bluewave

It’s remarkable how that November 1995 pattern locked in right through April. That was an example of a stuck weather pattern from before the 2010s era. It will be interesting to see how low we can extend that 6-10 day +EPO, SW ridge, and -NAO.

The day 6-10 EPS 500 mb pattern is similar to November 1995. While it’s showing a more +EPO than 1995, the SW ridge near California and the -NAO block resembles 1995. It will be interesting to see how long we can hold that kind of a pattern.

Great illustration of how an extreme La Niña Pacific Jet can trigger a wave breaking event that pumps the -NAO -AO block.

All the guidance is correcting stronger with the -NAO -AO blocking for late November. This is what we want to see during La Ninas in November for winter blocking intervals and better snowfall chances.The individual storm details will probably have to wait until we get within the 120 hr range. New run Old run

We will need a strong enough storm Thanksgiving week for our first -10 departure of fall behind the cold front. Our last multi station average below -10 was the July 4th weekend. The only recent fall without one averaged for our climate division was the 2016 La Niña. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=32&network=NYCLIMATE&station=NYC004&year=2021&var=high&gddbase=50&gddceil=86&how=diff&cmap=jet&_r=t&dpi=100&_fmt=png

Yeah, the warmest SSTs for the period of record during this time of year. https://mco.umaine.edu/gom_sst/

And these unusually potent late fall severe weather patterns in recent years. https://weather.com/storms/tornado/news/2018-10-04-pennsylvania-record-october-tornado-outbreak Tuesday's swarm of tornadoes in parts of the Northeast set an October record in Pennsylvania. It was the state's most tornadic day in over 20 years. https://www.washingtonpost.com/weather/2018/10/24/rare-late-october-tornado-outbreak-hit-massachusetts-rhode-island-tuesday/ October 24, 2018 Cape Cod is a fun summertime vacation destination, and the weather is usually turning increasingly wintry this time of year. Tuesday, the Cape looked more like Oklahoma than New England as several tornadoes tore through Massachusetts and Rhode Island. At least three tornadoes seem likely to have touched down. It’s a region that doesn’t see many twisters any time of year, and this is as late as they come in Southern New England.

Record number of tornado warnings issued from the NWS at OKX for October and November since 2018. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=171&opt=wfo&station=OKX&state=NY&_ugc_state=NY&ugc=NYC059&phenomena=TO&significance=W&cmap=Greens&_r=t&dpi=100&_fmt=png

The December pattern will probably begin to set up during the last week of November. We need a strong cutter or hugger to pump the -NAO into December like last year. All our La Ninas that have near to above normal snows have a front loaded part when we put down snow at some point in December. This was true during our last La Niña Decembers in 2016 and 2017.

Partial collapse of the restaurant according to a report on twitter.

Small planes flipped at Brookhaven airport.

Damage at Chipotle in Suffolk.

This was the first time that I saw asperatus clouds ahead of severe storms on Long Island.

Damage reports in Lynbrook.

Newark gusting to 52 mph with the sting jet like feature behind the line. Newark Liberty PTSUNNY 51 43 74 W38G52

These near record midlevel lapse rates have given us unusually widespread coverage of hail across the area.

Enough hail to whiten the ground in NJ.

These near record midlevel lapse rates are as steep as we see on the Plains with their spring and summer severe outbreaks.

Hopefully, the JMA is correct about us getting -NAO -AO intervals this winter.

We may continue to get -NAO -AO intervals as long as the troposphere remains uncoupled from the SPV.

We could use a powerful storm like we got at the end of November last year. That system created a big wave breaking event over the North Atlantic. It pumped the -NAO ridge into December.

In addition to the severe potential that Walt outlined, there is a sting Jet-like feature right behind the low. So we could be looking at two rounds of higher winds. The low level lapse rates steepen behind the storm in the CAA which could allow westerly 50-60 mph gusts.

Yeah, that’s why we see the temperature back and forth continuing. The models have been too weak day 10 with the Pacific Jet. Notice how the day 5 has more of an Alaska +EPO trough than the day 10 was forecasting. New 120 Old 240

It looks like a battle between the warmer Alaska +EPO trough and cooler ridge near the US West Coast. So we get a series of Pacific storms with warm ups ahead of them and cool downs behind. The monthly temperature departure may not be decided until the end of the month.

The Southeast is winning the November cold departure battle so far.