January 2026 OBS and Discussion

[AdMC]

Less mosquitos this summer I guess?

[MJO812]

HRRR. BRRR.

[psv88]

1 hour ago, AdMC said:

Less mosquitos this summer I guess?

No, because the cold air is here with snow on the ground...acts like a warm blanket for them

[bluewave]

An icy New Haven Harbor today looking west from the Pardee Seawall Park.

 

[donsutherland1]

A fresh surge of Arctic air is moving into the region. Tonight and tomorrow night will likely see the temperature bottom out at their lowest levels this winter. Single digits are likely in Central Park. The last winter with more than one single-digit day was Winter 2022-23 when there were three such days. 

Highs will be mainly in the upper teens and lower 20s through Saturday. The last winter with more than one high in the teens was Winter 2018-19 when there were two such days. 

Temperatures should begin to moderate on Sunday into early next week and could briefly rise to or above freezing. Nevertheless, readings are likely to remain below normal into at least the start of next week.

Some light snow or flurries remains possible on Sunday if a developing storm passes close enough to the coast. This outcome is not assured. Eastern Long Island into southeastern New England would have the greatest chance of seeing an accumulating snowfall. 

Overall, January 20th-February 3rd will likely be the coldest and perhaps snowiest two-week period this winter. The forecast WPO-/EPO-/AO-/PNA+ pattern is typically the coldest pattern in January and among the coldest during the first half of February. A persistently positive PNA will have above climatological risk of moderate or significant snowfalls. 

For perspective, the coldest two-week period this winter prior to January 20th was January 3-16, 2026 and January 4-17, 2026 with a mean temperature of 30.3°. The snowiest two-week period was December 14-27, 2025 when 7.2" of snow fell. Already, snowfall since January 20th has surpassed that figure.

The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -0.7°C for the week centered around January 14. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.48°C and the ENSO Region 3.4 anomaly has averaged -0.68°C. La Niña conditions will likely continue into at least late winter.

The SOI was +6.84 yesterday. 

The preliminary Arctic Oscillation (AO) was -4.195 today. 

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal January (1991-2020 normal). January will likely finish with a mean temperature near 30.2° (3.5° below normal). 

Supplemental Information: The projected mean would be 2.4° below the 1981-2010 normal monthly value. 

 

[Prue11]

6 minutes ago, donsutherland1 said:

A fresh surge of Arctic air is moving into the region. Tonight and tomorrow night will likely see the temperature bottom out at their lowest levels this winter. Single digits are likely in Central Park. The last winter with more than one single-digit day was Winter 2022-23 when there were three such days. 

Highs will be mainly in the upper teens and lower 20s through Saturday. The last winter with more than one high in the teens was Winter 2018-19 when there were two such days. 

Temperatures should begin to moderate on Sunday into early next week and could briefly rise to or above freezing. Nevertheless, readings are likely to remain below normal into at least the start of next week.

Some light snow or flurries remains possible on Sunday if a developing storm passes close enough to the coast. This outcome is not assured. Eastern Long Island into southeastern New England would have the greatest chance of seeing an accumulating snowfall. 

Overall, January 20th-February 3rd will likely be the coldest and perhaps snowiest two-week period this winter. The forecast WPO-/EPO-/AO-/PNA+ pattern is typically the coldest pattern in January and among the coldest during the first half of February. A persistently positive PNA will have above climatological risk of moderate or significant snowfalls. 

For perspective, the coldest two-week period this winter prior to January 20th was January 3-16, 2026 and January 4-17, 2026 with a mean temperature of 30.3°. The snowiest two-week period was December 14-27, 2025 when 7.2" of snow fell. Already, snowfall since January 20th has surpassed that figure.

The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -0.7°C for the week centered around January 14. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.48°C and the ENSO Region 3.4 anomaly has averaged -0.68°C. La Niña conditions will likely continue into at least late winter.

The SOI was +6.84 yesterday. 

The preliminary Arctic Oscillation (AO) was -4.195 today. 

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal January (1991-2020 normal). January will likely finish with a mean temperature near 30.2° (3.5° below normal). 

Supplemental Information: The projected mean would be 2.4° below the 1981-2010 normal monthly value. 

 

Don, do you know how many single digit readings have occurred at ISP this winter?

[donsutherland1]

3 minutes ago, Prue11 said:

Don, do you know how many single digit readings have occurred at ISP this winter?

So far, one. 

[nycsnow]

AIGFS has the 6th&11th storms 

[nycsnow]

Shaping up to be an awesome AIGFS and gfs run lot of snow chances 

[Stormlover74]

 

8 minutes ago, nycsnow said:

Shaping up to be an awesome AIGFS and gfs run lot of snow chances 

Feb thread

[Dark Star]

2 hours ago, AdMC said:

Less mosquitos this summer I guess?

Dunno.  They have killer mosquito swarms in the arctic, always have...

[Dark Star]

59 minutes ago, donsutherland1 said:

A fresh surge of Arctic air is moving into the region. Tonight and tomorrow night will likely see the temperature bottom out at their lowest levels this winter. Single digits are likely in Central Park. The last winter with more than one single-digit day was Winter 2022-23 when there were three such days. 

Highs will be mainly in the upper teens and lower 20s through Saturday. The last winter with more than one high in the teens was Winter 2018-19 when there were two such days. 

Temperatures should begin to moderate on Sunday into early next week and could briefly rise to or above freezing. Nevertheless, readings are likely to remain below normal into at least the start of next week.

Some light snow or flurries remains possible on Sunday if a developing storm passes close enough to the coast. This outcome is not assured. Eastern Long Island into southeastern New England would have the greatest chance of seeing an accumulating snowfall. 

Overall, January 20th-February 3rd will likely be the coldest and perhaps snowiest two-week period this winter. The forecast WPO-/EPO-/AO-/PNA+ pattern is typically the coldest pattern in January and among the coldest during the first half of February. A persistently positive PNA will have above climatological risk of moderate or significant snowfalls. 

For perspective, the coldest two-week period this winter prior to January 20th was January 3-16, 2026 and January 4-17, 2026 with a mean temperature of 30.3°. The snowiest two-week period was December 14-27, 2025 when 7.2" of snow fell. Already, snowfall since January 20th has surpassed that figure.

The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was -0.7°C for the week centered around January 14. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.48°C and the ENSO Region 3.4 anomaly has averaged -0.68°C. La Niña conditions will likely continue into at least late winter.

The SOI was +6.84 yesterday. 

The preliminary Arctic Oscillation (AO) was -4.195 today. 

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal January (1991-2020 normal). January will likely finish with a mean temperature near 30.2° (3.5° below normal). 

Supplemental Information: The projected mean would be 2.4° below the 1981-2010 normal monthly value. 

 

Wow,  -4.195 AO !!!!