Jump to content
  • Member Statistics

    17,116
    Total Members
    7,904
    Most Online
    SCseminole
    Newest Member
    SCseminole
    Joined

wdrag
 Share

Recommended Posts

16 hours ago, snowman19 said:

This La Niña is about to strengthen big time @donsutherland1 @bluewave

 

 

I feel as if we see these posts every year for El Nino and La Nina in mid to late November and it never transpires.  Its extremely rare to see a Nina Nino undergo any noticeable strengthening once you get this late into the fall.

  • Like 4
Link to comment
Share on other sites

44 minutes ago, SnowGoose69 said:

 

I feel as if we see these posts every year for El Nino and La Nina in mid to late November and it never transpires.  Its extremely rare to see a Nina Nino undergo any noticeable strengthening once you get this late into the fall.

Except data says buckle up its coming

  • Like 1
Link to comment
Share on other sites

We will need a strong enough storm Thanksgiving week for our first -10 departure of fall behind the cold front. Our last multi station average below -10 was the July 4th weekend. The only recent fall without one averaged for our climate division was the 2016 La Niña.

https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=32&network=NYCLIMATE&station=NYC004&year=2021&var=high&gddbase=50&gddceil=86&how=diff&cmap=jet&_r=t&dpi=100&_fmt=png

FA0CEF2D-C2C3-4B8C-9A6A-FFE47889E1DD.thumb.png.b2e6aa4c620994debe8b18884da29252.png


33361DB4-A2C9-4E50-8674-13B902BD0B3C.thumb.png.260ae23c71f620773a905c1fd1eb36b1.png

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

So,  I know some others here have been talking about snow to the coast on the ensembles, in the previous few days for Thanksgiving week. It (like the period of the 12th-15th) is an impressive trough digging into the east next week (12z/14 multi ensembles) and seems to want to go negative.

Also noting these shortwaves are ending up a little further west each run in an unstable flow pattern across the northern USA. 

IF this still looks reasonable in the 00z/15 multimodal ensembles,  would start a thread tomorrow morning for the period 11/21-23 with 1" qpf, maybe iso max 4"?, or damaging wind (40-55kt coast), possible snow or flurries to the coast-favoring backside wraparound flurries. 

What further caught my eye is that it seems the NA block is more favorable (fully anchored) for a coastal storm sometime between the 26th-29th. By that time we'll know of the 21st-23rd storm develops a deep closed low heading toward 50N/50W. 

  • Like 5
Link to comment
Share on other sites

Tomorrow will be another unseasonably cool day. Much of the region will again see temperatures rise no higher than the middle and upper 40s. The cool weather will likely continue until midweek.

Overall, there remains uncertainty about the temperature anomaly for the second half of November. However, the latest teleconnections forecasts now suggest that the AO will drop sharply to somewhere between -3.000 and -1.000 on or after November 20. Such an outcome 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°

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 14 4 pm is 16.11".

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 -0.8°C and the Region 3.4 anomaly was -1.0°C for the week centered around November 3. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.27°C and the ENSO Region 3.4 anomaly has averaged -0.78°C. La Niña conditions will likely persist into at least late winter.

The SOI was +7.12 today.

The preliminary Arctic Oscillation (AO) figure was +0.428 today.

On November 12 the MJO was in Phase 5 at an amplitude of 1.104 (RMM). The November 11-adjusted amplitude was 1.135 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied 56% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 47.7° (0.3° below normal).

 

Link to comment
Share on other sites

33 minutes ago, Tatamy said:

On the topic of snow it is snowing up in Mt.  Pocono this evening with the trough swinging through.  This is the second day in a row this has happened. This time it is actually accumulating on grassy areas.

I can confirm this. There is a coating on the grass here in Newfoundland Pa, 30 min north of Mt. Pocono, on the northern Pocono plateau. Elevation just under 2,100’. 

5C472C4D-924A-4EA5-977C-B32408B52F64.jpeg

  • 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...