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July 2019 General Discussions & Observations Thread


bluewave
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On 7/9/2019 at 5:55 AM, etudiant said:

There is logic in the decision to retain the Central Park benchmark. The aim is to report the weather rather than to measure urban heat island effects.

I have no doubt that the concrete jungles we live in are hotter than the relatively green acres of Central Park, but that does not make the Central park data 'flawed'.

 

its not a valid scientific comparison.  When all the other data uses airports, having New York City use a park thats overfoliated makes it an apples to oranges comparison- it simply doesn't work.  The data is flawed in the sense that the ASOS there does not adhere to policies that the equipment has to be a certain distance away from foliage.

The ridiculous aspect of all this is Central Park was 5 degrees cooler than JFK even when JFK had a strong southerly wind (a sea breeze.)  It just isn't valid for a variety of reasons. If everyone else uses an airport, New York City must use airport data too.

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On 7/9/2019 at 7:46 AM, bluewave said:

The Central Park data is flawed due to the sensor being blocked by trees and foliage from sunlight and open airflow. Not because it’s located in a park. The open areas of the park  are probably 1-3 degrees warmer for highs than the sensor area that is blocked. The old sensor was in an open area before 1996 with no obstructions. This is why NYC has an artificial 90 degree day cooling trend with more 90 degree days in 1991 and 1993 than 2010.

Place sensors at a horizontal distance of 2 times the height of the nearest object (tree,
structure, etc). [Example: 40 feet away from a 20 foot tall tree].

B7509AEE-1193-47DD-BB7C-C32CDA95FB26.thumb.jpeg.7adacd001697a5cb2101a8e65ca190ac.jpeg

But it's also not a valid comparison because all other cities use airports, why on Earth do we use a park?  Also why was the sensor moved in 1996 and why doesn't NWS move the sensor back to the old location?  There seems to be some laziness going on over there.....

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On 7/9/2019 at 3:34 PM, bluewave said:

Unusual pattern coming up. The 12z Euro gets the tropical system stuck under the building heat ridge. It crawls for days over the Central US dumping torrential rains. Acts as a heat and humidity pump for us with a deep SW flow.Temperatures in the 90’s with dewpoints in the 70’s will result in very high heat indices. Some hints at beneficial rains for us near the end of the 10 day period with the tropical remnants.

 

847348A1-A3A5-451F-ADD7-C2609C564A84.thumb.png.1d94e70201087ea54e0f7bf6f7e1cd27.png

7E6B4104-3A06-42AE-AF17-0ADFF959C36D.thumb.png.c23bd744c558677b74b654431d717f38.png

 

Do you think anything will be left of that storm in 10 days, Chris?  As for the slow moving storm, that seems to be part of our new climate, as it's been a repeating pattern for several years now.

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15 hours ago, LongBeachSurfFreak said:

Absolutely! When it doesn’t rain my job becomes ten times harder. I have dozens of planters on campus that require hand watering. And huge terraces that were designed (without my input) an irrigation system. I wish I could posts pics but it always says attachments full.

That heat potential next week is awful. I had a feeling sooner or later we would get some real heat. And moving forward that 110 degree day will eventually happen...

Why is it that we have all these 75+ dew points but it doesn't translate to heavy rain- even when a front moves through?  If the moisture isn't being wrung out with rain, where does the humidity go?

 

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12 hours ago, LongBeachSurfFreak said:

Yeah that’s exactly what it is. The top few inches. Trees and established shrubs and perennials have no problem.

Today feels like the hottest day of the week on the uws. It’s not hard to hit 90 in Manhattan with sunshine in July.  

It was 91 here today on the south shore without any sun, it was really hazy I think from all those fires in Manitoba.

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6 hours ago, donsutherland1 said:

The first 10 days of July featured above and much above normal temperatures in the Middle Atlantic region. That theme will likely continue through July with only a few breaks. In addition, the prospect of at least one heat wave in the northern Middle Atlantic and southern New England region could increase during the second half of July.

The ENSO Region 1+2 anomaly was -0.3°C and the Region 3.4 anomaly was +0.6°C for the week centered around July 3. 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 +0.67°C. Neutral-warm ENSO conditions may now be evolving for at least a period of time.

The SOI was -8.93 today.

Today, the preliminary Arctic Oscillation (AO) figure was -1.299. Blocking will likely persist through July 20.

Blocking is consistent with warmth on the East Coast during the middle and latter part of summer. Already, even as the July 1-10 period saw a preliminary AO average of -1.108, readings were above and much above normal in the Middle Atlantic region. Should blocking generally persist, a warm or perhaps very warm second half of summer is likely.

Since 1950, there was only a single year that saw the AO average -1.000 or below in May and -0.500 or below in June (the preliminary June 2019 average was -0.665): 1993. 1993 featured much above normal readings in the East during the late summer (August 15-September 15 period) and predominantly cooler than normal readings across the western third of the nation during much of the summer. Some of the early guidance for August hints at above to possibly much above normal readings in parts of the Northeast.

On July 9, the MJO was in Phase 1 at an amplitude of 1.622 (RMM). The July 8-adjusted amplitude was 1.909.

As had been seen from the prior MJO and SOI data, the first 10 days of July proved much warmer than normal (mean: 78.9°; 2.9° above normal; tied with 1934 for the 25th warmest July 1-10 period) and drier than normal in the region (precipitation: 0.06" 1.25" below normal). Since 1974 when MJO data was first reported, years in which the MJO was in Phase 5 at an amplitude of 1.500 or above for at least two days were followed by warmer and drier than normal weather during the first 10 days of July.

Since 1994, cases when the SOI fell to -35.00 or below during the June 16-30 period saw July 1-15 temperature average approximately 3.5° above the June 16-30 figure in New York City.

The second half of July is very likely to be warmer than normal in much of the Middle Atlantic region. Since 1974 when MJO data was first recorded, there have been 6 cases (1988, 1996, 2004, 2008, 2010, and 2013) when the MJO was in Phase 1 at an amplitude of 1.500 or above for 4 or more days during the July 1-10 period. The average temperature for those cases in New York City was 78.2° (1.7° above normal). The latest guidance suggests a mean temperature just below 79.0°. In 4/6 (67%) cases, there was at least one heat wave during the July 16-31 period and 4/6 (67%) those cases had a peak temperature of 95° or above during that period.

The implied probability of a warmer than normal July in New York City is currently 70%.

 

 

Whats the probability of a regionwide 100 degrees in July this year, Don?

 

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2 hours ago, JerseyWx said:

By meteorological standards, the seasons change when we flip the calendar on our wall.  That's why I think the Astronomical guidelines are more realistic, but that's just me.  

How far we're into the season is not overly significant anyway, because just as it can remain cold right into April, we can torch straight through October and beyond.  

They are more realistic because actual summer weather began around June 21, the solstice.  Also, our Septembers are often very warm to hot and I wouldn't be surprised if we had a few 90s right up to the equinox.

 

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1 hour ago, NYCweatherNOW said:

Yes but September and October this year in my opinion won’t torch, instead they will be cooler than other years. You do have the remainder of July and August to torch. Plenty of torching here. It hasn’t been terrible this year it’s been a dry heat type of summer thank goodness

ugh not that dry, dew points have been 70 and above here on a regular basis, and one day near 80!

 

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3 hours ago, LibertyBell said:

But it's also not a valid comparison because all other cities use airports, why on Earth do we use a park?  Also why was the sensor moved in 1996 and why doesn't NWS move the sensor back to the old location?  There seems to be some laziness going on over there.....

It’s not laziness. First of all they are out in Brookhaven. Second, moving the sensor would screw up the data set. 

Honestly, I could easily go and prune off the vegetation. But I’d be afraid of it getting back to my employer if I get caught.

Bring on the rain tonight, I’m really pulling for this one. I like the setup, in comparison to the past few. I think this is a region wide .5” plus.

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6 hours ago, NYCweatherNOW said:

Yes but September and October this year in my opinion won’t torch, instead they will be cooler than other years. You do have the remainder of July and August to torch. Plenty of torching here. It hasn’t been terrible this year it’s been a dry heat type of summer thank goodness

Well you may be right, but I'd stick with the trend of recent falls having some heat.

4 hours ago, LibertyBell said:

They are more realistic because actual summer weather began around June 21, the solstice.  Also, our Septembers are often very warm to hot and I wouldn't be surprised if we had a few 90s right up to the equinox.

 

Right, and it just makes sense because the earth's tilt and rotation determine the seasons, and astronomical dates actually take that into consideration.  It's not technically Summer until we hit the solstice or "longest day," rather than when our calendars turn to June.

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14 minutes ago, JerseyWx said:

Well you may be right, but I'd stick with the trend of recent falls having some heat.

Yeah we always get that late August or early September cooldown that people take to mean an early autumn but it never lasts. Last year we had those ridiculously high dewpoint days well into October 

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5 minutes ago, Stormlover74 said:

Yeah we always get that late August or early September cooldown that people take to mean an early autumn but it never lasts. Last year we had those ridiculously high dewpoint days well into October 

Definitely, most of our recent Fall's have become a continuation of Summer.

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25 minutes ago, JerseyWx said:

Definitely, most of our recent Fall's have become a continuation of Summer.

September is quickly becoming our 4th month of summer. Notice how the last 8 out of 9 September’s at LGA averaged at 70 degrees or higher. Big jump since the 1980’s. Several recent Septembers were as warm or warmer than June.

Monthly Mean Avg Temperature for LA GUARDIA AP, NY
Click column heading to sort ascending, click again to sort descending.
Year
Jun
Jul
Aug
Sep
Season
Mean 73.2 80.0 77.9 71.6 75.8
2010 76.0 82.8 78.6 72.5 77.5
2011 72.7 80.4 76.0 70.7 75.0
2012 72.9 80.4 78.7 70.7 75.7
2013 74.0 81.2 75.8 68.1 74.8
2014 72.5 77.0 75.1 70.4 73.8
2015 71.3 79.2 79.3 74.1 76.0
2016 73.6 81.1 81.6 73.8 77.5
2017 73.6 78.1 75.4 71.5 74.7
2018 72.9 79.8 81.0 72.8 76.6
2019 72.8 80.2 M M 76.5
Monthly Mean Avg Temperature for LA GUARDIA AP, NY
Click column heading to sort ascending, click again to sort descending.
Year
Jun
Jul
Aug
Sep
Season
Mean 71.4 77.0 75.6 68.4 73.1
1980 70.1 78.6 78.1 70.4 74.3
1981 72.6 78.1 75.7 66.4 73.2
1982 66.8 76.3 72.3 66.9 70.6
1983 72.5 78.3 76.7 70.6 74.5
1984 73.6 73.5 76.2 65.6 72.2
1985 68.8 76.6 75.7 70.7 72.9
1986 71.4 76.1 73.4 67.9 72.2
1987 72.9 77.6 74.0 68.1 73.2
1988 72.0 78.6 78.8 67.8 74.3
1989 72.9 76.1 75.3 69.7 73.5

 

 

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the warmer Septembers run in cycles although they are getting warmer on average...we are in a cycle where we are getting more cold March's and more warmer Septembers...throughout the years NYC has seen its hottest temperature of the year in September...1914 and 1895 had its hottest temp near the first day of the Fall...

NYC's highest temperature and month.

 

2015...........97.................Sept

2014...........92.................Sept

1983...........99.................September

1970...........94.................July/Aug/Sept.

1881...........101...............September

1895...........97.................September

1914...........95.................September

1915...........94.................September

1921...........96.................September

1931...........99.................September

1932...........96.................September

1953...........102...............September

The latest date for the hottest annual temperature is 97 on 9/23/1895...

95 on 9/22/1914 99 9/11/1983...The earliest annual date is 96 on 4/18/1976...

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6 hours ago, LibertyBell said:

But it's also not a valid comparison because all other cities use airports, why on Earth do we use a park?  Also why was the sensor moved in 1996 and why doesn't NWS move the sensor back to the old location?  There seems to be some laziness going on over there.....

When scientists measure out temps from 100s of years ago (tree rings, etc), the way the central park data is currently is probably more representative to how the vast majority of the planet was (overgrown and not de-forested) .  Do we add 2-3 degrees from past temps to match how we measure temps now? 

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7 hours ago, LibertyBell said:

But it's also not a valid comparison because all other cities use airports, why on Earth do we use a park?  Also why was the sensor moved in 1996 and why doesn't NWS move the sensor back to the old location?  There seems to be some laziness going on over there.....

Weather stations in parks or more rural areas are fine. But the sensors must be in a clearing so they are not blocked by trees. The big error was moving the thermometer in NYC from an open area of the park to under a canopy. 

 

 

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3 hours ago, bluewave said:

First, we get the heavy convection tonight with the tropical PWAT feed down to Barry and front. 0z Euro shifted the track of Barry to our south next week. So it gives us more rain and less heat than earlier runs. The further south track may be a result of the continuing record -NAO streak. So the exact Barry track will determine how much heat and rain we get. 

New run

83A68E59-E78E-4E46-949A-607DE3D67DC5.thumb.png.07449fa7379f56d92bcd1816d3512d5b.png

Old run

869E209A-B37A-47A9-BD0E-56EFD19BBA86.thumb.png.51339d7c415f466313b154a9e1d19270.png

Agreed and have been of the belief the caveat in extreme heat next week Tue - Sat will be the remnants of the system in the Gulf and its eventual trek east.  You have to imagine a day or two of clouds and storms to low the heat punch.    Either way even beyond there (7/21 and beyond) looks to continue hot with 850s 16-20.  So heat if anything may ne delayed or shortened but not denied. 

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50 minutes ago, frankdp23 said:

When scientists measure out temps from 100s of years ago (tree rings, etc), the way the central park data is currently is probably more representative to how the vast majority of the planet was (overgrown and not de-forested) .  Do we add 2-3 degrees from past temps to match how we measure temps now? 

The world is increasingly covered in concrete and less covered in forest. This should be included in the documented temp rise, notwithstanding AGW. Yes, NY temp used to be measured in a more rural area, but the city is less rural, causing temps to rise. Whether its AGW or UHI it doesnt matter in reality, the temp has increased. 

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8 minutes ago, uncle W said:

go touch a cement wall that was exposed to Sun light just after the sun sets...it is significantly warmer than the air temp...it's like an open oven...

True, and like it or not, a large portion of NYC is covered in cement. So, climate records should reflect the changed landscape, and not strive to replicate what the city resembled in the 1800s

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flash flood watch includes the city now. a sort of triple point low will slowly move across this evening, helping to focus showers and storms. some of the hi-res absolutely nails the area w/ some 4-6", locally higher, amounts. thinking more along the lines of 1-2" w/ local amounts to 4" (favored in NJ).

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flash flood watch includes the city now. a sort of triple point low will slowly move across this evening, helping to focus showers and storms. some of the hi-res absolutely nails the area w/ some 4-6", locally higher, amounts. thinking more along the lines of 1-2" w/ local amounts to 4" (favored in NJ).
Via WPCfa10d0d331127ec5c6950476081fc617.gif6b458991522606405b4e7276fa08142f.jpg
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