September 2020 wx discussion

[bluewave]

1 hour ago, gravitylover said:

Run that with 5/27 as the start date. The departure in SE NY should be much more significant.

 

 

 

[Rtd208]

[Brian5671]

4 minutes ago, Rtd208 said:

models starting to agree on  big rain event this week-much needed.

[bluewave]

3 hours ago, Brian5671 said:

models starting to agree on  big rain event this week-much needed.

Hartford is hoping for their first 1”+ rain event since late April.

 

[donsutherland1]

Under partly to mostly cloudy skies, temperatures rose mainly into the middle 70s across the region.

In parts of South America, a historic early spring heatwave toppled monthly records. Some monthly records included:

Asuncion, Paraguay: 108°
Corrientes, Argentina: 109°
Foz Do Iguacu, Brazil: 102°
Pozo Hondo, Paraguay: 114° ***New all-time national high temperature record***

Meanwhile, in parts of Europe, early-season snows blanketed even the lower elevations of the Alps.

Temperatures will likely remain at generally above normal levels for the remainder of September. A cool shot is likely during the opening week of October, but warmer readings could return during the following week.

Phoenix has an implied 95% 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.

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 +16.11.

Today, the preliminary Arctic Oscillation (AO) figure was +0.683.

On September 25, the MJO was in Phase 5 at an amplitude of 1.350 (RMM). The September 24-adjusted amplitude was 1.442.

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 68.6°.

 

[SACRUS]

9/26

PHL: 78
ACY: 77
LGA: 77
ISP: 76
JFK: 76
TEB: 76
TTN: 75
EWR: 75
New Brnswck: 75
NYC: 74
BLM: 73

[CIK62]

The last 4 days of September are averaging 73degs.         Making it 69degs., or +4.

Month to date is  -0.2[68.5].      September should end at 68.6, within +1.0.

69*(93%RH) here at 6am.        75*(80%RH) by 1pm.-clouds back in after hours of some sun.     More sun again and up to  78* by 4pm.

[bluewave]

Very unusual rainfall distribution this month. Portions of Long Island experienced one of their wettest starts to September. This was followed by record dry conditions since then. Heavy rains to end the month will only add to the oddity.

9-10....Pt Lookout....6.47.....Massapequa....5.41...Wantagh Mesonet...4.64....Amityville....4.04....Copaigue....4.05

 

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

Rank	Ending Date	Total Precipitation Sep 11 to Sep 26	Missing Count
1	1910-09-26	0.00	0
-	1908-09-26	0.00	0
-	1884-09-26	0.00	0
2	2020-09-26	T	0
-	1941-09-26	T	0
-	1917-09-26	T	0

 

[donsutherland1]

Morning thoughts...

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

New York City (Central Park): 76°
Newark: 78°
Philadelphia: 79°

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

 

[Brian5671]

1 hour ago, bluewave said:

Very unusual rainfall distribution this month. Portions of Long Island experienced one of their wettest starts to September. This was followed by record dry conditions since then. Heavy rains to end the month will only add to the oddity.

9-10....Pt Lookout....6.47.....Massapequa....5.41...Wantagh Mesonet...4.64....Amityville....4.04....Copaigue....4.05

 

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

Rank	Ending Date	Total Precipitation Sep 11 to Sep 26	Missing Count
1	1910-09-26	0.00	0
-	1908-09-26	0.00	0
-	1884-09-26	0.00	0
2	2020-09-26	T	0
-	1941-09-26	T	0
-	1917-09-26	T	0

 

basically 2 big rainfall events and absolutely nothing in between, not even a .10 shower....very odd

[bluewave]

4 minutes ago, Brian5671 said:

basically 2 big rainfall events and absolutely nothing in between, not even a .10 shower....very odd

Another  example of these abrupt precipitation shifts that many areas are experiencing. Very challenging time to be in the agricultural industry. We can swing from one extreme to another. 

 

[SACRUS]

72/66 and some breaks in the mainly low clouds.  Low of 62 last night.  Pending on sunshine today will be warm with highs near or low 80s.  More of the same on Monday and Tuesday and perhaps the warmest days till next March / April. Front moves in and brings the first measurable rain since 9/11 Tue (9/29) - Thu (9/30) .  Front linger near the areas Tuesday - Thursday.  Wednesday and Thursday look the wettest with wave of low pressure running up the front with >1 inch and possible widespread 1 - 3 inch amounts.

Fri 10/1 - Tue 10/6 : Cooler as trough digs into the Plains, MW and swings through.  Brunt of the strongest cold stays west and overall not as cool as the past period (9/19 - 9/22)  but there will be some chilly air swinging through 10/4 - 10/6 before we moderate and warmup 10/7.  Beyond there need to see if the West Coast ridge rebuilds or flatter flow keeps us near/warmer than normal.  EC ridging is possible with some stronger warmth (against normal) the back half of the month.

9/27 - 9/30 : Warmer to much warmer than normal (+5 to +7).   

9/30 - 10/1 : Rain, first in 3 weeks or since 9/11.  1 - 3 inches 

10/2 - 10/7: Cooler / chilly (-3 to -5) overall coolest 10/4- 10/6 / frost inland

10/7 : warmup (temp or more sustained near/above normal ?)

 

 

[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.