June 2025 discussion-obs: Summerlike

[LibertyBell]

Just now, Sundog said:

Your wife needs to be "reeducated" lol

Permanent EDT is the way to go

I think moving half an hour ahead is a fair compromise.

[Sundog]

2 minutes ago, LibertyBell said:

Possibly, but otherwise these weather *wars* will continue.  If we could come up with a single number to describe the city it would dampen down biases any one individual station might have (NYC poorly sited, LGA/EWR running too hot, JFK seabreeze interference, etc.)

 

The city is huge, that's like taking a snowfall average across the city and only using one number for the total city wide. 

Meanwhile JFK can have an inch while Northern Bronx has 8 inches, which has happened many times before. 

Or in Feb 5th 2010 when I had flurries and southern Staten Island had 10 inches. 

You can't do that with temps either. 

[SACRUS]

3 minutes ago, LibertyBell said:

The longest day isn't really on the summer solstice, it's different days in different places depending on your latitude and some other factors. For us it's usually June 26th.

 

Longest day for us is 6/20 

 

[Sundog]

2 minutes ago, LibertyBell said:

I think moving half an hour ahead is a fair compromise.

I'd rather keep the current system rather than lose a half hour of light in the evening for 7 months. 

[Dark Star]

18 minutes ago, LibertyBell said:

Do you think at least partially transferring the NWS/NOAA functions to private ownership would help matters? Perhaps we can get a rich billionaire who cares about climate and weather to fund a supercomputing system sufficiently powerful to run 4dVar?

I'm being ironic, I don't think any of them care, but the funding has to come from somewhere and we have a few billionaires funding space trips so why not get them to invest in climate and weather too? Note how NASA has partnerships with these private space companies, maybe NWS and NOAA need to do the same thing?  Public funding only gets you so far and we are in the era when people want to spend less and save more, so maybe we are on the way to privatizing everything now and shifting the burden to those who can afford it....

 

Weather models are just not as sexy as space exploration.  Plus, if you achieve your goals in space, or landing on Mars, you can see your achievements.  Even if you improve the GFS, there are still other reliable models, so the increase in forecasting accuracy overall probably wouldn't be noticeable.  In the end, no real significant reward for the investment.

[LibertyBell]

3 minutes ago, Sundog said:

The city is huge, that's like taking a snowfall average across the city and only using one number for the total city wide. 

Meanwhile JFK can have an inch while Northern Bronx has 8 inches, which has happened many times before. 

Or in Feb 5th 2010 when I had flurries and southern Staten Island had 10 inches. 

You can't do that with temps either. 

and I guarantee that NYC will be a lot closer to JFK than it would be to the Northern Bronx ;-) The Northern Bronx is like a lower Hudson Valley climate to me

I remember 2/5/2010 we had 1.5 inches here and Staten Island had 6 inches.  That's why we have snowfall ranges, for that storm 1-6 inches would have been a far range for the southern half of the city.

 

[LibertyBell]

18 minutes ago, SACRUS said:

Longest day for us is 6/20 

 

This is one of the reasons it doesn't match up with the solstice most of the time:

https://www.timeanddate.com/news/astronomy/earth-fast-rotation-2025

Earth Will Spin Unusually Quickly in July and August

Since 2020, Earth has notched up unprecedentedly short days midway through the year. It will happen again in 2025 around July 9, July 22, and August 5.

Surprise! In recent years, Earth has been spinning a bit more quickly. Scientists are unsure why.

©NASA’s Goddard Space Flight Center

Earth’s Variable Spin Speed

Our planet is an almost-but-not-quite-perfect timekeeper. Every day, from the point of view of the Sun, Earth completes one full rotation on its axis in exactly 86,400 seconds, give or take a millisecond or so.

86,400 seconds is another way of saying 24 hours. A millisecond (ms) is 0.001 seconds—considerably less than a blink of an eye, which lasts around 100 milliseconds.

The only way to measure these tiny day-to-day variations in Earth’s spin speed is with atomic clocks, which were introduced in the 1950s. The number of milliseconds above or below 86,400 seconds is known as length of day (LOD).

Look it up: How long was yesterday?

Earth Speeds Up

Until 2020, the shortest LOD ever recorded by atomic clocks was -1.05 ms. This means that Earth completed one rotation with respect to the Sun in 1.05 milliseconds less than 86,400 seconds.

Since then, however, Earth has managed to shatter this old record every year by around half a millisecond. The shortest day of all was -1.66 ms on July 5, 2024. Earth is expected to get close to this again in 2025 around July 9, July 22, and August 5.

From the archive: Earth in a hurry (2020)

The following table shows the shortest LOD in every year for the past five years, together with three possible dates for the shortest LOD in 2025.

Shortest Length of Day, 2020–2025

Year	Date	LOD
2020	July 19	-1.47 ms
2021	July 9	-1.47 ms
2022	June 30	-1.59 ms
2023	July 16	-1.31 ms
2024	July 5	-1.66 ms
2025	July 9	-1.30 ms (prediction)
2025	July 22	-1.38 ms (prediction)
2025	August 5	-1.51 ms (prediction)

Sources: timeanddate.com, IERS, USNO. Estimates are based on observations and models, and include systematic corrections and smoothing.

Why Three Possible Dates?

Short-term variations in LOD are affected by the orbit of the Moon. Our planet spins quicker when the Moon’s position is far to the north or south of Earth’s equator.

The Moon will be around its maximum distance from Earth’s equator on the three possible dates for the shortest LOD in 2025. The following links for our Moon Light World Map show the Moon’s position—indicated by the Moon symbol—at 12:00 UTC on July 9, July 22, and August 5.

Why Is All This Happening?

Why has Earth accelerated, and when will it slow down again? These are difficult questions. Long-term variations in Earth’s spin speed are affected by a long list of factors that includes the complex motion of Earth’s core, oceans, and atmosphere.

“Nobody expected this,” says Leonid Zotov, a leading authority on Earth rotation at Moscow State University. “The cause of this acceleration is not explained.”

Most scientists believe it is something inside the Earth. Ocean and atmospheric models don’t explain this huge acceleration.

Leonid Zotov

 

[Brian5671]

10 minutes ago, Sundog said:

I'd rather keep the current system rather than lose a half hour of light in the evening for 7 months. 

Nothing is changing.   We will continue to move clocks twice a year 

[LibertyBell]

3 minutes ago, LibertyBell said:

This is one of the reasons it doesn't match up with the solstice most of the time:

https://www.timeanddate.com/news/astronomy/earth-fast-rotation-2025

Earth Will Spin Unusually Quickly in July and August

Since 2020, Earth has notched up unprecedentedly short days midway through the year. It will happen again in 2025 around July 9, July 22, and August 5.

https://www.timeanddate.com/astronomy/equilux.html

This article explains why day and night aren't equal on the equinox too.

Equinox—Close, but Not Quite Equal

Many of us think that an even balance of day to night happens during an equinox. After all, the word translates as “equal night.”

So, a little confusion is understandable. But there’s a subtle time difference between an equinox and an equilux.

Approx. equilux dates

Latitude	March	September
60° North	Mar 18	Sep 25
55° North	Mar 17	Sep 25
50° North	Mar 17	Sep 25
45° North	Mar 17	Sep 25
40° North	Mar 17	Sep 26
35° North	Mar 16	Sep 26
30° North	Mar 16	Sep 27
25° North	Mar 15	Sep 27
20° North	Mar 14	Sep 28
15° North	Mar 12	Sep 30
10° North	Mar 8	Oct 4
5° North	Feb 24	Oct 17
Equator	No equal day and night
5° South	Apr 14	Aug 29
10° South	Apr 1	Sep 10
15° South	Mar 28	Sep 14
20° South	Mar 26	Sep 16
25° South	Mar 25	Sep 17
30° South	Mar 24	Sep 18
35° South	Mar 24	Sep 19
40° South	Mar 23	Sep 19
45° South	Mar 23	Sep 19
50° South	Mar 23	Sep 20
55° South	Mar 23	Sep 20
60° South	Mar 22	Sep 20

Equal Light

“Equilux” is drawn from the Latin terms for equal (equi) and light (lux). So how do we find out which dates fit the description and qualify as truly equal day and night?

To measure the day/night split in a 24-hour span, astronomers use common definitions of sunrise and sunset. Simply put, sunrise is defined as when the first bit of the Sun’s disk appears and sunset is when the last bit of the disk vanishes.

Calculating the length of day between those two moments, we find that two dates every year reach equilux in most latitudes.

In the Northern Hemisphere, these happen a few days before the spring equinox (vernal equinox) and a few days after the autumn equinox. South of the equator, it's the other way around.

A location's equilux dates depend on the latitude (see table). Locations on or near the equator never experience equal day and night.

Imagine a Disk

But why aren’t day and night of equal length at an equinox?

To answer that question, it helps to think of the Sun in two different ways—as a disk and as a point.

To pinpoint the days of equilux, the Sun is considered a disk, and we measure daytime from the first appearance of the Sun’s disk to the last bit slipping below the horizon.

A Point at the Center of the Sun

To calculate an equinox, on the other hand, the Sun is thought of as a single point, set in the center of the disk. An equinox occurs when the subsolar point—the spot on the Earth directly beneath the Sun—crosses the equator, equally straddling the Southern and Northern Hemispheres.

On those days, the center point of the Sun indeed rises and sets 12 hours apart.

But since we measure sunrise and sunset by thinking of the Sun as a disk, the top edge of the Sun appears a little earlier and sets a bit later than the center point. This difference creates a few extra minutes of daylight on the date of an equinox at most latitudes.

[LibertyBell]

11 minutes ago, Dark Star said:

Weather models are just not as sexy as space exploration.  Plus, if you achieve your goals in space, or landing on Mars, you can see your achievements.  Even if you improve the GFS, there are still other reliable models, so the increase in forecasting accuracy overall probably wouldn't be noticeable.  In the end, no real significant reward for the investment.

I wonder if space exploration will spur advancements in other areas, including climate and weather science (this has happened before.)  Perhaps this will encourage greater investment.  If we establish space colonies, weather prediction will become important on these worlds too

[JustinRP37]

18 minutes ago, LibertyBell said:

The longest day isn't really on the summer solstice, it's different days in different places depending on your latitude and some other factors. For us it's usually June 26th.

 

No you are confusing latest sunset and longest day. The longest day is always on the solstice. We peak tomorrow in Manhattan at 15h5m38s, we lose a second by the 21st. By the 26th we have lost a full minute.

 

Same as winter: https://sunrise-sunset.org/a/why-the-shortest-day-is-not-the-day-with-the-earliest-sunset-or-latest-sunrise.

[SACRUS]

1 minute ago, JustinRP37 said:

No you are confusing latest sunset and longest day. The longest day is always on the solstice. We peak tomorrow in Manhattan at 15h5m38s, we lose a second by the 21st. By the 26th we have lost a full minute.

 

Same as winter: https://sunrise-sunset.org/a/why-the-shortest-day-is-not-the-day-with-the-earliest-sunset-or-latest-sunrise.

exactly the sunsets around 8:30 till Jul 9th then slow decline - overall daylights minimal decline is attributed to later sunrise till then.

[LibertyBell]

1 minute ago, JustinRP37 said:

No you are confusing latest sunset and longest day. The longest day is always on the solstice. We peak tomorrow in Manhattan at 15h5m38s, we lose a second by the 21st. By the 26th we have lost a full minute.

 

Same as winter: https://sunrise-sunset.org/a/why-the-shortest-day-is-not-the-day-with-the-earliest-sunset-or-latest-sunrise.

I realized I actually confused it with the equinox/equilux lol.  I read that fascinating article I just posted last year, our equal day / equal night (equilux) is typically around the 26th of March and September.

 

[IrishRob17]

1 minute ago, JustinRP37 said:

No you are confusing latest sunset and longest day. The longest day is always on the solstice. We peak tomorrow in Manhattan at 15h5m38s, we lose a second by the 21st. By the 26th we have lost a full minute.

 

Same as winter: https://sunrise-sunset.org/a/why-the-shortest-day-is-not-the-day-with-the-earliest-sunset-or-latest-sunrise.

He sure is. Here is a screenshot from the timeanddate site for Manhattan which clearly shows the difference between day length and sunrise and sunset times changing 

[bluewave]

42 minutes ago, LibertyBell said:

The solution is to average out NYC, EWR, JFK, LGA and then you get the full of range of weather in New York City (which covers 5 boroughs). I believe LGA runs too hot now, look at how elevated their lows are compared to everyone else and it has the highest concentration of traffic now, which is much worse now than it was during the 30s-50s period when NYC was hotter (as was JFK.)

 

 

LGA has been running cooler than the micronet stations away the water influence in Queens such as Corona. Plus the maximum compressional warming in NYC occurs closer to interior Queens. Their lows aren’t any warmer than the other Queens stations. 

[LibertyBell]

4 minutes ago, SACRUS said:

exactly the sunsets around 8:30 till Jul 9th then slow decline - overall daylights minimal decline is attributed to later sunrise till then.

that might be why July is our hottest month, similar to how January might be our coldest month because of that lag.

[LibertyBell]

1 minute ago, bluewave said:

LGA has been running cooler than the micronet stations away the water influence in Queens such as Corona. Plus the maximum compressional warming in NYC occurs closer to interior Queens. Their lows aren’t any warmer than the other Queens stations. 

why does LGA consistently run warmer on overnight lows and almost always are the last ones to get their first freeze? I feel like it is a much more artificial climate than either the Park or JFK, who get their first freezes before they do.

 

[Superstorm]

2 minutes ago, LibertyBell said:

that might be why July is our hottest month, similar to how January might be our coldest month because of a lag.

Ding, ding....thermal lag

 

[FPizz]

1 minute ago, Superstorm said:

Ding, ding....thermal lag

 

Main reason why met seasons don't line up as well here than actual seasons. Thermal lag.

[TJW014]

Southeast sea breeze already doing its thing here. Gonna be a beautiful beach day if you took off. Should put a chokehold on any potential pop-up storms from migrating to the Jersey coast. 

We'll see what the potential squall line does later. 

[LibertyBell]

6 minutes ago, bluewave said:

LGA has been running cooler than the micronet stations away the water influence in Queens such as Corona. Plus the maximum compressional warming in NYC occurs closer to interior Queens. Their lows aren’t any warmer than the other Queens stations. 

How much does population density have to do with this? I've been to interior Queens and it's always hotter than the surrounding area, I put it down to increased traffic and higher population density plus those subway vents are always emitting hair dryer levels of heat ugh.  It's hotter in the summer AND in the winter. It doesn't feel natural, but artificial because of the environment there.

[LibertyBell]

1 minute ago, TJW014 said:

Southeast sea breeze already doing its thing here. Gonna be a beautiful beach day if you took off. Should put a chokehold on any potential pop-up storms from migrating to the Jersey coast. 

We'll see what the potential squall line does later. 

Not a single cloud in the sky here.

[Sundog]

3 minutes ago, FPizz said:

Main reason why met seasons don't line up as well here than actual seasons. Thermal lag.

Weren't you just arguing that our seasons match up with the astronomical dates?

[LibertyBell]

2 minutes ago, Sundog said:

Weren't you just arguing that our seasons match up with the astronomical dates?

I think he meant JJA vs June 20 - Sept 20

our weather lines up with astronomical summer not met summer. At least the first three weeks of September typically have summer weather.

 

[bluewave]

2 minutes ago, LibertyBell said:

How much does population density have to do with this? I've been to interior Queens and it's always hotter than the surrounding area, I put it down to increased traffic and higher population density plus those subway vents are always emitting hair dryer levels of heat ugh.  It's hotter in the summer AND in the winter. It doesn't feel natural, but artificial because of the environment there.

The LGA ASOS is within a few hundred feet of the bay. So this keeps the high temperatures cooler than stations further south. Low temperatures a pretty similar in Queens. 

[LibertyBell]

1 minute ago, bluewave said:

The LGA ASOS is within a few hundred feet of the bay. So this keeps the high temperatures cooler than stations further south. Low temperatures a pretty similar in Queens. 

But why are LGA mins elevated compared to the Park and JFK (both in the summer and winter), is it because UHI affects them more than the more natural environment around the Park and JFK?

[IrishRob17]

34 minutes ago, LibertyBell said:

Possibly, but otherwise these weather *wars* will continue.  If we could come up with a single number to describe the city it would dampen down biases any one individual station might have (NYC poorly sited, LGA/EWR running too hot, JFK seabreeze interference, etc.)

 

Just quickly measured on Google Earth these approximate distances from Central Park: LGA 5 miles, JFK 12 miles, EWR 12 miles. Those are large distances when you are looking at weather readings. I’m not getting into conditions at site locations, I understand there are issues with that but averaging anything over such large distances is not the answer.  

[LibertyBell]

4 minutes ago, IrishRob17 said:

Just quickly measured on Google Earth these approximate distances from Central Park: LGA 5 miles, JFK 12 miles, EWR 12 miles. Those are large distances when you are looking at weather readings. I’m not getting into conditions at site locations, I understand there are issues with that but averaging anything over such large distances is not the answer.  

That is a pretty large distance.  I guess there really is no way to use one number to describe the city.  We don't even have any sensors in Staten Island, Brooklyn or The Bronx, so no way to know if the 4 official stations we have properly cover the weather in those boroughs (we can always use wunderground, but I've found quite a few of those run too hot. maybe they're not properly sited.)

 

[Sundog]

8 minutes ago, LibertyBell said:

I think he meant JJA vs June 20 - Sept 20

our weather lines up with astronomical summer not met summer. At least the first three weeks of September typically have summer weather.

 

No that's what I was saying, he was saying astronomical dates are more in line with our seasons. 

[IrishRob17]

3 minutes ago, LibertyBell said:

That is a pretty large distance.  I guess there really is no way to use one number to describe the city.  We don't even have any sensors in Staten Island, Brooklyn or The Bronx, so no way to know if the 4 official stations we have properly cover the weather in those boroughs (we can always use wunderground, but I've found quite a few of those run too hot. maybe they're not properly sited.)

 

There are the Mesonet locations