December 2025 OBS and Discussion

[uofmiami]

22 minutes ago, psv88 said:

I hope you married her!

The amount of dumb shit i did for gfs I didnt marry was insane. If i had only known better haha. What a waste!

I didn't marry her, LOL!  I concur, young & dumb back then.

[donsutherland1]

Winter beauty:

[Roger Smith]

Don, where does 2025-26 sit now in your winter severity index? 

[donsutherland1]

The wind will diminish overnight, but a cold regime will remain in place. Below normal temperatures will continue into at least the middle of the first week of January. Some flurries or snow showers are possible late Thursday into Friday in parts of the region. 

The first week of January will likely have a mean temperature below 30° in New York City. The last time that happened was in 2018. The only years since 2000 with a sub-30° mean temperature for the opening week of January were 2001, 2010, 2014 and 2018.

December 2025 will finish with a maximum monthly temperature of 58° in New York City. The last time December had a monthly maximum temperature below 60° was in 2019 when the monthly high was 58°. This will be only the fifth such occurrence since 2000 (2003, 2004, 2005, and 2019 are the cases since 2000).

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 December 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.33°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 +6.49 today. 

The preliminary Arctic Oscillation (AO) was -1.580 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 December (1991-2020 normal). December will likely finish with a mean temperature near 33.9° (5.2° below normal). That will make December 2025 the coldest December since 2010 when the monthly mean temperature was 32.8°. It would also make 2025 the third coldest December since 2000.

Supplemental Information: The projected mean would be 3.5° below the 1981-2010 normal monthly value.

[donsutherland1]

52 minutes ago, Roger Smith said:

Don, where does 2025-26 sit now in your winter severity index? 

I will check it when I get back home tomorrow evening.

[lee59]

Some snow showers that could leave a light accumulation  tomorrow evening. Could be the first time in years on New Years Eve.

[bluewave]

The really big story this year has been the record breaking number of days by a wide margin with wind gusts exceeding 40 and 50 mph across the area. This is the result of an unusually active storm track through the Great Lakes and to the west of the I-95 corridor.

Nearly all the days with these stronger gusts had a west to northwest flow. The lack of coastal systems this year really stood out as there was only a small number of days with 40 or 50 mph gusts from a southeast to northeast direction.

So a continuation of the very dominant northern stream of the Pacific Jet pattern. At least December allowed our region to get two 4-8” clipper systems for the first time during the month. But since these were northern stream storm systems, we couldn’t get into a coastal KU benchmark track. Plus the Great Lakes cutter pattern remained active so we had two warm ups with rain and fog shortly after the two snowstorms.

These clippers narrowly focused the snowfall to such an extent, that it’s the first time since the 1980s and 1950s in December that the heavier 10”+ snows focused around NYC Metro. Which didn’t allow Philly and or Boston to share in the heavier 10”+snows. 

 

 

[SACRUS]

28  / 12 cloudy.  In a 2 day turn around the latest forecasts have spun a gentler period to one that transfers to a warmer one.  We'll see if the current Dec and ate Nov trend continues to see any pronounced warmup short and muted once here and more focused south and wetst.  Otherwise once to around the 7th its near to above normal.  

12/31 - 1/5 :   Colder than normal - potential light snow with reinforcing clippers 12/31 , 1/2-1/3
1/6 - 1 / 11 :  Near normal - warmer
1/12 - beyond :   ridge into the east - warmer

 

[SACRUS]

Records:

Highs:

EWR: 63 (1965) 
NYC: 63 (1965)
LGA: 63 (1965)
JFK: 55 (2011) 


Lows:

EWR: 2 (1962)
NYC: -7 (1917)
LGA: 3 (1962)
JFK: 5 (1962)

HIstorical:

1862: Confederate soldiers used the cover of fog in the Battle of Stone's River in Tennessee to attack Union encampments. (Ref. AccWeather Weather History)

1863: The famous "New Year's Blizzard" swept across the Midwest. Temperatures dropped during the daytime from -8 °F to -24 °F in parts of Iowa. (Ref. AccWeather Weather History)

1880: DCA had the lowest minimum temperature recorded for December -13 degrees F. The temperature reading was made at the weather bureau office at 24th and M Street, NW. This same air mass gave the lowest minimum temperature ever recorded in January for Washington -14 degrees F. Thus, one air mass set the all-time record low temperature for the two months of January and December in Washington. (Ref. Washington Weather Records - KDCA) (Ref. Wilson - Additional Temperatures Listed On This Link)

1882: Downtown San Francisco saw 3.5 inches of snow.

1917 - The temperature at Lewisburg, WV, plunged to 37 degrees below zero to set a state record. (Sandra and TI Richard Sanders - 1987)

1929 - Greenland Ranch, in Death Valley, California, went the entire year without measurable precipitation. (The Weather Channel)

1933 - A 24 hourrainfall of 7.36 inches set the stage for the worst flood in Los Angeles history. Flooding claimed 44 lives. (David Ludlum)

1933: During the last week of December, a series of winter storms pounded the mountainside with 12 inches of rain near Los Angeles. More rain occurred on New Year’s Eve, including 4.86 inches in downtown Los Angeles. The 4.86 inches is currently the fourth most rainfall to occur in one day in downtown Los Angeles since 1877. Around midnight, hillsides in at least three mountain locations collapsed sending millions of tons of mud and debris into the Crescenta Valley neighborhoods below. Crescenta Valley is a few miles north of Los Angeles. This mudslide destroyed more than 400 homes. Following the disaster, the U.S. Army Corps of Engineers and the County of Los Angeles built a flood control system of catch basins, and concrete storm drains, designed to prevent a repeat of the 1934 disaster. The Historical Society of the Crescenta Valley has a few “Then and Now” photos from this event.

1941 - Snow which began on New Year's Eve became a major blizzard on New Year's Day, burying Des Moines, IA, uunder 19.8 inches of snow in 24 hours, an all-time record for that location. (The Weather Channel)

1947 - A late afternoon tornado touched down 10 miles north of Shreveport LA, and dissipated south of El Dorado AR. The tornado, as much as 400 yards in width, killed 18 persons. It damaged or destroyed two thirds of the structures at Cotton Valley LA. (The Weather Channel)

1951: No annual measurable snow in Richmond, Virginia from 1897 to 2010 was observed only once in 1951. (Ref. Richmond Weather Records)

1955: Hurricane Alice became both the latest and the earliest hurricane on record in the Atlantic when she became a hurricane on December 31, 1954 and battered the Leeward Islands with winds of 85 mph on this date. Hurricane Alice is the only known Atlantic hurricane to span two calendar years and one of only two named Atlantic tropical cyclones, along with Tropical Storm Zeta of 2005, to do so. It was officially recognized as a significant tropical cyclone on January 2, 1955. At the time, the National Weather Service used the same naming list each year, so the name given to this storm was "Alice" and it was designated as a part of the 1955 Atlantic hurricane season. However, it was found during post-storm analysis that the storm had actually formed on December 30, and was instead a part of the 1954 season. Therefore, the season had two storms named "Alice" — the first storm of the season, and the last. Had Alice been discovered before the end of the calendar year, it would have been named Irene, the next name on the 1954 list. Some reports named this storm Alice2 to avoid confusion with the earlier Alice from June 1954.(Ref. Wikipedia.org) (Ref. AccWeather Weather History)

1962: Perhaps the worst blizzard in the history of the state of Maine finally came to an end. The storm produced 40 inches in 24 hours at Orono, and a total of 46 inches at Ripogenus Dam. Gale force winds produced snowdrifts twenty feet high around Bangor. A disastrous ice storm was over Georgia and South Carolina. It ravaged the two states for days causing more than seven million dollars damage. (Also see Dec. 30th, 1962) (David Ludlum) (The Weather Channel)

1962 - Perhaps the worst blizzard in the history of the state of Maine finally came to an end. The storm produced 40 inches in 24 hours at Orono, and a total of 46 inches at Ripogenus Dam. Gale force winds produced snow drifts twenty feet high around Bangor. A disastrous icestorm was over Georgia and South Carolina. It ravaged the two states for days causing more than seven million dollars damage. (David Ludlum) (The Weather Channel)

1963 - A snowstorm struck the Deep South. Meridian, MS, received 15 inches of snow, 10.5 inches blanketed Bay St Louis MS, and 4.5 inches fell at New Orleans LA. Freezing temperatures then prevailed for New Year's Day. (David Ludlum)

 

1967: The kickoff temperature for the NFL Championship Game between the Dallas Cowboys and the Green Bay Packers was -13°F with a wind chill of -36°F. This game is known as the “Ice Bowl.”


1982: The rain gauge total for this December in Puu Kukui, HI (elevation almost 5,800 feet near the top of the West Maui Mountains) was 42.00 inches; the year’s total: 704.83 inches (or 58.7 feet or 19.6 yd). This is the all-time greatest calendar year rainfall for the U.S. (Ref. Weather Guide Calendar with Phenomenal Weather Events 2011 Accord Pub. 2010, USA)

1987 - Torrential rains caused extensive flash flooding over eastern sections of the island of Ohau in Hawaii, resulting in many rock and mud slides. Rainfall totals ranged up to 22.89 inches in a 24 hour period, and property damage was estimated at 35 million dollars. Strong winds continued to usher arctic cold into the north central U.S. The temperature at Alexandria MN remained below zero through the day, and Jamestown ND reported a wind chill reading of 58 degrees below zero. Gales lashed the Great Lakes, with wind gusts to 54 mph reported at Lansing MI. (Storm Data) (The National Weather Summary)

1988 - Warm and wet weather prevailed in the southeastern U.S. Six cities in Florida reported record high temperatures for the date. Thunderstorms produced locally heavy rains from the Lower Mississippi Valley to the Southern Atlantic Coast. (The National Weather Summary)

1989 - The year and decade ended on a soggy note in the eastern U.S. Thunderstorm rains pushed precipitation totals for the year to 88.32 inches at Baton Rouge, and to 75.37 inches at Huntsville AL, establishing all-time records for those two locations. Dry weather continued in California. Sacramento and San Francisco finished the month without any rain or snow, and Santa Maria reported their driest year of record with just 3.30 inches of precipitation. (The National Weather Summary) (Storm Data)

1992: Wenatchee, WA received 6 inches of snow to bring the snow depth to 26 inches, to set a record for the location. The previous record was 24 inches on 2/11/1969. (Ref. AccWeather Weather History)

1994: A late afternoon tornado touched down 10 miles north of Shreveport, LA, and dissipated south of El Dorado AR. The tornado, as much as 400 yards in width, killed 18 persons. It damaged or destroyed two thirds of the structures at Cotton Valley, LA. (The Weather Channel)

1996: Storms that have battered the Northwest since Christmas boosted Eureka, California, to its wettest December on record, with 21.26 inches. Portland, Oregon, wound up its second wettest year on record with 63.56 inches. The record was 67.24 inches in 1871. Many other reporting stations in the Pacific Northwest also recorded their wettest years on record in 1996.(Ref. AccWeather Weather History)Fog caused a 70 car pileup on I-10 between Ne

2000: The “Snow Bowl” was played between Mississippi St and Texas A&M at Independence Stadium in Shreveport, Louisiana. Snow began about a half hour before kickoff and didn’t stop until well after the bowl game.

2010 - Unusually warm air fueled strong storms in the midwestern and southern U.S., producing high winds and a preliminary count of 53 tornadoes across five states. At least eight people were killed in Missouri and Arkansas and dozens of others were injured. In Mississippi, about 200 people were evacuated from the Jackson-Evers International Airport, where an EF-2 tornado crossed a runway. (NCDC)

[MANDA]

December Precipitation at my location:

Melted: 3.88"

Snowfall: 13.1"

Precipitation total for 2025: 43.43". 

Not a bad total just that is was very lean rainfall wise during the time of year that it was needed most.  In addition there were wetter periods followed by long periods with little precipitation.

Healthy and Happy New Year to all.

[IrishRob17]

18 minutes ago, MANDA said:

December Precipitation at my location:

Melted: 3.88"

Snowfall: 13.1"

Precipitation total for 2025: 43.43". 

Not a bad total just that is was very lean rainfall wise during the time of year that it was needed most.  In addition there were wetter periods followed by long periods with little precipitation.

Healthy and Happy New Year to all.

December IMBY:

Melted: 3.24"

Snowfall: 17.0"

Precipitation Total for 2025: 42.38

4" at the stake this morning.