bluewave

Yeah, it’s always rough when areas that are heavily wooded get that much ice. The Long Beach area didn’t have any major power outages in Jan 94 with .5 to .75 of radial ice. We just don’t have that many tall trees near the beach. While the SPC HREF Fram had a cold bias south of 287, it really honed in on those hard hit interior areas with the blue .5+ of ice from the 12z Thursday forecast.

The GFS was the only model that really struggled with its cold bias. All the other guidance had the most icing up toward Ulster and Orange Counties. The NYC and Long Island areas generally need the cold to be in place when the freezing rain begins for significant icing build up on trees and power lines. Models were signaling for days that we would start out in the 40s and 50s with rain before any changeover. Past major icing events near the coast generally began with the temperatures below freezing.

Yeah, you can see the competing influences of the IO and PAC tropical forcing so far this month. We finally made it into the 50s yesterday for the first time in a month. So the extended cold pattern of January is beginning to shift to more of a back and forth temperature regime. Colder this weekend before we go back into the 40s next week. Then another cool down mid-February. The big question Is what happens in late February. It will all come down to where the forcing consolidates. If the IO forcing takes over, then it could get quite warm as the SE Ridge would be favored. But if the forcing can linger from the WPAC to CP, then a continuation of the back and forth temperature pattern.

The EPS has more of a -PNA look near the end of the 0z run. But the GEPS and GEFS not as much. The big story this winter was the historic PNA rise from December to January. It was the greatest on record from December to January. So even if the +PNA weakens or reverses in late February, the February PNA reading won’t be anything like December was. So in two consecutive La Niña winters, this December will be the only severe -PNA out of 6 winter months. The December PNA was a record breaking -2.56 and January jumped to +1.01.

Finally dropped to 31° here in SW Suffolk but rain still not freezing yet.

The leading edge of the cold air was very shallow so the higher terrain outside the immediate Hudson Valley slowed the advance.

33 here in SW Suffolk with moderate rain.

Yeah, extremes have become the new normal around here.

We got lucky that the impressive SPV never really coupled with the lower atmosphere. Plus we had the strong +PNA and -EPO to compensate. So even if there is a reversal like weeklies have, it’s uncertain how much would propagate down to the troposphere.

Last February was an outlier for us on extended snow cover. This winter so far is like other recent years with quick warm ups and snowmelt. While we had an increase in snowfall since 1981, the snow cover days haven’t kept up.

The whole FV3 upgrade process seems to be very bumpy. The GFS initially had the January 3rd heavy snow event in ACY further north up into our area. Then we saw it too far to the east with the blizzard last weekend. It seems that some forecast outlets held off on the snow forecast until they saw the GFS coming back NW. So this adds an unnecessary layer of confusion to the forecast process. It also raises the question of what will happen once the NAM is discontinued. Its already been 5 years since the last NAM upgrade and it’s showing with other models like the improving RGEM jumping around less than the NAM from run to run. It would be even more confusing if a FV3 NAM replacement introduces a whole new set of biases that complicate the forecast process. We are getting to the point where it seems better to rely more on the GEM, RGEM, and Euro. Sometimes the HREF and HRRR does well. But even they have their issues at times.

NYC just experienced its biggest February hourly temperature drop on record. The temperature fell 18° in just one hour. This beats the previous February record which was 10°. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=NY_ASOS&zstation=NYC&hours=1&month=feb&dir=cool&_r=t&dpi=100&_fmt=png

Still a +PNA with a trough over the Great Lakes like the GEPS at the end of the run on the 19th.

We are entering a big temperature swings pattern. An earlier high of 57 in NYC is quickly dropping. Cold returns for the weekend before another warm up next week. Then this is followed by another cool down in mid-February.

One of our biggest temperature differences between NYC and the Bronx with 56° in NYC and 37° In the Bronx. Regional Weather Roundup National Weather Service New York NY 700 AM EST FRI FEB 04 2022 Note: "FAIR" indicates few or no clouds below 12,000 feet with no significant weather and/or obstructions to visibility. NYZ071-072-176-178-NJZ106-104-041300- New York City Metro Area CITY SKY/WX TMP DP RH WIND PRES REMARKS Central Park LGT RAIN 56 53 90 MISG 29.84F World Trd Ctr NOT AVBL Bronx Lehman C N/A 37 36 93 N9 N/A WCI 31 LaGuardia Arpt LGT RAIN 52 48 86 S7 29.82S Queens College N/A 48 46 93 S14 N/A Kennedy Intl LGT RAIN 48 47 96 S21 29.84F Breezy Point N/A 45 N/A N/A S12 N/A Brooklyn Coll N/A 52 50 93 SE8 N/A Staten Island N/A 57 55 94 S7 N/A Newark/Liberty CLOUDY 55 55 100 S10 29.81F Teterboro LGT RAIN 39 38 96 N10 29.84R FOG WCI 32

90 days is the record in NYC. But we recently made it above 50 days in 2015. Before that it was 1977. Number of Consecutive Days Max Temperature < 50 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date 1 90 1881-02-10 2 77 1969-03-15 3 74 1910-02-26 - 74 1877-01-31 4 69 1905-03-17 5 68 1885-03-26 6 65 1977-02-10 7 63 2015-03-08 8 62 1941-03-02 9 59 1948-02-13 - 59 1883-02-03 10 54 1971-02-11 11 53 1889-03-11 - 53 1884-02-05 12 52 1916-03-24 - 52 1895-02-28 13 51 1907-03-12 - 51 1873-01-15 14 50 1981-02-01 - 50 1927-01-18

I remember light freezing rain starting in Long Beach around 7am in January 1994. It became moderate during the afternoon. Then briefly heavy in the evening before the temperatures went above freezing around 9 pm. Probably the most challenging driving conditions that I have ever experienced. The trees were gorgeous the next day when sun came out.

You might have to find some old news articles. There was another ice storm in January 1978 along the Long Island South Shore . It wasn’t so bad in Long Beach with the temperature around 32°. But there was about .5 to .75 of ice along Sunrise highway were it was 30°. Long Beach had smaller ice storms only around .25 on Valentines Day 2007 and 2-2-11.

Yeah, 1994 was our most impressive ice storm. It seems like we had around .5 to .75 ice build up on the trees. To get those totals we were near 20° at the start of the event. The winds were very light in that storm so there weren’t any power outages in the Long Beach area. I can’t imagine what it would be like to get 3.00 of ice like areas to our north had in January 1998. https://www.weather.gov/media/btv/events/IceStorm1998.pdf This storm had historic impacts across northern New York, northern New England and southeast Canada due to the prolonged duration of the event (both meteorological and recovery period) and the magnitude of ice accretion and precipitation amounts. The most famous meteorological aspect of this storm was the devastating and destructive ice accumulation of more than 3 inches (75mm) in portions of northern New York and southeast Canada, with heavy ice accumulation across northern New England as well. Another major aspect of this storm was the extremely heavy precipitation across the region, including over 5 inches of rain that caused major flooding in portions of western New York.

The -AO block in 93-94 was one of the strongest on record near the pole. That’s why the winter was so cold and snowy with the TPV locking in near Hudson Bay. 02-03 had a -AO from December through January. So the 50/50 low remained stuck in place for PD2 even though it was weeks after the -AO faded.

It’s much easier for the jackpot to be closer to NYC when there is -AO or -NAO. LGA had some of the highest totals with the January 7th event near the tail end of the December -AO pattern. All last winter the jackpots were closer to NYC with the -AO. The snowfall totals were more equitably distributed in the January 2016 event with 30” extending into Queens and the -AO. The Boxing Day blizzard jackpotted around Newark in 2011 with the record -AO. Newark needed the -AO for the 60” in 33 days that winter. NYC got the heaviest totals over 25” with the February 2006 -AO event. The +PNA opens the door to heavy snows, but the -AO or -NAO is needed for NYC to get the heaviest totals relative to the other areas. NYC can get a 50” on the season like 14-15 with just a +PNA and -EPO block. But NYC hasn’t made it to 75” like 95-96 without the -NAO that we had that season. So while NYC can have nice to great snowfall outcomes just on the Pacific blocking, the -AO and -NAO is needed for greatness like a 95-96 in NYC.

That’s a great example of the split forcing pattern. The forcing near the dateline and WPAC is driving that ridge off the West Coast. While the IO convection is trying to pull the trough back from the East Coast. So the model comes to a compromise between the competing areas of tropical covection.

The whole chasing convection and bifurcated low thing was due to the upper low closing off late. So the low tracked further east. The +AO pattern was too progressive. The big snowstorm last February 1st was during a near record -3 to -5 -AO interval. So NYC and Newark were close to the jackpot. JFK got less than half the snowfall the other day than ISP. The 93-94 winter was -AO with a near record block over the pole. +AO more progressive favoring eastern areas -AO allowed low to close of on time with jackpot over NNJ and NYC

This year seems to be confirming what has been past experience with snowfall jackpots. The +PNA opens the door to heavy snowfall events. But NYC and nearby NJ need a -AO and -NAO to have the heaviest totals in their area. Long Island can get the heaviest snowfall with either a +AO or -AO in a +PNA. This was the case in January and with Juno in 2015. KUs can close off late with a +AO due to the lack of a 50/50 and weaker ridging in SE Canada. So eastern sections into New England picked ip the 30”+ totals. Last year we had a near record -AO and Newark and NNJ was the big snowfall leader relative to the local area.

To the extent that January got much colder following near record warmth in December. But the snowfall reversal in January was in a totally different league. January 22 and 15 were the only years that Islip went from under an inch of snow in December to 30”+ in January. The other years with such extreme jumps were El Niño’s bolded below. So this is completely new for a La Niña year. Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Dec Jan Season 2006-2007 0.0 1.0 1.0 2003-2004 0.0 19.1 19.1 2001-2002 0.0 3.7 3.7 2018-2019 T 0.9 0.9 2015-2016 T 24.8 24.8 2011-2012 T 3.8 3.8 1999-2000 T 8.3 8.3 1994-1995 T T T 1978-1979 T 6.9 6.9 1974-1975 T 1.8 1.8 1973-1974 T 9.0 9.0 1972-1973 T 1.5 1.5 1971-1972 T 2.1 2.1 1965-1966 T 12.1 12.1 1989-1990 0.2 2.0 2.2 1977-1978 0.2 27.7 27.9 2021-2022 0.3 31.8 32.1 1970-1971 0.3 11.3 11.6 2014-2015 0.4 30.2 30.6 1980-1981 0.5 13.2 13.7 2012-2013 0.6 3.3 3.9