September 2019 General Discussions & Observations Thread

[Rtd208]

It has been pretty dry and uneventful here the last 30 days or so. Eventually the pendulum is going to swing the other way and when it does it will hopefully take us through the rest of the fall and winter months.

[Gravity Wave]

I'm not seeing 90s on the 12z GFS, at least for the metro and points N&W. Saturday, Wednesday and Thursday look like the peak heat days, but even then it's mid 80s, not 90s. Legacy GFS and CMC are the same except they cut the heat off 1 day earlier. Am I missing something?

[doncat]

Remember the time of year it is, so even a temp in the upper 80's, would be the equivalent  of a 100° reading in July, departure wise. Temps  over 90° would be impressive indeed.

[IrishRob17]

1 hour ago, doncat said:

Remember the time of year it is, so even a temp in the upper 80's, would be the equivalent  of a 100° reading in July, departure wise. Temps  over 90° would be impressive indeed.

Spot on, I’ve been thinking the same thing.  I think sometimes people see all the red on the models and think it’s going to be 100 degrees and then you have people that go the other way and say it’s only 85, it’s not that hot out. Relative to normal it certainly is. 

[Stormlover74]

39 minutes ago, IrishRob17 said:

Spot on, I’ve been thinking the same thing.  I think sometimes people see all the red on the models and think it’s going to be 100 degrees and then you have people that go the other way and say it’s only 85, it’s not that hot out. Relative to normal it certainly is. 

Upton has been playing catchup though. No forecast was close to low 90s yesterday until late sunday even though models were indicating it

[CIK62]

The EURO is still beating the GFS on the NYC highs in early Oct.     It has switched the 94*  back to Oct. 02.     That is 3 straight runs with a 94* showing.     Will the EURO be the next model to put on its underwear backwards?    Which model can we rely upon anyway?    Lol

[SI Mailman]

3 hours ago, doncat said:

Remember the time of year it is, so even a temp in the upper 80's, would be the equivalent  of a 100° reading in July, departure wise. Temps  over 90° would be impressive indeed.

Exactly.  The average high today is 73.  Models are showing +15 to +20 temperature departures.  

[BombsAway1288]

1 hour ago, bluewave said:

The top 5 warmest October maximum temperatures at Newark are in the 89 to 93 range. The warmest monthly minimums are 68 to 73. Top for average monthly temperature is 62.2 to 63.8.

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Oct
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Highest Max Temperature	Missing Count
1	1941	93	0
2	1949	92	0
3	1959	91	0
4	1939	90	0
-	1938	90	0
5	2013	89	0
-	2007	89	0
-	1954	89	0

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Oct
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Highest Min Temperature	Missing Count
1	2017	73	0
2	1959	71	0
3	2018	70	0
-	2005	70	0
-	1990	70	0
-	1986	70	0
-	1954	70	0
4	2014	69	0
-	1941	69	0
5	2007	68	0
-	1969	68	0

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Oct
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Mean Avg Temperature	Missing Count
1	2017	63.8	0
2	2007	63.5	0
3	1971	63.1	0
4	1990	62.4	0
5	1984	62.2	0

 

 

Do you have the link for whatever site it is that you can look up and create this information?

[donsutherland1]

Following yesterday's unseasonably warm temperatures, cooler air returned to southern New England and the Mid-Atlantic region. However, warmer readings are likely later this week. The potential for much above normal warmth to start October exists.

Courtesy of low sea ice, abnormal warmth continued to prevail in northern Alaska. There is an implied 98% probability that Utqiagvik (formerly Barrow) will record its warmest September on record. It is possible that Utqiagvik could register its first 40° mean temperature for September. A 40.0° mean temperature would rank 30th out of 99 years for the warmest August on record). The existing monthly record of 37.7° has stood since 1998.

The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.2°C for the week centered around September 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.77°C and the ENSO Region 3.4 anomaly has averaged -0.16°C. The recent strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have continued to increase. Such a scenario is now more likely than not.

Since 1991 when weekly ENSO region data was available, five years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2007, 2010, and 2017. 4/5 (80%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. Those cases include La Niña winters. However, the larger pool of neutral-cool ENSO winters, many of which predate the weekly ENSO regional data, have often featured frequent Atlantic blocking. For now, there is a mixed winter signal.

The SOI was -2.43 today.

On September 19, the SOI fell to -35.30. Often an SOI figure at or below -30.00 during the second half of September has been followed by a warmer than normal October. 2002, which saw severe October blocking during which the Arctic Oscillation fell to as low as -5.098 on October 18, was an exception.

Today, the preliminary Arctic Oscillation (AO) figure was +1.475. That's the highest figure since April 23 when the AO was +1.503.

Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall.

Among those five cases, 2015 made a transition from predominantly negative AO values to predominantly positive ones during the fall. The combination of the AO's recent increase to the strongest positive values since April and some of the extended range guidance leave open a scenario where the AO is currently in the early stages of evolving to a predominantly positive regime. Such an outcome would also favor a warmer than normal fall and possible warm start to winter in the Middle Atlantic and southern New England regions. This is merely a hypothetical discussion of one potential path toward winter. Many other variables are involved.

Therefore, a warmer than normal September and fall appear likely. The potential for autumn 2019 to rank among the 30 warmest cases on record remains on the table. For New York City, that would translate into a September-November mean temperature of 58.8°.

On September 23, the MJO was in Phase 1 at an amplitude of 2.288 (RMM). The September 22-adjusted amplitude was 1.727.

Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 95% and the probability of a monthly mean temperature of 70.0° or above is 56%. Should September 2019 have a mean temperature of 70.0° or above, 2019 would be the 5th consecutive year with such September warmth. Prior to the current stretch, the record was 2 consecutive years (1930 and 1931; 1970 and 1971; 1979 and 1980; and, 2010 and 2011).

[CIK62]

The last 6 days of September are averaging 70degs., or about 6degs. AN.

Month to date is  +1.9[70.4].

September should end near  +2.3[70.3].

Maybe the GFS has been over corrected by the programmers  to the low side because it is 20 degrees below the EURO now for the 2nd. and 3rd. on average.     Also it has a problem reaching 60degs. starting Oct. 05.

(92 versus 79) and (92 versus 66).    A problem with placement of the players.

62.6* here at 6am.  65.3* by 9am.   65.8* at 10am.   75.5* by 3pm.

[SnoSki14]

Just now, bluewave said:

All the models backed off the degree of warmth that they were showing for Saturday. Disagreement between the models for next Tuesday and Wednesday. Euro warmer with slower frontal passage. GFS and CMC cooler with faster frontal passage.

Pretty dramatic cool down on some of the models by next Thu/Fri, certainly possible given it'll be October.

[NYCweatherNOW]

I just don’t see 90’s happening in New York City 

[SnoSki14]

1 hour ago, NYCweatherNOW said:

I just don’t see 90’s happening in New York City 

Next Wednesday before the front has the best chance. Current forecast is mid to upper 80s. 

If -NAO is stronger then low to mid 80s more likely.

Several warm impulses before that though with Thursday, Sat-Sun, and next Tuesday possibly seeing mid 80s or better.

I'm leaning higher given how dry its been. Local spots could easily hit 90 on 1 or more of those days. 

[Brian5671]

Nice to see the -NAO coming back-perhaps a good sign for some winter blocking

[IrishRob17]

16 hours ago, Stormlover74 said:

Upton has been playing catchup though. No forecast was close to low 90s yesterday until late sunday even though models were indicating it

I agree but my comment wasn't in reference to Upton.  That said, I'll use Upton's current forecast here in my example, they are currently forecasting 81 for the high here Saturday and average is 69.  Lets say it only hits that 81, there will be plenty of people who won't consider it hot, just a nice warm late September day.  If you take that +12 and apply it to 7/28's average here and the high would be 96, everyone would say that's hot.  When looking at the numbers though, both are +12.   

[Eduardo]

15 hours ago, donsutherland1 said:

Should September 2019 have a mean temperature of 70.0° or above, 2019 would be the 5th consecutive year with such September warmth. Prior to the current stretch, the record was 2 consecutive years (1930 and 1931; 1970 and 1971; 1979 and 1980; and, 2010 and 2011).

That’s an astonishing stat!  Amazing how much September has felt like a summer month since 2010.

[purduewx80]

4 hours ago, Brian5671 said:

Nice to see the -NAO coming back-perhaps a good sign for some winter blocking

Not much correlation between a -NAO during the warmer months extending into winter. We'd want to see that blocking continue to show up in October and especially November to have some hope.

[purduewx80]

6 hours ago, NYCweatherNOW said:

I just don’t see 90’s happening in New York City 

maybe if you say it a few more times, you'll wishcast an 89 at EWR, LGA, NYC....

[bluewave]

September 2019 is a continuation of the 2010’s endless summer pattern. 9 out of 10 years featuring above normal temperatures.

SEP....EWR...NYC...LGA

2019...+1.5...+1.3...+2.0.....so far

2018...+3.2...+2.7....+3.7

2017...+2.7...+2.5....+2.4

2016...+3.6...,+3.8...+4.7

2015...+5.2....+6.5...+5.0

2014..+1.6....+1.7....+1.3

2013...-1.0....-0.1.....-1.0

2012...+1.3...+0.8....+3.4

2011....+3.0..+2.0....+1.6

2010...+3.4....+3.1...+3.4

[NJwx85]

A negative NAO developing into early October would certainly increase the chances of some tropical activity making it up this way.

[NYCweatherNOW]

14 minutes ago, NJwx85 said:

A negative NAO developing into early October would certainly increase the chances of some tropical activity making it up this way.

Did you see the latest GFS end of runs, it gets cold and everything gets blocked. It shows snow and cold for high country in New England. Heat might have to go early this year in my house if it cools down to low 40’s like the gfs shows by October 7-10 timeframe 

[MJO812]

The negative nao is going to be interesting  to see how it will influence the weather pattern come October. 

[donsutherland1]

A generally warmer than normal pattern will likely prevail into the start of October with some fluctuations. There is potential for much above normal warmth to start October. However, cooler than normal readings will likely move into the region during the latter part of the first week of October.

The PNA is forecast to plunge in coming days. Typically, a strongly negative PNA (-1.50 or below) during the October 1-3 period has translated into readings averaging 2°-4° above normal in the Middle Atlantic and southern New England regions. The warmth has been even more pronounced when the strongly negative PNA has coincided with a negative SOI.

Courtesy of low sea ice, abnormal warmth continued to prevail in northern Alaska. There is a >99% implied probability that Utqiagvik (formerly Barrow) will record its warmest September on record. It is possible that Utqiagvik could register its first 40° mean temperature for September. A 40.0° mean temperature would rank 30th out of 99 years for the warmest August on record). The existing monthly record of 37.7° has stood since 1998.

The ENSO Region 1+2 anomaly was -1.3°C and the Region 3.4 anomaly was -0.2°C for the week centered around September 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.77°C and the ENSO Region 3.4 anomaly has averaged -0.16°C. The recent strong cooling in Region 1+2 indicates that the prospects for a neutral-cool ENSO during the winter have continued to increase. Such a scenario is now more likely than not.

Since 1991 when weekly ENSO region data was available, five years have seen September record 2 or more weeks with -1.0°C or cooler weekly anomalies in Region 1+2: 1996, 1999, 2007, 2010, and 2017. 4/5 (80%) of those cases went on to feature warm December-February temperature anomalies in the Middle Atlantic and southern New England regions. Those cases include La Niña winters. However, the larger pool of neutral-cool ENSO winters, many of which predate the weekly ENSO regional data, have often featured frequent Atlantic blocking. For now, there is a mixed winter signal.

The SOI was +6.00 today.

On September 19, the SOI fell to -35.30. Often an SOI figure at or below -30.00 during the second half of September has been followed by a warmer than normal October.

Today, the preliminary Arctic Oscillation (AO) figure was +1.869. That is the highest AO value since March 31 when the AO was +2.329.

Since 1950, there have been five prior cases when the AO averaged -0.500 or below in both July and August: 1950, 1958, 1960, 1968, and 2015. The average temperature for September was 69.1° (69.8° after adjusting for ongoing warming) and 58.9° (59.6° adjusted) for September through November in New York City. The 1981-2010 baseline normal figures are 68.0° and 57.5° respectively. The majority of cases saw a warmer than normal September and all cases featured a warmer than normal fall.

Among those five cases, 2015 made a transition from predominantly negative AO values to predominantly positive ones during the fall. The combination of the AO's recent increase to the strongest positive values since April and some of the extended range guidance leave open a scenario where the AO is currently in the early stages of evolving to a predominantly positive regime. Such an outcome would also favor a warmer than normal fall and possible warm start to winter in the Middle Atlantic and southern New England regions. Many additional variables are involved.

A warmer than normal September is very likely. A warmer than normal fall is likely. The potential for autumn 2019 to rank among the 30 warmest cases on record has increased in recent weeks. For New York City, that would translate into a September-November mean temperature of at least 58.8°.

On September 24, the MJO was in Phase 1 at an amplitude of 2.541 (RMM). The September 23-adjusted amplitude was 2.291.

Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is approximately 98% and the probability of a monthly mean temperature of 70.0° or above is 56%. Should September 2019 have a mean temperature of 70.0° or above, 2019 would be the 5th consecutive year with such September warmth. Prior to the current stretch, the record was 2 consecutive years (1930 and 1931; 1970 and 1971; 1979 and 1980; and, 2010 and 2011).

[CIK62]

The last 5 days of September are averaging 70degs., or about 7degs. AN.

Month to date is  +1.5[70.4].       September should end near  +2.4[70.4].

EURO is back to the 90's, at 93, 94 versus 90, 86 on the GFS for the 2nd, 3rd.

64.5* here at 6am.     68.5* by 9am.

A decent 150m drop in the THK near the 3rd forward.     OP is probably too much on the height decreases.

[Brian5671]

Euro has mid to upper 90's next Wed and Thurs from NYC South and west.   Philly has 97-98.  Would be incredible if it verifies

[SnoSki14]

14 minutes ago, Brian5671 said:

Euro has mid to upper 90's next Wed and Thurs from NYC South and west.   Philly has 97-98.  Would be incredible if it verifies

Yeah wow that's like 110-112+ for summer. 

We'll have to see if days like today and this weekend overperform by more than a degree. If they do then I'd lean towards those higher readings. 

Huge help from the flash drought.

[bluewave]

Rapid expansion of the flash drought across our region on the latest update.

https://droughtmonitor.unl.edu

[binbisso]

Upton lowered my forecast highs for both today and Saturday to 78 and 80 respectively. There have been post on here saying that temperatures for these two days are going to be well into the 80s so what is Upton missing to be 5 + degrees lower then what the posters are saying.. I'm at 63 degrees at 8:45 a.m. it's going to be very hard to get well into the eighties today with the front progged to pass by mid to late afternoon

[binbisso]

1 hour ago, bluewave said:

Looks like the record breaking PNA drop for late September will have a greater influence for us than the -NAO. If this were the winter, then there would be very little we could do with such an unfavorable Pacific.

 

 

Blue Wave isn't a negative PNA and negative Nao good for our area during winter in regards to snowstorms.  the wavelengths would be different in djf if im not mistaken.

[winterwarlock]

2 hours ago, SnoSki14 said:

Yeah wow that's like 110-112+ for summer. 

We'll have to see if days like today and this weekend overperform by more than a degree. If they do then I'd lean towards those higher readings. 

Huge help from the flash drought.

Didnt i warn you