September 2020 wx discussion

[CIK62]

The next 8 days are averaging 79degs., or 8.5degs. AN.        Make it +3.5.

GFS lost all rains till next weekend.     EURO is the wet one---Wed. thru Sunday.

69*(52%RH) here at 6am., m. clear.

[bluewave]

It would be really odd if LGA didn’t have another 90° day this year. LGA never reached 30 days before without any 90° days in the spring or fall. LGA is currently in 4th place with 34 days reaching 90°. LGA finished JJA with the 2nd highest number of 90° days behind 2010.

 

Monthly Number of Days Max Temperature >= 90 for LAGUARDIA AIRPORT, NY
Click column heading to sort ascending, click again to sort descending.

Year	Apr	May	Jun	Jul	Aug	Sep	Oct	Season
2010	1	2	12	18	11	4	0	48
2018	0	4	4	10	16	4	0	38
2002	2	0	5	14	13	1	0	35
2020	0	0	5	19	10	0	M	34
1991	0	4	9	10	9	2	0	34
2016	0	3	1	15	10	3	0	32
1983	0	0	5	11	8	7	0	31
2005	0	0	7	10	10	3	0	30
1953	0	1	7	10	9	3	0	30

 

Monthly Number of Days Max Temperature >= 90 for LAGUARDIA AIRPORT, NY
Click column heading to sort ascending, click again to sort descending.

Year	Jun	Jul	Aug	Season
2010	12	18	11	41
2020	5	19	10	34

 

[donsutherland1]

Morning thoughts...

Today will be mostly sunny and cooler than yesterday. Temperatures will likely reach the upper 70s and lower 80s across the region. Likely high temperatures around the region include:

New York City (Central Park): 79°
Newark: 81°
Philadelphia: 81°

A deep trough will continue to move into the Northern Plains in coming days. However, the cold will likely remain west of the Appalachians through at least much of next week.

Extreme heat will again scorch the Southwest. Numerous cities will approach or set daily record temperatures with some September records approached or broken. Death Valley could see the temperature top out near or just above its monthly record of 123°.

 

[lee59]

61 degrees this morning, felt good.

[uofmiami]

59.3 in Syosset & 56.5 in Muttontown this morning.

[Ericjcrash]

Got down to 45° up here. 

[forkyfork]

thank you WAR for keeping that awful airmass away 

[Stormlover74]

A "cool" day that will still end up above average

[CIK_62]

On beach in Coney Island.      75*(40%RH) at 3pm, breezy, some cirrus.   77* at 3:30pm.        78* at 4pm.

Sub par crowd but, Aquarium was Covid maxed out by Noon.

[wdrag]

For next week: No change in overall modeling posted from the NAEFS since Sunday the 30th, supported by other forum participants looking at varying guidance. It's looking like normal or above normal QPF for much our our area between Tue and next Monday the 14th. With PWAT near 2" late Tue through next weekend... some places will have  2+" inch totals... conceivably much heavier, but,  overlapping daily or every other day rains are not guaranteed and so no numbers offered above 2" at this time.  

Sunday (tomorrow) not only has a decent shower threat along and north of I80 in the afternoon, there could be low top isolated thunder. 3P/5

 

[doncat]

4 hours ago, Stormlover74 said:

A "cool" day that will still end up above average

Normals for my station for today are 80/62 so just about spot on. Can certainly see some more 70°+ mins coming up by midweek adding to that record number.

[CIK62]

COME BACK WHEN YOU GROW UP STORM------

First mentioned a possible Biggie on Aug. 27 due here,  say Sept. 14.         I guess this baby with a different etiology, will have to do.    LOL      At any rate, it looks like that Mid-West front will kick it away, under setup shown.      Let's see how long this holds up as a threat.

[Maureen]

5 hours ago, forkyfork said:

thank you WAR for keeping that awful airmass away 

Who hurt you?

[donsutherland1]

Tomorrow will see sunshine and readings generally in the lower 80s across the region.

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 after mid-month has increased.

The historic September heat wave of 2020 scorched the Southwest for another day. Select high temperatures included:

Casper: 98° (old record: 95°, 1978) ***Tied September Record***
Cheyenne: 94° (old record: 92°, 1998 and 2019)
Death Valley, CA: 125° (old record: 120°, 1955) ***New September Record***
Denver: 101° (old record: 98°, 2019) ***New September Record***
El Centro, CA: 121° (old record: 114°, 1934 and 1945) ***New September Record***
Flagstaff: 90° (old record: 89°, 1945)
Kingman, AZ: 109° (old record: 104°, 1908) ***New September Record***
Lake Havasu City, AZ: 117° (old record: 115°, 2011)
Las Vegas: 112° (old record: 109°, 1947, 1955 and 1977)
Needles, CA: 119° (old record: 114°, 1891 and 1923)
Palm Springs, CA: 122° (old record: 116°, 1955) ***New September Record***
Phoenix: 115° (old record: 113°, 1945)
Pueblo, CO: 100°
Reno: 100° (old record: 99°, 2017)
Tucson: 108° (old record: 107°, 1945)
Yuma, AZ: 120° (old record: 115°, 1945)

Death Valley reached 125°. That broke the September record of 123°, which was set on September 2, 1996.

El Centro, CA reached 121°. That surpassed both the existing August and September records. The previous latest 120° or above reading on record there occurred on July 28, 1995 when the temperature reached 121°. Since 1925, there have been just 10 days on which the temperature reached 120° or above at El Centro. Seven occurred since 2000 and six occurred since 2010.

Phoenix reached at least 115° for the 14th time this year. The previous annual record for 115° or warmer was 7 days in 1974.

Separately, Miami reached 93°, which tied the daily record set in 1996 and tied in 2017 and 2019. Today was Miami's 49th day where the temperature reached 93° or above. The previous record was 44 days, which was set just last year.

The ENSO Region 1+2 anomaly was -0.6°C and the Region 3.4 anomaly was -0.7°C for the week centered around August 26. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.02°C and the ENSO Region 3.4 anomaly has averaged -0.63°C. Neutral-cool conditions will likely evolve into La Niña conditions during the fall.

The SOI was +8.56.

Today, the preliminary Arctic Oscillation (AO) figure was -0.045.

On September 4, the MJO was in Phase 3 at an amplitude of 1.015 (RMM). The September 3-adjusted amplitude was 1.018.

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.   

Finally,on September 4, Arctic sea ice extent data was not available. On September 2, Arctic sea ice extent was 3.861 million square kilometers (JAXA). Based on the August 31 figure, minimum Arctic sea ice extent will most likely finish somewhere from 3.645 million to 3.695 million square kilometers in September. The highest 25% bound is 3.742 million square kilometers. The lowest 25% bound is 3.581 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.

 

[SACRUS]

9/5

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

[TriPol]

11 hours ago, Stormlover74 said:

A "cool" day that will still end up above average

That's because we're using "average" to calculate the "average" temperature. Climate is anything but "average." 

[CIK62]

The next 8 days are averaging 79degs., or 8.5degs. AN.       Make it +3.5.

Only Sept. 12th. is showing as a 90-Degree Day possibility on two of the last four runs, GFS.

68*(70%RH) here at 6am, m. clear.        70*(65%RH) by 10am.

Too many waves out there for their own good.      The consolidated Cat. 4 of yesterday's 12Z GFS has not reappeared yet.

[bluewave]

Plenty of onshore flow coming up with high pressure to our north and east. So no 90° potential for the foreseeable future. The last time Newark didn’t reach 90° in September was 2011 and 2012 for LGA.
 

 

[lee59]

59 degrees for  a low here this morning.

[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: 83°

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

The historic September heat will continue in the Southwest. Death Valley, which reached 125° yesterday, could approach or even exceed that mark today.

 

[SACRUS]

73/ 59.  Just a great labor day weekend.  Sunshine and low to mid  80s today and Labor day.  We start seeing humidity sneaking up tomorrow as flow goes around more SW.  

9/8 - 9/13 Western Atlantic Ridge keep things warm and humid with a persistent ESE / SE and S flow.  Thu there is more of a SW component and 850s are in the >16c range but there is increasing storms/rain chances, so any shot at 90 looks disrupted by clouds and storms chances  Thu (9/10)  /Fri (9/11)  - Sunday (9/13). 

 

Longer range tropics EC watching 9/12 - 9/16.  Western ridge flexes and wanes and eventually pushes east into the plains . which see  MW trough push into the northeast briefly and extent and length of any cool down is still likely brief before a warmer end to the month with more EC ridging.

[SACRUS]

2 hours ago, bluewave said:

Plenty of onshore flow coming up with high pressure to our north and east. So no 90° potential for the foreseeable future. The last time Newark didn’t reach 90° in September was 2011 and 2012 for LGA.
 

 

id say Thu - Sat would see more of a SW component to flow with 850s >16c but looks like much more abundant clouds and storms chances.  Otherwise like  most of June it looks warm overall with limited 90s.

 

So far near misses for both sites this Sep.

EWR: 89 (1) / 88 (1)
LGA: 89 (1)

[MJO812]

[MJO812]

So NHC highlighted a lemon just off the mid atlantic coast. Icon now has this.

[CIK_62]

On beach.    Similar to yesterday.

76* at 2pm.

[LoboLeader1]

Gorgeous weather up here in the northern Berks, temps in the low 60's.

 

[donsutherland1]

Temperatures rose into the lower 80s across much of the region today. A similar day is in store for tomorrow.

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 after mid-month has increased.

The historic September heat wave of 2020 brought more searing temperatures to the Southwest. The extreme heat will break will break after tomorrow. Select high temperatures included:

Blythe, CA: 118° (old record: 114°, 1955)
Burbank, CA: 114° (old record: 111°, 1955) ***Tied September and all-time record***
Death Valley, CA: 123° (old record: 118°, 1955 and 2006)
Denver: 97° (tied record set in 2013)
El Centro, CA: 118° (old record: 114°, 1934)
Flagstaff: 91° (old record: 87°, 1977)
Kingman, AZ: 110° (old record: 104°, 1930, 1932 and 1955) ***New September record***
Lake Havasu City, AZ: 118° (old record: 113°, 1977, 1986 and 2012) ***Tied September record***
Las Vegas: 114° (old record: 110°, 1955) ***New September record***
Needles, CA: 120° (old record: 114°, 1924) ***Tied September record***
Palm Springs, CA: 120° (old record: 114°, 1923, 1957 and 1986)
Phoenix: 113° (old record: 111°, 1986 and 2013)
Pueblo, CO: 103° (old record: 100°, 1933) ***New September record***
Reno: 95°
Tucson: 107° (old record: 106°, 1952)
Yuma, AZ: 115° (old record: 113°, 1986)

Death Valley recorded its 3rd consecutive day with high temperatures of 120° or above. That ties the September record, which was set during September 1-3, 1950 and tied during September 2-4, 2007. In addition, it ties the record for the most such days in September, which was set in 1950 and 2007.

Palm Springs recorded its second consecutive day with a high temperature of 120° or above for the first time on record in September.

Phoenix recorded its 3rd consecutive day with a high temperature of 113° or above. That is the longest such stretch in September.

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 -0.6°C and the Region 3.4 anomaly was -0.7°C for the week centered around August 26. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -1.02°C and the ENSO Region 3.4 anomaly has averaged -0.63°C. Neutral-cool conditions will likely evolve into La Niña conditions during the fall.

The SOI was +12.18.

Today, the preliminary Arctic Oscillation (AO) figure was +0.514.

On September 5, the MJO was in Phase 4 at an amplitude of 0.819 (RMM). The September 4-adjusted amplitude was 1.015.

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.   

Finally,on September 5, Arctic sea ice extent data was not available. On September 2, Arctic sea ice extent was 3.861 million square kilometers (JAXA). Based on the August 31 figure, minimum Arctic sea ice extent will most likely finish somewhere from 3.645 million to 3.695 million square kilometers in September. The highest 25% bound is 3.742 million square kilometers. The lowest 25% bound is 3.581 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.

 

[SACRUS]

9/6

TTEN: 86
LGA: 85
EWR: 84
New Brnswck: 84
BLM: 84
PHL: 84
ACY: 83
TEB: 83
ISP: 81
NYC: 81
JFK: 80

[forkyfork]

15 hours ago, bluewave said:

Plenty of onshore flow coming up with high pressure to our north and east. So no 90° potential for the foreseeable future. The last time Newark didn’t reach 90° in September was 2011 and 2012 for LGA.
 

 

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

[CIK62]

The next 8 days are averaging 78.5degs., or 8degs. AN.        Make it +3.

69*(79%RH) here at 6am, m. clear.      76* by 1pm.

Just one rain event of note during the next 15 Days, and that is 1" on this Sunday.   This could be the ICON's potential EC spinup.      The GFS has no circulation.  Hurricanes remains at bay?

This AM there are three suspicious spots for TS development:                                  29N 67W      16N 43W       16N 21W.

As for additional 70* minimum days, the GFS has 7, until you subtract that +5 bias, and then there is just 1 more during the next 15 days.