Jump to content
  • Member Statistics

    16,981
    Total Members
    7,904
    Most Online
    Dankles
    Newest Member
    Dankles
    Joined

September 2021


wdrag
 Share

Recommended Posts

6 hours ago, donsutherland1 said:

An area of showers and thundershowers moved through the region late this morning and early this afternoon. A total of 0.27" of rain fell in New York City's Central Park pushing the monthly rainfall total to 10.03". As a result, New York City has seen a record 3 consecutive months with 10" or more of rain. Records go back to 1869.

In addition, 10" or more of rain each month from July-September is unprecedented this far north. In 1894 and again in 1945, Downtown Charleston, SC (32.78°N) saw 10" or more of rain during this period. In 1946, Wilmington, NC (34.21°N) saw 10" or more of rain during this period. Then, in 2018, Dunn (4 NW), NC (35.31°N) recorded 10" or more during July, August, and September.

Year-to-date rainfall in New York City is now 51.96". That ranks 2021 as New York City's 33rd wettest year on record.

In the Northern Plains, today witnessed searing heat. The thermometer topped out at 98° at Bismarck, which surpassed the daily mark of 97° from 1905. This is also the latest 98° or above reading on record.

This evening, a few isolated showers and thundershowers are possible in parts of the region, but skies will clear. Tomorrow through Friday will feature plentiful sunshine and cool temperatures.

2021 remains on course to become the 6th out of the last 7 years during which September has had a mean temperature of 70° or above in New York City. Prior to 2000, New York City saw such warmth on average once every five years. In short, September has become more an extension of summer than a gateway to autumn in the New York City area.

There is strong consensus on the long-range guidance that October will be an unseasonably warm month. The first half could feature much above normal readings in the Northern Plains into Central Canada. Overall, the Middle Atlantic and southern New England areas appear to be in line with a warmer to much warmer than normal October.

Fall 2021 will likely be wetter to much wetter than normal in the northern Middle Atlantic region. Since 1869, there have been 9 August cases where New York City picked up 20.00" or more rainfall during the summer. Two thirds of those cases (and 4/5 of those with summer mean temperatures of 73.0° or above) had 17.00" or more fall precipitation in New York City. 2011 is probably the closest match in terms of precipitation and a nearly identical summer mean temperature. Mean fall precipitation for those 9 cases was 14.86". The median was 17.35". The 1991-2020 normal value is 12.27".

The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.3°C for the week centered around September 22. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.05°C and the ENSO Region 3.4 anomaly has averaged -0.43°C. Neutral ENSO conditions will likely prevail through September. Afterward, La Niña conditions could begin to develop during October.

The SOI was +36.90 today.

The preliminary Arctic Oscillation (AO) figure was -1.474 today.

On September 26 the MJO was in Phase 4 at an amplitude of 1.081 (RMM). The September 25-adjusted amplitude was 0.823 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a warmer than normal September (1991-2020 normal). September will likely finish with a mean temperature near 70.3° (1.1° above normal).

 

September will end up with a mean temperature above 70, probably around 70.3. The Central Park thermometer

tried its best to make sure that it would not happen but the month ended one day too early. 

 

A few weeks ago someone was going to write a letter concerning the foliage issue to the powers that be. I wonder if anything

ever came of that. 

Link to comment
Share on other sites

3 hours ago, mjr said:

September will end up with a mean temperature above 70, probably around 70.3. The Central Park thermometer

tried its best to make sure that it would not happen but the month ended one day too early. 

 

A few weeks ago someone was going to write a letter concerning the foliage issue to the powers that be. I wonder if anything

ever came of that. 

If I correctly recall the posted message, the letter had been sent and the regional headquarters was going to take a closer look. So far, nothing has changed at the Park.

Link to comment
Share on other sites

Morning thoughts…

Today will be partly sunny and cooler. High temperatures will likely reach the upper 60s and lower 70s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 68°

Newark: 73°

Philadelphia: 71°

Normals:

New York City: 30-Year: 71.0°; 15-Year: 72.3°

Newark: 30-Year: 72.6°; 15-Year: 74.1°

Philadelphia: 30-Year: 73.9°; 15-Year: 75.1°

Dry but cool weather will continue through Friday.

  • Like 1
Link to comment
Share on other sites

The last two days of September are averaging 63degs.(56/70), or -2.

Month to date is  71.0[1.4].       September will end at  70.4[+1.2]      September reached 10.03".

Reached 75* here yesterday in an up/down day.

First 10 days of October looking somewhat AN, but w/o any breakouts either way..... say 57/68 average for the period, versus 54/67, Normal.

Today:   66-71, nw. wind, p. cloudy.

56*(60%RH) here at 6am, m. clear.    After 3hrs. at 56*, 57* at 9am.     60* by 10am.     62* at Noon.    64* at 1pm.        67* at 3pm.       Reached 68* at 3:30pm.

  • Like 1
Link to comment
Share on other sites

September 29th is the 2nd latest in the fall that HPN has dropped below 50°. It’s currently at 49°. All the top 5 latest dates have been since 2015.

Weather Conditions For:
White Plains - Westchester County Airport, NY. KHPN 
29 Sep 6:56 am   49

First/Last Summary for WESTCHESTER CO AP, NY
Each section contains date and year of occurrence, value on that date.
Click column heading to sort ascending, click again to sort descending.
Year
Last
Value
First
Value
Difference
2018 06-12 (2018) 49 10-12 (2018) 47 121
2017 06-09 (2017) 47 09-29 (2017) 47 111
2002 06-08 (2002) 48 09-29 (2002) 48 112
1970 05-30 (1970) 44 09-29 (1970) 42 121
1968 05-28 (1968) 46 09-29 (1968) 49 123
2005 05-25 (2005) 46 09-28 (2005) 46 125
2015 06-02 (2015) 48 09-27 (2015) 47 116
1980 06-14 (1980) 47 09-27 (1980) 44 104
2016 05-21 (2016) 48 09-25 (2016) 44 126
Link to comment
Share on other sites

22 hours ago, bluewave said:

This is now the wettest September on record at Newark. Wet September patterns in the past have been much cooler. So this will be the first in the top 5 wettest to average above 70°.

Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Sep
Click column heading to sort ascending, click again to sort descending.
Rank
Year
Total Precipitation 
Avg  Temperature
1 2021 10.32 73.2°
2 1944 10.28 68.2°
3 1999 9.38 69.3°
4 1975 9.00 64.3°
5 1933 8.33 68.0°

How did the winters end up those years for Newark if you don’t mind telling me?

Link to comment
Share on other sites

So, nothing yet, but am on the edge of another thread.  This one like the 10+ Sept for longest monthly stretch of 10+, this one for 7 or 8+" of rain in October (teaming with the 3 prior months for a first time ever). Nothing in my stats on this but I think we're heading wet. It's not directly tropical related the first half of the month, more of a synoptic scale cool season batches of of heavy rain that may begin late this weekend through the 9th.  The second half off the month might be tropical related---long-long ways to go to gain some confidence.  I'll probably wait til Fri evening on this.  

I guess the only other thing i can say on this: These brief weather predicting icons of 5+ consec days of dry weather are unfair to the skill of our industry in the northeast USA. We're just not that good at predicting 5 gorgeous days in a row- barring a big anomalous stationary ridge aloft overhead.

  • Like 3
Link to comment
Share on other sites

4 minutes ago, wdrag said:

So, nothing yet, but am on the edge of another thread.  This one like the 10+ Sept for longest monthly stretch of 10+, this one for 7 or 8+" of rain in October (teaming with the 3 prior months for a first time ever). Nothing in my stats on this but I think we're heading wet. It's not directly tropical related the first half of the month, more of a synoptic scale cool season batches of of heavy rain that may begin late this weekend through the 9th.  The second half off the month might be tropical related---long-long ways to go to gain some confidence.  I'll probably wait til Fri evening on this.  

I guess the only other thing i can say on this: These brief weather predicting icons of 5+ consec days of dry weather are unfair to the skill of our industry in the northeast USA. We're just not that good at predicting 5 gorgeous days in a row- barring a big anomalous stationary ridge aloft overhead.

yeah alot of times the models will show 7-10 days with little rain, but look at yesterday-that snuck up on us within 48 hrs

  • Like 1
Link to comment
Share on other sites

Down to 50 last night, looks cooler through Saturday (10/2) before warming up Sun (10/3) and  Mon (10/4) could see last surge of near 80 degree warmth sneak in depending on clouds.  Cut off / ULL into next week before more ridging towards next weekend (10/8).

 

 

Link to comment
Share on other sites

1 hour ago, RippleEffect said:

How did the winters end up those years for Newark if you don’t mind telling me?

well 1933-34 was one of the coldest winters of all time and holds the record for the lowest minimum ever recorded in Central Park with a -15 on Feb 9th...there was a blizzard after Christmas and almost 30" of snow in February...1944-45 was very cold with average snow...1999-00 had one cold and snowy month starting mid January...otherwise terrible...1975-76 was cold but with below average snowfall...all four winters were la nina or a weak negative...2021 fits right in...we most likely will not see anything like a 1933-34 winter...1999-00 was a second year la nina but stronger than this year....1975-76 was a second year la nina but stronger...the average for the four of these winters would be an average winter...

Link to comment
Share on other sites

Five of our stations have already reached 50” of precipitation for the year.

 

Data for January 1, 2021 through September 29, 2021
Click column heading to sort ascending, click again to sort descending.
State
Name
Station Type
Total Precipitation 
NJ HARRISON COOP 54.25
NY NY CITY CENTRAL PARK WBAN 51.96
NJ NORTH ARLINGTON 0.7 WNW CoCoRaHS 51.05
NJ RINGWOOD 3.0 SSE CoCoRaHS 50.37
NJ WEST CALDWELL TWP 1.3 NE CoCoRaHS 50.27
  • Thanks 1
Link to comment
Share on other sites

1 hour ago, Brian5671 said:

yeah alot of times the models will show 7-10 days with little rain, but look at yesterday-that snuck up on us within 48 hrs

I view (unfortunately) media is less about news now, and more about 'stories-drama'.  Weather information and giving the viewer-listener what they need to make informed decisions is lacking. We (the presenter) boil it down too what we think is of essence, omitting some of the alternate possibilities, especially beyond 5 days.

06z GEFS is showing impressive positive anomalies of qpf for a 10 day period beginning the 3rd in the northeast.  I can still see southward slippage, depending on northern stream into NNE and the location of the upper low between the Apps and Miss River.  I do 'think' we're going to see some flooding rains (a couple of overlapped decent events) somewhere between the Ohio Valley and mid-north Atlantic. 

 

Edit add: also this seems to be without any tropical cyclone contribution (first two weeks Oct).

  • Like 1
Link to comment
Share on other sites

Long range ensembles seem to be better at seeing the ridges. It usually takes a while longer for the individual shortwaves that produce  the precipitation to show up. But we often see upper lows eventually getting stuck somewhere under strong blocks to our north.

  • Like 1
Link to comment
Share on other sites

24 minutes ago, bluewave said:

Long range ensembles seem to be better at seeing the ridges. It usually takes a while longer for the individual shortwaves that produce  the precipitation to show up. But we often see upper lows eventually getting stuck somewhere under strong blocks to our north.

Maybe a home brew storm to watch next week

Link to comment
Share on other sites

here's a statistical tidbit for September...todays low temp in Central Park was 54...lowest so far this month...if it stands it will be with these years that had a September minimum of 54 since 1960...

1960...

1982...

2002...

2010...

2016...

2017...

some great analogs for snow in there...

  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...