September 2024

[bluewave]

1 hour ago, jm1220 said:

You can see that ESE-oriented precip crunch which means high pressure/confluence definitely at work. 

I think the reason the warm front was a little further south than forecast yesterday was due to the models underestimating the influence of the high pressure in New England.

[jm1220]

1 hour ago, ForestHillWx said:

Brick wall in effect 

Typical ESE bent confluence look on radar with the rain stopping dead north of Trenton.

[Stormlover74]

11 minutes ago, jm1220 said:

Typical ESE bent confluence look on radar with the rain stopping dead north of Trenton.

At least it's not January 

[Allsnow]

1 minute ago, Stormlover74 said:

At least it's not January 

Looks like the rain won’t start until after midnight 

[qg_omega]

just nothing at all remotely interesting weather wise for the foreseeable future

[nycwinter]

5 minutes ago, qg_omega said:

just nothing at all remotely interesting weather wise for the foreseeable future

if you are unhappy i am happy...

[winterwx21]

1 hour ago, Allsnow said:

Looks like the rain won’t start until after midnight 

18z HRRR has our area getting a half inch to an inch. We pray that it's correct. 

[donsutherland1]

It will turn slightly cooler for the weekend with highs mainly in the upper 60s and Lower 70s.

Helene has brought historic rains to the Asheville area. Its 2-day total exceeded the highest amount recorded over 5 days and its 3-day total exceeded its highest 15-day figure prior to 2024. Atlanta picked up 3" or more rain on three consecutive days, which broke the record set during December 8-9, 1919 and tied during July 4-5, 1994.

In the Southwest and parts of California, near record and record heat continues. The extreme heat will last through the coming weekend. Phoenix and Tucson will experience their highest temperatures so late in the season.

Continuing long-range guidance suggests that October could wind up warmer than normal across much of the U.S. The western U.S. could be particularly warm relative to normal. Widespread October warmth occurred during the last case where the AO fell to -2.000 or below while the PNA rose to +1.000 or above with a cool ENSO Region 3.4 anomaly in late September (2010), as was the case this year.

The NAO fell to a preliminary -2.751 on September 24th (all-time September record: -2.371, September 12, 1971). That was the 9th lowest value on record. La Niña winters following September cases where the NAO fell to -1.900 or below featured a predominantly positive NAO. The most recent such winters were 2016-2017 and 2022-2023. The mean temperatures for those winters in New York City were 39.3° and 41.0° respectively. The 1991-2020 normal value is 36.2°. A warmer outcome is favored by the September run of the C3S multi-model forecast for Winter 2024-2025.

The ENSO Region 1+2 anomaly was +0.2°C and the Region 3.4 anomaly was -0.5°C for the week centered around September 18. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.20°C and the ENSO Region 3.4 anomaly has averaged -0.18°C. Neutral ENSO conditions will likely evolve into a La Niña event during the fall.

The SOI was +6.42 today.

The preliminary Arctic Oscillation (AO) was -0.304 today.

Based on sensitivity analysis applied to the latest guidance, there is an implied 57% probability that New York City will have a cooler than normal September (1991-2020 normal). September will likely finish with a mean temperature near 69.1° (0.1° below normal).