bluewave

.2 of a mile for a few minutes so far at TEB. http://wxweb.meteostar.com/meteogram/link.shtml?choice=KTEB

Visibility dropped to .2 of a mile at FWN when the squall came through. http://wxweb.meteostar.com/meteogram/link.shtml?choice=KFWN

The models do show the squall over NEPA holding together down to the coast later.

At least get your facts straight if you are going to be posting comments like that. The Euro isn’t 15 degrees colder than the GFS MOS on Christmas Eve. The 23rd and 24th high temperatures are similar to the GFS MOS. We’ll just have to wait and see how close the forecasts come to the actual high temperatures on those days. NEW YORK CITY-CENTRAL PARK KNYC GFSX MOS GUIDANCE 12/18/2019 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 WED 18| THU 19| FRI 20| SAT 21| SUN 22| MON 23| TUE 24| WED 25 CLIMO X/N 37| 17 25| 21 34| 26 36| 31 45| 36 51| 44 53| 38 46 28 41 TMP 29| 18 24| 23 32| 27 35| 33 43| 38 48| 45 48| 39 43

This was only the 10th year that JFK finished with over 50 inches of precipitation. 5 of the top 10 wettest years occurred since 2004. Time Series Summary for JFK INTL AP, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 1983 59.12 0 2 2018 57.40 0 3 1975 57.18 0 4 2011 55.78 0 5 1989 55.73 0 6 1984 53.22 0 7 1996 51.45 0 8 2019 51.13 14 9 2004 50.95 0 10 2014 50.75 0

Pretty impressive for JFK to record its wettest December on record by the 17th of the month. The top 3 spots have occurred in just the last 6 years. Just goes to show how wet our climate has become. Time Series Summary for JFK INTL AP, NY - Month of Dec Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 2019 7.17 14 2 2014 7.04 0 3 2018 6.76 0 4 1986 6.73 0 5 2009 6.25 0 6 1969 6.16 0 7 1983 6.14 0 8 1974 6.07 0 9 1948 6.05 0 10 1996 6.00 0

Quick Arctic shot coming up next few days. Then we get our annual warm up potential before Christmas. The monthly departures will be decided by the temperatures during the last week of the month. The average NYC high and low for the last week of December is 40/29. So anything above 40 degrees is considered mild. NEW YORK CITY-CENTRAL PARK KNYC GFSX MOS GUIDANCE 12/18/2019 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 WED 18| THU 19| FRI 20| SAT 21| SUN 22| MON 23| TUE 24| WED 25 CLIMO X/N 37| 17 25| 21 34| 26 36| 31 45| 36 51| 44 53| 38 46 28 41 TMP 29| 18 24| 23 32| 27 35| 33 43| 38 48| 45 48| 39 43

Warm and wet storm track followed by cold and dry. But the last true Arctic air mass was over a month ago. Plenty of Pacific modification to the air mass over the CONUS.

The EPS is a carbon copy of the GEFS.

Yeah, one the heaviest 2 day rainfalls on record for December. Maximum 2-Day Total Precipitation for JFK INTL AP, NY Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date Missing Days Period of record: 1948-07-17 to 2019-12-16 1 3.23 2008-12-12 0 2 3.15 2014-12-10 0 3 3.04 2014-12-09 0 4 3.00 1992-12-11 0 5 2.95 1996-12-07 0 6 2.86 1948-12-31 0 7 2.77 2019-12-14 0 8 2.75 1992-12-12 0 9 2.46 1974-12-17 0 - 2.46 1974-12-16 0

This was the wettest first 16 days of December on record at JFK. Time Series Summary for JFK INTL AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation Dec 1 to Dec 16 Missing Count 1 2019-12-16 6.10 0 2 2014-12-16 5.60 0 3 1974-12-16 5.48 0 4 1996-12-16 5.07 0 5 2008-12-16 3.99 0

The first 17 days of the month have been near the wettest on record. So we need a break. The holiday shoppers and travelers will appreciate the step down in heavy precipitation.

The next week to 10 days looks drier than 12/1 to 12/17 as the ridge builds over the East.

December has become our most positive +NAO month of the year since 2011.

March has become the new December since 2011. 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 Mean 0.4 1.4 2.6 11.3 9.5 7.3 0.7 33.2 2018-2019 0.0 6.4 T 1.1 2.6 10.4 0.0 20.5 2017-2018 0.0 T 7.7 11.2 4.9 11.6 5.5 40.9 2016-2017 0.0 T 3.2 7.9 9.4 9.7 0.0 30.2 2015-2016 0.0 0.0 T 27.9 4.0 0.9 T 32.8 2014-2015 0.0 0.2 1.0 16.9 13.6 18.6 0.0 50.3 2013-2014 0.0 T 8.6 19.7 29.0 0.1 T 57.4 2012-2013 0.0 4.7 0.4 1.5 12.2 7.3 0.0 26.1 2011-2012 2.9 0.0 0.0 4.3 0.2 0.0 0.0 7.4 Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season Mean 0.0 1.1 2.3 15.5 12.8 9.9 0.6 42.3 2018-2019 0.0 4.3 T 0.9 3.5 4.1 T 12.8 2017-2018 0.0 T 6.0 22.0 1.4 31.9 4.6 65.9 2016-2017 T T 3.2 14.0 14.7 7.4 T 39.3 2015-2016 0.0 0.0 T 24.8 13.2 3.2 0.2 41.4 2014-2015 0.0 T 0.4 30.2 13.4 19.7 0.0 63.7 2013-2014 0.0 0.3 8.1 25.2 24.5 5.4 0.2 63.7 2012-2013 0.0 4.2 0.6 3.3 31.4 7.4 0.0 46.9 2011-2012 0.3 0.0 T 3.8 0.6 T 0.0 4.7

Tough to beat December 2000-2010. A remarkable 5 years with double digit snowfall amounts in NYC. Big shift to a more +NAO during December after 2010. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Dec Click column heading to sort ascending, click again to sort descending. Year Total Snowfall Missing Count 2019 1.8 15 2018 T 0 2017 7.7 0 2016 3.2 0 2015 T 0 2014 1.0 0 2013 8.6 0 2012 0.4 0 2011 0.0 0 2010 20.1 0 2009 12.4 0 2008 6.0 0 2007 2.9 0 2006 0.0 0 2005 9.7 0 2004 3.0 0 2003 19.8 0 2002 11.0 0 2001 T 0 2000 13.4 0

We don’t need very much amplitude in the MJO the to shift the CONUS back to a mild Pacific air mass. Look how much influence the low frequency WP forcing regime has had on the pattern going back to November. We

The high temperatures after this Arctic shot will be mostly dependent on wind direction. Days with more SE flow and a high pressure to our NE will mostly max out in the 40’s. But any SW flow days could reach the 50’s between the 23rd and 31st.

Yeah, we were right on the line between 32 and 33 degrees here. Less than a degree made the difference between some icing and none.

Some portions of the South Shore got into the icing. Looks like the winds verified a bit more NE than forecast. Most models yesterday had more ENE.

Next few days should be our last Arctic air mass for a while. The MJO forecast to move near phase 6 means mostly a mild Pacific influence into the longer range.

That’s all you need for minor ice accretion. My last significant events were Valentine’s Day 07 and 2-2-11. But Jan 94 and 78 are still the benchmark ice storms for me.

I remember that one. It was the most significant ice storm on Long Island until January 1994.

But nothing as significant as our big events like Jan 94 when temps were in the 20’s.

From my experience with icing here on Long Island. The most memorable events occur with temperatures in the 20’s. We get more rainfall runoff especially with faster rates in the low 30’s.