September 2020 wx discussion

[LibertyBell]

9 minutes ago, bluewave said:

Still early to guess at any analog types. But winters have been following a 1 or 2 year pattern for a while now. So it will be interesting to see if this winter reverts back to a snowier La Niña or does a rare 3 below normal snowfall seasons. We haven’t gone below normal for snowfall during 3 consecutive seasons since the late 90s. 
 

19-20....18-19....Niña-like above normal temperatures and below normal snowfall

17-18.....16-17...La Niña above normal temperatures and snowfall

15-16..................Super El Niño with above normal temperatures and snowfall

14-15.....13-14....Record + North Pacific Mode with below normal temperatures and above normal snowfall. Also remembered as the record NEPAC warm blob winters.

12-13.....Niño-like above normal temperatures backloaded snowfall

11-12.....La Niña with above normal temperatures and below normal snowfall

10-11....09-10.....record -NAO and -AO with an El Niño then La Niña ....below normal temperatures and above normal snowfall. 

 

 

One of the reasons I chose 08-09 is because it came after two back to back well below normal snowfall seasons and also follows the snowy March theme we have seen in recent years.

 

[bluewave]

47 minutes ago, LibertyBell said:

One of the reasons I chose 08-09 is because it came after two back to back well below normal snowfall seasons and also follows the snowy March theme we have seen in recent years.

 

It will be interesting to see. 08-09 finished closer to normal in the snowfall department. It was one of the few closer to average snowfall seasons in a sea of below and above normal snowfall extremes. So like you said, many here would be happy with a season like that after the last two.

[Brian5671]

11 minutes ago, bluewave said:

It will be interesting to see. 08-09 finished closer to normal in the snowfall department. It was one of the few closer to average snowfall seasons in a sea of below and above normal snowfall extremes. So like you said, many here would be happy with a season like that after the last two.

was also a year with snows early and late-best storms mid December and a big one around March 1st

[bluewave]

15 minutes ago, Brian5671 said:

was also a year with snows early and late-best storms mid December and a big one around March 1st

08-09 was our last winter without some type of wild extreme.

[forkyfork]

On 9/12/2020 at 4:23 PM, forkyfork said:

birds.

https://birdcast.info/news/migration-alert-major-northeast-flight-on-14-september-2020/

[forkyfork]

this is pretty wild

[LibertyBell]

the sky is a pale yellow here.....

 

[Cfa]

18 minutes ago, forkyfork said:

this is pretty wild

Looked like that here a few hours ago, my initial thought was smoke, but since it was somewhat cloudy earlier I wasn’t sure.

Sky here is blue right now though.

[bluewave]

The smoke shows up really well on the satellite image.

[gravitylover]

4 hours ago, forkyfork said:

looks smoky right now outside

 

3 hours ago, IrishRob17 said:

Agreed, its quite noticeable above the clouds

I noticed that last week. You have been able to see it above the clouds since last Thursday. As I started to type this Janice Huff was doing a smoke forecast.

[Allsnow]

It’s odd to actually have September weather in September 

[doncat]

Tracing the smoke over us now...you can trace it west, looks like to a fire in Utah...Of course there are several big fires out west contributing.

[donsutherland1]

Today featured partly to mostly sunny weather. Temperatures were still mild, with most areas topping out in the middle 70s.

In Europe, France experienced record September heat. Monthly record temperatures included:

Angers Beaucouze: 96°
Bourges: 96°
Nevers: 96°
Orthez: 100°
Sabres: 99°
St. Dizier: 95°
Tours: 95°

The coldest air so far this season is now overspreading the region. Tonight, the temperature will fall into the 50s in New York City's Central Park for the first time since June 15. Tomorrow, temperatures could remain in the 60s in much of the region.

Hurricane Sally will likely make landfall near the Mississippi-Alabama border tomorrow or tomorrow night. Its passage will be fairly slow, which could result in parts of the Gulf Region picking up 15" or more rain.

An even cooler air mass could arrive late in the week. Generally below normal readings could persist into at least the last week of September. There is an increasing possibility that September could wind up on the cool side of normal, which would be an uncommon event in recent cases preceding La Niña winters.

The most recent subseasonal guidance is in strong consensus that a generally cool regime could last through the first week of October. The latest EPS weeklies forecast an end to the cool anomalies near the end of September.

The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around September 9. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.08°C and the ENSO Region 3.4 anomaly has averaged -0.75°C. La Niña conditions have developed and will likely prevail through the remainder of autumn.

The SOI was +2.14.

Today, the preliminary Arctic Oscillation (AO) figure was -0.128.

On September 13, the MJO was in Phase 3 at an amplitude of 0.743 (RMM). The September 12-adjusted amplitude was 0.816.

Since 1990, there have been 11 La Niña events, 6 of which followed an El Niño winter. 10/11 (91%) case saw warmer than normal September. All 6 following an El Niño winter were warmer than normal. September mean temperatures for New York City for those cases were: 11 cases: 69.9°; Subset of 6 cases: 70.8°; Entire 1990-2019 period: 69.0°. The September mean temperature for all La Niña and neutral-cool cases following an El Niño winter (1950-2019: n=13) was 69.9°.

Since 1950, there have been five cases where a La Niña developed during June-July-August or afterward following an El Niño winter. 4/5 (80%) of those cases saw a predominant EPO+/AO+ winter pattern. The most recent such case was 2016-17. 9/10 (90%) of the La Niña winters that followed an El Niño winter featured a predominantly positive EPO.   

Based on sensitivity analysis applied to the latest guidance, there is an implied 50% probability that New York City will have a warmer than normal September. September will likely finish with a mean temperature near 68.5°.

Finally,on September 13, Arctic sea ice extent was 3.555 million square kilometers (JAXA). Based on 2010-2019 data, the highest 25% bound was 3.742 million square kilometers. The lowest 25% bound was 3.581 million square kilometers. The lowest 10% bound is 3.465 million square kilometers. 2020 is the second consecutive year with a minimum extent figure below 4.000 million square kilometers and the third such year on record. 2020 also has, by far, the second lowest extent on record.

 

[wdrag]

On 9/13/2020 at 11:38 AM, forkyfork said:

https://birdcast.info/news/a-primer-for-using-weather-surveillance-radar-to-study-bird-migration/

Again, for those that are interested. Nothing circular in that radar presentation... this is classic AP.  A loop of the radar would show a migration if any ... very highly doubt birds. Instead insects, moisture discontinuities with inversions developing and hills intercepted. I did check with a retired NWS specialist. 

[forkyfork]

ap looks like this: 

[forkyfork]

19 minutes ago, wdrag said:

Again, for those that are interested. Nothing circular in that radar presentation... this is classic AP.  A loop of the radar would show a migration if any ... very highly doubt birds. Instead insects, moisture discontinuities with inversions developing and hills intercepted. I did check with a retired NWS specialist. 

a cbw radar loop right now shows southward moving echoes 

[forkyfork]

https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2664.13174

[lee59]

I  could actually look at the sun just before sunset. The smoke made it as if you were looking thru filtered eclipse glasses.

[lee59]

Went down to Jones Beach this evening. Swells very high but really could not get near the ocean. The entire beach had over wash, right up to the boardwalk.

[SACRUS]

9/14:

EWR: 78
ACY: 77
BLM: 77
TEB: 77
LGA: 77
PHL: 76
NYC: 75
New Brnswck: 75
ISP: 75
JFK: 75
TTN: 74

[lee59]

I wonder if the smokey sky will keep night time temps a few degrees higher and put a cap on day temps.

[SRRTA22]

You know its boring when theres a bird migration debate lol 

[doncat]

4 minutes ago, lee59 said:

I wonder if the smokey sky will keep night time temps a few degrees higher and put a cap on day temps.

I know a smokey sky can keep temps down during the day but does it affect outgoing radiation.?

[wdrag]

Just a model idea of how thick the smoke may be overhead tomorrow at 12z and 21z/15.  Also a cross section of how it should remain at least above 5000 feet late tomorrow, tho descending closer to ground level as we go into Wednesday (modeled data not shown). 

[lee59]

41 minutes ago, doncat said:

I know a smokey sky can keep temps down during the day but does it affect outgoing radiation.?

I am thinking it might act like a thin cloud layer

[forkyfork]

2 hours ago, forkyfork said:

a cbw radar loop right now shows southward moving echoes 

 

[dmillz25]

Down to 62 here

[ForestHillWx]

53 currently; might get into the 40s tonight. 

[Rtd208]

Current temp is down to 55 here. Fall weather has arrived.

[dmillz25]

55 here