Mailbag: When will it feel like fall outside?

Hello NYC, and welcome to our third summer of the year. It’s warm and humid out there this afternoon – again. It’s not all bad news though, as a cold front will swing through the area later Saturday. Cooler and much more pleasant air will follow behind it on Sunday and Monday.

In the meantime, we’ve got the second edition of our Weather Mailbag ready to roll. You hit us with some great questions this week. We tried to answer them all, but we had to push some of them back for next weeks mailbag – we promise we will answer them! Here goes nothin’

@sugarpond (Twitter):Why do weather forecasts usually focus on temperature when what I what to know is the dew point!?!?

Honestly, we’ve been wondering this ourselves. The truth is though, the temperature and dew point are both quite important. We would love to see more focus on the dew point from public outlets, so we try to talk about it as much as we can. It really does make a huge difference in how it feels outside. The weather on Sunday and Monday will be proof-positive of this, with much lower dew points and comfortable conditions.

@naturf4ever (Twitter): When’s this Florida humidity ending???

Sunday, my friend! We’re anticipating a big cold front on Saturday evening, with rain and some rumbles of thunder. Once that clears out later Saturday Night, much cooler and drier air will filter in to the area. West/northwest winds will keep the air feeling cool and crisp on Sunday, and those pleasant conditions will continue right into next week.

@saranrapjs (Twitter): Do you know how small inside-of-nyc heat pockets [are forecast]?

New York City is home to some wild variations in weather conditions. You may remember those days in summer when JFK Airport, on the south shore of Long Island, struggles to reach 75 F, while Central Park and Newark are in the low 90’s. The truth is that the geography of the region is quite unique, with various impacts from elevation, urban growth, and of course – the ocean and rivers.

Microscale forecasting in the NYC Metro Area is quite challenging as a result of all of these things. Forecast models have gotten better and better over the years, and their resolution has increased to ridiculous levels. Forecasting outlets are able to produce graphics with high resolution that factor in things such as elevation, wind direction relative to bodies of water nearby, urban heat, etc. This all leads to temperature forecasts that have gotten more and more accurate on small scales like you see in the graphic you referenced.

@alexanderhall (Twitter): What is *the* snowstorm pattern to look out for in winter?

This is a cool question! Every weather pattern is different, and snowstorms are *so* unique. Even if you were to pick out what looked like a “perfect” pattern for a snowstorm in NYC, there is a good chance that it wouldn’t work out. However, we have done some research on this in the past!

We took a list of the snowstorms that produced snowfall of 15″ or greater in the NYC Metro, dating back to when records began. We then combined all of them and looked at the average height pattern across the atmosphere. There are two main features that stand out right away. First of all, a big ridge in red over Greenland – known as a Greenland Block or -NAO. Second, a corresponding trough in blue to the southeast of there, over Eastern Canada.

These two features accomplish two major things: The ridge over Greenland dislodges cold air from Canada southward, while the troughing over Eastern Canada keeps that cold air locked in place. This pattern in general is very favorable for winter storms in the NYC Metro area as a result.

@MurnanDavid (Twitter): What’s the winter outlook?

We will be releasing our Winter Forecast on Friday, November 5th, 2021. Stay tuned for more information, we’ll be doing a live chat and some cool interactive stuff for it this year!

@petaloid_bract (Twitter): Was this summer like, objectively worse than previous summers in terms of avg temperature/humidity/heat index? It certainly felt like it was.

Great question – and we did a bit of research on this. The short answer to your question is yes, this summer featured higher dew points than normal in the NYC Metro Area. The attached chart shows the last 21 years of summer (JJA) dew points in the NYC Metro Area. You’ll also notice that the average dewpoint in summer is gradually trending upward.

That’s all we’ve got for this week! Remember that if we didn’t answer your question this week, it’s queued up for next week’s mailbag.

Have a great weekend y’all!