 80° a few days ago makes it feel colder. Almanac for NEWARK LIBERTY INTL AP, NJ November 9, 2022 Daily Data Observed Normal Record Highest Record Lowest Max Temperature M 57 77 in 2020 38 in 1976 Min Temperature M 41 57 in 1975 23 in 1976

Yeah, the blocking over the NE PAC and Alaska has been unprecedented since 2013. This type of extreme EPO blocking is something new. All-time 500 mb height records have been set over the last decade.

The top 6 strongest EPO blocking Novembers were 2019, 2018, 2014,2013,1996, and 1978. Quite a bit of variability between those winters. The recent examples of 19-20 and 18-19 were the opposite of 14-15 and 13-14. Similar to the spread between the 96-97 and 78-79 winter. So just looking at the November EPO wasn’t much help.

Transitioning to a colder near record -EPO blocking pattern in mid-November as Nicole pulls the trough into the East and weakens the SE Ridge.