September 2020 wx discussion

[SACRUS]

9/13

PHL: 80
New Brnwck: 79
ACY: 78
TTN: 78
LGA: 77
EWR: 77
TEB: 76
JFK: 76
BLM: 75
ISP: 75
NYC: 74

[CIK62]

Cool and dry for the next 15 days to be the watchword around here.

Also,  latest GFS shifts rains from Sally to the east of New Orleans, and reduces the precipitation there by a factor of 10X from this morning.

[doncat]

75/61 split today.

[wdrag]

Good Monday morning everyone,

Sally should pass out to sea well south of our area, per NWS guidance as added below. The only major model uncertainty is the CMC ensemble which biases the NAEFS rather wet up here with southerly flow 850MB moisture contribution and potential mid-level FGEN. Ensemble guidance of 00z/14 EPS/GEFS is also wetter than the 00z/14 operational cycle and seems to have trended slightly north from yesterdays post of 00z/13.  The NAEFS prob for 2" axis is directed into the northeast USA for Thu night-Friday.  So, this is posted not to say Sally will impact our area with moisture contribution but forecaster's considerations that may need blending higher?  QPF is yes/no.  In this case, operational modeling says much more strongly NO, but ensembles suggest another look see is required. Monitor the future trends to see if a somewhat wetter scenario will develop for the I95 corridor of the NYC forum late this workweek.  It's basically our only hope for substantive qpf between the event of this past Wed night-friday morning (9th-11th) and Tuesday Sept 22nd. 648A/14

[CIK62]

The next 8 days are averaging 67degs.       Make it 62degs., or about -6.

70*(75%RH) here at 6am, thin overcast.     76*(46%RH) by 2pm.         77*(40%RH) by 4pm.

Tropical systems near:   28N, 87W (I can do the Twist) 32.5N, 64.7W(in Bermudan waters Oh! so clear and bulging) 13N 41W,  18N 28W..

[bluewave]

Big interior radiational cooling event in the forecast for next weekend. Temperatures should be even cooler than on Tuesday morning. So more fall-like temperatures after a warm start to September.

 

 

 

[wdrag]

Adding on to the coming cooler trend expressed above in Bluewave post...NAEFS D8-14 (Sept 22-29)attached pretty much is cooling us a little a closer to the monthly normal from the above normal first two weeks of Sept. 

[donsutherland1]

Morning thoughts...

Ahead of the arrival of much cooler air, today will be mostly sunny and mild. Temperatures will likely top out in the middle and upper 70s. Likely high temperatures around the region include:

New York City (Central Park): 77°
Newark: 79°
Philadelphia: 79°

Much of the week will feel like early autumn. An even colder air mass could arrive late in the week.  

 

[SnoSki14]

Yeah the cooling is not something we're used to. I see multiple highs in the 60s starting Friday with lows in the mid 40s for next weekend. 

Tonight into tomorrow looks coolish as well. Should help jumpstart the foliage.

[forkyfork]

tomorrow looks smoky

[LibertyBell]

On 9/11/2020 at 8:44 PM, uncle W said:

they dont make September cool spells like they used to...NYC has no hot days this month so far and no real cool morning like low 50's or upper 40's like the 1960's had frequently...I forget the date but 1961 set the record low...1964 broke it...then 1966 broke it again...I remember one year 1963 set a record low and 1964 broke it...both set a record high on the same date two months later...45 used to be the average low for September in NYC...now its closer to 50...

Yes, I remember having to wear sweaters quite regularly in late September going back to the 90s, haven't done that in at least a decade or more.

 

[LibertyBell]

3 minutes ago, forkyfork said:

tomorrow looks smoky

brilliant sunrises/sunsets for us?

 

[SACRUS]

72/ 57 and real nice dry breeze.  Warm and dry today as the front moves through and sun comes out.  Mid / upper 70s.  Tuesday cooler with highs near 70 and lows 50s.  Warmer Wed/ Thu highs near 80 and perhaps low 80s on Thu if we see enough sun.  Friday (9/18) the next front arrives and we cool off to levels not seen since May.  9/19 - 9/24 cooler than normal but lookng mainly dry vert Fall-ish airmass.  30s inland Sunday or next monday?

Longer range looks to end the month on a warm note pushing the overall avg positive.

 

[LibertyBell]

On 9/12/2020 at 2:44 PM, bluewave said:

 

We have a pretty good idea that this will be the 5th consecutive winter with a La Niña-like base state. The North Pacific Ridge was able to extend NE into Alaska in 16-17 and 17-18 allowing for snowy and warm. The El Niño couldn’t couple in 18-19 due to all the record Niña-like SST warmth in the WPAC. So we had the La Niña ridge north of Hawaii and SE ridge for a mild and nearly snowless DJF. The record WPAC warmth in 19-20 set new records north of Australia. So we got a continuation of record MJO 4-6 amplitude and the Niña-like ridge north of Hawaii and SE Ridge. Warm and even less snowy overall than the previous year since we didn’t get the Nov and Mar snows. This fall we will be looking for clues as to which type of La Niña winter we will have this year. It often comes down to how much snow NYC can pick up in December. All the Niña-like Decembers with under 3.0” of snow in NYC since 1995 featured below normal snowfall seasons. While all above 3.0” finished normal to above normal.

Monthly Total Snowfall for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Oct	Nov	Dec	Jan	Feb	Mar	Apr	Season
2019-2020	0.0	0.0	2.5	2.3	T	T	T	4.8
2018-2019	0.0	6.4	T	1.1	2.6	10.4	0.0	20.5
2017-2018	0.0	T	7.7	11.2	4.9	11.6	5.5	40.9
2016-2017	0.0	T	3.2	7.9	9.4	9.7	0.0	30.2

 

 

2011-2012	2.9	0.0	0.0	4.3	0.2	0.0	0.0	7.4
2010-2011	0.0	T	20.1	36.0	4.8	1.0	T	61.9

 

2008-2009	0.0	T	6.0	9.0	4.3	8.3	T	27.6
2007-2008	0.0	T	2.9	T	9.0	T	0.0	11.9

 

2005-2006

0.0

T

9.7

2.0

26.9

1.3

0.1

40.0

 

2001-2002	0.0	0.0	T	3.5	T	T	T	3.5
2000-2001	T	0.0	13.4	8.3	9.5	3.8	0.0	35.0
1999-2000	0.0	0.0	T	9.5	5.2	0.4	1.2	16.3
1998-1999	0.0	0.0	2.0	4.5	1.7	4.5	0.0	12.7

 

1996-1997	0.0	0.1	T	4.4	3.8	1.7	T	10.0
1995-1996	0.0	2.9	11.5	26.1	21.2	13.2	0.7	75.6

Yes all those la nina winters that I remember from the late 80s thru early 90s had very little snow in December, some of them only a T.  I'd be thrilled if we even had an average winter, something like 08-09!

 

[winterwx21]

We still see plenty of warm days mixed in with the cool ones. After the cool day tomorrow, we're looking at high temps in the upper 70s to near 80 wednesday and thursday. And after the cool weekend into monday, it warms back up mid next week. Next wednesday and thursday look like a repeat of this week with highs close to 80. Still plenty of 80 degree warmth mixed in the cool days.

[Stormlover74]

2 minutes ago, winterwx21 said:

We still see plenty of warm days mixed in with the cool ones. After the cool day tomorrow, we're looking at high temps in the upper 70s to near 80 wednesday and thursday. And after the cool weekend into monday, it warms back up mid next week. Next wednesday and thursday look like a repeat of this week with highs close to 80. Still plenty of 80 degree warmth mixed in the cool days.

Yeah its sad what counts as an impressive cool down these days

[SACRUS]

9 minutes ago, Stormlover74 said:

Yeah its sad what counts as an impressive cool down these days

Sat (9/19) - Tue (9/22) do look solidly below avg. -5 to -7 each day.  

[winterwx21]

2 minutes ago, SACRUS said:

Sat (9/19) - Tue (9/22) do look solidly below avg. -5 to -7 each day.  

I think by next tuesday we're already warming back up to low-mid 70s. No question we have a few solidly below normal days this weekend into monday. But other than that, I see a lot of days with high temps well up into the 70s to near 80. Today, wednesday and thursday this week and most of next week after monday. One cool stretch for a few days but otherwise normal to above normal temps.

[bluewave]

Anything below +2 to +6 is considered cool by recent September standards. We would have to go back to 2013 to 2014 for departures under those levels. A continuation of less warm is the new cool.

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

2019...+2.6....+2.4....+3.0

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

[lee59]

Would not be surprised to see some 30s in our colder suburbs before this week is over.

[MJO812]

Teddy gone wild

Shifted  west. Bermuda direct hit. 

[lee59]

12 minutes ago, MJO812 said:

Teddy gone wild

Shifted  west. Bermuda direct hit. 

Bermuda taking it on the chin, just got thru Paulette. Looks like Sally will hit a little further east, maybe around Mobile.

[forkyfork]

looks smoky right now outside

[bluewave]

2 hours ago, LibertyBell said:

I'd be thrilled if we even had an average winter, something like 08-09!

 

With these Niña-like winter patterns, it really comes down to how far north the Pacific ridge extends. When it builds northward into Alaska, we can get -NAO intervals and snowier winters. But when that ridge flattens out north of Hawaii, we often get a strong +EPO/+NAO and well below normal snowfall.

Near to above normal snowfall La Niña composite

Below normal La Niña snowfall composite

 

 

 

[LibertyBell]

1 hour ago, MJO812 said:

Teddy gone wild

Shifted  west. Bermuda direct hit. 

We'll be onto the Greek alphabet before the end of this month.  Will beat 2005 in total tropical storms, but not in hurricanes or majors.

 

[LibertyBell]

2 hours ago, lee59 said:

Would not be surprised to see some 30s in our colder suburbs before this week is over.

Prediction is for lows of 37-38 at my other home in NE PA and highs in the upper 50s for next weekend.

 

[LibertyBell]

1 hour ago, lee59 said:

Bermuda taking it on the chin, just got thru Paulette. Looks like Sally will hit a little further east, maybe around Mobile.

may be a major at landfall

[LibertyBell]

54 minutes ago, bluewave said:

With these Niña-like winter patterns, it really comes down to how far north the Pacific ridge extends. When it builds northward into Alaska, we can get -NAO intervals and snowier winters. But when that ridge flattens out north of Hawaii, we often get a strong +EPO/+NAO and well below normal snowfall.

Near to above normal snowfall La Niña composite

Below normal La Niña snowfall composite

 

 

 

does 08-09 sound like a reasonable analog to you?

[IrishRob17]

1 hour ago, forkyfork said:

looks smoky right now outside

Agreed, its quite noticeable above the clouds

[bluewave]

42 minutes ago, LibertyBell said:

does 08-09 sound like a reasonable analog to you?

Still early to guess at any analog types. But winters have been following a 1 or 2 year pattern for a while now. So it will be interesting to see if this winter reverts back to a snowier La Niña or does a rare 3 below normal snowfall seasons. We haven’t gone below normal for snowfall during 3 consecutive seasons since the late 90s. 
 

19-20....18-19....Niña-like above normal temperatures and below normal snowfall

17-18.....16-17...La Niña above normal temperatures and snowfall

15-16..................Super El Niño with above normal temperatures and snowfall

14-15.....13-14....Record + North Pacific Mode with below normal temperatures and above normal snowfall. Also remembered as the record NEPAC warm blob winters.

12-13.....Niño-like above normal temperatures backloaded snowfall

11-12.....La Niña with above normal temperatures and below normal snowfall

10-11....09-10.....record -NAO and -AO with an El Niño then La Niña ....below normal temperatures and above normal snowfall.