September 2019 General Discussions & Observations Thread

[Rjay]

Ok. Back to the weather

[IrishRob17]

On 9/25/2019 at 10:11 AM, IrishRob17 said:

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.   

It turned out to be a decent call by Upton, high of 79 here today looks to do it. A decent temp drop this week from Wed to Thu, the 12z GFS has a 20 degree drop in high temps while the 12z Euro has a 28 degree drop for highs from Wed to Thu IMBY. 

[bluewave]

The update looks great. The record high for Newark today is 87. Looks like they made it to 86.

MAXIMUM         86    259 PM  87    2014  72     14      

[donsutherland1]

Under bright sunshine and temperatures in the lower 80s, the Monarch migration was well underway. Some photos from the New York Botanical Garden:

[donsutherland1]

Tomorrow will complete a warmer than normal weekend in the region. Following a brief push of cooler air for Monday, there is potential for much above normal warmth to start October. The heat will likely peak on October 2 with readings in the middle and upper 80s into southern New England. Locations, including Washington, Baltimore, Philadelphia, Newark, and possibly even New York City could reach 90°.

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.

Afterward, a period of cooler than normal readings will move into the region during the latter part of the first week of October. This pattern could last 7-10 days.

Events during September, including the SOI's falling to -35.30 on September 19 and the possible ongoing evolution toward a generally positive AO regime, favor a warmer than normal October based on past outcomes. However, recent guidance has increased uncertainty regarded to the AO's longer-term evolution. That situation bears watching, but the base case remains a warmer than normal October.

Courtesy of low sea ice, there is a near 100% implied probability that Utqiagvik (formerly Barrow) will record its warmest September on record. It is very likely that Utqiagvik will register its first 40.0° mean temperature for September with an average temperature near 40.5°. A 40.5° mean temperature would rank 28th 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 -1.66 today.

Today, the preliminary Arctic Oscillation (AO) figure was -0.291.

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.

A warmer than normal September is now all but certain. A warmer than normal fall remains 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 27, the MJO was in Phase 1 at an amplitude of 2.483 (RMM). The September 26-adjusted amplitude was 2.727.

During the September 20-30 period, 2019 has seen five consecutive days where the MJO was in Phase 1 with an amplitude of 2.000 or above. Only 1977 (6 days) and 1999 (3 days) had three or more such days. The average temperature decline from the September 16-30 average in New York City was 8.8° (1977 had the largest at 9.4°). That would imply an October mean temperature near 60°, which reinforces the other data suggesting a warmer than normal October in the Middle Atlantic region.

Based on sensitivity analysis applied to the latest guidance, the implied probability of New York City having a warmer than normal September is near 100% and the probability of a monthly mean temperature of 70.0° or above is 63%. 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).

[NYCweatherNOW]

It’s gotten a bit sticky tonight maybe a bit of rain. Looking at the radar looks kinda bleak. The precip looks more concentrated to our south. Hope it does rain we need it. Currently 74 degrees with 81% humidity.

[SnoSki14]

6 hours ago, Stormlover74 said:

Of course by then our average highs are down to the upper 60s so unless we see highs in the 50s it really won't be significantly below average 

We'll be going from extended 80s to even 90s this coming Wednesday to low 60s next weekend and 40s for lows, pretty big change imo. 

And we'll feel it too. 

[Dan76]

3 hours ago, donsutherland1 said:

Under bright sunshine and temperatures in the lower 80s, the Monarch migration was well underway. Some photos from the New York Botanical Garden:

I have noticed them whithen last two weeks .

[SACRUS]

9/28:

Clouds in the way today

 

TEB: 88
New Bnswk: 86
EWR: 86
TTN: 84
PHL: 84
NYC: 82
ACY: 82
LGA: 81
BLM: 80
JFK: 77
ISP: 76

[SACRUS]

18 minutes ago, NYCweatherNOW said:

No 90’s for New York City but a miracle could happen. It has been heating up a bit more than models have projected.

Wed is the day if the park can make it.  Thu looks cloudy.   Then next shot in April 

[CIK62]

The last 2 days of September are averaging 69degs. or 6degs. AN.

Month to date is  +2.1[70.5].       September should end near   +2.4[70.4].

First 3 days of Oct.:

EURO.  80, 92, 79.     GFS  78, 90, 84        Deviations AN vary from +5 to +20 at locations relatively near each other, so who knows what the ultimate highs will be---like any other day.

72.5* here at 6am.      74.0* by 11am.      80.0*  by around 3:30pm.

[bluewave]

The expansion of the flash drought continues in the East. A top 3 driest September for several local stations to date. After record rainfall since February 2018, you knew that we would eventually flip to dry for a period if time.

Time Series Summary for LA GUARDIA AP, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Total Precipitation	Missing Count
1	2005	0.39	0
2	1941	0.62	0
3	2019	0.64	2
4	1951	1.01	0
5	1980	1.16	0

 

Time Series Summary for JFK INTL AP, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Total Precipitation	Missing Count
1	1959	0.87	0
2	1965	0.96	0
3	2019	1.10	2
4	2007	1.11	0
5	1982	1.15	0

 

Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Total Precipitation	Missing Count
1	2019	0.61	2
2	1985	0.81	0
3	1986	0.82	0
4	1965	1.01	0
5	1982	1.12	0

 

Time Series Summary for WESTCHESTER COUNTY AP, NY - Month of Sep
Click column heading to sort ascending, click again to sort descending.

Rank	Year	Total Precipitation	Missing Count
1	2009	0.60	0
2	2019	0.71	2
3	2014	0.75	2
4	1948	1.13	0
5	1986	1.15	0

 

[the_other_guy]

Warm and humid out in Wading River this morning. 70F

[JustinRP37]

3 hours ago, jfklganyc said:

Warm and humid out in Wading River this morning. 70F

I gotta ask, that is the jetBlue retrojet as your avatar right?

[bluewave]

One of the warmest and driest Septembers across the US with a tiny area recording their greatest September snowstorm.

 

[forkyfork]

considering the nam usually runs too cool in these situations we're probably a lock for 90 wednesday

[donsutherland1]

5 minutes ago, bluewave said:

One of the warmest and driest Septembers across the US with a tiny area recording their greatest September snowstorm.

 

 

Interestingly enough, 1941 (historic October heat in NYC) and 1954 (record high temperatures on October 12-13 NYC) showed up in the list of late September daily snowfall records. That provides possible insight into at least the near-term pattern and adds confidence to the idea of the very temperatures likely to start the month.

[LongBeachSurfFreak]

The drought continues to intensify with another precip fail yesterday. We need a full scale pattern change or things could start to get serious. 

If your starting to see color change on trees it’s likely due to drought stress 

[bluewave]

8 minutes ago, donsutherland1 said:

Interestingly enough, 1941 (historic October heat in NYC) and 1954 (record high temperatures on October 12-13 NYC) showed up in the list of late September daily snowfall records. That provides possible insight into at least the near-term pattern and adds confidence to the idea of the very temperatures likely to start the month.

I can’t remember the last time we saw a nearly 4 SD PNA drop at the end of September.

 

[forkyfork]

28 minutes ago, bluewave said:

Even Long Island could reach 90 with more of a westerly flow.  Just remarkable for the first week of October.

 

all time oct highs:

ewr 93, nyc 94, lga 93, isp 88, bdr 89, and jfk 90

[sferic]

2 hours ago, bluewave said:

I can’t remember the last time we saw a nearly 4 SD PNA drop at the end of September.

 

Excuse my ignorance, but is this for cold weather lovers?

[bluewave]

44 minutes ago, sferic said:

Excuse my ignorance, but is this for cold weather lovers?

Only if you are a cold and snowy weather lover living around Montana. 

 

[ForestHillWx]

That will lay down some pretty significant snow pack in Canada and Russia/Siberia. Time will tell if it will trickle down. 

[psv88]

3 hours ago, LongBeachSurfFreak said:

The drought continues to intensify with another precip fail yesterday. We need a full scale pattern change or things could start to get serious. 

If your starting to see color change on trees it’s likely due to drought stress 

Lots of leaves coming down now, but they are brown. Extremely dry here

[doncat]

Fwiw  the 12z euro is very wet in the longer range....gfs, cmc  not nearly so.

[IrishRob17]

2 minutes ago, doncat said:

Fwiw  the 12z euro is very wet in the longer range....gfs, cmc  not nearly so.

It sure is, a little over 4” up this way. 

[uofmiami]

7 minutes ago, doncat said:

Fwiw  the 12z euro is very wet in the longer range....gfs, cmc  not nearly so.

Looks like it forms a low on the front.  I’m sure it’ll disappear next run even though we need the rain desperately.

[forkyfork]

the euro might be too far north with the heavy convective rain thursday. it's pretty far north of the sfc front

[MJO812]

1 hour ago, sferic said:

Excuse my ignorance, but is this for cold weather lovers?

Too early to think about the cold

[bluewave]

JFK just missed the record high today by a degree.

WEATHER ITEM   OBSERVED TIME   RECORD YEAR NORMAL DEPARTURE LAST
                VALUE   (LST)  VALUE       VALUE  FROM      YEAR
                                                  NORMAL
..................................................................
TEMPERATURE (F)
 TODAY
  MAXIMUM         81    215 PM  82    1948  71     10       76
  MINIMUM         68    415 AM  44    2000  56     12       58
  AVERAGE         75                        63     12       67