August 2020 General Discussions & Observations Thread

[SACRUS]

69/67 light rain and another cloudy/wet Friday a theme this past month or so.  Cloudy/showers and potential storms today.  Dry things out Saturday and begin a warmup Sunday with some of the hotter spots reaching a 90.  Mon - Wed hot and 90s widespread but storms chances each day and need to watch clouds/cloud debris.  850 temps spiking >18c Tue/Wed so potential for strong heat 95+ if we an stay sunny.   Beginning Thu (8/13) of Fri (8/14)  ridge building over head and WAR position expanding west looks to cause some period of easterly flow before ridge pushes east or hooks with the WAR and more sustained heat returns towards week 3 of August with a potential very hot finish.

 

[bluewave]

It has rained on every Friday going back to July 3rd.

[CIK62]

Seems like we will have little sun between Aug. 13-20 as a front stalls and a low spins around us.       Could lower +T deviation for the month a lot.

Even the 'screw loose' GFS has a 1 week average of 74*, or about 2degs.  BN-------and the GFS runs +5* nowadays.

[bluewave]

2020 may go down as one of the strongest winter-summer +EPO couplets. It will be interesting to see if this means we are switching back to a more +EPO regime like we had before 2013. The +EPO combined with the +NAO to produce a mild and snowless winter. This summer it was the heat ridge axis centered to our north getting undercut by tropical moisture.

 

[Stormlover74]

Decent batch of showers in eastern pa. Let's see if they hold

[donsutherland1]

54 minutes ago, bluewave said:

2020 may go down as one of the strongest winter-summer +EPO couplets. It will be interesting to see if this means we are switching back to a more +EPO regime like we had before 2013. The +EPO combined with the +NAO to produce a mild and snowless winter. This summer it was the heat ridge axis centered to our north getting undercut by tropical moisture.

 

Let’s hope we don’t see it during the coming winter. 

[Tatamy]

36 minutes ago, Stormlover74 said:

Decent batch of showers in eastern pa. Let's see if they hold

Heavy rain with thunder out here.  This batch means business.

[bluewave]

1 hour ago, donsutherland1 said:

Let’s hope we don’t see it during the coming winter. 

Yeah, we have been lucky since 02-03.Two consecutive winters with below normal snowfall have been few and far between. It happened from 06-07 to 07-08. And then from 18-19 to19-20. We’ll find out next winter if we rebound like we did after 07-08. Or we enter an extended slowdown like from 96-97 to 01-02. 

[Nibor]

51 minutes ago, Tatamy said:

Heavy rain with thunder out here.  This batch means business.

Same areas that got hit hard with rainfall from Isaias. 

[Rtd208]

Tornado Warning issued for the Wilmington Del. area.

[ForestHillWx]

Decent rains. Some lighting/thunder now. Power was back 8:00 am this morning. Thank you Jcp&L. 

Hope the rest of you get power back asap. 

[dWave]

Was such a organized batch of steady rain this evening in the forcast? This sure aint chance of showers out here. 

[LongBeachSurfFreak]

That cell in southernmost nj has incredible rotation

[donsutherland1]

Strong thunderstorms moved into parts of the Middle Atlantic region late this afternoon and evening. Two-hour rainfall figures included: Allentown: 0.62"; Reading: 0.82" (4-hour figure: 1.19"); and Wilmington, DE: 0.62".

Showers and thundershowers will continue to move through parts of the region during the first half of tonight. Tomorrow will be variably cloudy with some additional showers and thundershowers. Sunday will be much warmer with temperatures returning to the upper 80s and perhaps even lower 90s in many parts of the region.

The current predominantly warmer than normal pattern will likely persist through much of September, paving the way for a solidly warmer than normal summer and a warm start to fall throughout the region. Occasional short-lived cool shots remain possible.  

The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -0.8°C for the week centered around July 29. 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 -0.25°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions could develop.

The SOI was +22.40.

On August 6, the SOI was +25.73. That was the highest figure since October 14, 2018 when the SOI was +27.20. In all three August cases where the August ENSO Region 1+2 anomaly was -0.75°C or colder, a La Niña winter followed. The most recent such case was August 2010.     

Today, the preliminary Arctic Oscillation (AO) figure was +0.141.

On August 6, the MJO was in Phase 4 at an amplitude of 1.985 (RMM). The August 5-adjusted amplitude was 1.853.

The MJO's passage through Phase 4 at such a high amplitude is uncommon during the first half of August. During the 1981-2019 period only 1983 and 2019 saw the MJO move through Phase 4 with an amplitude of 1.500 or above during the first half of August. August 1983 had the longest such stretch. Both cases saw the second half of August average generally warmer than normal in the Middle Atlantic region. Both cases also featured a warmer than normal September.

A warm start to the second-half of August is supported by the extended range of the 12z EPS.

Last year, the MJO went through a very strong passage through Phase 1 during the closing days of May. About four weeks later, a warmer than normal pattern locked in and predominated through early autumn. This year, the MJO was in Phase 1 for 3 consecutive days with an amplitude of 1.500 or above during the June 1-3 period.

Last year, the SOI fell to -42.04 on June 22 when the MJO was in Phase 6. This year, the SOI plunged below -46.68 on June 5, its lowest level in more than three years. The dramatic plunge in the SOI could be the proverbial spark that kicks off a sequence of events leading to the development of a sustained warmer than normal period. The cases that saw both the MJO and SOI thresholds satisfied generally saw 10-20 days where the temperature reached or exceeded 90° in New York City during the July 1-August 31 period.

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°. Overall, the evolution of ENSO, along with the observed ongoing monthly warming (1.6°/decade in NYC and 1.5°/decade in the Northeast Region during September 1990-2019), favors a warmer than normal September.

Based on sensitivity analysis applied to the latest guidance, there is an implied 68% probability that New York City will have a warmer than normal August. August will likely finish with a mean temperature near 77.2°.

[Stormlover74]

10 minutes ago, LongBeachSurfFreak said:

That cell in southernmost nj has incredible rotation

89 mph gust apparently 

[SACRUS]

8/7

PHL: 84
NYC: 81
JFK: 80
ACY: 80
LGA: 80
TEB: 80
ISP: 80
EWR: 80
New Brnswck: 79
TTN: 78
BLM: 76

[doncat]

78/67 temp split today... 0.43" rain, most of it this evening along with some thunder.

[CIK62]

The next 8 days are averaging 84degs., or 8degs. AN.

73*(87%RH) here at 6am, scattered overcast.       

[Rtd208]

Picked up 0.38" of rain for the day yesterday.

Current temp 72/DP 69/RH 90%

[bluewave]

Sometimes in the past, we could break warm temperature streaks following tropical systems. But our warm minimum run looks to continue right into the next heatwave. Highs getting back above 90° with dew points in the 70s should return by Sunday or Monday.

Number of Consecutive Days Min Temperature >= 70 
for LAGUARDIA AIRPORT, NY
Click column heading to sort ascending, click again to sort descending.

Rank	Run Length	Ending Date
1	36	2020-08-07
2	34	2006-08-10
3	32	1980-08-15
4	29	2018-08-19
5	28	2010-07-30

 

Number of Consecutive Days Min Temperature >= 68 
for FARMINGDALE REPUBLIC AP, NY
Click column heading to sort ascending, click again to sort descending.

Rank	Run Length	Ending Date
1	36	2020-08-07
2	31	2013-07-24
3	22	2010-07-25

 

Number of Consecutive Days Min Temperature >= 65 
for ISLIP-LI MACARTHUR AP, NY
Click column heading to sort ascending, click again to sort descending.

Rank	Run Length	Ending Date
1	42	1988-08-16
2	36	2020-08-07
3	32	2013-07-24
-	32	1980-08-15

 

Number of Consecutive Days Min Temperature >= 67 
for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

Rank	Run Length	Ending Date
1	46	2005-08-24
2	45	1988-08-18
3	42	2020-08-07
4	41	2011-08-11

 

Number of Consecutive Days Min Temperature >= 64 
for WESTCHESTER CO AP, NY
Click column heading to sort ascending, click again to sort descending.

Rank	Run Length	Ending Date
1	36	2020-08-07
2	31	2013-07-24
3	25	2011-08-10
4	24	1961-09-14
5	23	2019-08-07

 

 

[SACRUS]

77/70 low clouds stingy as flow swings around to the N/NW later today.  Clouds should burn off by the afternoon but we've seen this before and they tend to stick (literally) around longer.  Tomorrow - Warming things up the next 4 - 5 days starting Sunday where the warmer spots should get to 90.  Mon - Wed - 850 temps >16c and peaking Tue/Wed near 18c.  >20C temps look go wide/north of the area into NYS and New England  but still low/mid 90s here perhaps a stray upper 90s or two in the usual warmer spots.

By Thu 8/13 the massive ridge is building in the upper Mid west and GL into Canada creating  a weakness into the Northeast.  The W.estern Atlantic Ridge  is near Bermuda and pending on its expansion it looks like a 3 - 5 day trip with onshore flow and pop up storms that could train with clouds.  Perhaps a cooler day melded in with enough of a NNE flow but overall  warm and wet 8/13 - 8/19.  Beyond there in the long range built up heat is on its way east for the  end of the month.  WAR may build and link with Plains ridge.

 

 

[dmillz25]

What are the effects of the standing wave in the IO have on the upcoming winter pattern? 

[bluewave]

It would be great for long range forecasting if this works out.

 

 

[etudiant]

10 minutes ago, bluewave said:

It would be great for long range forecasting if this works out.

 

 

That seems to leave open the step of ensuring the models reflect reality. I'd have been happier if the paper had linked to actual historical data.

[bluewave]

30 minutes ago, etudiant said:

That seems to leave open the step of ensuring the models reflect reality. I'd have been happier if the paper had linked to actual historical data.

They went back six decades in the paper. 

https://phys.org/news/2020-07-north-atlantic-climate-major-scientific.html

Published in Nature, the study analyzed six decades of climate model data and suggests decadal variations in North Atlantic atmospheric pressure patterns (known as the North Atlantic Oscillation) are highly predictable, enabling advanced warning of whether winters in the coming decade are likely to be stormy, warm and wet or calm, cold and dry.

However, the study revealed that this predictable signal is much smaller than it should be in current climate models. Hence 100 times more ensemble members are required to extract it, and additional steps are needed to balance the effects of winds and greenhouse gasses. The team showed that, by taking these deficiencies into account, skillful predictions of extreme European winter decades are possible.

Lead author Dr. Doug Smith, who heads decadal climate prediction research and development at the Met Office Hadley Center, said: "The message from this study is double-edged: climate is much more predictable than we previously thought, but there is a clear need to improve how models simulate regional changes."

Advance warning of severe winter weather is imperative to those who make risk-based decisions over longer timescales.For example, better forecasts can help the Environment Agency plan water management and flood defenses, insurance companies plan for the changing risks, the energy sector to mitigate against potential blackouts and surges, and airports plan for potential disruption.

Improving model simulations will enhance the countries' response, resilience and security against the effects of extreme weather and climate change—influencing future policy decisions to protect people's lives, property and infrastructure.

 

 

[rclab]

4 hours ago, bluewave said:

They went back six decades in the paper. 

https://phys.org/news/2020-07-north-atlantic-climate-major-scientific.html

Published in Nature, the study analyzed six decades of climate model data and suggests decadal variations in North Atlantic atmospheric pressure patterns (known as the North Atlantic Oscillation) are highly predictable, enabling advanced warning of whether winters in the coming decade are likely to be stormy, warm and wet or calm, cold and dry.

However, the study revealed that this predictable signal is much smaller than it should be in current climate models. Hence 100 times more ensemble members are required to extract it, and additional steps are needed to balance the effects of winds and greenhouse gasses. The team showed that, by taking these deficiencies into account, skillful predictions of extreme European winter decades are possible.

Lead author Dr. Doug Smith, who heads decadal climate prediction research and development at the Met Office Hadley Center, said: "The message from this study is double-edged: climate is much more predictable than we previously thought, but there is a clear need to improve how models simulate regional changes."

Advance warning of severe winter weather is imperative to those who make risk-based decisions over longer timescales.For example, better forecasts can help the Environment Agency plan water management and flood defenses, insurance companies plan for the changing risks, the energy sector to mitigate against potential blackouts and surges, and airports plan for potential disruption.

Improving model simulations will enhance the countries' response, resilience and security against the effects of extreme weather and climate change—influencing future policy decisions to protect people's lives, property and infrastructure.

 

 

Thank you for the article and the “explore further” articles. The articles were written for understanding by the literate non technical/professional individual. I qualify beautifully. What troubles me is the word prediction. Will the literate individual take it literally? I guess it depends on who is selling vs track record. Will the prediction be direct or couched. I enjoy Dons sensitivity analysis. Would it take that form?  Can the atmosphere really be simulated for prediction? Thank you again, BW, for the article and for having to read a seniors contrary questions. As always ....

 

[bluewave]

33 minutes ago, rclab said:

Thank you for the article and the “explore further” articles. The articles were written for understanding by the literate non technical/professional individual. I qualify beautifully. What troubles me is the word prediction. Will the literate individual take it literally? I guess in depends on who is selling vs track record. Will the prediction be direct or couched. I enjoy Dons sensitivity analysis. Would it take that form?  Can the atmosphere really be simulated for prediction? Thank you again, BW, for the article and for having to read a seniors contrary questions. As always ....

 

Patterns are understandable and predictable to the extent that our technology is up to the task. Numerical weather prediction was one of the greatest scientific achievements of the 20th century. Maybe more specialized long range regional weather prediction will be one of the biggest scientific breakthroughs of this century. 

[donsutherland1]

The temperature rose into the lower 80s across much of the region today. Tomorrow will be warmer with temperatures returning to the upper 80s in much of the region and perhaps even lower 90s in some parts of the region.

The current predominantly warmer than normal pattern will likely persist through much of September, paving the way for a solidly warmer than normal summer and a warm start to fall throughout the region. Occasional short-lived cool shots remain possible.  

The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -0.8°C for the week centered around July 29. 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 -0.25°C. Neutral-cool conditions will likely into the start of autumn. During the autumn, La Niña conditions could develop.

The SOI was +8.44.

On August 6, the SOI was +25.73. That was the highest figure since October 14, 2018 when the SOI was +27.20. In all three August cases where the August ENSO Region 1+2 anomaly was -0.75°C or colder, a La Niña winter followed. The most recent such case was August 2010.     

Today, the preliminary Arctic Oscillation (AO) figure was +0.165.

On August 7, the MJO was in Phase 4 at an amplitude of 1.966 (RMM). The August 6-adjusted amplitude was 1.988.

The MJO's passage through Phase 4 at such a high amplitude is uncommon during the first half of August. During the 1981-2019 period only 1983 and 2019 saw the MJO move through Phase 4 with an amplitude of 1.500 or above during the first half of August. August 1983 had the longest such stretch. Both cases saw the second half of August average generally warmer than normal in the Middle Atlantic region. Both cases also featured a warmer than normal September.

Last year, the MJO went through a very strong passage through Phase 1 during the closing days of May. About four weeks later, a warmer than normal pattern locked in and predominated through early autumn. This year, the MJO was in Phase 1 for 3 consecutive days with an amplitude of 1.500 or above during the June 1-3 period.

Last year, the SOI fell to -42.04 on June 22 when the MJO was in Phase 6. This year, the SOI plunged below -46.68 on June 5, its lowest level in more than three years. The dramatic plunge in the SOI could be the proverbial spark that kicks off a sequence of events leading to the development of a sustained warmer than normal period. The cases that saw both the MJO and SOI thresholds satisfied generally saw 10-20 days where the temperature reached or exceeded 90° in New York City during the July 1-August 31 period.

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°. Overall, the evolution of ENSO, along with the observed ongoing monthly warming (1.6°/decade in NYC and 1.5°/decade in the Northeast Region during September 1990-2019), favors a warmer than normal September.

Based on sensitivity analysis applied to the latest guidance, there is an implied 69% probability that New York City will have a warmer than normal August. August will likely finish with a mean temperature near 77.2°.

 

[SACRUS]

8/8

New Brnswk: 85
LGA: 85
TEB: 85
PHL: 85
TTN: 84
EWR: 84
NYC: 83
JFK: 83
ACY: 82
BLM: 79
ISP: 79

[CIK62]

The next 8 days are averaging 82degs., or 6degs. AN.

73*(92%RH) here at 6am and 7am., m. clear, but fuzzy.        Just 78*(86*RH) by Noon, with clouds building up to the west.