December 2024

[Rjay]

6 minutes ago, bluewave said:

The highs already beat guidance today as we are low 50s around NYC and Long Island instead of mid 40s.

52 and poop weather here

[bluewave]

2 minutes ago, uofmiami said:

It’s elevation dependent for my stations. 230 ASL got to 49 but down to 46 now. 150 ASL been stuck at 41 only for the high. No low 50s to speak of. 

From JFK to ISP and Shirley it’s in the low 50s.

[uofmiami]

8 minutes ago, bluewave said:

From JFK to ISP and Shirley it’s in the low 50s.

S Shore special, no surprise. 

[psv88]

52 here now…north shore elevation 140. Much of northern Nassau in upper 40s to near 50. Not seeing any station close to 40

[NorthShoreWx]

50 in North Smithtown.  Quite wet.

Elevation 122

[steve392]

47 and just gross out.  The mist just makes it a crappy day. 

[donsutherland1]

Warmer air began overspreading the region today. December will close with above to much above normal temperatures and additional periods of rain. The temperature will likely peak in the 60s in Washington, Baltimore, and Philadelphia and the 50s in New York City and Boston. 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. The second week of January will likely feature widespread cold anomalies in much of the eastern half of the CONUS and Canada south of the Hudson and James Bays. The potential exists for widespread cold anomalies of 6°-10° below normal during that week in that region.

Should the AO dive below -3.000, the prospects for a significant or major snowfall in the New York City area could be reduced. Since 1950, a January AO ranging from -2.600 to -1.400 accounted for the largest share of 6" and 10" or above January snowfalls for storms that dumped 4" or more snow in New York City. For the 4" or above storms, 67% saw 6" or more while 56% went on to see 10" or more. When the AO was -3.000 or below, 60% of 4" or above snowstorms saw 6" or more snowfall, while 20% of those storms saw 10" or more. The exact synoptic details will be crucial to determining whether that potential will be realized.

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

Boston: 2023-2024 Total to Date: 26.9"; 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 was favored by the November run of the ECMWF for Winter 2024-2025. Even as the NAO outlook appears on course to be relatively accurate, Winter 2024-2025 will likely wind up being notably colder than the subset of winters listed above.

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 +4.72 today.

The preliminary Arctic Oscillation (AO) was +0.373 today.

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a colder than normal December (1991-2020 normal). December will likely finish with a mean temperature near 37.7° (1.4° below normal).

 

[Stormlover74]

Rain overperformed it seems: .6"

[SACRUS]

0.61 here so far.

[uofmiami]

5 hours ago, psv88 said:

52 here now…north shore elevation 140. Much of northern Nassau in upper 40s to near 50. Not seeing any station close to 40

Didn’t beat 49 in N Syosset and topped out at 45 in Muttontown fwiw. 

[Rjay]

2 hours ago, uofmiami said:

Didn’t beat 49 in N Syosset and topped out at 45 in Muttontown fwiw. 

Low 80s today at ISP

[NorthShoreWx]

1 hour ago, Rjay said:

Low 80s today at ISP

Dew point?

[sn0w]

Tonight

A slight chance of drizzle or light rain between 1am and 4am, then a chance of rain after 4am. The drizzle could be heavy at times. Patchy dense fog. Otherwise, cloudy, with a low around 40. Calm wind. Chance of precipitation is 30%.

 

Can't say I've seen this before 

[ForestHillWx]

45 now; finished 44/34 for splits yesterday. 

[the_other_guy]

42F here. Didnt see 50s yesterday. I think you needed to be near coast with wind off the water

[IrishRob17]

Didn't see 40s up here yesterday, 37 now. Some serious fog eating snow though, so the pack is gone, as expected. 

[donsutherland1]

Week ahead outlook:

The coming week will be a transitional period. Very mild weather will give way to progressively colder weather. Snowfall will still likely be limited in the Mid-Atlantic and southern New England areas.

[SACRUS]

49 / 48 cloudy, 0.66 in the bucket. Next batch if rain comes later this evening and overnight with an additional near 0.50 for most before the third wave comes new years eve with an additional 0.50 - 1 inch. Warmer through the 1st then the much discussed cold period from the 2nd into the middle of the month.

 

[SACRUS]

 

Records:

Highs:

EWR: 71 (1984)
NYC: 70 (1984)
LGA: 68 (1984)
JFK: 65 (1984)

Lows:

EWR: -2 (1933)
NYC: -6 (1917) *start of brutal record cold wave into the city
LGA: 12 (2017)
JFK: 12 (2017)

Historical:

1830 - A very heavy snowstorm ushered in the "winter of the deep snow." The storm produced 30 inches of snow at Peoria IL and 36 inches at Kansas City MO. Cold and snow continued until the middle of February causing great suffering among pioneers. (David Ludlum)

 

1876: The Pacific Express train was crossing the Ashtabula River in Ohio when the bridge collapsed. The bridge collapsed at 7:28 PM, during a snowstorm that left two feet of snow and produced 40 mph winds. The only railcar not to fall into the icy river below was the first locomotive.

1894 - A severe freeze hit Florida destroying fruit and causing considerable damage to trees. (David Ludlum)

1954 - Fort Scott, KS, was buried under 26 inches of snow in 24 hours to establish a state record. (28th-29th) (The Weather Channel)

1984 - One hundred cities in the central and eastern U.S. reported record high temperatures. Kansas City, MO, experienced its warmest December day of record with a morning low of 60 degrees and an afternoon high of 71 degrees. (The National Weather Summary) (Sandra and TI Richard Sanders - 1987)

1987 - A storm off the Middle Atlantic Coast produced heavy snow in the Appalachians and the northeastern U.S. Snow and high winds created blizzard conditions in southeastern Massachusetts. Cape Cod received thirteen inches of snow, and snow drifts three feet deep were reported around Chatham MA. Strong winds produced wind chill readings as cold as 60 degrees below zero in southwestern New England. In the western U.S., a Pacific coast storm produced heavy snow in the Sierra Nevada Range of California, with 24 inches reported at Mammoth Mountain. (The National Weather Summary) (Storm Data)

1988 - A cold front brought rain and snow to the northwestern U.S. The rainfall total of 2.70 inches at Astoria OR was a record for the date. High winds along the eastern slopes of the Northern Rockies gusted to 81 mph at Livingston MT. (Storm Data) (The National Weather Summary)

1989 - Snow and ice prevailed from the southwestern U.S. to the Great Lakes Region. Flagstaff, AZ, received nine inches of snow in just six hours. Bitter cold weather continued over Maine. Portland ME reported a record twenty-two straight days with highs 32 degrees or colder. (The National Weather Summary) (Storm Data)

[SACRUS]

 

Some light drizzle with the next steady area of rain about 10 - 12 hours away

 

[bluewave]

Low 60s today from CNJ to Newark with 50s most other spots.

[SACRUS]

 

Rainfall (so far)  

EWR: 0.87
LGA: 0.75
New Brnswck: 0.67
NYC: 0.65
JFK: 0.65

[NorthShoreWx]

0.91" 2-day total here.  53/53 now.  nice and soupy...typical late December wx for recent years,

[SACRUS]

 

Up to 56 here.

[Stormlover74]

Decent amount of rain predawn tomorrow 

[Stormlover74]

54 minutes ago, SACRUS said:

 

Up to 56 here.

66 in wrightstown

[bluewave]

The breaks of sun allowed Central Park to jump up to 61°.

[ForestHillWx]

52 here; the pack is gone. 

[SnoSki14]

4 hours ago, bluewave said:

Low 60s today from CNJ to Newark with 50s most other spots.

We're cooking today. 65F right now, above forecast. Feels awesome 

[Stormlover74]

Ewr may just barely hold on to a negative monthly departure. Erasing 2 degrees in final 4 days

Precip and snowfall very average as well