bluewave

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.

Suffolk County is already in the low 60s. Once the winds switch offshore, they will probably go mid to possibly upper 60s.

Looks like the CFS will end up winning the October Nino 3.4 forecast vs the Euro and the dynamical average. October is on track to finish around +1.6. This is right where the CFS forecasted it to be. The Euro was way too high from the forecast issued last month. The dynamical average was also too high at +1.83. OISST…25 OCT…+1.6….18 OCT….+1.6….11 OCT…+1.5…4 OCT…+1.5 OCT Nino 3.4 forecast issued in September CFS……………….…+1.60 ECMWF……………+2.03 Dynamical avg….+1.83

Similar pattern to recent years with a number of stations finishing above 60° in October and 70° in September. Monthly Data for October 2023 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. State Name Station Type Mean Avg Temperature NY WEST POINT COOP 64.9 NY PORT AUTH DOWNTN MANHATTAN WALL ST HEL ICAO 63.8 NY LAGUARDIA AIRPORT WBAN 62.7 NJ NEWARK LIBERTY INTL AP WBAN 62.5 NY WORLD TRADE CENTER WBAN 61.8 NY NY CITY CENTRAL PARK WBAN 61.1 NY ORIENT POINT STATE PARK COOP 60.9 NJ HARRISON COOP 60.5 NJ TETERBORO AIRPORT COOP 60.3 NY RIVERHEAD RESEARCH FARM COOP 60.3 NY MONTAUK AIRPORT WBAN 60.3 NJ TETERBORO AIRPORT WBAN 60.2 NY FARMINGDALE REPUBLIC AP WBAN 60.2 NY JFK INTERNATIONAL AIRPORT WBAN 60.2 CT NEW HAVEN TWEED AP WBAN 60.2 NY MOUNT SINAI COOP 60.1 Monthly Data for September 2023 for Upton NY NWS CWA Click column heading to sort ascending, click again to sort descending. State Name Station Type Mean Avg Temperature NY PORT AUTH DOWNTN MANHATTAN WALL ST HEL ICAO 71.7 NJ NEWARK LIBERTY INTL AP WBAN 71.2 NY LAGUARDIA AIRPORT WBAN 71.0 NY MOUNT SINAI COOP 70.2 NY WORLD TRADE CENTER WBAN 70.1

We are currently running at levels close to this time last year. https://www.star.nesdis.noaa.gov/smcd/emb/snow/HTML/snow_extent_monitor.html

Last December was unprecedented for having the 2nd lowest December -AO on record with only a neutral NAO. This was one of the reasons along with the hostile Pacific that it was warmer and less snowy than the other Decembers with a -2 or lower AO reading. December 2009….AO….-3.413….NAO….-1.93 2022….AO….-2.719…..NAO….-0.15 2010…..AO….-2.631…..NAO….-1.85 2000…..AO….-2.354….NAO….-0.58 1995…..AO…..-2.127…..NAO….-1.67 2005…..AO…..-2.104….NAO…..-0.44 1976…..AO…...-2.074…NAO…….-1.60

Temperatures this October in Australia pretty much the opposite of what would be expected during an El Niño with the record cold.

The early to mid 90s were the glory days for them. Time Series Summary for STATE COLLEGE, PA - Oct through Sep Click column heading to sort ascending, click again to sort descending. Rank Season Total Snowfall Missing Count 1 1993-1994 109.3 0 2 1995-1996 99.0 0 3 1977-1978 98.2 0 4 1992-1993 92.5 0 5 1960-1961 91.9 0 6 1969-1970 89.9 0 7 2002-2003 83.6 0 8 1963-1964 78.2 0 9 1913-1914 77.4 122 10 1941-1942 75.0 2

This would help State College make up many of the lower snowfall seasons since the 90s.