December 2024

[Roger Smith]

9 hours ago, LibertyBell said:

Don, is December our most quickly warming month?

In 1981, the warmest Dec was 1891 It is now 11th warmest! 

1982 began the parade of warmer Dec averages. Data in C deg and a comparison of Toronto averages and ranks (basically same story, 1923 was warmest, and is now t-6th; it's 13th for NYC) ... the older cases fare a bit better if we assume a gradually increasing urban heat island stabilizing at 2F (1.1 C) deg after 1980. ... 2015 was also warmer in Britain (by 1.6 C) than any other Dec. (9.7 C vs 8.1 in 1934). It would have been the second warmest Nov in the CET series! (It would also have been 15th warmest Nov at NYC, t42nd at Toronto).

Rank _ Year _Avg __Tor rank_ avg (C)

___01 __ 2015 __ 10.44 ____ 01 ___ 5.2

___02 __ 2023 ___7.00 ____ 02 ___ 3.6 

___03 __ 2001 ____6.72 ___ 03 ___ 3.2

___04t__ 1984 ___ 6.56 ___ 11 ____ 1.7

___04t__ 2021 ___ 6.56 ___ 05 ___ 2.5

___06 __ 2006 __ 6.44 ___ 04 ___ 2.9

___07 __ 2011 ___ 6.28 ___ 10 ___ 2.0

___08 __ 1998 ___ 6.22 __t06 ___ 2.3

___09 __ 1982 ___ 6.00 _ t06 ___ 2.3

___10 __ 1990 ___ 5.89 __ 34 ___ 0.7

___ 11 __ 1891 ___ 5.72 __ t28 ___ 0.8

___ 12 __ 1994 ___ 5.67 __ 12 ___ 1.6

___ 13 __ 1923 ___ 5.56 __ t06 ___ 2.3

___ 14 __ 2012 ___ 5.28 __ 09 ___ 2.1

___ 15t __1953 ___ 5.17 __ t20 ___ 1.1

___ 15t __1996 ___ 5.17 __ t15 ___ 1.2

___ 17 __ 1979 ___ 5.06 __ 41 ___ 0.3

___ 18 __ 1931 ___ 5.00 __t28 ___ 0.8

___ 19 __ 1956 ___ 4.94 __ 44 ___ 0.1

___ 20 __ 1971 ___ 4.89 __t28 ___ 0.8

___ 21t __ 1965 ___ 4.72 __t13 ___ 1.3

___ 21t __ 2014 ___ 4.72 __t26 ___ 0.9

___ 23 __ 1957 ___ 4.56 __t15 ___ 1.2

___ 24 __ 2018 ___ 4.50 __t26 ___ 0.9

___25t __1889 ___ 4.44 __t15 ___ 1.2

___25t __1999 ___ 4.44 __t22 ___ 1.0

___ 27 __ 1991 ___ 4.22 __ 55 ___ -0.5

___ 28 __ 1987 ___ 4.17 __t15 ___ 1.2

___29t __ 1881 ___ 4.11 __t22 ___ 1.0

___29t __ 1911 ___ 4.11 __t20 ___ 1.1

___29t __ 1918 ___ 4.11 __t50 ___-0.4

___29t __ 1949 ___ 4.11 __t42 ___ 0.2

___29t __ 1974 ___ 4.11 __t13 ___ 1.3

___34t __ 1912 ___ 4.06 __t38 ___ 0.4

___34t __ 1928 ___ 4.06 __t36 ___0.5

___36 __ 2020 ___ 4.00 __t28 ___ 0.8

___37 __ 1932 ___ 3.94 __t60 ___-0.9

___38t __1973 ___ 3.89 __t82 ___-1.9

___38t __1986 ___ 3.89 __t38 ___ 0.4

___40t __1905 ___ 3.83 __t50 ___ -0.4

___40t __1978 ___ 3.83 __t60 ___-0.9_

Also in top 50, recent 2013 and 2022 (t46); 2004 (t49)

 

 

[wdrag]

I saw a couple of comments and I'm replying here.

 

on NOHRSC snowfall... you may find a few discrepancies with your snowfall data but overall I trust the inputs are doing  good job of servicing and commenting on model guidance results. I didn't take the time to check but maybe reviewing the output 12 hours later might have found that particular discrepancy was resolved.  

 

on WSSI-P... probabilistic slices that lower have probs than elsewhere could be for any number of reasons but the ensemble (60) does its best to integrate the base Blend of Models snowfall and ice data and go from there on WSSI-P. In this case, I did not check back...again, time limitations as I still part rime work and have plenty of daily activity going on, but it might have been land use.  I'm leaving this link for you to review...it's 17 pages but gives you some background.  

https://www.wpc.ncep.noaa.gov/wwd/wssi/WSSI-P_user_guide.pdf

As you may know, it tends to be too conservative inside of 3-4 days and can abruptly change at D6-7.  Nevertheless, I think it's an important addition that needs to be incorporated into approach on winter events.  

 

[LibertyBell]

4 hours ago, bluewave said:

Many spots will be approaching 10.00 or rain since November 20th which is a nice change from the drought last fall.

 

Data for November 20, 2024 through December 26, 2024
Click column heading to sort ascending, click again to sort descending.

CT	PAWCATUCK 0.8 SE	CoCoRaHS	9.39
CT	COLCHESTER 0.6 ENE	CoCoRaHS	9.16
NY	MOUNT SINAI	COOP	9.06
CT	STONINGTON 1.4 NNW	CoCoRaHS	9.02
NY	NESCONSET 1.4 SSW	CoCoRaHS	9.01
CT	SALEM 3.6 SE	CoCoRaHS	9.01
CT	PAWCATUCK 1.8 SSE	CoCoRaHS	8.94
CT	OAKDALE 2.6 WNW	CoCoRaHS	8.93
CT	MYSTIC 1.6 W	CoCoRaHS	8.76
NY	ST. JAMES	COOP	8.71
NY	CENTER MORICHES 0.5 N	CoCoRaHS	8.64
NY	MANORVILLE 1.8 SSE	CoCoRaHS	8.63
NY	BAITING HOLLOW	COOP	8.57
NY	CENTERPORT 1.1 SE	CoCoRaHS	8.54
CT	EAST LYME 0.6 N	CoCoRaHS	8.53
NY	RIDGE 1.8 SE	CoCoRaHS	8.51
CT	NEW CANAAN 1.9 ENE	CoCoRaHS	8.44
NY	SELDEN 1.6 ESE	CoCoRaHS	8.42
NY	PORT JEFFERSON STATION 0.3 SSW	CoCoRaHS	8.39
NY	CENTERPORT	COOP	8.37
CT	CHESTER CENTER 2.7 WNW	CoCoRaHS	8.37
CT	NORWICH 5.4 SE	CoCoRaHS	8.35
CT	HIGGANUM 0.8 NE	CoCoRaHS	8.31
CT	HIGGANUM 0.7 N	CoCoRaHS	8.29
CT	STONINGTON 0.5 NNE	CoCoRaHS	8.27
CT	GUILFORD	COOP	8.24
NY	UPTON COOP - NWSFO NEW YORK	COOP	8.23
NY	FISHERS ISLAND 0.5 NE	CoCoRaHS	8.23
NY	CENTEREACH 1.3 NE	CoCoRaHS	8.21
CT	EAST LYME 0.5 SW	CoCoRaHS	8.17
NY	RIVERHEAD RESEARCH FARM	COOP	8.13
NY	ISLIP TERRACE 1.1 NNE	CoCoRaHS	8.09
CT	MOODUS 0.7 SSW	CoCoRaHS	8.07
CT	NORWICH 5.2 SE	CoCoRaHS	8.03
CT	NEW LONDON 1.0 NNW	CoCoRaHS	8.01

I enjoyed the dry weather. October with 0 rainfall was my favorite fall month ever.  I wish we could get one month like that every year.

 

[wdrag]

Regarding threads: NWS PHI already is onto the probable ice via an advisory (frozen ground even if air temp at 5' is 33-34).  

I think the RGEM and WSSI-P are leading the way with support from the usually colder and sometimes too cold SPC HREF.

I may start a thread on this tomorrow morning.  It appears to me it will radiate a bit between 5P and 7P then temps level off as the lower-mid clouds arrive. It would not be impossible to see ice 5 or 10 Mi w-n of NYC and then spotty on the island with freezing rain-drizzle developing near midnight or whatever you think from the modeling.  EC op devoid through the `2z cycle but it's ensemble has a little ice. 

I'd be careful about any warmup Saturday... only if the drizzle quits.  There wont be much wind til Sat night or Sunday. 

My long shot of 5H undercutting a closed low to LI and backside sleet-snow arriving NY eve is probably a non player but still monitoring. For now, no thread on that.

Rainfall: Solid 1.5-3" by NY day... the drought monitor finally ticked down a bit in NNJ...still moderate as of 12/24  

Appended rainfall from CoCoRaHs since 11/20 which shows a general 6-9" over our area in 5 weeks. 

[LibertyBell]

4 hours ago, hooralph said:

Really impressive how tough this little snowpack has been. White Boxing Day too. In the shade the pack is only interrupted by leaves that weren’t cleaned up.

Yup all the cold weather has really helped as well as the compacting

[SACRUS]

1 hour ago, Roger Smith said:

I wonder how well the 1947 storm was predicted? 

I was active in forecasting in 1970s and generally I recall standards were almost equal to present day (if that's a good thing), but in 1947 they were going by hand-drawn prog maps and no NWP, satellite or radar. 

If somebody can get hold of a newspaper forecast for that storm it would be interesting. (the blizzard of 1888 had a reasonably good forecast for NYC issued from DC, problem being, it never arrived, as the storm destroyed telegraph lines that would have placed a snowstorm warning in the newspaper a few hours before it began ... in 1888 the forecast in the newspaper was basically tonight and tomorrow, sometimes an outlook for next day also. I looked this up a few years ago, DC forecaster knew it was going to change from rain to snow at midnite but nobody in NYC got that warning so people (may have) had no idea what was coming. At forecast time snow had already begun in DC).

I recall a 16" snowstorm in Toronto in Jan 1966 that was well predicted, and also a 17" fall west of Toronto in Feb 1965 that we knew was going to occur. But by then satellite imagery was available and very rudimentary models were being tested. I don't think the Chicago Blizzard of Jan 1967 was any big surprise either, we knew in Toronto it was going to go rain-sleet-snow and temp would drop 30F from our record setter on Jan 25th (61F). I was following weather as a high school student then, and as a home wx-stn observer during those tremendous weather events (winter 1963-64 was a bit of a dud but all the others to about 1971-72 were good ones). I observed at various locations to about 1980.

Off topic but I have 24" snow pack and 8" of it fell yesterday. It is mild but we're above rain-snow line (barely, Columbia valley has only patchy snow and bare ground in places, at 1500' below my elevation of 3300'). 

 

It was not well forecasted according to several reports.  Looked like on and off flurries was the Dec 24th forecast

 

https://www.northjersey.com/story/news/new-jersey/2018/01/04/remembering-blizzard-1947-epic-snowstorm-took-new-jersey-surprise/748415001/

 

 

 

 

 

[NorthShoreWx]

1 hour ago, Roger Smith said:

I wonder how well the 1947 storm was predicted? I was active in forecasting in 1970s and generally I recall standards were almost equal to present day (if that's a good thing), but in 1947 they were going by hand-drawn prog maps and no NWP, satellite or radar. If somebody can get hold of a newspaper forecast for that storm it would be interesting.

From the NYT top right-hand corner of the front page on 12/25/1947:

LATE CITY EDITION 

Mostly sunny and cold today.

Cloudy and warmer tomorrow.

Temperature Range Today-Max., 35; Min., 20

Temperatures Yesterday -- Max., 33; Min., 22

Full U.S. Weather Bureau Report, Page 43

[WIN]

5 hours ago, psv88 said:

That’s amazing. I’d love to go with my kids but they are too young still 

Yeah, maybe someday. I can see these guys continuing for a while.

[Allsnow]

Down to 19 already 

 

this cold is just lingering. 

[snywx]

Currently 8f

[the_other_guy]

19 F this morning in Westchester. 30 F at JFK.

 

It is so disturbing how much climate change has exacerbated the urban heat Island. 

 

There really needs to be more of an effort to green up the city, or it’s going to be living in its own micro climate in the future. Very sad

[SnoSki14]

9 hours ago, Allsnow said:

Down to 19 already 

 

this cold is just lingering. 

Made it to 17F, many low teens not far away. Very efficient radiational cooling. 

I could see ice being a bigger concern than forecast tonight 

[qg_omega]

1 hour ago, the_other_guy said:

19 F this morning in Westchester. 30 F at JFK.

 

It is so disturbing how much climate change has exacerbated the urban heat Island. 

 

There really needs to be more of an effort to green up the city, or it’s going to be living in its own micro climate in the future. Very sad

 

Location	Time (est)	Sky/Weather	Temp. (ºF)	Dewpt. (ºF)	Humidity (%)	Wind (mph)	Pressure (in)
Farmingdale - Republic Airport	06:53	Fair	24	20	84	N 3	30.48
Islip, Long Island Mac Arthur Airport	06:56	Fair	21	19	92	Calm	30.47
New York City, Central Park	06:51	Fair	27	18	69	Calm	30.49
New York, Kennedy International Airport	06:51	A Few Clouds	28	18	66	N 5	30.49
Newark, Newark International Airport	06:51	Partly Cloudy	24	15	68	NE 7	30.49
Shirley, Brookhaven Airport	06:56	Fair	18	14	84	Calm	30.48
Somerville, Somerset Airport	06:53	Fair	14	11	88	Calm	30.46
Teterboro, Teterboro Airport	06:51	Fair	21	15	78	Calm	30.49
The Gabreski Airport	06:53	Fair	11	8	88	Calm	30.48
Trenton, Mercer County Airport	06:53	Fair	20	16	85	NW 3	30.46

[SACRUS]

 

20 / 17 off a low of 17.  Warmer and wetter throught the 2nd, near / low 60s and heavy rain sunday night.  Colder air returns by the 3rd more rooler coaster + 15 and perhaps some - 15 daily departure 29th and 4th.

 

[SACRUS]

 

Records:

Highs:

EWR: 63 (1949)
NYC: 63 (1949)
LGA: 63 (1949)
JFK: 63 (2015)

Lows:

EWR: 3 (1948)
NYC: 6 (1872)
LGA: 9 (1989)
JFK: 8 (1948)

Historical:

 

1869 - A post Christmas storm in New York and Vermont produced record storm totals of 30 inches at Burlington, VT, and 39 inches at Montpelier VT. A public emergency was declared in Vermont. (David Ludlum)

1892 - An Atlantic coast storm produced a record 18.6 inches of snow at Norfolk, VA, including 17.7 inches in 24 hours. The storm also produced 9.5 inches of snow at Raleigh NC, and brought snow to northern Florida for the first time in 35 years. (26th- 28th) (The Weather Channel)

1982 - The worst Louisiana rainstorm in more than 100 years came to an end. More than 18 inches fell at Vinton, LA, during the three day storm. Flooding was widespread, and property damage was estimated at 100 to 200 million dollars. President Reagan visited the state and declared ten parishes in northeastern Lousiana disaster areas. (The Weather Channel)

1987 - A winter storm produced snow and high winds in Wyoming, Colorado and Nebraska. Denver CO experienced its worst snowstorm since December 1983 as high winds gusting to 46 mph created near blizzard conditions, whipping the fifteen inch snow into drifts five feet high, and closing Stapleton Airport. Snowfall totals in the foothills southwest of Denver ranged up to 42 inches, at Intercanyon. Blizzard conditions raged across southeastern Wyoming through the day, stranding 300 holiday travelers in the tiny town of Chugwater. Heavier snowfall totals included 19 inches at La Grange WY, and 22 inches at Elsmere NE. (Storm Data) (The National Weather Summary)

 

1987:  Today marks the end of the infamous 2-day ice storm which began as freezing rain and sleet before sunrise on Christmas Day in Oklahoma. This ice storm left parts of Oklahoma without power for over a week. Sleet prevailed across the western and northern parts of Oklahoma City, while freezing rain devastated southern and eastern parts of the metro area. Despite heavy sleet and ice accumulations of up to 2 inches, total snowfall was only a trace.

1988 - Severe thunderstorms developing along a cold front in the south central U.S. spawned a dozen tornadoes in Mississippi between early afternoon and sunrise the following day. A tornado at Harperville destroyed five chicken homes killing thousands of chickens. Strong thunderstorm winds gusted to 80 mph at Rolling Fork MS. (The National Weather Summary) (Storm Data)

1989 - Half a dozen cities in the northeastern U.S. reported record low temperatures for the date, including Elkins, WV, with a reading of 13 degrees below zero. Watertown NY was the cold spot in the nation with a morning low of 37 degrees below zero. (Storm Data) (The National Weather Summary)

2004 - A major storm system affected parts of the western United States during December 27-29, bringing a variety of weather conditions to the region. Heavy rainfall broke daily precipitation records at some locations in California. Very heavy snow fell across the Sierra Nevada Mountains, with some areas receiving several feet of accumulation. Winds with this weather system gusted over 65 mph at some coastal and mountain locations in California.

[uofmiami]

1 hour ago, the_other_guy said:

19 F this morning in Westchester. 30 F at JFK.

 

It is so disturbing how much climate change has exacerbated the urban heat Island. 

 

There really needs to be more of an effort to green up the city, or it’s going to be living in its own micro climate in the future. Very sad

17 in N Syosset & 14 in Muttontown this morning.  NYC is its own microclimate already IMO.

[bluewave]

20 minutes ago, uofmiami said:

17 in N Syosset & 14 in Muttontown this morning.  NYC is its own microclimate already IMO.

The UHI in Manhattan has been in effect since the 1890s and Queens since the 1930s to 1950s. But it’s just more obvious when we have calm winds. Plenty of strong high pressure this month for radiational cooling.

 

[Dark Star]

13 hours ago, wdrag said:

Regarding threads: NWS PHI already is onto the probable ice via an advisory (frozen ground even if air temp at 5' is 33-34).  

I think the RGEM and WSSI-P are leading the way with support from the usually colder and sometimes too cold SPC HREF.

I may start a thread on this tomorrow morning.  It appears to me it will radiate a bit between 5P and 7P then temps level off as the lower-mid clouds arrive. It would not be impossible to see ice 5 or 10 Mi w-n of NYC and then spotty on the island with freezing rain-drizzle developing near midnight or whatever you think from the modeling.  EC op devoid through the `2z cycle but it's ensemble has a little ice. 

I'd be careful about any warmup Saturday... only if the drizzle quits.  There wont be much wind til Sat night or Sunday. 

My long shot of 5H undercutting a closed low to LI and backside sleet-snow arriving NY eve is probably a non player but still monitoring. For now, no thread on that.

Rainfall: Solid 1.5-3" by NY day... the drought monitor finally ticked down a bit in NNJ...still moderate as of 12/24  

Appended rainfall from CoCoRaHs since 11/20 which shows a general 6-9" over our area in 5 weeks. 

Freezing rain at 32 degrees F is difficult, depending upon the time of day.  Coming right out of an overnight period which is below 32, has a chance of freezing on contact.  However, sustained moderate rain usually warms the surface fairly quickly at temps at or above 32.  A light drizzle would have a better chance of freezing on contact at or around 32 degrees?  At least this is from my observational experience.  

[bluewave]

The cold departures will be shrinking to close out the month with 3 days going +10 or higher.

[LibertyBell]

59 minutes ago, bluewave said:

The UHI in Manhattan has been in effect since the 1890s and Queens since the 1930s to 1950s. But it’s just more obvious when we have calm winds. Plenty of strong high pressure this month for radiational cooling.

 

didn't we set a high pressure record at 30.97 this month?

highest pressure since February 13, 1981 31.08

[LibertyBell]

1 hour ago, uofmiami said:

17 in N Syosset & 14 in Muttontown this morning.  NYC is its own microclimate already IMO.

close to single digits at KFOK?

[FPizz]

13.2 yesterday, 14.3 this morning.   Both days my forecast was 19.  I guess hanging on to 100% snowcover helped

[psv88]

16 this morning 

[MANDA]

Snow cover status:  75-80% coverage with an average depth of 1".  South facing exposures patchy coverage to bare ground.  North facing and shadier locations holding on to 2" or a tad more this morning.

[CPcantmeasuresnow]

Low of 8 this morning, 8 yesterday morning and -3 on the 23rd. 
 

Let tomorrow and the couple of days after wreak their havoc on the snow cover. It was white several days before through and after Christmas. December is already a success. 

[forkyfork]

10 minutes ago, CPcantmeasuresnow said:

Low of 8 this morning, 8 yesterday morning and -3 on the 23rd. 
 

Let tomorrow and the couple of days after wreak their havoc on the snow cover. It was white several days before through and after Christmas. December is already a success. 

i think some here would collect what they can, put it in a freezer, and put it back on the ground when it cools down again