December 2025 OBS and Discussion

[MJO812]

[SnoSki14]

1 hour ago, MJO812 said:

Probably more likely than normal that we see some snow. Very volatile weather pattern though 

[MJO812]

7 minutes ago, SnoSki14 said:

Probably more likely than normal that we see some snow. Very volatile weather pattern though 

Hopefully 

[MJO812]

5 hours ago, eduggs said:

This is the kind of storm that I can imagine looking borderline for snow right down to the Bronx until the NAM sends the vortmax to Buffalo and torches 900mb to 8C... signaling the rest of guidance to rain to Albany.

That said, synoptically, right now as modeled, it's pretty close for snow even in the City itself. The ICON and GFS have shifted slightly colder/south at 12z and 6z respectively, and ensembles (if you believe they are useful at this range) are south of their parent operational runs. The antecedent cold is marginally supportive. It wouldn't take a huge change in the shortwave structure aloft to lead to a snowier outcome further south.

It's not what I would bet on, but there is still some reasonable chance... especially outside of concrete jungles.

Icon getting interesting for the coast

[ag3]

36 minutes ago, MJO812 said:

Icon getting interesting for the coast

It’s a raging rainstorm well north and west of NYC and into New England.

 

 

[sussexcountyobs]

14 minutes ago, ag3 said:

It’s a raging rainstorm well north and west of NYC and into New England.

 

 

That's funny. All my local forecasts for amounts, which, granted, is WAY to early to put out amounts. Is over 6". My point is. Where do you get this amazing info? Seeing a raging rainstorm well N&W of  NYC, and into New England? Please elaborate your brilliance in weather forecasting.

[qg_omega]

1 hour ago, MJO812 said:

Icon getting interesting for the coast

What?

[Stormlover74]

43 minutes ago, sussexcountyobs said:

That's funny. All my local forecasts for amounts, which, granted, is WAY to early to put out amounts. Is over 6". My point is. Where do you get this amazing info? Seeing a raging rainstorm well N&W of  NYC, and into New England? Please elaborate your brilliance in weather forecasting.

Not sure because his response was to the 18z icon which doesn't show that at all. Now the gfs is another story

[MJO812]

December is still looking good with possible multiple threats.

[Snowlover11]

12 minutes ago, MJO812 said:

December is still looking good with possible multiple threats.

10 day always looks good

[MJO812]

1 minute ago, Snowlover11 said:

10 day always looks good

Pattern is looking good in December. Should be a good month. 

Threats are already showing up 

[bluewave]

Looks like a split decision showing up for the first week of December. Long range models shifted colder with the trough into the East instead of the ridge from previous runs. But the large storm on the 2nd and 3rd shifted warmer with a further north track and stronger WAR.

Main issue with the storm is the very fast flow and lack of blocking allowed the high over New England to move off the coast. So the further north storm and slightly stronger WAR on the day of the storm pushed the rain to snow gradient just to the north and west of NYC.

Since the colder start to December is a new pattern not showing up until day 6-10, it’s uncertain how the current day 11-15 and beyond will actually play out. If you look back on our recent Decembers, they have a tendency to start out cold from the 1st through 15th. Then we get the warm up every year since 2011 between the 17th and 25th.

So it will be interesting to see how things actually play out vs what the models are currently showing. We would want to eventually see a colder storm for our area while we still have the cold. This is very important during La Nina’s since we need to get over 4” of snow in December to match the above vs below seasonal snowfall that I outlined a few days back in this thread. 

So hopefully we can connect with at least one storm next few weeks while the colder start is still nearby.

New early December pattern colder than old runs

Old run too warm for early December

 

New run warmer storm further north on the 2nd and 3rd

 

Old run storm track colder to the south and more suppressed

 

 

[Bxstormwatcher360]

27 minutes ago, bluewave said:

Looks like a split decision showing up for the first week of December. Long range models shifted colder with the trough into the East instead of the ridge from previous runs. But the large storm on the 2nd and 3rd shifted warmer with a further north track and stronger WAR.

Main issue with the storm is the very fast flow and lack of blocking allowed the high over New England to move off the coast. So the further north storm and slightly stronger WAR on the day of the storm pushed the rain to snow gradient just to the north and west of NYC.

Since the colder start to December is a new pattern not showing up until day 6-10, it’s uncertain how the current day 11-15 and beyond will actually play out. If you look back on our recent Decembers, they have a tendency to start out cold from the 1st through 15th. Then we get the warm up every year since 2011 between the 17th and 25th.

So it will be interesting to see how things actually play out vs what the models are currently showing. We would want to eventually see a colder storm for our area while we still have the cold. This is very important during La Nina’s since we need to get over 4” of snow in December to match the above vs below seasonal snowfall that I outlined a few days back in this thread. 

So hopefully we can connect with at least one storm next few weeks while the colder start is still nearby.

New early December pattern colder than old runs

Old run too warm for early December

 

New run warmer storm further north on the 2nd and 3rd

 

Old run storm track colder to the south and more suppressed

 

 

Crazy because a track to the bm would almost tend to be frozen even to the coast. Another month or so this would be a snow event for all of us. Eventhough I think the warm air is overdone by a degree or 2. 

[bluewave]

34 minutes ago, Bxstormwatcher360 said:

Crazy because a track to the bm would almost tend to be frozen even to the coast. Another month or so this would be a snow event for all of us. Eventhough I think the warm air is overdone by a degree or 2. 

I am hoping we can get follow up storm systems tracking south of Long Island in the coming weeks and months when it’s colder. We saw a storm take a similar track on 12-5-20 to our south with mostly rain along the coast. With very amped systems early in the season we need strong Arctic high pressure over New England like we got back on 11-15-18.

[EastonSN+]

2 hours ago, Bxstormwatcher360 said:

Crazy because a track to the bm would almost tend to be frozen even to the coast. Another month or so this would be a snow event for all of us. Eventhough I think the warm air is overdone by a degree or 2. 

A track like this, this early in the season, was always tough for snow in the city (not something new).

I remember the December 2003 storm was around the 5th. That was BARELY all snow even back then (that had actual blocking). 

A benchmark track this early needs a deep cold air mas in place or blocking to keep a cold high / ne wind in place.

[TriPol]

I'm reminded of the December 2000 snowstorm. Different setup, but we had SSW, just like we do now. 

[NorthShoreWx]

The 12/5/2002 snowfall was a gem.

[jm1220]

1 hour ago, NorthShoreWx said:

The 12/5/2002 snowfall was a gem.

And then we had 12/5-6/03 which was even better. And the 12/5 snow was mostly unexpected. 

[North and West]

.

[MJO812]

35 minutes ago, North and West said:

.

Ensembles are starting to show snow for our area.

[Bxstormwatcher360]

6 minutes ago, MJO812 said:

Ensembles are starting to show snow for our area.

If surprize snow does fall,this is the week historically for it. It might even snow a little tomm am. Who really knows anymore? 

[anthonymm]

6 hours ago, bluewave said:

I am hoping we can get follow up storm systems tracking south of Long Island in the coming weeks and months when it’s colder. We saw a storm take a similar track on 12-5-20 to our south with mostly rain along the coast. With very amped systems early in the season we need strong Arctic high pressure over New England like we got back on 11-15-18.

u know it's getting serious when bluewave lets out a hint of optimism.

[Roger Smith]

<<<<< DECEMBER NYC RECORDS 1869 to 2024 >>>>>

_________ High max ___ high min _____ Low max ___ Low min ___________ Max prec ___ Max snow ___ Max 2d snow _

Dec 01 ___ 70 2006 __ 52 2001 ____ 18 1875 _____ 8 1875 __________ 1.72 1920 ___ 1.5 1880 __ 9.0 1882 **

Dec 02 ___ 66 1970 __ 52 1982 _____ 24 1876 _____11 1875 (27) _____2.16 1974 ___ 3.9 1929 __ 3.9 1929 *

Dec 03 ___ 69 1998 __ 53 1998 _____ 23 1976 _____ 9 1976 __________1.63 1925 ___ 3.0 1903 __ 3.8 1903 

Dec 04 ___ 74 1998^__ 59 1998 _____ 22 1889 ____ 10 1882 (34) ____ 1.84 1983 ___ 7.5 1957 __ 8.0 1957

Dec 05 ___ 70 2001 __ 56 1973,82 __ 22 1886 ____ 11 1926 (24) _____ 1.28 1993 ___ 8.0 2003 __ 8.0 2003 *

Dec 06 ___ 71 2001 __ 58 2001 ______ 22 1926 ____13 1871, 1926_____ 1.60 1884 ___ 6.0 2003 __14.0 2003

Dec 07 ___ 75 1998 __ 54 2022^ ____ 26 1869 ____ 10 1926 (30) _____1.98 1908 ___2.0 1886 __ 6.0 2003 **

Dec 08 ___ 65 1927 __ 52 1951 ______ 19 1882 _____10 1882 __________ 1.54 1917 ___ 2.0 1928 __ 2.0 1928

Dec 09 ___ 66 1966 __ 54 1966 ______ 18 1902 ____ 7 1876 ___________2.54 2014 ___5.8 2005 __5.8 2005 *

Dec 10 ___ 70 1946 __ 54 1946,66 ___ 16 1880 ____ 3 1876 (17) ______ 1.62 1878 ___ 1.4 2013 __ 5.8 2005 **

Dec 11 ___ 66 2021^__ 53 1887 ______ 20 1876 _____ 6 1880 (27) _____ 2.41 1992*___3.6 1960 __ 3.6 1960 *

Dec 12 ___ 68 1931 __ 55 2015 ______ 20 1988 _____ 5 1988 ___________1.60 1983 ____11.6 1960 _15.2 1960

Dec 13 ___ 67 2015 __ 55 2015 ______ 20 1960 _____ 8 1960 __________3.03 1909^___8.0 1917 _11.6 1960 **

Dec 14 ___ 67 1881,2015_ 53 1901,2001,15_21 1902 ____12 1976 (31) _____2.22 1897 ____5.8 2003 __ 9.5 1917

Dec 15 ___ 68 2015 __ 53 2015 _______ 20 1874,1914_ 8 1874 _________1.34 1981 ____ 12.7 1916 __12.7 1916 *

Dec 16 ___ 63 1971 __ 54 2021*_______ 19 1886 _____ 7 1876 (15 17th)_ 2.25 1974 ___6.8 1896 __12.7 1916 **

Dec 17 ___ 62 2000 _ 50 1888,2015 __ 15 1876 _____ 1 1919 (21) ______2.28 1888 ____6.7 1932 _ 10.5 2020^

Dec 18 ___ 63 1937,84  47 1996 _______ 11 1919 _____-1 1919 ___________2.21 2023* ___4.5 1887 __ 7.8 1932

Dec 19 __58 1899,1931 _ 45 1949,57,2017_ 16 1884 __-1 1884 __________1.19 1934 _____ 9.1 2009 __ 9.1 2009 *

Dec 20 __ 60 1895,1999,2002_54 1957 __7 1884 __-4 1942 (8) _______1.92 1874 ____15.8 1948 __15.8 1948^

Dec 21 ___ 65 2013 __ 51 2013 ________ 9 1871 _______ -2 1871 _________ 2.49 1973 ___ 4.0 1884 __16.0 1948

Dec 22 ___ 71 2013 __ 61 2013 ________ 18 1989 _____ 4 1872 (28) _____ 2.18 1983 ___ 10.3 1959 __13.7 1959

Dec 23 ___ 66 1891,1990_57 1990 _____ 10 1883 _____-1 1883 __________ 1.83 2022^ __ 6.0 1963 __10.3 1959 **

Dec 24 ___ 72 2015 __ 63 2015 _______ 13 1872 _____ 6 1983 (22) _____ 1.42 2003 ___11.4 1912 __11.4 1912

Dec 25 ___ 66 2015^__57 2015 ________ 13 1983 _____-1 1980 (20) _____ 1.30 2002 __ 7.0 1909 __12.3 1883 (7.3+5.0)

Dec 26 ___ 63 1936,82_ 50 1964 ______ 12 1872 _____ 3 1914 (15) ______ 2.36 1947 __ 26.1 1947 _ 26.1 1947 *

Dec 27 ___ 63 1949 __ 57 1949 ________ 15 1872 _____ 6 1872 ___________ 1.39 1930 ___ 7.8 2010 _ 26.4 1947^

Dec 28 ___ 65 1982, 2008 __49 2024^ __17 1894 ____ 8 1917 (35) _____ 1.35 1926 ___ 6.6 1990 __ 7.8 2010 ** (7.2 1990)

Dec 29 ___ 70 1984 __ 55 1984 ________ 8 1917 _____ -6 1917 ___________ 2.52 1901 ___ 4.0 1880 __ 6.6 1990**

Dec 30 ___ 65 1984 __ 52 1948 ________ 2 1917 ____ -13 1917^ _________ 1.69 1912 __ 12.0 2000 __12.0 2000 *

Dec 31 ___ 63 1965 __ 51 1965 _________ 6 1917 _____ -7 1917 ____________ 1.40 1948 ___4.0 1948 __12.0 2000 **

-- - - - - - - - - - - - - - - - --

NOTES: 

... Temp values in brackets after low min show that day's max if it was not also the low max record.

... For 48h record snow values, which always run from previous date to current indicated date

... ... * indicates all precip fell same day, and ** indicates all fell previous day. The rest have some on both days.

other notes: 

^ 4th max 72 1982

^ 7th high min 54F (2022) replaced 53F (1951, 1956)

^ 11th new record 66F 2021 broke 64F 1879. 

* 11th 2.35" 2008 (not record), 3.28" Dec 11-12 2008. 

^ 13th 2.97" R 1941

^ 16th-17th 2d snow 10.5" 2020 (6.5 + 4.0)

* 16th 54F high min 2021 replaced 48F 1971

* 18th rainfall record replaced 1.30" 1876

^ 19th-20th 2d snow 10.9" 2009 (9.1 + 1.8) also 10.0" 1874 20th

^ 23rd high precip 1.83" (2022) replaced 1.61" (1913)

^ note also 23rd new highest diurnal range at NYC (58, 8 = 50 range), replaced 48 from Mar 28, 1921 (82, 34).

^ 25th max 64 1889

^ 26th 18.0" snow 1872, 12.2" 2012, (26-27 2d snow 2010 of 20.0") also 11.2" 1933 26th

^ 28th _ 49F high min (2023) replaced 47F 2008.

xx 29th _ As the severe cold deepened in 1917, 2.0" snow was recorded on this date. 

^ 30th min -6 1933 (max 12 29th, 16 30th)

[donsutherland1]

Central Park's frequency of measurable snowfall in December and record daily snowfall.

December 26 is New York City's snowiest December date. Frequency of select daily snowfall amounts (1869-2024):

Measurable snowfall: 22 times 
1" or more: 16 times
6" or more: 5 times
10" or more: 5 times

[bluewave]

16 hours ago, anthonymm said:

u know it's getting serious when bluewave lets out a hint of optimism.

That being said, gradient patterns in recent years have been setting up just north of NYC. We haven’t been near a gradient pattern jackpot zone since February 2014 and 1994. The WAR amps just enough on the storm days and the highs move east of New England. This is what the current models runs are showing for early December.