December 2021

[TugHillMatt]

1 minute ago, lee59 said:

Maybe in about a weeks time.

I agree. There will be a short window of time (a couple days) as a transient cold shot moves through next week. But with no sustained cold as we head into January, we might have to wait longer and rely on synoptic systems racing along with the flow to give us something.

[donsutherland1]

A very warm December is now nearing its conclusion. Although tomorrow will be cloudy and cold with readings remaining mainly in the 30s across the region, the remaining days of the month will be generally warmer than normal. A few locations could pick up some light frozen precipitation tomorrow.

Near record to record cold, along with snowfall, is possible during the closing days of December in such cities as Portland, Seattle, and Vancouver.

Daily record low temperatures included:

Dease Lake, BC: -44° (old record: -29°, 2012)
Fort Nelson, BC: -41° (old record: -40°, 1961)
Fort St. John, BC: -31° (tied record set in 1961)
Prince George, BC: -40° (old recorfd: -36°, 1971)
Prince Rupert, BC: 2° (old record: 23°, 2012)
Quesnel, BC: -30° (old record: -10°, 2008)
Watson Lake, YT: -55° (old record: -42°, 2008)

Rabbit Kettle, NT recorded a low temperature of -60°.

In the South, more record heat prevailed. Records included:

Abilene, TX: 90° (old record: 81°, 2005) ***New December record***
Athens, GA: 77° (tied record set in 2015)
Birmingham: 76° (old record: 74°, 2016)
Charlotte: 77° (old record: 76°, 1889)
Columbia, SC: 78° (old record: 77°, 1964)
Dodge City, KS: 75° (old record: 71°, 2015)
Galveston: 79° (old record: 78°, 2016)
Mobile: 78° (tied record set in 1964)
Wichita Falls, TX: 88° (old record: 81°, 2005)
Wilmington, NC: 79° (old record: 78°, 1964)

In addition, Houston recorded its 13th 80° day of this month. The old December record was 10 days, which was set in 2012. Houston is on track to finish with a monthly mean temperature near 67.5°. That would demolish the longstanding December mark of 64.4° from 1933. It would also be high enough to rank as the 5th warmest November on record.

January will likely commence with an AO-/PNA- pattern. That typically favors somewhat cooler than normal readings in the East. For NYC, the January 1-10, 1991-2020 mean temperature for such cases was 33.5° (normal: 34.8°).

The latest guidance suggests that temperatures could head toward seasonal levels and then periodically below seasonal levels as the first week of January progresses. The coldest air will likely remain confined to the Pacific Northwest, Northern Plains, and western and central Canada. No severe cold is likely through at least the first week of January. The cooler pattern could last for two or perhaps three weeks before it breaks down.    

In the Midwest, through 4 pm CST today, Chicago has yet to receive its first measurable snowfall. The old record latest first measurable snowfall was December 20, 2012.

Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19.

The ENSO Region 1+2 anomaly was -1.7°C and the Region 3.4 anomaly was -1.1°C for the week centered around December 15. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.15°C and the ENSO Region 3.4 anomaly has averaged -0.93°C. La Niña conditions will likely persist through meteorological winter.

The SOI was +46.71 today.

The preliminary Arctic Oscillation (AO) figure was -2.517 today.

On December 24 the MJO was in Phase 7 at an amplitude of 2.127 (RMM). The December 23-adjusted amplitude was 2.297 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 43.4° (4.3° above normal). That would rank 2021 as the 5th warmest December on record.

 

[wdrag]

Hi! Have seen the 18z EC... still not beefy enough for me to thread, so out of respect for the  group varying views, I'll refrain from a thread this eve. IF modeling from 00z/27 NAM, RGEM, GFS continues as per 18z/26 and we see a bit beefier 00z EC for nearby ice, will go with it for Mon afternoon-night and wait on the Tuesday thread segment til Tue morning (if at all) since it should be more I84.  

However, this attached 3PM 18z/26 EC image tells me that a bit of snow is coming to NYC but it will probably melt on contact, but it's not 100% that there won't be 0.1-0.5" in parts of NYC/LI Mon afternoon.

Not sure if anyone was aware that the past two events here since the 24th have had some decent bands of qpf and so I am not dismissing the heavier modeled NAM QPF. 

Meanwhile we snow up here for several hours in nw NJ/ne PA before it changes to sleet-freezing rain Monday evening,.

Finally: EC/RGEM is growing the FGEN wet snow band late Tue. That one slightly warmer but I'm cautious about reaching the modeled temps. 

Interesting minor stuff that may interfere a bit with outdoor travel Mon and late Tue or for some who want the big snows... much ado about nothing. The problem: no guarantees that we'll see big snow this winter... Jan 2-3 is still so much up in the air about scenarios. Am going to make the most of the little stuff. 

[MJO812]

4 hours ago, wdrag said:

I respectfully disagree...  GFS is coming around on both episodes as is the RGEM.  No time right now for thread.  Will look at more data and probably start it at 9P tonight. I think NYC will see a little sleet Monday evening while freezing rain is within 15 miles of the city.  The ice probably won't be a hazard except untreated surfaces, which is where stepping outside unaware becomes a problem. 

Tuesday evening is looking a bit more potent along the NYS/PA border to portions of the I84 corridor and I think that FGEN has a good chance of working some surprises. 

Tomorrow on 0z gfs

[LibertyBell]

5 hours ago, wdrag said:

Hi! Have seen the 18z EC... still not beefy enough for me to thread, so out of respect for the  group varying views, I'll refrain from a thread this eve. IF modeling from 00z/27 NAM, RGEM, GFS continues as per 18z/26 and we see a bit beefier 00z EC for nearby ice, will go with it for Mon afternoon-night and wait on the Tuesday thread segment til Tue morning (if at all) since it should be more I84.  

However, this attached 3PM 18z/26 EC image tells me that a bit of snow is coming to NYC but it will probably melt on contact, but it's not 100% that there won't be 0.1-0.5" in parts of NYC/LI Mon afternoon.

Not sure if anyone was aware that the past two events here since the 24th have had some decent bands of qpf and so I am not dismissing the heavier modeled NAM QPF. 

Meanwhile we snow up here for several hours in nw NJ/ne PA before it changes to sleet-freezing rain Monday evening,.

Finally: EC/RGEM is growing the FGEN wet snow band late Tue. That one slightly warmer but I'm cautious about reaching the modeled temps. 

Interesting minor stuff that may interfere a bit with outdoor travel Mon and late Tue or for some who want the big snows... much ado about nothing. The problem: no guarantees that we'll see big snow this winter... Jan 2-3 is still so much up in the air about scenarios. Am going to make the most of the little stuff. 

if we get one 6 inch event this season we'll be lucky

[MJO812]

[CIK62]

The last 5 days of December are averaging  42(39/46), or +8>>>+5 nowadays.

Month to date is  43.8[+4.1].       December should end near  43.5[+4.4].

Reached 53 here yesterday{midnite},49 daytime.

Today: 35-37 daytime, rising overnight to 44 by morning, wind n. to s., clouding up, rain overnight.

37*(57%RH) here at 6am.      40* at 11am.

 

[bluewave]

Not that much cold this year as Newark is near the warmest year on record with 5 days to go. Islip is in 4th place. You can see how many top 10 warmest years there were just since 2010.

 

Time Series Summary for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Mean Avg Temperature	Missing Count
1	2021	58.0	5
2	2012	57.8	0
3	1990	57.5	0
4	2020	57.3	0
-	2011	57.3	0
5	2016	57.2	0
-	1998	57.2	0
6	2010	57.0	0
-	2006	57.0	0
-	1973	57.0	0
7	1991	56.9	0
8	2002	56.5	0
-	1993	56.5	0
9	2017	56.4	0
10	1999	56.3	0

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Mean Avg Temperature	Missing Count
1	2012	55.2	0
2	1998	55.0	0
3	2020	54.9	0
4	2021	54.7	5
-	2016	54.7	0
5	1999	54.3	0
6	2017	54.2	0
-	2011	54.2	0
-	1991	54.2	0
-	1990	54.2	0
7	2010	54.0	0
8	2006	53.9	0
9	2018	53.7	0
10	2002	53.6	0

[donsutherland1]

Morning thoughts…

It will be mostly cloudy and cold. Light snow or sleet will move into the region this afternoon before transitioning to light rain or freezing rain well north and west of New York City. A small accumulation of sleet and snow is possible in places. High temperatures will likely reach mainly the upper 30s and lower 40s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 39°

Newark: 41°

Philadelphia: 42°

Normals:

New York City: 30-Year: 41,5°; 15-Year: 42.4°

Newark: 30-Year: 42.0°; 15-Year: 43.1°

Philadelphia: 30-Year: 43.3°; 15-Year: 44.3°

The remainder of December will see above normal temperatures.

[eduggs]

Lots of virga so far. Not sure many places see much snow with this. Some guidance holds off until later when it goes right to ZR and light rain.

Tue. night continues to look interesting - as Walt has been highlighting - for extreme NWNJ through the HV. The 06z shifted slightly south into Sussex and Westchester with the snow line. NAM, CMC, EC are a little further north from I-84 to the PA-NY border. There's potential for a light plowable snowfall in a fine line wherever this frontal boundary sets up. It would be fun if this shifted further south. Something to watch...

[KEITH L.I]

Snowing moderate in Central PA ..about a half of inch everything is covered

[eduggs]

12z GFS sounding for Tue. night looks nearly isothermal below 850mb down to almost the I-80 corridor in NJ stretching across the LHV. I could see any banding that sets up and survives the eastward trek through PA possibly flipping the column to snow pretty far south, at least briefly. It definitely looks interesting Sussex, Orange, Putnam counties and north. The NAM looks like more of a mix ptype from the soundings. Don't have soundings for UK, CMC, EC but they are close to a wintry event for this area.

[LongBeachSurfFreak]

A few flurries on the uws currently. Finishing a project at work and heading to my house in SVT for the week, where winter is winter 

[donsutherland1]

There are snow flurries in Larchmont, NY.

[eduggs]

The 12 EC keeps most of the snow for Tue night up along the PA/NY border through the Catskills. The I-84 corridor looks to be right on the southern edge. Definitely bears watching but it's hard to see it sliding much south of there.

[eduggs]

The 18z NAM shifted slightly south with the frozen precip for Tue. night. Looks like up to a few tenths frozen down to northern Sussex and Orange/Putnam. Some sleet south of there to the northern NYC burbs.

[donsutherland1]

Historic December warmth in Alaska:

https://twitter.com/NWSAlaska/status/1475566727127654400?s=20

[LoboLeader1]

34 here, few snow flurries earlier this afternoon.

[bluewave]

26 minutes ago, donsutherland1 said:

Historic December warmth in Alaska:

https://twitter.com/NWSAlaska/status/1475566727127654400?s=20

Almost like a cold season version of what happened with the extreme heat in the PACNW last summer.

 

 

[weathermedic]

1 hour ago, bluewave said:

Almost like a cold season version of what happened with the extreme heat in the PACNW last summer.

 

 

And that's with only 6.5 hours of sun:

Dec 27, 2021

9:54 AM

-- 4:26 PM

6 hours and 32 minutes

[bluewave]

5 minutes ago, weathermedic said:

And that's with only 6.5 hours of sun:

Dec 27, 2021

9:54 AM

-- 4:26 PM

6 hours and 32 minutes

At least the Sierras are getting some much needed snowpack.

 

 

[donsutherland1]

1 hour ago, bluewave said:

Almost like a cold season version of what happened with the extreme heat in the PACNW last summer.

 

 

It was an extraordinary event.

[donsutherland1]

A very warm December is now nearing its conclusion. Following today's seasonal chill, the remaining days of the month will be generally warmer than normal.

Near record to record cold, along with snowfall, has continued to occur in the Pacific Northwest and western Canada.

Daily record low temperatures included:

Banff, AB: -34° (old record: -18°, 1996)
Bellingham, WA: 7° (tied record set in 1968)
Edmonton: -27° (old record: -20°, 1996)
Edson, AB: -45° (old record: -12°, 2012)
Grande Prairie, AB: -48° (old record: -46°, 1984)
Jasper, AB: -39° (old record: -34°, 1995)
Medicine Hat, AB: -30° (old record: -18°, 2017)
Pitcher Creek, AB: -32° (old record: -10°, 2012)
Red Deer, AB: -35° (old record: -28°, 1965)
Seattle: 17° (old record: -20°, 1968) ***Coldest since November 24, 2010***
Vancouver: 4° (old record: 9°, 1971) ***Coldest since January 29, 1969***

In the South, more near record and record heat prevailed. Records included:

Abilene, TX: 78° (old record: 77°, 2005)
College Station, TX: 81° (old record: 80°, 1889)
Midland, TX: 79° (old record: 75°, 1964, 1970, and 1996)

In addition, Houston recorded its 14th 80° day of this month. The old December record was 10 days, which was set in 2012. Houston is on track to finish with a monthly mean temperature near 67.5°. That would demolish the longstanding December mark of 64.4° from 1933. It would also be high enough to rank as the 5th warmest November on record.

January will likely commence with an AO-/PNA- pattern. That typically favors somewhat cooler than normal readings in the East. For NYC, the January 1-10, 1991-2020 mean temperature for such cases was 33.5° (normal: 34.8°).

The latest guidance suggests that temperatures could head toward seasonal levels and then below seasonal levels as the first week of January progresses. The coldest air will likely remain confined to the Pacific Northwest, Northern Plains, and western and central Canada. No severe cold is likely through at least the first week of January. Afterward, the cold could try to press farther south into at least the northern Middle Atlantic and Ohio Valley regions. The colder pattern could last for two or perhaps three weeks before it breaks down.    

In the Midwest, through 4 pm CST today, Chicago has yet to receive its first measurable snowfall. The old record latest first measurable snowfall was December 20, 2012.

Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19.

The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -1.1°C for the week centered around December 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.25°C and the ENSO Region 3.4 anomaly has averaged -0.98°C. La Niña conditions will likely persist through meteorological winter.

The SOI was +27.66 today.

The preliminary Arctic Oscillation (AO) figure was -2.033 today.

On December 25 the MJO was in Phase 7 at an amplitude of 1.956 (RMM). The December 24-adjusted amplitude was 2.131 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal December (1991-2020 normal). December will likely finish with a mean temperature near 43.5° (4.4° above normal). That would rank 2021 as the 5th warmest December on record.

 

[lee59]

Some of those record lows were smashed. Edson, AB. -45 old record -12.

[Rjay]

6 minutes ago, lee59 said:

Some of those record lows were smashed. Edson, AB. -45 old record -12.

That one stood out to me too.  I'm guessing their records don't go back too far but haven't looked into it yet. 

[donsutherland1]

11 minutes ago, Rjay said:

That one stood out to me too.  I'm guessing their records don't go back too far but haven't looked into it yet. 

Edson only goes back to 1996.

[lee59]

1 hour ago, donsutherland1 said:

Edson only goes back to 1996.

Yes that makes sense

[eduggs]

0z NAM is noticeably north for Tue. night. Probably almost time to give up on much frozen south of the Catskills.

[Franklin0529]

Here's a pic out my front door in highlands new Jersey, basically sandy hook.  Boxing day 2010, 33" that day

[Roger Smith]

Most of these western Canada locations would have their all-time record lows in January 1950, for example Vancouver (YVR) airport was zero F during that record cold month and some places in northlcentral BC and Alberta were below -45 F. That location Edson does not have a long period of record but is also in a chinook location east of Jasper national park, so it runs a bit milder than many places in Alberta. Anyway the locals are saying this is about as cold as it gets although most of them were not born in 1950 so they may be in for a bit of a surprise. 

Okanagan Lake rarely freezes over but could this winter after this very cold spell so early in the season. The Arrow Lakes which are man-made on the Columbia River sometimes freeze and often have large patches of floating ice by February, so they might freeze this winter. Slocan Lake is a deeper but smaller lake than those and it has only frozen in three winters since 1950, including 1969 and 1986. It became partially frozen late in Feb 2019 which was a very cold month in this region too. The ice cover was not thick or continuous but people reported seeing floating rafts of ice in the central portion of the lake. 

Currently at -20 C or -4 F here, with a snow cover of 30 cm (12"), slight wind chill.