September 2020 wx discussion

[wdrag]

Good morning this Labor Day 2020,

Yesterday: no showers late afternoon evening s of I84... a few just n of I84 in se NYS and sw CT. No thunder per lighting archive. 

 

The week from Tuesday through Monday the 14th.  Less chance for 2+" rains (near out above normal qpf), per the Rockies cutoff slowing and opening up late,  but not yet a done deal for less.

This coming Wed-Thu, and Sunday and Monday still may see significant qpf production around here.  We seem to be more on the northern edge of decent qpf but some room for modeling error exists. PW rises to near 2" with pairs of days.  Any showers outside those 4 days would appear to be an unexpected bonus. 634A/7

[bluewave]

8 hours ago, forkyfork said:

a continuation of our generally much above normal but no extreme highs pattern 

We had several more 70° minimums since the start of September. So our local sites are still moving up on the list. We could add a few more this week as the higher dew points return.

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	1973	62	0
2	2011	59	0
3	2005	58	0
4	2010	57	0
5	2020	55	116
-	1993	55	0

 

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

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	1906	61	0
2	2005	60	0
3	2020	57	116
4	2015	56	0
5	2018	55	0
-	2010	55	0

 

Time Series Summary for LAGUARDIA AIRPORT, NY - Jan through Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	2018	78	0
2	2005	77	0
3	2016	73	0
4	2020	71	116
-	2012	71	0
5	2015	69	0
-	2010	69	0

 

Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Jan through Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	2016	55	0
2	2015	53	0
3	2010	51	0
4	2018	49	0
5	2020	48	116
-	2012	48	0
-	1983	48	0

 

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Jan through Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	2018	41	0
2	2010	36	0
-	1980	36	0
3	2020	35	116
-	2016	35	0
4	2013	34	0
-	1999	34	0

 

[lee59]

62 here this morning, 3 pleasant early mornings in a row.

[Cfa]

NYC, LI’s south shore, and the jersey shore are one of the warmest spots on the east coast right now north of the Outer Banks.

Low of 61 here, currently 74. 83/59 yesterday.

[donsutherland1]

Morning thoughts...

Today will be mostly sunny and pleasant. Temperatures will likely reach the lower 80s across much of the region. Likely high temperatures around the region include:

New York City (Central Park): 81°
Newark: 83°
Philadelphia: 84°

Somewhat warmer than normal conditions will likely prevail through much of next week.

Today will be the last day of the historic heat in parts of the Southwest. Record cold is likely tomorrow in the Rockies, along with accumulating snow.

 

[dWave]

15 minutes ago, Cfa said:

NYC, LI’s south shore, and the jersey shore are one of the warmest spots on the east coast right now north of the Outer Banks.

Low of 61 here, currently 74. 83/59 yesterday.

I notice its not that uncommon to see that. More in July and August though. You see it at DCA too (but not today).

[rclab]

2 hours ago, bluewave said:

We had several more 70° minimums since the start of September. So our local sites are still moving up on the list. We could add a few more this week as the higher dew points return.

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	1973	62	0
2	2011	59	0
3	2005	58	0
4	2010	57	0
5	2020	55	116
-	1993	55	0

 

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

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	1906	61	0
2	2005	60	0
3	2020	57	116
4	2015	56	0
5	2018	55	0
-	2010	55	0

 

Time Series Summary for LAGUARDIA AIRPORT, NY - Jan through Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	2018	78	0
2	2005	77	0
3	2016	73	0
4	2020	71	116
-	2012	71	0
5	2015	69	0
-	2010	69	0

 

Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Jan through Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	2016	55	0
2	2015	53	0
3	2010	51	0
4	2018	49	0
5	2020	48	116
-	2012	48	0
-	1983	48	0

 

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Jan through Dec
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Number of Days Min Temperature >= 70	Missing Count
1	2018	41	0
2	2010	36	0
-	1980	36	0
3	2020	35	116
-	2016	35	0
4	2013	34	0
-	1999	34	0

 

With apologies to all forum members with real skills in statistics and analysis I decided to take pencil to paper and visit my arithmetic past.  Using the number of occurrence years in the top five I found 81.8% of the  minImum readings occurred post 2000, 72.7% occurred post 2010. Only 18.2% occurred last century. Remembering the sage words of a now famous/infamous professional “the trend is your friend” in this case is it really ( if any one finds a computation error, it’s fine and thank you. I’ll just fall back on my chronological crutch. ........As always ....

[gravitylover]

3 hours ago, wdrag said:

Good morning this Labor Day 2020,

Yesterday: no showers late afternoon evening s of I84... a few just n of I84 in se NYS and sw CT. No thunder per lighting archive. 

 

The week from Tuesday through Monday the 14th.  Less chance for 2+" rains (near out above normal qpf), per the Rockies cutoff slowing and opening up late,  but not yet a done deal for less.

This coming Wed-Thu, and Sunday and Monday still may see significant qpf production around here.  We seem to be more on the northern edge of decent qpf but some room for modeling error exists. PW rises to near 2" with pairs of days.  Any showers outside those 4 days would appear to be an unexpected bonus. 634A/7

I could see significantly denser clouds to my north from those showers. They did spill over somewhat and were pushing quite cooler air as that happened but it was momentary and fleeting. If you're more sensitive to the details in times of more passive weather it can still be plenty active, this was one of those times.

[SACRUS]

76/63 off a low of 55.  Another goreous day out there today.  Warm and humid overall 9/7 - 9/15. Some high clouds bleeding in from storms in W PA but for the most part partly sunny today.  Tue / Wed more S / SSE / SE flow and with that the humidity spikes.  850 MB temps >16c Tue - Fri but onshore flow and increasing storms by Wed PM and Thursday  shoud cap max temps in the upper 80s in the warmer spots with more common mid 80s this week.  

Looks like a 2 day cool down arriving this coming Friday (9/11) - Sat (9/12) before a warmer  more southerly/onshore develops Sunday (9/13) - Tue (9/15).

 

Beyond there 9/16 - 9/21 looks near or below normal before a warmer finish to the month.

[bluewave]

More record breaking 500 mb heights.

[doncat]

78/61 temp split today with the onshore wind.

[dWave]

Large junkyard fire in Hunts Point. South wind is sending smoke and hazy skies miles north at least to Westchester county line, esp on the Yonkers/Mt Vernon side. Teterboro is offically reporting Smoke and 76* 

Smoke/Haze here, 75 with chemical smokey smell in the air

[lee59]

Definitely feel the season gradually changing. Actually a cool feel to the air at 73 degrees. The consistent days of high 80s have been replaced with high 70s to about 80. Night time lows closer to 60 than 70 and my pool temp. has dropped some 10 degrees.

[psv88]

24 minutes ago, lee59 said:

Definitely feel the season gradually changing. Actually a cool feel to the air at 73 degrees. The consistent days of high 80s have been replaced with high 70s to about 80. Night time lows closer to 60 than 70 and my pool temp. has dropped some 10 degrees.

Yea sadly summer is over. Those scattered leaves are starting to drop from the trees. The descent into darkness begins 

[Brian5671]

38 minutes ago, lee59 said:

Definitely feel the season gradually changing. Actually a cool feel to the air at 73 degrees. The consistent days of high 80s have been replaced with high 70s to about 80. Night time lows closer to 60 than 70 and my pool temp. has dropped some 10 degrees.

also after 4pm the lower sun angle is quite evident-temps really start to drop off vs mid summer where it stays hot til 6pm or later

[Dan76]

1 hour ago, dWave said:

Large junkyard fire in Hunts Point. South wind is sending smoke and hazy skies miles north at least to Westchester county line, esp on the Yonkers/Mt Vernon side. Teterboro is offically reporting Smoke and 76* 

Smoke/Haze here, 75 with chemical smokey smell in the air

Could see the smoke from long beach

[MJO812]

[donsutherland1]

Tomorrow will be mostly sunny and somewhat warmer than today. Overall, the first half of September will likely wind up somewhat warmer than normal. The probability of the arrival of an autumn-like air mass near or just after mid-month has increased.

On its final day, the historic September heat wave of 2020 brought high temperatures to the Southwest. Select high temperatures included:

Blythe, CA: 113° (old record: 112°, 1994)
Death Valley, CA: 116°
El Centro, CA: 113° (old record: 112°, 1934, 2008, 2011, 2018 and 2019)
Flagstaff: 88°
Kingman, AZ: 107° (old record: 105°, 1932)
Lake Havasu City, AZ: 117° (old record: 114°, 1977, 1986 and 1994)
Las Vegas: 106°
Needles, CA: 117° (old record: 116°, 1923)
Palm Springs, CA: 109°
Phoenix: 109°
Sacramento: 105° (old record: 103°, 1957)
Tucson: 103°
Yuma, AZ: 108°

An update for the September 1-7 period for Phoenix can be found here:

https://www.americanwx.com/bb/topic/53697-phoenix-records-its-hottest-summer-on-record/?do=findComment&comment=5650331

Following the historic heat, record cold will plunge into the Rockies late Monday and Monday night. As the temperature plunges, Denver could pick up only its fourth measurable snowfall on record prior to September 15. Recordkeeping began in 1872. The prior events were:

September 3, 1961: 4.2"
September 8, 1962: 0.7"
September 13, 1993: 5.4"

In addition, Denver could see its earliest temperature below 30° during the coming cold shot. The current record is September 14, 2003 when the temperature fell to 29°.

The ENSO Region 1+2 anomaly was -1.6°C and the Region 3.4 anomaly was -0.9°C for the week centered around September 2. 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 -0.72°C. La Niña conditions are now developing.

The SOI was +13.31.

Today, the preliminary Arctic Oscillation (AO) figure was +1.079.

On September 6, the MJO was in Phase 3 at an amplitude of 0.721 (RMM). The September 5-adjusted amplitude was 0.821.

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.

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 65% probability that New York City will have a warmer than normal September. September will likely finish with a mean temperature near 69.5°.

 

[SACRUS]

9/7

PHL: 83
TTN: 82
New Brnswck: 82
LGA: 81
TEB: 81
ACY: 80
NYC: 79
JFK: 79
EWR: 79
ISP: 78
BLM: 78

[Will - Rutgers]

3 hours ago, MJO812 said:

full disclosure: i was about to say "i don't see what you're seeing, i see the two TS and a lemon."  before saying something stupid i decided to click around and discovered there's a 5 day NHC forecast graphical.  been following weather my entire life, had literally no idea.  don't think i ever saw it posted here.

alright now that we all agree i'm not mentally competent to stand trial, i have a question.  does the NHC have any kind of follow-up post-season analysis of storm intensity predictions?  probably not?  i ask because it seems like storms have historically over-performed, but i have no data, just a WAG from hanging around here too much.

not looking to impinge the good work of the folks at the NHC, literally just curious.  i recognize the amazing strides in weather prediction made in the last 20 years and i'm glad we have accurate tropical forecasting at all, especially with the added wild card of global warming.

[CIK62]

The next 8 days are averaging 76degs., or 6degs. AN.         Make it +1.

70*(86%RH) here at 6am, m. clear, some clouds.    75*(80%RH) by 9am.          78*(74%RH) by 4pm.

The three systems this morning:    29N 69W,     18N 43W,      16N 25W.     The latter two seem stronger today compared to yesterday.    Only the ICON model has the first one affecting us Sunday. 

 

[bluewave]

Another warmer than average start to September across the area. The first week came in at +2.3 to +4.1.

EWR...+2.7

NYC...+2.3

LGA....+4.1

JFK....+2.5

ISP.....+3.8

BDR...+4.1

[lee59]

Another pleasant morning here with low 60s, however very damp.

[lee59]

14 minutes ago, bluewave said:

Another warmer than average start to September across the area. The first week came in at +2.3 to +4.1.

EWR...+2.7

NYC...+2.3

LGA....+4.1

JFK....+2.5

ISP.....+3.8

BDR...+4.1

Central Park +2.1. Looks like some cooler weather coming in later this week.

[donsutherland1]

Morning thoughts...

Today will be partly sunny and quite warm. Temperatures will likely reach the lower and middle 80s across much of the region. Likely high temperatures around the region include:

New York City (Central Park): 82°
Newark: 84°
Philadelphia: 86°

Somewhat warmer than normal conditions will likely prevail through much of the week. Cooler air could arrive late in the week.

Elsewhere, yesterday saw Casper pick up 2.3" snow. That was that location's earliest measurable snowfall on record. The previous earliest snowfall occurred on September 8, 1962 when 0.3" fell. At Lander, WY, 2.0" snow fell. That surpassed the daily record of 0.3", which was recorded in 1941.

[Ericjcrash]

Meanwhile in Laramie, WY https://visitlaramie.org/laramie-webcam

[donsutherland1]

8 minutes ago, Ericjcrash said:

Meanwhile in Laramie, WY https://visitlaramie.org/laramie-webcam

Some webcams in the Casper area: https://www.wyoroad.info/highway/webcameras/I25Casper/I25Casper.html

 

[FPizz]

Been enjoying this stretch of mornings in the low to mid 50s. 

[SACRUS]

75/55 off a low of 59.  9/8 - 9/16 overall warmer than normal, humid persistent onshore flow.   Warmer today and Wed with  partly to mostly sunny skies with a S / SSW flow keeping temps capped in the mid 80s.  By Thursday  a more SW flow will develop but clouds and storms will cap temps again in the 80s.   Fri and Sat look cooler with a N / NE flow before a  warmer and more humid southerly flow develops by Sunday  - next Wed (9/16).

9/16 - 9/21 : looks closer to normal with an eye on the tropics.  Ridging looks to close the month out in the EC.

[ARyan]

10 hours ago, Will - Rutgers said:

full disclosure: i was about to say "i don't see what you're seeing, i see the two TS and a lemon."  before saying something stupid i decided to click around and discovered there's a 5 day NHC forecast graphical.  been following weather my entire life, had literally no idea.  don't think i ever saw it posted here.

alright now that we all agree i'm not mentally competent to stand trial, i have a question.  does the NHC have any kind of follow-up post-season analysis of storm intensity predictions?  probably not?  i ask because it seems like storms have historically over-performed, but i have no data, just a WAG from hanging around here too much.

not looking to impinge the good work of the folks at the NHC, literally just curious.  i recognize the amazing strides in weather prediction made in the last 20 years and i'm glad we have accurate tropical forecasting at all, especially with the added wild card of global warming.

Yes. Every branch of the NWS does forecast verification. Although, they're usually buried and can be hard to find.

https://www.nhc.noaa.gov/verification/

Also, I didn't know they did those forecasts either.