December 2024

[LibertyBell]

Actually hit 42 degrees a few minutes ago, late day high, just before it started to get darker.

[donsutherland1]

The cold will begin to recede toward the end of the week.  December will likely close with above normal temperatures and periods of rain. The opening days of January will likely also begin with above normal temperatures, but it will start to turn colder.

Snowfall prospects will remain limited through the end of December. However, the pattern could become more favorable for moderate or perhaps larger snowfalls as the cold returns during the first week of January. There is growing potential for the second week of January to feature widespread cold anomalies in much of the eastern half of the CONUS and Canada south of the Hudson and James Bays.

On account of a lack of snowfall, 2023-2024 will likely set a new records for the lowest snowfall over a two-year period for Boston and New York City.

Boston: 2023-2024 Total to Date: 26.7"; Record: 38.2", 1979-1980
New York City: 2023-2024 Total to Date: 12.6"; Record: 17.4", 1997-1998

The NAO fell to a preliminary -2.751 on September 24th (all-time September record: -2.371, September 12, 1971). That was the 9th lowest value on record. La Niña winters following September cases where the NAO fell to -1.900 or below featured a predominantly positive NAO. The most recent such winters were 2016-2017 and 2022-2023. The mean temperatures for those winters in New York City were 39.3° and 41.0° respectively. The 1991-2020 normal value is 36.2°. A warmer to much warmer than normal outcome is favored by the November run of the ECMWF for Winter 2024-2025.

The ENSO Region 1+2 anomaly was -0.2°C and the Region 3.4 anomaly was -0.8°C for the week centered around December 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.17°C and the ENSO Region 3.4 anomaly has averaged -0.35°C. Neutral ENSO conditions may still evolve into a La Niña event during the winter. Uncertainty as to whether a La Niña will actually develop persists. On the December 19 outlook, 56% of dynamical models but 0% of the statistical models forecast the development of a La Niña.

The SOI was +12.30 today.

The preliminary Arctic Oscillation (AO) was -0.355 today.

Based on sensitivity analysis applied to the latest guidance, there is an implied 96% probability that New York City will have a colder than normal December (1991-2020 normal). December will likely finish with a mean temperature near 37.0° (2.1° below normal).

 

[winterwx21]

1 hour ago, Allsnow said:

I still have snow on my driveway and street…

 

damage wasn’t as bad as advertised 

I was just outside for a run, and I saw several front lawns in my neighborhood that now have zero snow on them. But the majority of lawns are mostly or completely covered. Obviously it depends on the amount of sun a spot gets. My back lawn is completely covered, but on the front lawn it's patchy. 

[bluewave]

Only the 11th time that NYC had an 1” or more of snow on Christmas Eve.

 

Data for December 24 - NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

1912-12-24	32	24	1.10	11.4	12
1883-12-24	31	7	0.80	7.3	M
1966-12-24	26	22	0.74	6.7	T
1884-12-24	24	18	0.27	3.5	M
1961-12-24	33	25	0.35	3.4	3
1919-12-24	40	26	0.22	2.7	1
1998-12-24	32	23	0.11	2.0	M
1880-12-24	32	23	0.14	2.0	M
1930-12-24	35	29	0.07	1.9	3
1980-12-24	37	20	0.10	1.0	1
2024-12-24	39	28	0.10	1.0	1

[Rjay]

2 hours ago, the_other_guy said:

we need this fucking sun to set. a lot of melt going on with the warmer temperatures. I was hoping the clouds would stick around to the middle of the afternoon to take away the worst of it.

Mine got mostly vaporized 

[the_other_guy]

I’m shocked how warm it is even after dark.

 

The city is above freezing. 

 

I’m surprised with the north wind and the relatively clear skies that it’s staying this warm

[psv88]

16 minutes ago, the_other_guy said:

I’m shocked how warm it is even after dark.

 

The city is above freezing. 

 

I’m surprised with the north wind and the relatively clear skies that it’s staying this warm

27 here. Looks like it’s only the metro above freezing. Even outer boros are 32 or below 

[Wxoutlooksblog]

Euro with a major storm New Years Eve into New Years Day, the question is temperatures which might be marginal. You got a great track but there are a few things off. Both antecedent and incoming HP air masses are marginally cold and not quite in the ideal position. Incoming cold HP is not exactly on the heels of the storm's departure. We'll see what happens over time.

WX/PT

https://www.tropicaltidbits.com/analysis/models/ec-fast/2024122500/ec-fast_z500_mslp_us_9.png

[LibertyBell]

15 hours ago, winterwx21 said:

I was just outside for a run, and I saw several front lawns in my neighborhood that now have zero snow on them. But the majority of lawns are mostly or completely covered. Obviously it depends on the amount of sun a spot gets. My back lawn is completely covered, but on the front lawn it's patchy. 

It's officially a white Christmas for Central Park and I consider it one here too since we have at least 80% snowcover (outside of concrete sidewalks asphalt roads and driveways, etc.) Artificial crap doesn't count.

[bluewave]

Temperature pattern very similar to 2022. Warm up followed by a -20 departure close to Christmas. Then another warm up as we approach New Years. So the timing of the snow and cold worked out for the more wintry feel around Christmas. Since -20° departures are such a rarity these days, it will be interesting to see if this was the lowest for the winter like back in 22-23. The 2-4-23 departure came close at -19 but couldn’t beat the -25 on 12-24. I hope everyone has a great holiday period coming up. 
 

2024-12-17	59	49	54.0	15.4	11	0	0.02	0.0	0
2024-12-18	53	42	47.5	9.1	17	0	0.32	0.0	0
2024-12-19	45	37	41.0	2.9	24	0	0.05	0.0	0
2024-12-20	37	33	35.0	-2.9	30	0	0.04	T	0
2024-12-21	33	19	26.0	-11.6	39	0	0.15	1.8	2
2024-12-22	21	13	17.0	-20.4	48	0	0.00	0.0	1
2024-12-23	31	13	22.0	-15.1	43	0	0.00	0.0	1
2024-12-24	39	28	33.5	-3.4	31	0	0.10	1.0

 

2022-12-23	58	8	33.0	-4.1	32	0	1.83	T	0
2022-12-24	15	7	11.0	-25.9	54	0	0.00	0.0	0
2022-12-25	28	14	21.0	-15.7	44	0	0.00	0.0	0
2022-12-26	29	18	23.5	-12.9	41	0	0.00	0.0	0
2022-12-27	35	29	32.0	-4.2	33	0	0.00	0.0	0
2022-12-28	47	33	40.0	4.0	25	0	0.00	0.0	0
2022-12-29	51	40	45.5	9.7	19	0	0.00	0.0	0
2022-12-30	62	46	54.0	18.4	11	0	0.00	0.0	0
2022-12-31	55	50	52.5	17.1	12	0	0.28	0.0

December thaw pattern to close out the year

 

[LibertyBell]

14 hours ago, bluewave said:

Only the 11th time that NYC had an 1” or more of snow on Christmas Eve.

 

Data for December 24 - NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

1912-12-24	32	24	1.10	11.4	12
1883-12-24	31	7	0.80	7.3	M
1966-12-24	26	22	0.74	6.7	T
1884-12-24	24	18	0.27	3.5	M
1961-12-24	33	25	0.35	3.4	3
1919-12-24	40	26	0.22	2.7	1
1998-12-24	32	23	0.11	2.0	M
1880-12-24	32	23	0.14	2.0	M
1930-12-24	35	29	0.07	1.9	3
1980-12-24	37	20	0.10	1.0	1
2024-12-24	39	28	0.10	1.0	1

wild about 1980, what was the temperature when that 1 inch of snow fell? it was also our coldest Christmas.  It's the first Christmas I actually remember lol.

[weathermedic]

7 minutes ago, LibertyBell said:

wild about 1980, what was the temperature when that 1 inch of snow fell? it was also our coldest Christmas.  It's the first Christmas I actually remember lol.

I remember about an inch of snow but that temperature near zero and wind was brutal. Salt trucks couldn’t do much since they didn’t have the liquid calcium chloride to mix in when they spread salt in those years. Roads were  sheet of ice.

 

[LibertyBell]

1 minute ago, weathermedic said:

I remember about an inch of snow but that temperature near zero and wind was brutal. Salt trucks couldn’t do much since they didn’t have the liquid calcium chloride to mix in when they spread salt in those years. Roads were  sheet of ice.

 

I wonder if it all fell in less than an hour (was it a snow squall?)

 

[SACRUS]

 

31 / 26 low clouds.  Snow on the ground at 7AM in NYC (central park) and a good majority of the area for the first white Christmas in 15 years.  The allusive snowfall on christmas day extends to 22 years (2002).  Near normal the next two days ahead of the warm/wetter close to the month with another 1 - 2 inches of rain and some +12 to +15 departures.  Roller coaster comes down (temps) around Jan 4th.

Merry Christmas to all. 

 14 years ago the tracking was shifting into a frenzied pace as the Boxing day storm was becoming unanimous on all guidance - the year before this board was born.

 

 

[SACRUS]

 

 

Records:
 

Highs:

EWR: 69 (1964)
NYC: 66 (2015)
LGA: 64 (2015)
JFK: 64 (2015)


Lows:

EWR: 0 (1980)
NYC: -1 (1980)
LGA: -1 (1980)
JFK: 2 (1983)

 

Historical:

1776: Thomas Jefferson noted that the first winter snow fell on December 20th, but did not last on the ground one day. Temperatures dropped to 30 degrees or colder on Christmas Day. That night, 22 inches of snow fell. From the 25th of December until March 6, 10 snow covered the ground, and some of them were deep. The first rain came on the 9th of March. In Frederick County, two feet of snow was recorded.

1872: Since records began back in 1887, Columbia, South Carolina, only a trace of snow has been reported on Christmas Day. Before records, 13-hour sleet, and snowstorm occurred in Columbia and surrounding areas. Credit goes to Cary Mock, a USC geography professor who specializes in historical weather research.

1966 - A white Christmas was enjoyed by residents from North Carolina to New England in the wake of a major snowstorm. Even coastal Virginia was white. (David Ludlum)

1980 - It was the coldest Christmas Day of modern record in the northeastern U.S. Temperatures as cold as 36 degrees below zero were reported in New York State, and as the sharp cold front swept southeastward the temperature at Boston MA plunged from 34 degrees to seven degrees below zero during the day. (David Ludlum)

1983 - It was the coldest Christmas Day of modern record for the central and eastern U.S. More than 125 cities reported record low temperatures for the date, and thirty-four of those cities reported all-time records for the month of December. The temperature plunged to one degree below zero at Huntsville AL, and dipped to 14 degrees at Galveston TX. Snow covered the ground from the Pacific Northwest through much of the Great Plains Region to the Northern Appalachains. (The National Weather Summary)

1987 - Residents of Tucson, AZ, awoke to a white Christmas for the first time in forty-seven years of records, as a winter storm blanketed the area with up to four inches of snow. While heavy rain inundated Arkansas, freezing rain was reported from northwest Texas to southwestern Missouri, with an inch of ice reported at Harrison AR. Unseasonably mild weather prevailed in the southeastern U.S. Seven cities reported record high temperatures for the date. For the second day in a row McAllen TX was the hot spot in the nation with an afternoon high of 91 degrees. (The National Weather Summary) (Storm Data)

1988 - A massive winter storm made for a very white Christmas in the western U.S. Las Vegas, NV, reported snow on the ground for the first time of record. Periods of snow over a five day period left several feet of new snow on the ground of ski areas in Colorado, with 68 inches reported at Wolf Creek Pass. (Storm Data) (The National Weather Summary)

1989 - It was a record cold Christmas Day for parts of the southeastern U.S. Morning lows of zero degrees at Wilmington, NC, and five degrees below zero at Jacksonville NC established all-time records for those two locations. Miami Beach FL equalled a December record established the previous morning with a low of 33 degrees. (The National Weather Summary) (Storm Data)

 

2002: A major snowstorm moved up the east coast on Christmas Day, 2002. Widespread snowfalls of a foot or more occurred across much of central New York and northeast Pennsylvania, with amounts as high as 30 inches reported over the northwest slopes of the Catskills.

2003 - Heavy rains affected areas of southern California that were just recently ravaged by wildfires in October. The downpour produced flash flooding that resulted in mudslides, taking the lives of 15 people at area campgrounds in San Bernardino (AFP).

2004 - Snow fell on Christmas Day in Deep South Texas. Snow totaled 4.4 inches in Corpus Christi, making it the second White Christmas ever. Farther north, Victoria had their first white Christmas on record when 12.5 inches of snow fell.

2006 - Severe thunderstorms produced four tornadoes in Florida. Columbia, Pasco, Lake and Volusia counties were hardest-hit, including the Daytona Beach area. A tornado generated considerable damage on the campus of Embry-Riddle Aeronautical University, delaying the start of the spring semester (Orlando Business Journal).

2010 - Up to 32 inches of snow and blizzard conditions affected parts of the eastern U.S. on December 25th�27th. A state of emergency was declared in North Carolina, Virginia, Maryland, New Jersey, Massachusetts, and Maine. In New York City, up to 24.5 inches of snow fell, effectively shutting down rail lines, major airports, and bus services. Thousands of flights were cancelled and stranded subway riders were forced to spend a night in unheated train cars. One person was reported killed in Maine due to the weather conditions. (NCDC)

[SACRUS]

 

NYC:

 

1909 : 7 inches of snow, Most snowfall recorded on Christmas day (1869 - present)

 

Dec 25 1969:   Snow started late night and through the 26th mixed with rain after a half foot then changed back to snow.  6.8 inches fell at central park.

 

Dec 25 2002:   A wet storm dropped 5.5 inches of wet snow and a total precipitation of 1.30 inches.  

 

 

[SACRUS]

 

1969

 

[LibertyBell]

1 minute ago, SACRUS said:

 

NYC:

 

1909 : 7 inches of snow, Most snowfall recorded on Christmas day (1869 - present)

 

Dec 25 1969:   Snow started late night and through the 26th mixed with rain after a half foot then changed back to snow.  6.8 inches fell at central park.

 

Dec 25 2002:   A wet storm dropped 5.5 inches of wet snow and a total precipitation of 1.30 inches.  

 

 

we should include 1947 too Tony, that was one of our largest snowstorms of all time

[LibertyBell]

7 minutes ago, SACRUS said:

 

 

Records:
 

Highs:

EWR: 69 (1964)
NYC: 66 (2015)
LGA: 64 (2015)
JFK: 64 (2015)


Lows:

EWR: 0 (1980)
NYC: -1 (1980)
LGA: -1 (1980)
JFK: 2 (1983)

 

Historical:

1776: Thomas Jefferson noted that the first winter snow fell on December 20th, but did not last on the ground one day. Temperatures dropped to 30 degrees or colder on Christmas Day. That night, 22 inches of snow fell. From the 25th of December until March 6, 10 snow covered the ground, and some of them were deep. The first rain came on the 9th of March. In Frederick County, two feet of snow was recorded.

1872: Since records began back in 1887, Columbia, South Carolina, only a trace of snow has been reported on Christmas Day. Before records, 13-hour sleet, and snowstorm occurred in Columbia and surrounding areas. Credit goes to Cary Mock, a USC geography professor who specializes in historical weather research.

1966 - A white Christmas was enjoyed by residents from North Carolina to New England in the wake of a major snowstorm. Even coastal Virginia was white. (David Ludlum)

1980 - It was the coldest Christmas Day of modern record in the northeastern U.S. Temperatures as cold as 36 degrees below zero were reported in New York State, and as the sharp cold front swept southeastward the temperature at Boston MA plunged from 34 degrees to seven degrees below zero during the day. (David Ludlum)

1983 - It was the coldest Christmas Day of modern record for the central and eastern U.S. More than 125 cities reported record low temperatures for the date, and thirty-four of those cities reported all-time records for the month of December. The temperature plunged to one degree below zero at Huntsville AL, and dipped to 14 degrees at Galveston TX. Snow covered the ground from the Pacific Northwest through much of the Great Plains Region to the Northern Appalachains. (The National Weather Summary)

1987 - Residents of Tucson, AZ, awoke to a white Christmas for the first time in forty-seven years of records, as a winter storm blanketed the area with up to four inches of snow. While heavy rain inundated Arkansas, freezing rain was reported from northwest Texas to southwestern Missouri, with an inch of ice reported at Harrison AR. Unseasonably mild weather prevailed in the southeastern U.S. Seven cities reported record high temperatures for the date. For the second day in a row McAllen TX was the hot spot in the nation with an afternoon high of 91 degrees. (The National Weather Summary) (Storm Data)

1988 - A massive winter storm made for a very white Christmas in the western U.S. Las Vegas, NV, reported snow on the ground for the first time of record. Periods of snow over a five day period left several feet of new snow on the ground of ski areas in Colorado, with 68 inches reported at Wolf Creek Pass. (Storm Data) (The National Weather Summary)

1989 - It was a record cold Christmas Day for parts of the southeastern U.S. Morning lows of zero degrees at Wilmington, NC, and five degrees below zero at Jacksonville NC established all-time records for those two locations. Miami Beach FL equalled a December record established the previous morning with a low of 33 degrees. (The National Weather Summary) (Storm Data)

 

2002: A major snowstorm moved up the east coast on Christmas Day, 2002. Widespread snowfalls of a foot or more occurred across much of central New York and northeast Pennsylvania, with amounts as high as 30 inches reported over the northwest slopes of the Catskills.

2003 - Heavy rains affected areas of southern California that were just recently ravaged by wildfires in October. The downpour produced flash flooding that resulted in mudslides, taking the lives of 15 people at area campgrounds in San Bernardino (AFP).

2004 - Snow fell on Christmas Day in Deep South Texas. Snow totaled 4.4 inches in Corpus Christi, making it the second White Christmas ever. Farther north, Victoria had their first white Christmas on record when 12.5 inches of snow fell.

2006 - Severe thunderstorms produced four tornadoes in Florida. Columbia, Pasco, Lake and Volusia counties were hardest-hit, including the Daytona Beach area. A tornado generated considerable damage on the campus of Embry-Riddle Aeronautical University, delaying the start of the spring semester (Orlando Business Journal).

2010 - Up to 32 inches of snow and blizzard conditions affected parts of the eastern U.S. on December 25th�27th. A state of emergency was declared in North Carolina, Virginia, Maryland, New Jersey, Massachusetts, and Maine. In New York City, up to 24.5 inches of snow fell, effectively shutting down rail lines, major airports, and bus services. Thousands of flights were cancelled and stranded subway riders were forced to spend a night in unheated train cars. One person was reported killed in Maine due to the weather conditions. (NCDC)

Unfortunately the 2010 storm started on the day after Christmas (like the 1947 storm), had they both occurred just a day earlier they would have been even more memorable.

 

[SACRUS]

 

Week to go and the coming warmth between the 27 - 31 will erode some of this but a negative departures will likely prevail at NYC/LGA/TTN with EWR close and JFK likely getting on the plus side of average.

JFK: - 0.9
EWR: -2.1
NYC: -3.1
LGA: -3.1
TTN: -4.0

[LibertyBell]

Tony what was the low at JFK on Christmas morning 1980? I noticed it's not included in the records (which was set there 3 years later in 1983.)

[LibertyBell]

Just now, SACRUS said:

 

Week to go and the coming warmth between the 27 - 31 will erode some of this but a negative departures will likely prevail at NYC/LGA/TTN with EWR close and JFK likely getting on the plus side of average.

JFK: - 0.9
EWR: -2.1
NYC: -3.1
LGA: -3.1
TTN: -4.0

Tony, is the departure at JFK much less because it was warmer at JFK or because the mean December temperature at JFK is lower?

I noticed the mean December temperature at Central Park is over 37 now-- it used to be around 36!