Jump to content
  • Member Statistics

    19,012
    Total Members
    49,013
    Most Online
    loganboehmewx
    Newest Member
    loganboehmewx
    Joined

wdrag
 Share

Recommended Posts

28 minutes ago, SnoSki14 said:

Definitely adjusting towards a more Nina December but still has a long way to go. 

We need few more corrections stronger with the Aleutians ridge to get the gradient south of us. But today is an improvement over yesterday on the GEFS. Our better La Niña winters for snowfall usually have more of a poleward extension of the Aleutians ridge. 
 

New run

F7CE3A38-4429-4C01-A61C-330905A7EBB8.thumb.png.789491af50783565f72cc678eb3903c1.png

Old run

B51C1DC9-D7EE-419E-8A06-126E7C4CEDA2.thumb.png.0f20c117bb3047d9e4bed5d3cab99e94.png

 

  • Like 1
Link to comment
Share on other sites

16 minutes ago, snowman19 said:

Another -EPO fantasy/phantom ridge in the long range that’s going to disappear lol And people are falling for it again hook, line and sinker. Hit the repeat button

The day 10 EPS  looks more like a -WPO based near the Aleutians than a -EPO. 


New run

660DA6BC-273F-4E44-B5BB-D40C356CE4F4.thumb.png.c2ef1c30f3fc4227d8a467d2e27b537b.png
 

Old run


3B752841-E221-41D7-B7B9-6A4ADAC91653.thumb.png.b6e15904ceb66d7e0ee3cd2e163e4d62.png

 

  • Like 1
Link to comment
Share on other sites

31 minutes ago, snowman19 said:

Another -EPO fantasy/phantom ridge in the long range that’s going to disappear lol And people are falling for it again hook, line and sinker. Hit the repeat button

A -EPO will be tough to get but you don't need arctic cold for snowfall opportunities. 

Despite a very positive EPO November will still be BN. 

  • Like 2
Link to comment
Share on other sites

The coldest air of the season so far covers the region. Tomorrow will be another fair but cold day.

Thanksgiving Day will witness the return of a milder air mass, but its duration will be short-lived. Another strong cold front will move across the region Thursday night. In its wake, an unseasonably cold weekend will follow. There is a small chance that a weak system could bring a period of light snow or flurries to parts of the region on Sunday.

First measurable snowfall statistics for select cities:

Allentown: Normal: December 6; 2020-21: December 9
Bridgeport: Normal: December 3; 2020-21: December 16
Islip: Normal: December 10; 2020-21: December 16
New York City: Normal: December 13; 2020-21: December 16
Newark: Normal: December 9; 2020-21: December 9
Philadelphia: Normal: December 19; 2020-21: December 16

The temperature anomaly for November 20-30 is on course to average below normal due to the development of AO blocking. The recent guidance has been correcting colder in response to this blocking. The Arctic Oscillation fell below -1.000 on November 23. Such strong blocking typically favors a period of colder than normal weather (November 20-30, 1991-2020 period):

Boston: Normal: 42.2°; AO cases: 38.4°
New York City: Normal: 45.5°; AO cases: 41.7°
Philadelphia: Normal: 45.4°; AO cases: 41.7°

The duration of the blocking remains uncertain. Should blocking dissipate, warmer conditions could develop near the start of December. Both the CFSv2 and EPS weeklies favor a return of warmer air at some point during the first week of December.

Fall 2021 is well on course to being 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". Fall rainfall through November 23 4 pm is 16.28".

Following very wet July-September periods, winter (December-February) precipitation has typically been near or below normal. The most recent exception was winter 2018-19.

The ENSO Region 1+2 anomaly was -1.0°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 17. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.67°C and the ENSO Region 3.4 anomaly has averaged -0.92°C. La Niña conditions will likely persist into at least late winter.

The SOI was +8.40 today.

The preliminary Arctic Oscillation (AO) figure was -1.410 today.

On November 21 the MJO was in Phase 4 at an amplitude of 1.023 (RMM). The November 20-adjusted amplitude was 1.305 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 95% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.4° (1.6° below normal).

 

  • Like 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...