December 2022

[qg_omega]

3 hours ago, NJwx85 said:

The GFS has really backed off on impacts for our area as well.

Only real notables will be high wind potential late Thursday into Friday and potential flash freeze. 

LLJ is not really impressive until well east of the area, I am not seeing the big wind threat with this one

[nycsnow]

24 minutes ago, qg_omega said:

LLJ is not really impressive until well east of the area, I am not seeing the big wind threat with this one

40-60mph wind gust across majority of the north east is pretty impressive it’s been a while since we had a widespread high impact wind event 

[dseagull]

From a meteorological perspective, it's an absolute beast of a system that may set some records in regards to pressure drops in Canada.  

When people don't see the outcome and extremes in their own backyard, of course they will downplay the system and call it a bust. 

This has been a fun system evolution, especially useful in regards to how the models handled it.  It's still l, for all intents and purposes, a bust for the NE.  But what a fun system to learn from and watch evolve. 

[donsutherland1]

Dry but cool weather will continue through tomorrow. A powerful storm could bring heavy rain, high winds, and coastal flooding to the region Thursday and Friday. A general 1"-2" of precipitation appears likely with locally higher amounts. A light snow accumulation remains possible at the onset of the storm and as it moves away from the region. A flash freeze is possible.

Once that storm passes, the season's coldest air so far will pour into the region. Temperatures could tumble into the teens in New York City. Nevertheless, the core of the Arctic air mass will bypass the New York City region. As a result, New York City's ongoing record 1,419-day streak without a single-digit temperature will be extended. The last time Central Park saw a temperature below 10° was January 31, 2019 when the mercury dipped to 2°.

The AO fell reached -4.000 on December 10th. Since 1950, there were 11 cases that saw the AO reach -4.000 or below during December. Mean snowfall for those cases was 9.0" (Median: 9.1"). 64% of such cases saw 6" or more of snowfall in December while 45% of such cases saw 10.0" or more snow. In contrast, during all other December cases, mean December snowfall was 3.5" (Median: 2.5"). 91% of those cases also saw a colder than normal December in the northern Middle Atlantic region. In terms of seasonal snowfall, 64% of those seasons saw 30" or more snowfall in New York City with 45% having 40" or more. Just 18% of such cases had less than 20" seasonal snowfall, both of which had less than 10" for the December-January period.

However, there are cases where Decembers with strong blocking have seen much below normal snowfall. The three cases with less than 1" of monthly snowfall with a monthly average AO of -1.500 or below were: 1985: 0.9" (total seasonal snowfall: 13.0"); 1996: Trace (total seasonal snowfall: 10.0"); and, 2012: 0.4" (total seasonal snowfall: 26.1"). The lowest December snowfall when the AO averaged -2.000 or below was 5.1" in 1976. The lowest winter month snowfall with a monthly average AO of -2.000 or below was 0.5" in January 1998. There is a chance that both futility records could be surpassed this month.

The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around December 14. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.95°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist through mid-winter.

The SOI was +20.19 today.

The preliminary Arctic Oscillation (AO) was -3.327 today.

On December 18 the MJO was in Phase 3 at an amplitude of 0.636 (RMM). The December 17-adjusted amplitude was 0.642 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 81% probability that New York City will have a colder than normal December (1991-2020 normal). December will likely finish with a mean temperature near 37.6° (1.5° below normal).

 

[MANDA]

22 minutes ago, donsutherland1 said:

Dry but cool weather will continue through tomorrow. A powerful storm could bring heavy rain, high winds, and coastal flooding to the region Thursday and Friday. A general 1"-2" of precipitation appears likely with locally higher amounts. A light snow accumulation remains possible at the onset of the storm and as it moves away from the region. A flash freeze is possible.

Once that storm passes, the season's coldest air so far will pour into the region. Temperatures could tumble into the teens in New York City. Nevertheless, the core of the Arctic air mass will bypass the New York City region. As a result, New York City's ongoing record 1,419-day streak without a single-digit temperature will be extended. The last time Central Park saw a temperature below 10° was January 31, 2019 when the mercury dipped to 2°.

The AO fell reached -4.000 on December 10th. Since 1950, there were 11 cases that saw the AO reach -4.000 or below during December. Mean snowfall for those cases was 9.0" (Median: 9.1"). 64% of such cases saw 6" or more of snowfall in December while 45% of such cases saw 10.0" or more snow. In contrast, during all other December cases, mean December snowfall was 3.5" (Median: 2.5"). 91% of those cases also saw a colder than normal December in the northern Middle Atlantic region. In terms of seasonal snowfall, 64% of those seasons saw 30" or more snowfall in New York City with 45% having 40" or more. Just 18% of such cases had less than 20" seasonal snowfall, both of which had less than 10" for the December-January period.

However, there are cases where Decembers with strong blocking have seen much below normal snowfall. The three cases with less than 1" of monthly snowfall with a monthly average AO of -1.500 or below were: 1985: 0.9" (total seasonal snowfall: 13.0"); 1996: Trace (total seasonal snowfall: 10.0"); and, 2012: 0.4" (total seasonal snowfall: 26.1"). The lowest December snowfall when the AO averaged -2.000 or below was 5.1" in 1976. The lowest winter month snowfall with a monthly average AO of -2.000 or below was 0.5" in January 1998. There is a chance that both futility records could be surpassed this month.

The ENSO Region 1+2 anomaly was -0.1°C and the Region 3.4 anomaly was -0.9°C for the week centered around December 14. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.95°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist through mid-winter.

The SOI was +20.19 today.

The preliminary Arctic Oscillation (AO) was -3.327 today.

On December 18 the MJO was in Phase 3 at an amplitude of 0.636 (RMM). The December 17-adjusted amplitude was 0.642 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 81% probability that New York City will have a colder than normal December (1991-2020 normal). December will likely finish with a mean temperature near 37.6° (1.5° below normal).

 

Interesting to note:  The first half of the month was not as mild as originally forecast and the last half of the month does not look as cold as originally forecast.  Consequently there was little warmth to erase starting at mid month and as it looks now the month will finish a degree or so below normal.   There has been a rather consistent chill near to just below normal for most of the month after the milder opening.  The coming cold shot looks to ensure we finish just below normal.  There was a time earlier in the month when it was questionable if the cold second of the month would get us to normal or below.  As it turns out there was not much warmth to erase.  Without the coming cold shot we probably would have finished flat give or take a tenth or two.

 

 

[jm1220]

NAM is taking longer to close the trough off again and it keeps happening further NE/getting broader. The real "storm" aspect of it might be worse for us than over the Midwest if we're not counting the lake effect taking place in the cold behind it. Since the low is taking longer to develop and the overall trough looks broader, the wind aspect might not be as bad but still nasty. NAM gets it significantly colder than the GFS though behind the front, gets NYC to below 10 on Christmas Eve AM and still quite windy. NAM has practically no precip with the cold front so no/little flash freeze threat, rain is all with the warm front. 

The lake effect will be the main takeaway I'm thinking. Buffalo's in for another walloping but this time it might be the downtown area and the north side with the more SW flow. 

[tmagan]

6 hours ago, CIK62 said:

UP UP And AWAY.............with my beautiful Thermometer:       Gonna be the hottest start to any year ever with this nonsense.    +17 by Jan. 06???????

Of Note:    From:  10pm Friday  to  1pm Tuesday<<<<<<32 continuously.     From Dec.29 to Jan. 05 and beyond?>>>>>32 continuously.

 

The Ens. is +11 here.     Op is +17.

It will not be the hottest start to any year, as January 2007 has the record for warmest first week ever in the Park. That week featured a 72 degree day on the sixth, something that will not happen this time.

[jm1220]

Yikes RGEM. It's the RGEM but it has 3-5" rain for LI and much of New England. 

[tmagan]

On 12/19/2022 at 5:43 AM, LibertyBell said:

Wow that was another season of extremes!  You said 9 out of the other 10 were before WWII-- was the 10th one more recent than 1989-90?

 

No, actually during WWII, 1942 - 1943.

[tmagan]

On 12/19/2022 at 12:01 PM, donsutherland1 said:

A warmup just before or around the New Year seems likely. Its duration and magnitude is far from certain. Some residual Atlantic blocking could persist in combination with a neutral or somewhat positive PNA. That could temper the warmth--warmer than normal at least for a time, but not necessarily record-challenging warmth. A popular argument might entail the MJO's returning to colder phases by mid-January (?) to argue for a return of colder weather, but MJO forecasts are low skill beyond 7-10 days.

Going to be quite hard to ever exceed the warmth of January 1932 in the Park. That month was so warm, it had a higher monthly average than March 1932. In fact January of 1932 was only 5.8 degrees cooler than April 1932.

[SnoSki14]

28 minutes ago, jm1220 said:

Yikes RGEM. It's the RGEM but it has 3-5" rain for LI and much of New England. 

Nam also has some pretty hefty totals (3+) just further west 

They also suggest single digits are very possible just outside the city. 

[Winterweatherlover]

The storm next week being halfway out in the atlantic on the GFS and CMC is probably where we want it at 180 hours out the way the winter is going. 

[dseagull]

5 hours ago, Winterweatherlover said:

The storm next week being halfway out in the atlantic on the GFS and CMC is probably where we want it at 180 hours out the way the winter is going. 

 

I guess it's a good thing we are only about 5 hours into winter so far.  

[donsutherland1]

Morning thoughts…

Today will be partly to mostly sunny and cool.  High temperatures will reach 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: 41°

A soaking rain will arrive tomorrow and continue through Friday. Afterward, it will turn sharply colder.

Normals:

New York City: 30-Year: 42.8°; 15-Year: 43.6°

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

Philadelphia: 30-Year: 44.5°; 15-Year: 45.6°

[CIK62]

The next 8 days are averaging     29degs.(23/35) or -5.

Month to date is     40.3[-0.2].         Should be   37.1[-1.6] by the 29th.

Reached 39 here yesterday.

Today:    36-40, wind n. to e.- variable. p. sunny, 35 tomorrow AM.

BALL DROP T---45       POLAR BEAR DIP T---50, Drizzle, Wind S.

SUGGESTION:   Get the GFS  to just keep on going and we can skip the winter............................

 

The next likely BN 7-Day Period:   centered on mid-month.

32*(67%RH) here at 6am.       35* at 9am.       36* at 11am.       37* at Noon.      40* at 2pm.       Reached 42* at 4pm.        40* at 6pm.

 

[wishcast_hater]

How is 30 Year an average?  Its dishonest as its not a true representation of the entire data set. That's like my kid telling me he got a 90 average but failed to include his spanish grade where he got a 40. I realize that the post actually does say 30 years but on TV or Radio that disclaimer is not included.

[bluewave]

Models have our greatest December 12 hr temperature drop on Friday. Mid 50s around 8am dropping to mid 10s by 8 pm. So a possible 40° drop. The previous record drop was 35°. 
 

https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=NJ_ASOS&zstation=EWR&hours=12&month=dec&dir=cool&how=exact&_r=t&dpi=100&_fmt=png

 

[Great Snow 1717]

3 minutes ago, wishcast_hater said:

How is 30 Year an average?  Its dishonest as its not a true representation of the entire data set. That's like my kid telling me he got a 90 average but failed to include his spanish grade where he got a 40. I realize that the post actually does say 30 years but on TV or Radio that disclaimer is not included.

I have been saying the same for decades. There is no reason(s) why the entire database should not be used to make comparisons. 

[SnoSki14]

That's a wild temperature drop. I wouldn't be surprised if the starting point was a little higher (upper 50s).

Warm sectors can really overperform in temps. A 40F drop looks likely for many with some seeing 45+ drops over a 12-18hr period.

[IrishRob17]

Winds chills Christmas Eve morning

[Great Snow 1717]

4 minutes ago, bluewave said:

You can go in the database and use any interval that you want. They have now added 15 year averages along with 30. Many of my posts focus on the last 10 years of averages. So we can put the rapid temperature rise in perspective.

I am aware of that. The point is the use of the 30 year norms for needs to come to an end.  All it is doing is deceiving the public.

[MJO812]

What a bad turn of events for the Chicago weenies. 

At least we can  all weep in sorry.

They should still see a few inches given the ratios . 

[bluewave]

16 minutes ago, Great Snow 1717 said:

I am aware of that. The point is the use of the 30 year norms for needs to come to an end.  All it is doing is deceiving the public.

The December temperatures have risen about 5 degrees since 1981. 

[Great Snow 1717]

Just now, bluewave said:

The December temperatures have risen about 5 degrees since 1981. 

A significant increase 

[bluewave]

16 minutes ago, Great Snow 1717 said:

A significant increase 

Yeah, NYC now has a 10 year average around 40° in December. It only took 30 years for us to get what used to be normal for DC in the 1990s. So we are becoming more like the Midatlantic.

Monthly Mean Avg Temperature for Washington Area, DC (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	40.2	40.2
2000	31.8	31.8
1999	42.0	42.0
1998	44.4	44.4
1997	41.0	41.0
1996	43.0	43.0
1995	35.6	35.6
1994	44.2	44.2
1993	38.1	38.1
1992	39.6	39.6
1991	42.3	42.3

 

Monthly Mean Avg Temperature for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	40.6	40.6
2021	43.8	43.8
2020	39.2	39.2
2019	38.3	38.3
2018	40.1	40.1
2017	35.0	35.0
2016	38.3	38.3
2015	50.8	50.8
2014	40.5	40.5
2013	38.5	38.5
2012	41.5	41.5

[EastonSN+]

Although I like warm weather in general (outdoors, energy savings), I hate how boring weather tracking is and how dead the forum gets. 

Looks like we are getting a third loop in the MJO. CFS weeklies have a trough in the east mid way through. This likely aligns with phase 7/8 and associated lag.

[Great Snow 1717]

5 minutes ago, bluewave said:

Yeah, NYC now has a 10 year average around 40° in December. It only took 30 years for us to get what used to be normal for DC in the 1990s. So we are becoming more like the Midatlantic.

Monthly Mean Avg Temperature for Washington Area, DC (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	40.2	40.2
2000	31.8	31.8
1999	42.0	42.0
1998	44.4	44.4
1997	41.0	41.0
1996	43.0	43.0
1995	35.6	35.6
1994	44.2	44.2
1993	38.1	38.1
1992	39.6	39.6
1991	42.3	42.3

 

Monthly Mean Avg Temperature for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	40.6	40.6
2021	43.8	43.8
2020	39.2	39.2
2019	38.3	38.3
2018	40.1	40.1
2017	35.0	35.0
2016	38.3	38.3
2015	50.8	50.8
2014	40.5	40.5
2013	38.5	38.5
2012	41.5	41.5

the northeast is "sinking" southward

[EastonSN+]

4 minutes ago, bluewave said:

Yeah, NYC now has a 10 year average around 40° in December. It only took 30 years for us to get what used to be normal for DC in the 1990s. So we are becoming more like the Midatlantic.

Monthly Mean Avg Temperature for Washington Area, DC (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	40.2	40.2
2000	31.8	31.8
1999	42.0	42.0
1998	44.4	44.4
1997	41.0	41.0
1996	43.0	43.0
1995	35.6	35.6
1994	44.2	44.2
1993	38.1	38.1
1992	39.6	39.6
1991	42.3	42.3

 

Monthly Mean Avg Temperature for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Dec	Season
Mean	40.6	40.6
2021	43.8	43.8
2020	39.2	39.2
2019	38.3	38.3
2018	40.1	40.1
2017	35.0	35.0
2016	38.3	38.3
2015	50.8	50.8
2014	40.5	40.5
2013	38.5	38.5
2012	41.5	41.5

Found this interesting, wonder how the weather was in this period. Looking back in history may give us a glimpse into what the current warming will bring.

Greenland

Analyses from central and southern Greenland (see Greenland Stable Isotopes) show that this region did experience a Medieval Warm Period (culminating around ad 1000), a Little Ice Age cool period (ad 1500–1900), and warming to the mid-twentieth century (Alley and Koci, 1990; Cuffey et al., 1994; Dahl-Jensen et al., 1998). In contrast to some other regions of the Arctic, such as northern Alaska and Siberia, Greenland did not have renewed warming through the latter decades of the twentieth century. The Medieval Warm Period was approximately 1 °C warmer than present, and the Little Ice Age 0.6 °C cooler than present, in central Greenland.

 

[MJO812]

1 minute ago, Great Snow 1717 said:

the northeast is "sinking" southward

NYC annual snowfall have also risen to near 30 Inches 

[EastonSN+]

5 minutes ago, MJO812 said:

NYC annual snowfall have also risen to near 30 Inches 

Yeah, storms are more intense from the warmer waters and have paid dividends in January February and March. Too warm in December it appears.