bluewave

The other thing is how much warmer strong -AO patterns have become. This is only the 4th year with with a -1 AO or lower for all 3 winter months DJF. I believe Don had a great post a while back on the warming -AO patterns. This winter so far through February 10th is the warmest on the list. NYC average temperature for a -1 or lower AO for each individual month Dec, Jan, and Feb Dec 1 to Feb 10 average temperature NYC 20-21....36.4° 09-10....33.7° 76-77...26.0° 69-70°...30.1°

It’s tough to make comparisons to before the super El Niño in 15-16 since winters have been so much warmer.

Those old version GFS maps will become collectors items when the v16 goes operational on St Patrick’s Day. Still wish I kept a few old DGEX forecast maps.

The models lost the single digits lows for NYC a while ago. So the coldest temperatures will dump into the Plains. Probably related to the very strong MJO 7 pattern. But NYC still has a shot to drop below 20°. New run Old run

The strongest blocking of the whole winter was within the last few days. Looks like it gets weaker and becomes more east based going forward. You can see the shift on the long range models.

Looks like one of the greatest AO rises from -5 that we have seen coming up.

1.8” of fluffy powder here in SW Suffolk.

Only the 16 year since 1950 that NYC went 40 days without reaching 50°. 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 77 1969-03-15 2 65 1977-02-10 3 63 2015-03-08 4 54 1971-02-11 5 50 1981-02-01 6 47 2004-02-20 - 47 1985-02-18 - 47 1970-01-28 7 46 1968-03-07 8 44 2007-03-01 - 44 1996-01-17 - 44 1978-03-11 - 44 1956-02-07 9 43 2001-01-29 10 42 2011-02-13 11 40 2021-02-11

Yeah, those areas will be closer to the path of the current record breaking high pressure when it drops south. https://forecast.weather.gov/product.php?site=NWS&issuedby=FWD&product=AFD&format=CI&version=1&glossary=0 The freezer door will then be propped open on Sunday as mid level ridging amplifies over the Northwest U.S. and our polar low over Southern Canada pivots eastward allowing a chunk of arctic air to spread southward through the Plains. A 1050 mb high will surge southward behind a strong cold front but ahead of a compact shortwave ejecting out of the southwest U.S. This will set the stage for some exceptionally cold air to spread into North Texas over the latter half of the weekend into early next week. We`re becoming increasingly concerned for a prolonged cold spell with actual air temperatures falling into the single digits to near 0 across parts of the region by Monday. While the GFS is currently the coldest guidance, other global guidance and ensemble members indicate 850 mb temps falling into the -12 to -17 degree range which would be in the coldest 10% of temperatures in our observed sounding data. In addition, a pool of moisture will reside across much of East Texas and should quickly surge northwestward into the region as strong forcing overspreads North Texas late Sunday into Monday. With column temperatures as cold as currently forecast, widespread moderate to heavy snow would be expected to develop as the shortwave spreads across the Southern Plains. The current forecast will reflect these trends with all snow by late Sunday night and continuing into Monday. While it`s a little early to pin down exact accumulations, as of now, it appears that widespread snowfall amounts of 2 to 4 inches will be possible over a large area of the region. Column temperatures would be cold enough to support higher snowfall ratios than we typically see which could result in significantly heaftier snow totals. North winds 15 to 25 mph could also result in significant reductions to visibility during the snow. This will be a fast moving system, but definitely has the potential for significant impacts to travel and infrastructure across the region. Extremely cold weather will continue into the middle of next week. It should be stressed that this bout of extreme cold may have significant impact to infrastructure over the latter part of the weekend into early next week. Exposed pipes are likely to burst in the prolonged cold. Preparations should be made now to protect exposed pipes or other infrastructure sensitive to the cold. Plans should be made for pets and people.

The record Arctic high that slips south will provide plenty of CAD and low level Arctic air. But ice will be an issue with more amplified systems. We may need to get to within 2-3 days of each event to know how amped up they are going to be. Less amped is better if you want more snow and less ice.

It works in our favor for weak systems like tomorrow. So we get a nice light snow event. But MJO 7 with too amped a system can present ice issues.

Tough to bet against the SE Ridge helping us out in an amplified MJO 7 pattern. New run Old run

Looks like our first -5 AO reading during a La Niña February. The other 3 Februaries were El Niño years. 2-14-10...-5.132....2-6-10....-5.205....Niño 3.4....+1.5 2-5-78.....-5.291....................................................+0.7 2-13-69....-5.285...................................................+1.1

This big a swing from the exact date last year is unprecedented. The +AO almost made it to +6. Just ridiculous volatility for two consecutive Februaries. 2020 2 9 5.765 2020 2 10 5.910

Who knows, maybe some bonus light snows can still sneak in here on Thursday.

Yeah, we are now in the all or nothing snowfall era. All years...................09-10, 10-11, 12-13, 13-14, 14-15, 15-16, 16-17, 17-18, 20-21 Nothing years..........11-12, 18-19,19-20 Islip seasonal snowfall since 2010

The record warm pool east of New England this year could be another factor.

Who could have guessed after the raging polar vortex last winter that the AO would be negative nearly every day of this winter? 2020 12 1 0.236 2020 12 2 -0.011 2020 12 3 -1.188 2020 12 4 -1.713 2020 12 5 -1.363 2020 12 6 -1.468 2020 12 7 -1.555 2020 12 8 -1.108 2020 12 9 -1.002 2020 12 10 -1.395 2020 12 11 -2.139 2020 12 12 -2.657 2020 12 13 -2.813 2020 12 14 -2.857 2020 12 15 -2.937 2020 12 16 -2.760 2020 12 17 -2.260 2020 12 18 -1.736 2020 12 19 -1.125 2020 12 20 -0.884 2020 12 21 -1.214 2020 12 22 -1.739 2020 12 23 -1.511 2020 12 24 -0.451 2020 12 25 0.226 2020 12 26 -0.467 2020 12 27 -2.752 2020 12 28 -3.197 2020 12 29 -2.516 2020 12 30 -2.602 2020 12 31 -2.949 2021 1 1 -2.909 2021 1 2 -2.685 2021 1 3 -2.427 2021 1 4 -3.069 2021 1 5 -3.418 2021 1 6 -3.436 2021 1 7 -2.995 2021 1 8 -2.895 2021 1 9 -2.602 2021 1 10 -1.611 2021 1 11 -0.849 2021 1 12 -0.650 2021 1 13 -0.909 2021 1 14 -2.176 2021 1 15 -2.515 2021 1 16 -1.796 2021 1 17 -1.302 2021 1 18 -1.696 2021 1 19 -1.919 2021 1 20 -2.283 2021 1 21 -2.290 2021 1 22 -2.022 2021 1 23 -2.124 2021 1 24 -2.694 2021 1 25 -3.582 2021 1 26 -3.543 2021 1 27 -3.202 2021 1 28 -2.593 2021 1 29 -2.726 2021 1 30 -2.825 2021 1 31 -2.513

With more snowfall opportunities ahead of us, JFK is already top 10 for February snowfall. NYC and ISP aren’t too far behind. So our record snowfall pattern since the 02-03 winter continues. Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Feb Click column heading to sort ascending, click again to sort descending. Rank Year Total Snowfall Missing Count 1 2003 32.1 0 2 2010 29.6 0 3 1961 25.4 0 4 1983 24.7 0 5 1994 23.7 0 6 1969 22.4 0 7 2014 21.0 0 8 1967 19.9 0 9 2021 18.8 21 10 1996 18.4 0 Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Feb Click column heading to sort ascending, click again to sort descending. Rank Year Total Snowfall Missing Count 1 2010 36.9 0 2 2014 29.0 0 3 1934 27.9 0 4 2006 26.9 0 5 1994 26.4 0 6 1926 26.3 0 7 2003 26.1 0 8 1920 25.3 0 - 1899 25.3 0 9 1967 23.6 0 10 1978 23.0 0 11 1907 21.8 0 12 1983 21.5 0 13 1996 21.2 0 14 1894 20.5 0 15 1979 20.1 0 16 2021 19.9 21 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Feb Click column heading to sort ascending, click again to sort descending. Rank Year Total Snowfall Missing Count 1 2013 31.4 0 2 1969 29.5 0 3 1978 28.9 0 4 1983 26.1 0 5 2014 24.5 0 6 2010 21.7 0 7 1994 20.0 1 8 2006 19.9 0 9 1967 19.5 0 10 1996 19.0 0 11 2021 17.4 21

Long Beach has to be one of the most fun spots on Long Island. It was a really cool place to grow up. Very unique vibe and mix of people.

It started this morning with rain and 38° on the South Shore.

Mini version of the Long Beach polar bear plunge today.

Beautiful pink sunset with the snow sticking to all the trees. Finished with 5.0” here in SW Suffolk. Lost about 1” to rain and melting snow at the start.

Very impressive merger of the bands across Suffolk right now.

Approaching 6” on parts of Long Island under these heavy bands.