bluewave

I saw that also. What the Euro is forecasting would be rare. Only 5 out of 44 SSWs on record occurred before January 1st. https://csl.noaa.gov/groups/csl8/sswcompendium/majorevents.html

One of the issues with some of these monthly seasonal forecasts is that they just repeat the initial conditions at the start of the month for the whole month. The CANSIPS and the CFS do this often. But sometimes the Euro monthly issued on the 5th does well with the whole first month. But it has been rare for any of these seasonal models to get the 2nd month or beyond correct in recent years.

Looks like 35° was the official low in NYC. https://www.weather.gov/wrh/timeseries?site=knyc NYC…35° LGA….38° JFK….34° FRG…32° ISP…..28° EWR..35° HPN…28° HVN…29°

A record breaking 56° drop from the 80s to 20s here in Southern CT for a 5 day fall period. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=CT_ASOS&zstation=MMK&v=tmpf&hours=114&month=fall&dir=cool&how=exact&_r=t&dpi=100&_fmt=png

It makes it feel much colder compared to how warm it was.

3rd greatest 5 day temperature drop at SMQ during the fall of 53°. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=NJ_ASOS&zstation=SMQ&v=tmpf&hours=114&month=fall&dir=cool&how=exact&_r=t&dpi=100&_fmt=png

Temp still dropping here down to 30°.

My first freeze as it’s 31° near KHVN. I am closer to the shoreline with areas just to my north around 25°.

Yeah, sustained cold has been non-existent since the super El Niño in 15-16. The best cold periods were late Dec 17 into early Jan 18 and Jan 22. NYC Feb 23…+5.2 Jan 23…+9.8 Dec 22…-0.6 …………..+4.8 Feb 22….+1.4 Jan 22….-3.2 Dec 21….+4.7 ……………..+1.0 Feb 21….-1.7 Jan 21….+1.1 Dec 20…+1.7 …………..+0.4 Feb 20…+4.8 Jan 20….+6.5 Dec 19….+0.8 …………….+4.0 Feb 19….+0.9 Jan 19….-0.1 Dec 18…+2.6 …………….+1.1 Feb 18…+6.7 Jan 18….-0.9 Dec 17…..-2.5 …………….+1.1 Feb 17…..+6.3 Jan 17….+5.4 Dec 16….+0.8 …………….+4.2 Feb 16….+2.4 Jan 16….+1.9 Dec 15….+13.3 …………….+5.9

The Aleutian ridge NW of Hawaii keeps popping up driving a trough into the Western US and a ridge near our area.

They propose that the more -NAO in the summer is due to the decline in spring Canadian snow cover. While the more +NAO is winter is related to the cold blob. So a warming climate can affect the NAO in different ways depending on the season. https://www.nature.com/articles/s41467-023-39466-6

Islip may have the best chance. Islip Area, NYPeriod of record: 1963-09-05 through 2023-10-31DateLowest maximum temperatures (degrees F) 11/1 48 in 2010 48 in 1992 48 in 1976

The colder start to November is following the decadal pattern. Top 10 monthly warmth in September and October. Followed by older temperature departures in November.

Looks like first freeze Thursday morning away fro the UHI in NYC.

A -PDO El Niño also has an eastward displaced Aleutian low due to the warm pool and ridge axis NW of Hawaii to the Aleutians. The Aleutians ridge is so strong on the Euro seasonal, that the Aleutian low ends up in New Mexico. The better +PNA on the Euro seasonal could help out with snowfall chances even if the winter is warm. Very strong -PDO warm pool signature NW of Hawaii regardless of what the actual PDO value is.

The most reliable winter -AO -NAO predictor from the October pattern that I have been able to find only works during La Niña. Plus in recent years the response during the winter was more -AO than -NAO. But the snowfall relationship was very strong around NYC. All the La Ninas since 10-11 with a stronger October MJO 4-6 had much better winter snowfall with solid -AO intervals.

We are on track for our 5th -NAO October in a row. It’s one of the months of the year with a long term trend toward more negative. I am sure many on here would gladly trade the negative trend during October for one during the winter instead.

The interesting thing is how this October is a blend of 2022 and 2021 from the Northern Pacific to North America. I guess it makes sense due to such a strong La Niña background state during recent years. Some might even call it an atmospheric lag. Aleutian ridge NW Hawaii..Aleutian low west of California..strong Canadian 500 mb ridge…weak troughing underneath…not much cold available in North America.

The Euro isn’t a meso so it can’t resolve very well how far north the actual front is going to get on stalled frontal days like this. But it’s doing much better than the NAM in the actual warm sector. The NAM only had highs in the low 70s in SNJ its forecast from yesterday. It already made it to 80° near Cape May. So the Euro had a better forecast for the actual highs in the warm sector. But the mesos excell at the actual placement of where the fronts will stall. Also notice the cool bias with the Euro missing the 80° in SNJ.

The lower upper ocean heat around +1.0 is continuing to limit the warming potential in Nino 3.4. The peak daily maximum temperatures are struggling to get past +1.7. This is the same daily maximum temperature it didn’t push past in September.

It was too cool in its forecasts from yesterday missing the 60s in Suffolk. It has a bit of a cold bias like the other models. It had the 60s limited to south of BLM.

Montauk made it into the warm sector at 65° with SW wind. Montauk N/A 65 62 90 SW6

One of the main caveats with them is if the stratosphere and troposphere are coupled. The NAO and AO are forecast to remain slightly negative over the same period. So probably not much coupling going on right now.