donsutherland1

As of 1 pm CST, Chicago (3.2") and Rockford (3.2") had set new daily snowfall records for November 29. Chicago's old mark of 3.0" was set in 1942. Rockford's old record of 3.0" was set in 1925. Upstream, parts of Iowa had seen 12" of snow.

I'm in briefly. I checked. Here are the December composites (1980-2024) for EPO+/PNA+/AO-/NAO- 500 mb Height Anomalies: Temperature Anomalies: Precipitation Rate: n=121 dates I suspect that there's a lot of variability, though.

I will check when I get home this evening.

As of 7 am, Chicago had picked up 0.5" of snow. Rockford had received 1.0". The highest amounts were at Chatsworth (3.0") and Melvin (2.0").

Parts of the region saw some heavier snow showers yesterday. Binghamton wound up picking up 1.6". Even heavier snow fell in some of the lake effect areas. Syracuse picked up 10.3" of snow, breaking the daily record of 8.8" from 1958.

The snow is sticking in Chicago. Courtesy of EarthCam:

Central Park has recorded its first freeze of the 2025-2026 season. The 1991-2020 normal first date is November 21. The 1961-1990 baseline was November 11. Last winter's first freeze occurred on November 30.

Tomorrow will be unseasonably cold. There is potential for New York City's Central Park to experience its first freeze of 2025 tomorrow morning. The 1991-2020 normal first date is November 21. The 1961-1990 baseline was November 11. Last winter's first freeze occurred on November 30. Saturday and Sunday will see a snowstorm blanket parts of the Great Lakes Region. Chicago and Milwaukee could see 6"-12" of snow. Detroit could pick up 4"-8". Toronto could see 3"-6". Sunday and Monday will be somewhat milder. Showers are possible on Monday as a cold front moves across the region. Generally colder than normal conditions could then continue into or through the second week of December. Severe cold appears unlikely through at least the first 10 days of December. Nevertheless, December 1-10 will be a solidly colder than normal period. Moreover, a storm could affect the region on Tuesday into Wednesday, bringing 0.50"-1.50" precipitation to the region. There is a distinct possibility that New York City could see its first measurable snowfall of the season. Interior sections have the highest probability of seeing accumulations of snow. The ENSO Region 1+2 anomaly was -0.7°C and the Region 3.4 anomaly was -0.7°C for the week centered around November 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.16°C and the ENSO Region 3.4 anomaly has averaged -0.65°C. La Niña conditions will likely continue through at least mid-winter. The SOI was -3.12 today. The preliminary Arctic Oscillation (AO) was +0.081 today. Based on sensitivity analysis applied to the latest guidance, there is an implied 99% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 47.2° (0.8° below normal). Supplemental Information: The projected mean would be 0.5° below the 1981-2010 normal monthly value.

There was a heavier snow shower in the Harriman, NY area this afternoon.

The latest HREF output:

2009-10 was a strong El Niño. 2010-11 was a strong La Niña.

Yesterday, I noted that the GEFS was trying to push an EPO+, but its forecast 500 mb pattern was profoundly different from any of the December WPO-/EPO+/AO-/PNA- clusters. That suggested that either the teleconnection idea was off or the pattern was off, rather than some novel outcome. Overnight and through today's 6z cycle, the GEFS has continued to evolve. It has added a WPO+ to its EPO+ idea and restored its earlier idea of a AO+. It has now joined the Canadian ensembles that keep the MJO out of Phase 8 through its forecast horizon. In short, its previously significant areas of "disconnect" have disappeared overnight. Its forecast pattern is now more consistent with what one would expect. For now, the GEFS is trying to build a credible milder alternative scenario for the pattern/temperature evolution in North America toward mid-December. The EPS has not shifted toward that emerging GEFS idea. Therefore, the baseline idea remains that the northern tier of the U.S. and most of Canada should remain cold toward and probably beyond mid-December. The Southeast could still turn warm despite some shots of colder air. Mid-December and beyond is still in the low-skill distant realm. The big story through the weekend will be the significant snowstorm that will affect parts of the Midwest and Great Lakes Region. As a result, Chicago, Detroit, Milwaukee, and Toronto remain on track to experience their snowiest fall in five or more years. As an appetizer, Detroit added 0.1" snowfall yesterday and Toronto picked up 1.2 cm (0.5") yesterday.

Tomorrow and Saturday will be unseasonably cold days. Tomorrow will be windy with a possibility of some snow flurries. There is potential for New York City's Central Park to experience its first freeze of 2025 tomorrow or, more likely, Saturday morning. The 1991-2020 normal first date is November 21. The 1961-1990 baseline was November 11. Last winter's first freeze occurred on November 30. Saturday and Sunday will see a snowstorm blanket parts of the Great Lakes Region. Chicago and Milwaukee could see 6"-12" of snow. Detroit could pick up 4"-8". Toronto could see 3"-6". Sunday and Monday will turn somewhat milder. Showers are possible on Monday as a cold front moves across the region. Generally colder than normal conditions could then continue into or through the second week of December. Severe cold appears unlikely through at least the first 10 days of December. Moreover, a storm could affect the region on Tuesday into Wednesday, bringing 0.50"-1.50" precipitation to the region. There is a distinct possibility that New York City could see its first measurable snowfall of the season. Interior sections have the highest probability of seeing accumulations of snow. The ENSO Region 1+2 anomaly was -0.7°C and the Region 3.4 anomaly was -0.7°C for the week centered around November 12. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.16°C and the ENSO Region 3.4 anomaly has averaged -0.65°C. La Niña conditions will likely continue through at least mid-winter. The SOI was +1.97 today. The preliminary Arctic Oscillation (AO) was +0.036 today. Based on sensitivity analysis applied to the latest guidance, there is an implied 96% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 47.1° (0.9° below normal). Supplemental Information: The projected mean would be 0.6° below the 1981-2010 normal monthly value.

For reference: The 33.5 cm snowfall at Toronto on November 30, 1940 is the biggest daily snowfall on record for November. The 10.0" for Milwaukee on November 30, 1940 is the second biggest daily snowfall on record for November.