2024-2025 La Nina

[bluewave]

2 minutes ago, snowman19 said:

@Bluewave The entire ENSO gyre is switching into a mode much more favorable for region 3.4 cooling and enhanced trades finally. This should wipe out the +AAM/Nino like effects. Paul is expecting this to continue throughout December and possibly into early January. It’s also going to constructively interfere with the MJO Maritime Continent forcing and the -IOD. The question is do we see enough cooling to get a trimonthly weak Niña ONI? Paul thinks the distinction between weak La Niña and cold-neutral really isn’t going to matter in this case:
 

 

 

 

 

 

 

 

 

You can see the more Niña-like influence beginning to show up in the 500mb pattern as we approach mid-December with higher heights in the East relative to previous runs.

New run

 

Old run

 

[qg_omega]

3 minutes ago, bluewave said:

You can see the more Niña-like influence beginning to show up in the 500mb pattern as we approach mid-December with higher heights in the East relative to previous runs.

New run

 

Old run

 

there goes the winter window

[snowman19]

2 minutes ago, bluewave said:

You can see the more Niña-like influence beginning to show up in the 500mb pattern as we approach mid-December with higher heights in the East relative to previous runs.

New run

 

Old run

 

Agree. The consistent +SOI run is indicative of ENSO-atmospheric coupling. And if people are correct that there’s tropospheric coupling with the upcoming record strong SPV, that’s a really bad sign with the PAC changing the way it is. That’s going to re-enforce +AO/+NAO and leave no way to possibly blunt the PAC onslaught 

[bluewave]

9 minutes ago, snowman19 said:

Agree. The consistent +SOI run is indicative of ENSO-atmospheric coupling. And if people are correct that there’s tropospheric coupling with the upcoming record strong SPV, that’s a really bad sign with the PAC changing the way it is. That’s going to re-enforce +AO/+NAO and leave no way to possibly blunt the PAC onslaught 

You can see overlapping influences. The lingering +AAM still has a +PNA ridge near West Coast. But the higher 500mb heights in East than previous runs is the MJO 5-6, +SOI, more Niña-like influence. If later model runs develop more of a -PNA  then it will signify that the +AAM influence has decreased even more.  

[GaWx]

Latest Euro Weeklies E US: weeks as a whole still BN through midmonth; averaging NN rest of Dec through Jan 5; AN 1/6-12.

 This is still not a warm pattern way out 12/30-1/5 and actually is the coolest run for that week yet:

 

[brooklynwx99]

considering how god awful extended guidance has been so far, I do expect to relaxation around the 15th, but I wouldn’t lock it in. AK ridging lingering wouldn’t even make this a particularly warm pattern

also, if the Pacific jet is stronger than modeled as it usually is, wouldn’t it lead to the Aleutian trough showing up pushing farther east?

[brooklynwx99]

also, lmao

this is what happens when you rely on the MJO too much

[GaWx]

2 minutes ago, brooklynwx99 said:

also, lmao

this is what happens when you rely on the MJO too much

 Here was the Nov 15th run of the Euro Weeklies for 12/2-8:

And the same run for 12/9-15:

[Cobalt]

On 11/16/2024 at 10:35 AM, qg_omega said:

Record warmth looks likely to start December 

So close!! it's actually the coldest start in the East since at least 2010 ❤️❤️

[brooklynwx99]

2 minutes ago, Cobalt said:

So close!! it's actually the coldest start in the East since at least 2010 ❤️❤️

no changes

[donsutherland1]

So far, the ideas expressed last Sunday remain in good shape.

1. The first half of December continues to look cold with a weekly anomaly of 6°-10° below normal likely during that period. In fact, New York City could have its coldest December 1-10 period since 2002.

2. A significant lake effect snow event is underway. Several locations have seen excessive lake effect snow so far. Cassadaga, NY (31.6") and Mayville, NY (30.0") have the highest amounts so far. Buffalo has received a trace of snow, but as the lake effect snow bands move northward today, accumulating snow is likely there. Chicago (2.9"), Detroit (1.7"), and Toronto (0.2 cm) have all seen measurable snow. No measurable snow has fallen in Boston, New York City, or Philadelphia.

3. The potential for a colder than normal December has increased in parts of the eastern third of the U.S. Since 1980, all four cases where New York City had a mean temperature of 36.5° or below, wound up having a colder than normal December. The latest guidance shows New York City with a December 1-10 mean temperature near 32.5°.  The outcome farther west in such cties as Chicago, Detroit, and Indianapolis remains less certain and will depend on the timing of the pattern change. The farther east one is, the more likely that the month will come out with a colder anomaly.

4. The CFSv2 is pushing a warmup around mid-month. The November 29 12z ECMWF weeklies are holding it off for an additional week. As noted previously, the guidance has tended to rush the timing of pattern changes.

Four thoughts going forward:

1. The EPO is forecast to head toward neutral levels toward mid-month. The AO and PNA are also forecast to head toward neutral levels. Therefore, a pattern change seems likely, but probably with a lag that could favor the timing shown on the ECMWF weeklies.

2. Even as the pattern in the East is likely to be dry for much of the first week of December, a clipper system could bring some light snow or flurries to the northern Mid-Atlantic/southern New England areas  late Tuesday night and Wednesday. Boston might have a chance to pick up an inch of snow. Philadelphia and possibly New York City might only see some flurries.

3. Following the clipper, the coldest air so far this season will move into the eastern third of the U.S.

4. Out West, British Columbia could see a period of near record and record warmth develop for Tuesday through Thursday (December 3-5).

Overall, the exceptional warmth in BC and the cold in the East showed up quite well on the November 29 12z ECMWF Weeklies.

[TheClimateChanger]

1 hour ago, donsutherland1 said:

2. A significant lake effect snow event is underway. Several locations have seen excessive lake effect snow so far. Cassadaga, NY (31.6") and Mayville, NY (30.0") have the highest amounts so far. Buffalo has received a trace of snow, but as the lake effect snow bands move northward today, accumulating snow is likely there. Chicago (2.9"), Detroit (1.7"), and Toronto (0.2 cm) have all seen measurable snow. No measurable snow has fallen in Boston, New York City, or Philadelphia.

 

Highest amount [as of 7 pm yesterday] was 32.1" 2 miles ESE of North East, Pennsylvania, with another report of 30.2" from Girard, Pennsylvania shortly after 6 pm. No doubt well over three feet totals since that time.

[donsutherland1]

12 minutes ago, TheClimateChanger said:

Highest amount [as of 7 pm yesterday] was 32.1" 2 miles ESE of North East, Pennsylvania, with another report of 30.2" from Girard, Pennsylvania shortly after 6 pm. No doubt well over three feet totals since that time.

Thanks. I thought I had loaded the CLE local storm reports, but didn’t.

[George001]

3 hours ago, qg_omega said:

there goes the winter window

No, it’s just a relaxation period after 10 days of cold. How long the relaxation period lasts before the shift back to a colder pattern will be telling in terms of what direction this winter could be going.

[PhiEaglesfan712]

1 minute ago, George001 said:

No, it’s just a relaxation period

Yep, the pattern turns back to colder in February. As I said all along: cool December, very warm January, and cool February.

[MJO812]

Just now, PhiEaglesfan712 said:

Yep, the pattern turns back to colder in February. As I said all along: cool December, very warm January, and cool February.

Colder in January 

[PhiEaglesfan712]

25 minutes ago, MJO812 said:

Colder in January 

Possibly in late January, but most of the month is going to be warm. I don't see a 2010-11 or 2017-18 type winter.

[bluewave]

2 hours ago, George001 said:

No, it’s just a relaxation period after 10 days of cold. How long the relaxation period lasts before the shift back to a colder pattern will be telling in terms of what direction this winter could be going.

More like the start of December is a 10 day relaxation period from one of our warmest falls on record. It will feel much colder due to how warm it has been. But the cold departures will be modest compared to colder starts to December in the past. 
 

 

[TheClimateChanger]

3 hours ago, donsutherland1 said:

Thanks. I thought I had loaded the CLE local storm reports, but didn’t.

No problem, Don. Also, of note, the 22.6" officially recorded at ERI yesterday was just 2.2" shy of the entire seasonal total from last winter... which, incidentally, was the 4th lowest of record. The graphic below shows it as 6th; however, there is missing data for the winters of 1942-43 & 1943-44. If you cross-check the missing days from the climate reports using NCEI IPS, you'll see the seasonal total was over 48 inches in 1943-1944 and over 40 inches the preceding winter. The missing count for 1918-1919 & 1897-1898 appears just to correspond to months where no snow fell. No snowfall data was reported, which was interpreted as "missing" by the algorithm. And, of course, this ignores changes in snowfall measurement procedure which likely make the earlier data lower than it would otherwise be if the procedures were the same as today.

[MANDA]

1 hour ago, bluewave said:

More like the start of December is a 10 day relaxation period from one of our warmest falls on record. It will feel much colder due to how warm it has been. But the cold departures will be modest compared to colder starts to December in the past. 
 

 

A cold outbreak similar to some that occurred in the 70's and 80's would feel like the end of days compared to what we've seen in recent years with in and out modest cold shots.

[bluewave]

2 minutes ago, MANDA said:

A cold out break similar to some that occurred in the 70's and  80's would feel like the end of days.

Yeah, I grew during that much colder era. I can remember when NYC dipped into the single digits on 12-3-76. With the higher energy costs these days we are lucky we don’t get that kind of extended cold anymore.

[mitchnick]

3 minutes ago, bluewave said:

Yeah, I grew during that much colder era. I can remember when NYC dipped into the single digits on 12-3-76. With the higher energy costs these days we are lucky we don’t get that kind of extended cold anymore.

Coldest winter on record in the east will get you those numbers, but that was far from the norm. I walked 200' out onto the frozen Chesapeake Bay that winter in January, 1977 at Sandy Point State Park. The Chesapeake Bay never froze like that again.

[MJO812]

[bluewave]

7 minutes ago, mitchnick said:

Coldest winter on record in the east will get you those numbers, but that was far from the norm. I walked 200' out onto the frozen Chesapeake Bay that winter in January, 1977 at Sandy Point State Park. The Chesapeake Bay never froze like that again.

That winter was one for the ages. The early signs of the extreme cold began to become evident near the end of August. The last time NYC saw the December 1-10 average dip below freezing was 2002. 
 

Time Series Summary for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

1	1926-12-10	26.2	0
-	1886-12-10	26.2	0
3	1876-12-10	26.4	0
4	1989-12-10	28.5	0
-	1871-12-10	28.5	0
5	1880-12-10	28.7	0
6	1882-12-10	29.1	0
7	1910-12-10	29.2	0
8	1976-12-10	29.3	0
9	1890-12-10	30.0	0
-	1869-12-10	30.0	0
10	1904-12-10	30.1	0
11	2002-12-10	30.6	0
-	1875-12-10	30.6	0
12	1958-12-10	30.9	0
13	1917-12-10	31.0	0
14	1906-12-10	31.3	0
15	1964-12-10	31.8	0

[snowman19]

Your hero says the east is going mild mid-December. Didn’t expect you to post his new tweet

[MANDA]

39 minutes ago, mitchnick said:

Coldest winter on record in the east will get you those numbers, but that was far from the norm. I walked 200' out onto the frozen Chesapeake Bay that winter in January, 1977 at Sandy Point State Park. The Chesapeake Bay never froze like that again.

Imagine if it did !

[mitchnick]

1 hour ago, MANDA said:

Imagine if it did !

Not interested.  I think BWI (mby at the time) had a lousy 12" or so that winter.

[uofmiami]

 

[MANDA]

2 hours ago, mitchnick said:

Not interested.  I think BWI (mby at the time) had a lousy 12" or so that winter.

Yea but it sure hung around for a long time.  Here in NJ I had a solid snow cover from early/mid December until around February 10th.  Don't recall my total but probably around 15" I think.  Nothing melted.  It was light to some moderate snowfall falling on existing snow cover.

[mitchnick]

6 minutes ago, MANDA said:

Yea but it sure hung around for a long time.  Here in NJ I had a solid snow cover from early/mid December until around February 10th.  Don't recall my total but probably around 15" I think.  Nothing melted.  It was light to some moderate snowfall falling on existing snow cover.

100% on that. The ground was snow covered almost all of January.  Then, February flipped warm mid month and March was around +5 at BWI. 

Maybe because I was younger in 76/77, but I found 93/94 to be even more brutal, though not as unrelenting as 76/77.