December 2019

[Snowstorms]

3 hours ago, bluewave said:

The atmosphere keeps coming up with these Niña-like extended Pacific Jet patterns. The last official La Niña ended in March 2018. But at least 16-17 and 17-18 had their favorable KU event periods.

I thought jet extensions are more common in Nino's and jet retractions are commonly observed in Nina's? 

[Brasiluvsnow]

Novice checking in and  I get that there is oceans of science involved in much of this but I will not buy into any of it until I see what actually happens. Most of you guys have forgotten more of this science than I will probably ever understand but with that said , The long range says this the long range says that or so and so says this or what about the the Pacific Jet / this looks just like last year yada yada or how about the PV -----all I know that regardless of who says what or which model shows anything that it could EASILY still snow in the North East for New Years. Now back to your discussion.

[mikem81]

GFS looks pretty darn cold from 12/31 through end of the run. Lets see how long that look holds 

[Santa Claus]

Very nice day outside.  55/27 with no wind, partly cloudy.

[Cfa]

57 and sunny here, picture perfect.

[dWave]

54..

Its quite hazy out, looking west the air looks espically horrible toward NJ. A brown haze over Hudson Yards and into Jersey, Im actually high enough above it to see it below. 

[psv88]

23 minutes ago, Cfa said:

57 and sunny here, picture perfect.

57 here too, beautiful 

[dWave]

Hazy sun, 58. Warm up exceeding forecasts today, as it frequently does.

[SnoSki14]

11 minutes ago, WestBabylonWeather said:

I’d almost bet money that the first two weeks of January will be cold

 

ive seen this movie many times. Warm until New Years. 

Soaring AO/NAO, positive EPO, MJO near warm phases. It's a torch recipe. 

You can close the shades for many weeks.

Gorgeous day today, so much better than last week's cold.

[MJO812]

16 minutes ago, WestBabylonWeather said:

I’d almost bet money that the first two weeks of January will be cold

 

ive seen this movie many times. Warm until New Years. 

That's how the models look today

[White Gorilla]

27 minutes ago, Snow88 said:

That's how the models look today

Yes.  Everyone forgets that what we see today is often what we don't see tomorrow.  I love snow here as much as any weenie, but I am enjoying the milder temperatures for now as a break from the cold. 

[bluewave]

30 minutes ago, White Gorilla said:

Yes.  Everyone forgets that what we see today is often what we don't see tomorrow.  I love snow here as much as any weenie, but I am enjoying the milder temperatures for now as a break from the cold. 

The ensemble means don’t have much skill beyond day 6-10. So reliable model themes start to emerge right around day 8-10. Leaning too heavily on day 11-15 model output usually ends in disappointment. 

[Eduardo]

2 hours ago, bluewave said:

The ensemble means don’t have much skill beyond day 6-10. So reliable model themes start to emerge right around day 8-10. Leaning too heavily on day 11-15 model output usually ends in disappointment. 

This!!  So much this!  I’m as anxious as anybody to get some meaningful winter weather in here, but LR modeling isn’t worth chewing on until we are inside ten days (at least)!!

[CIK62]

Only reached 54* here.       Seems everybody else was higher.

Ensemble has it AN till the 30th on both the 850mb T's and 500mb. heights.     Apparently the 850mb T's do not stray far from Normal after that date till end of run, Jan. 07----while the 500mb heights go slightly Negative to the 4th., then slightly AN.

Meanwhile Christmas Day still looks like this:    (works out to +1.5sd) around here.

And at the putative transition point it looks like this:

[Rtd208]

 

[doncat]

Nice diurnal range today in suburbia.... 54°/28°. 

[donsutherland1]

Today, temperatures rose into the 50s in the Middle Atlantic and southern New England regions. High temperatures included:

Atlantic City: 56°; Baltimore: 55°; Boston: 57°; Bridgeport: 50°; Islip: 55°; New York City: 57°; Newark: 57°; Philadelphia: 52°; and, Washington, DC: 53°.

New York City's high temperature was the warmest reading since December 10 when the mercury topped out at 58°.

On average, the final days of December will likely be warmer to occasionally much warmer than normal. Based on the latest guidance, the warmth could be sufficient to ensure that at least parts of the Middle Atlantic region could finish with at least a somewhat warmer than normal December. A scenario where much of the region winds up somewhat warmer than normal is not out of the question. The probability of more widespread warm anomalies has increased in recent days.

Through December 22, monthly anomalies for select cities were:

Baltimore: +0.3°, Boston: -0.8°, Islip: -1.3°, New York City: -2.5°, Newark: -2.0°, Philadelphia: -1.2°, and Washington, DC: -0.4°.

Colder air could return during the first week of January. The progression of the MJO in concert with the teleconnections could be crucial in determining whether most of North America's cold air stays bottled up north of the Canada-U.S. border beyond the first week of January or it comes southward into the region shortly after the start of 2020. Transient shots of cold would be possible under the former scenario. Afterward, the predominant state of the EPO will likely be crucial to the persistence of the cold.

Despite the development of a sustained colder than normal temperature regime, Utqiagvik (formerly Barrow) is nearing the end of its warmest year on record. 2019 will likely conclude with a mean temperature of 20.8°. The existing record is 18.9°, which was set in 2016. Currently, 2017 ranks as the second warmest year and 2018 ranks as the fourth warmest year.

The ENSO Region 1+2 anomaly was +0.4°C and the Region 3.4 anomaly was +0.6°C for the week centered around December 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.12°C and the ENSO Region 3.4 anomaly has averaged +0.56°C. The remainder of winter 2019-2020 will likely feature neutral-warm to weak El Niño conditions.

The SOI was -9.97 today.

Today, the preliminary Arctic Oscillation (AO) figure was -0.212.

No significant stratospheric warming event appears likely through January 1, but some warming above 2 mb is possible near the end of December. Wave 2 activity will be muted as December nears an end. Overall, most of the stratosphere is forecast to remain cold through the remainder of December on the EPS.

On December 22, the MJO was in Phase 5 at an amplitude of 0.566 (RMM). The December 21-adjusted amplitude was 0.536.

Through December 20, the AO had averaged +0.878 in December. Since 1950, there were 12 cases where the AO averaged +0.500 to +1.250. The January mean temperature for New York City was 33.0°. However, six cases (50%) had temperatures 1.5° or more above that average, while five cases (42%) had temperatures 1.5° or more below that average. Put another way, this data suggests that January has the potential to either be warmer/much warmer than normal or colder/much colder than normal rather than near normal. When the January EPO had a positive average 6/8 (75%) of those cases were warmer to much warmer than normal. When the January EPO had a negative EPO average, 3/4 (75%) of those cases were colder to much colder than normal. In sum, the predominant state of the January EPO will very likely determine the January temperature outcome.

Based on sensitivity analysis applied to the latest guidance, there is an implied 65% probability that December will wind up warmer than normal in New York City with a monthly mean temperature near 38.0°.

[gravitylover]

I saw 58 in the Hartford area this afternoon. A little later I was north of Waterbury on the north side of a fairly high ridge and with the temp around 55 there was very little melt, there's still a solid 1" icepack there.

[uncle W]

53/31 imby today...

[Cfa]

59/30 here, warmest high temp of the month.

[CIK62]

The last 8 days of December are averaging  44.5degs., or about 10degs. AN.

Month to date is  -1.8[36.9].       December should end near  +1.4[38.9].

43* here at 6am.     44* by 9am.     47* by Noon.        50* by 3pm.      45* by 6pm.       42*by 9pm.      41* by 10pm.

 

All models are zippo on any snow.     The January 'cooldown' does not even look like a return to Normal right now.      Big uncertainty starts Jan. 03, however.

[bluewave]

The high temperature reached 57 degrees in NYC on Monday. This warmth right before Christmas has become really pronounced since 2001. NYC has gone 17 out of the last 19 years reaching 55 or warmer in the week before Christmas.

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

Ending Date	Highest Max Temperature Dec 18 to Dec 24	Missing Count
2019-12-24	57	1
2018-12-24	61	0
2017-12-24	55	0
2016-12-24	58	0
2015-12-24	72	0
2014-12-24	58	0
2013-12-24	71	0
2012-12-24	56	0
2011-12-24	62	0
2010-12-24	40	0
2009-12-24	39	0
2008-12-24	58	0
2007-12-24	61	0
2006-12-24	59	0
2005-12-24	55	0
2004-12-24	59	0
2003-12-24	56	0
2002-12-24	60	0
2001-12-24	58	0

 

 

[JerseyWx]

49 minutes ago, bluewave said:

The high temperature reached 57 degrees in NYC on Monday. This warmth right before Christmas has become really pronounced since 2001. NYC has gone 17 out of the last 19 years reaching 55 or warmer in the week before Christmas.

It's a heck of a trend to say the least.  Almost expected at this point.

[donsutherland1]

At 8 am, it was 42° in New York City and 38° in Newark. Today will be another warmer than normal day, though not quite as warm as yesterday. High temperatures in both cities will likely top out in the upper 40s to around 50°. These readings will further reduce the now shrinking cold anomalies that had been accumulated during much of December.

On December 21, New York City and Newark had monthly temperature anomalies of 2.7° below normal and 2.1° below normal respectively. After yesterday's warmth, those cold anomalies have been slashed to 1.8° and 1.5° below normal respectively.

[uncle W]

analogs with a milder than average December will win this month...with only 2.5" in Central Park 2004 becomes the closest to 2019...

year...ave temp...snow...

2019...…38.0*...…….2.5".....* possible ave...

1959......38.4.........15.8"

1992......37.9...…......0.4"

2003......37.6.........19.8"

2004.......38.4...........3.0"

2013.......38.5...........8.6"

 

[PaulyFromPlattsburgh]

You can see much better ridge placement on the 12z vs previous runs. The western shortwave is slightly weaker and rotates further southwest instead of getting sucked into the flow allowing more pieces from the north to funnel down. Looks like a very interesting run ahead. I can’t post images for some reason. At HR168 you can see the PJ halted for a sec there stopping those building heights.  At HR 180 you can see that SW about 150 miles west mitigating the flow. Gfs wobbling back and forth on where to put that SW. by keeping the SW further west we allow for a better polar connection as evident on 12 z starting at 168 compared to previous runs. On top of that the whole evolution of what happens after day 7 is skewed. The 6z will use that SW to build the next storm while the 12z will extrapolate a whole different solution.  I would rather have that SW hold back a bit tbh, HR 192 that SW about 250 miles east of 12z by Texas while it was in the eastern pacific on 6z. From 168-198 u can see 12z just dropping in northern wave short wave troughs. You NYC boys will like this run day 9 on!

[Zelocita Weather]

5 hours ago, WestBabylonWeather said:

Yup. I’ve seen this movie. It’s predictable. 

If you take out the impact of rapid 'heat island' and local urbanization effect, no trend is present. 

[MJO812]

1 hour ago, PaulyFromPlattsburgh said:

You can see much better ridge placement on the 12z vs previous runs. The western shortwave is slightly weaker and rotates further southwest instead of getting sucked into the flow allowing more pieces from the north to funnel down. Looks like a very interesting run ahead. I can’t post images for some reason. At HR168 you can see the PJ halted for a sec there stopping those building heights.  At HR 180 you can see that SW about 150 miles west mitigating the flow. Gfs wobbling back and forth on where to put that SW. by keeping the SW further west we allow for a better polar connection as evident on 12 z starting at 168 compared to previous runs. On top of that the whole evolution of what happens after day 7 is skewed. The 6z will use that SW to build the next storm while the 12z will extrapolate a whole different solution.  I would rather have that SW hold back a bit tbh, HR 192 that SW about 250 miles east of 12z by Texas while it was in the eastern pacific on 6z. From 168-198 u can see 12z just dropping in northern wave short wave troughs. You NYC boys will like this run day 9 on!

Gfs looks really good

[bluewave]

31 minutes ago, Zelocita Weather said:

If you take out the impact of rapid 'heat island' and local urbanization effect, no trend is present. 

This has nothing to do with urbanization. POU had exactly the same +16 high temperature departure as NYC yesterday. 
 

Data for POUGHKEEPSIE AIRPORT, NY
Click column heading to sort ascending, click again to sort descending.

Date	Max Temperature	Max Temperature Departure
2019-12-23	54	16.3
2019-12-24	M	M

 

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

Date	Max Temperature	Max Temperature Departure
2019-12-23	57	16.3
2019-12-24	M	M

 

 

[qg_omega]

13 minutes ago, Zelocita Weather said:

If you take out the impact of rapid 'heat island' and local urbanization effect, no trend is present. 

No not correct at all