September 2020 wx discussion

[Brian5671]

I noticed the RGEM on TT now goes out to 84 hrs...is that fairly new?

[Cfa]

A little bit of clearing and now it’s in the 80’s, dews in the 70’s, this is perfect.

[bluewave]

3 hours ago, Brian5671 said:

I noticed the RGEM on TT now goes out to 84 hrs...is that fairly new?

Within the last few days. Looks like it’s part of their big upgrade.

https://eccc-msc.github.io/open-data/msc-data/changelog_multisystems_en/#tuesday-january-21-2020

A major project to migrate to a new supercomputing infrastructure employed by the Meteorological Service of Canada was completed on January 21, 2020. This successful migration was the result of a joint, sustained effort over several months by experts at the Canadian Meteorological Centre, Science and Technology Directorate, and Shared Services Canada.

Over the coming years, this important upgrade will permit further technological transfers from Research and Development into Operations, supporting the continuous improvement of the meteorological and environmental forecast services offered to Canadians and to other federal and provincial government agencies, users, and partners.

The official note announcing the migration is available at this lin

[CIK62]

12Z's:

EURO is the wettest through Fri. AM at 3.1".    Ensemble is 2.0".      It also likes the Oct. 06 for another 3".

GFS is 1.3" but its Ensemble is 2.7".

GEM lagging behind at 0.6" and an Ensemble at 2".

[Stormlover74]

4 minutes ago, CIK62 said:

12Z's:

EURO is the wettest through Fri. AM at 3.1".    Ensemble is 2.0".      It also likes the Oct. 06 for another 3".

GFS is 1.3" but its Ensemble is 2.7".

GEM lagging behind at 0.6" and an Ensemble at 2".

And nam is around 1.5" just thru 6z Thursday 

[doncat]

77/66 temp split today with a se wind...17 day rain free streak going.

[Cfa]

83/64 split today. Cleared out for a bit before clouding back over.

[uncle W]

77/67 imby...

[donsutherland1]

Tomorrow will be partly sunny and continued warm. However, Tuesday through Thursday could be a wet period. The potential exists for a coastal storm to develop that could bring 1.00" or more rain to parts of the region. Temperatures will likely remain at generally above normal levels for the remainder of September.

Phoenix reached 102° today. That was Phoenix's 130th 100° day. Only 1989 with 143 such days had more. Phoenix has an implied 99% probability of recording just its 13th September on record with a mean temperature of 90° or above. The most recent such occurrence was 2018 with a mean temperature of 91.8°. Phoenix will very likely record its hottest June-September period on record with a four-month mean temperature of near 95.4°. That would exceed the previous June-August record of 95.1°, which was set in 2013 and tied in 2015. The existing record is 93.9°, which was set in 2011.

A cool shot is likely during the opening week of October, but warmer readings could return during the following week.

October could be wetter than September in and around the New York City area. Since 1950, 10 of the 12 (83%) of the La Niña cases that followed an El Niño winter saw October receive more precipitation than September, including 7 of the 8 (88%) cases since 1980. October 1954 and October 1998 were the exceptions. The largest increase in precipitation occurred in 2005. September 2005 saw just 0.48" precipitation in New York City. October 2005 received 16.73" precipitation.  

The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was -0.8°C for the week centered around September 16. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.93°C and the ENSO Region 3.4 anomaly has averaged -0.68°C. La Niña conditions have developed and will likely prevail through the remainder of autumn.

The SOI was +11.41.

Today, the preliminary Arctic Oscillation (AO) figure was +0.162.

On September 26, the MJO was in Phase 5 at an amplitude of 1.388 (RMM). The September 25-adjusted amplitude was 1.350.

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 85% probability that New York City will have a warmer than normal September. September will likely finish with a mean temperature near 68.7°.

 

[SACRUS]

9/27

PHL: 81
EWR: 80
New Brnswck: 80
ACY: 79
NYC: 79
TTN: 79
JFK: 79
TEB: 79
LGA: 78
ISP: 78
BLM: 76

[Rjay]

It's legit raining with not much on radar

[LongBeachSurfFreak]

5 hours ago, Rjay said:

It's legit raining with not much on radar

I noticed that driving last night. Basically heavy drizzle. I’ll take it. Anything that adds moisture to the upper soil level is a good thing until we get some real rain this week. 

[CIK62]

The last 3 days of September are averaging 73degs.        Making it 70degs., or 5.5degs. AN.

Month to date is  +0.1[68.7].      September should end at 68.8, within +1.0.

70*(97%RH) here at 6am.      69* at 6:30am-scattered clouds-Red Sky in Morning-Sailor Take Warning=did not work.       74* by 5pm.

My call on September was Near Normal, +bias.      This seems to have been the case.   

My call for October is for an even closer call of Near Normal +bias.         Week 1 BN,    Week 2  BN,      Week 3  AN,    Week 4  AN but going down.

[NJwx85]

Disgustingly humid out.

[donsutherland1]

Morning thoughts...

Today will be mainly cloudy with perhaps a few widely scattered showers. Temperatures will likely reach the middle and upper 70s across the region. Likely high temperatures around the region include:

New York City (Central Park): 77°
Newark: 80°
Philadelphia: 80°

The temperature will likely remain above normal through the remainder of the month. Cooler air will arrive to start October.

 

[SACRUS]

72/67 cloudy and muggy.  Should hopefully get into the sun for a period this afternoon and pish temps into the 80s and perhaps the warmest day till next year is upon us.  Tue - Thu front slowly comes through with wave of low pressure bringing some heavy rains (>1 inch liekly and more like 1 - 3 inches widespread)  Wed into Thursday.  The front finally clears THursday.  Cooler air will arrive Oct 2 and last through the first week.  Another strong trough and ULL looks to swing through early next week Oct 6th one a stronger push of cool.

 

Beyond there 10/7 warmup looks to push into the east for a period.  West coast ridge weakens and heights come up in the east.

9/28 - 9/29: Warmer +6 to +8

9/30 - 10/1 : Rain 1 - 3 inches

10/2 - 10/6 : Cool comes generally -4 to -6, coldest looks 10/4 - 10/6 perhaps left older cold 10/7

10/7 - beynond : warmup looking possible.
 

[SACRUS]

Not sure if this will have that wacky cahe issue (showing 24 hours prior), but clearing by noon 

 

[winterwx21]

1 hour ago, SACRUS said:

72/67 cloudy and muggy.  Should hopefully get into the sun for a period this afternoon and pish temps into the 80s and perhaps the warmest day till next year is upon us.  Tue - Thu front slowly comes through with wave of low pressure bringing some heavy rains (>1 inch liekly and more like 1 - 3 inches widespread)  Wed into Thursday.  The front finally clears THursday.  Cooler air will arrive Oct 2 and last through the first week.  Another strong trough and ULL looks to swing through early next week Oct 6th one a stronger push of cool.

 

Beyond there 10/7 warmup looks to push into the east for a period.  West coast ridge weakens and heights come up in the east.

9/28 - 9/29: Warmer +6 to +8

9/30 - 10/1 : Rain 1 - 3 inches

10/2 - 10/6 : Cool comes generally -4 to -6, coldest looks 10/4 - 10/6 perhaps left older cold 10/7

10/7 - beynond : warmup looking possible.
 

I keeping seeing some saying rain into thursday but NAM has rain over by midday wednesday and then sun coming out wednesday afternoon. This is looking more like a tuesday night into wednesday morning rain event.

[bluewave]

 

 

[donsutherland1]

40 minutes ago, bluewave said:

 

 

In part, the news article states:

The changes are part of wider moves across Europe to make public sector data free and open, to encourage innovation and to support a thriving, data-based digital economy.

Charts will cover the whole world, all types of weather situations including extreme events, and, very importantly, will also include probability-based information, providing guidance on forecast confidence.

This approach is consistent with the openness that is an inherent part of science. The real value added is not from who has access to the data itself, but with what one does with the data. Limited access to the data creates barriers to innovation. The ECMWF recognizes where the source of value existing in explaining that its providing open access to its data is to encourage innovation. 

This is a positive development that will benefit the overall forecasting field.

Rich opportunity to use the data to create customized and targeted solutions, maps, etc., will enhance forecasts and also afford the private sector forecasting community the ability to build and sustain revenue streams.

[SACRUS]

Up to 81 now and much sunnier.  Sneak warm today if we can stay clear mid 80s

[KEITH L.I]

24 minutes ago, SACRUS said:

Up to 81 now and much sunnier.  Sneak warm today if we can stay clear mid 80s

Could be our last 80?

[donsutherland1]

3 hours ago, bluewave said:

 

 

One additional note:

Even as the ECMWF is increasing public access to its data, it appears that the opposite trend is in its early stages in the U.S. One example:

https://psl.noaa.gov/forecasts/reforecast2/teleconn/index.html

If one goes to the referenced Amazon site, one finds grib files only through 2019. Maintenance of webpages with simple graphs or tables isn’t costly. 

[lee59]

76 degrees the high here today.

[doncat]

79/68 temp split today.

[uncle W]

80/68 max/min imby...last year had a warmer ending to September and beginning of October...

[uncle W]

3 hours ago, KEITH L.I said:

Could be our last 80?

I wouldn't bet on it...

[Cfa]

76/67 split here today. Couldn’t stay clear long enough to make a run at 80, unlike yesterday which hit 83.

0.05” fell last evening, 0.01” fell overnight.

[donsutherland1]

Clouds broke for sunshine this afternoon. In response, the temperature rose into the upper 70s and lower 80s. A frontal boundary will approach the region later tomorrow and a storm will develop along the front and move northward. Late Tuesday into Wednesday, the region will likely see a general 0.50"-1.50" of rain with some locally higher amounts. Temperatures will likely remain at generally above normal levels for the remainder of September.

Phoenix has an implied near 100% probability of recording just its 13th September on record with a mean temperature of 90° or above. The most recent such occurrence was 2018 with a mean temperature of 91.8°. Phoenix will very likely record its hottest June-September period on record with a four-month mean temperature of near 95.4°. That would exceed the previous June-August record of 95.1°, which was set in 2013 and tied in 2015. The existing record is 93.9°, which was set in 2011.

A cool shot is likely during the opening week of October, but warmer readings could return during the following week. The latest EPS weeklies favor the development of a sustained warmer than normal pattern for the second half of October.  

October could be wetter than September in and around the New York City area. Since 1950, 10 of the 12 (83%) of the La Niña cases that followed an El Niño winter saw October receive more precipitation than September, including 7 of the 8 (88%) cases since 1980. October 1954 and October 1998 were the exceptions. The largest increase in precipitation occurred in 2005. September 2005 saw just 0.48" precipitation in New York City. October 2005 received 16.73" precipitation.  

The ENSO Region 1+2 anomaly was -0.8°C and the Region 3.4 anomaly was -1.0°C for the week centered around September 23. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.92°C and the ENSO Region 3.4 anomaly has averaged -0.87°C. La Niña conditions will likely prevail into at least the start of winter.

The SOI was +8.62.

Today, the preliminary Arctic Oscillation (AO) figure was +0.139.

On September 27 the MJO was in Phase 5 at an amplitude of 1.275 (RMM). The September 26-adjusted amplitude was 1.392.

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 98% probability that New York City will have a warmer than normal September. September will likely finish with a mean temperature near 68.7°.

 

[SACRUS]

9/28

New Brnswck: 82
PHL: 82
EWR: 81
TTN: 81
LGA: 79
TEB: 79
ACY: 78
BLM: 77
JFK: 77
NYC: 77
ISP: 75