November 2021

[LibertyBell]

1 hour ago, bluewave said:

The thermometer needs to be in a fan aspirated radiation shield which all ASOS, NCDC, and mesonet weather stations have. But the sensor itself can’t be located under a dense canopy of trees which will keep it several degrees cooler than surrounding open grassy fields. The NY mesonet site has a great video on the proper sitting of weather sensors near heavily wooded areas away from tall trees.

NYC ASOS violates official sitting rules 

http://www.weather2000.com/ASOS/NYC_ASOS.html

You can imagine how much denser the canopy has become since the 2013 photo and 2003 story.

 

Central Park Weather: Vegetative Overgrowth Affecting Weather Readings - WABC-TV

(New York-WABC, August 22, 2003) - Forecasting the weather is not easy.
Government equipment can often be blamed for giving faulty weather
information. As Bill Evans explains, a big culprit may be some of the
equipment buried in Central Park.

Rainfall, snowfall, and the temperature are all vital information
recorded 24 hours a day at the weather station located in the heart of
Central Park.

But meteorologists like Michael Schlacter have serious concerns about the
accuracy of the stations data. It sits amid overgrown vegetation and he
says thats the problem. The leaves can trigger snow gauges and trees can
warp rain and wind measurements. On this hot day, a temperature gauge is
in the shade instead of direct sunlight.

Michael Schlacter, Weather 2000: "Its kind of like driving a car
without a speedometer, odometer, and gas gauge. You are running with
false information."

The weather instruments at Belvedere Castle have long adorned the top.
There used to be a government meteorologist here in the city to keep an
eye on them. But now the nearest meteorologist is 60 miles that way.

But National Weather Service meteorologists say they knew the weather
readings in the park would never be as keenly accurate as the ones at
the airports where guidelines prevent foliage from being within 100 feet
of the station.

Schlacter: "We knew that at times we would have flaky readings, that
leaves would fall in gauges, that we would have problems with
visibility sensors."

[NWS Meteorologist-in-Charge Michael] Wyllie says the weather station is
there because it was historically significant to maintain its presence
in the park.

He says theres been a lot of growth because of the wet spring at so much
in fact that temperatures have routinely been recorded lower in the park
than at the airports.

Wyllie: "We are actually having a micro climate system there because of
the vegetation."

Imperfect perhaps but nonetheless the system provides the official record
of weather for the country's largest city. And Michael Schlacter says
its a city that deserves better.

Schlacter: "I think New Yorkers deserve a lot better, and I think they
deserve the best weather station money can buy."


Copyright 2003 ABC Inc., WABC-TV Inc.

 

why the switch to ASOS anyway? The temps from the 80s and 90s were perfectly fine...if it aint broke dont "fix" it

 

[NorthShoreWx]

6 hours ago, coastalplainsnowman said:

Does this mean that the measured daytime temperatures at this time each year are influenced by the timing of when most of the leaves have fallen?

It was an old expression: "It's 75 in the shade".

The link above didn't have the specific ASOS sighting rules, but I imagine the rules regarding trees are most restrictive for wind sensing equipment.

[CIK62]

The last 2 days of November are averaging  37degs.(33/41), or -5.

Month to date is  46.9[-1.4].       November will end at  46.0[-2.0].

Reached 46 here yesterday.    SSTA must be keeping me warmer.

Today: 41-43, wind w., breezy late, some sun.        First 10 days of December now  36/47 = 41, or +2---Old Style Almanac. Lol.

GEFS Extended is more Gung-Ho on the 60's than the 20's, for the whole month of December.

39*(63%RH) here at 6am.    38* at 8am.      40* at 9am.      42* at Noon.      35* at 10pm.

[LoboLeader1]

34* here 

[donsutherland1]

Morning thoughts…

Today will be partly sunny and continued cooler than nor all. High temperatures will likely reach the lower and middle 40s in most of the region. Likely high temperatures around the region include:

New York City (Central Park): 43°

Newark: 46°

Philadelphia: 46°

Normals:

New York City: 30-Year: 49.4°; 15-Year: 49.7°

Newark: 30-Year: 50.0°; 15-Year: 50.4°

Philadelphia: 30-Year: 51.0°; 15-Year: 51.5°

The cool weather will continue through the remainder of November.

[lee59]

I have never seen the site in Central Park but I wonder if they want to keep it somewhat hidden because of possible vandalism. Of course they still can keep it reasonably under control with the overgrowth.

[dWave]

49 minutes ago, lee59 said:

I have never seen the site in Central Park but I wonder if they want to keep it somewhat hidden because of possible vandalism. Of course they still can keep it reasonably under control with the overgrowth.

I've always suspected that is a factor.  If it was out in the open I'm sure someone would mess with it just because. You still can now, its just not very noticeable unless you are looking for it.

[bluewave]

Before the Central Park thermometer was located under the trees, it used to have similar high temperatures to EWR and LGA during heatwaves. This shows open areas of the park outside of deep shade are much closer to LGA and EWR than people realize. The big 1970s heatwaves are a great example of this. 
 

1970s heatwaves in NYC before the trees were similar or warmer at times than EWR and LGA

Data for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Date	Max Temperature	Min Temperature
1973-08-28	98	77
1973-08-29	95	76
1973-08-30	98	78
1973-08-31	94	74
1973-09-01	95	72
1973-09-02	94	74
1973-09-03	96	75
1973-09-04	93	74

 

Data for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

Date	Max Temperature	Min Temperature
1973-08-28	100	79
1973-08-29	96	79
1973-08-30	98	79
1973-08-31	97	78
1973-09-01	95	75
1973-09-02	95	77
1973-09-03	94	79
1973-09-04	95	75

 

Data for LAGUARDIA AIRPORT, NY
Click column heading to sort ascending, click again to sort descending.

Date	Max Temperature	Min Temperature
1973-08-28	97	78
1973-08-29	94	77
1973-08-30	96	81
1973-08-31	94	75
1973-09-01	91	73
1973-09-02	92	75
1973-09-03	93	75
1973-09-04	93	75

 

Data for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Date	Max Temperature	Min Temperature
1977-07-13	93	73
1977-07-14	92	73
1977-07-15	96	72
1977-07-16	98	75
1977-07-17	97	78
1977-07-18	100	78
1977-07-19	102	78
1977-07-20	92	75
1977-07-21	104	78

 

Data for NEWARK LIBERTY INTL AP, NJ
Click column heading to sort ascending, click again to sort descending.

Date	Max Temperature	Min Temperature
1977-07-13	92	73
1977-07-14	91	73
1977-07-15	93	71
1977-07-16	97	72
1977-07-17	99	77
1977-07-18	98	75
1977-07-19	100	78
1977-07-20	90	75
1977-07-21	102	78

 

Data for LAGUARDIA AIRPORT, NY
Click column heading to sort ascending, click again to sort descending.

Date	Max Temperature	Min Temperature
1977-07-13	92	72
1977-07-14	89	72
1977-07-15	90	69
1977-07-16	96	72
1977-07-17	95	74
1977-07-18	95	76
1977-07-19	99	75
1977-07-20	90	74
1977-07-21	99	78

[psv88]

11 hours ago, NorthShoreWx said:

It was an old expression: "It's 75 in the shade".

The link above didn't have the specific ASOS sighting rules, but I imagine the rules regarding trees are most restrictive for wind sensing equipment.

No. The rules say the temp sensor needs to be a certain distance from all objects, including trees. We well know that a canopy of trees leads to cooler weather in the daytime and warmer weather at nightime, as it limits radiational cooling. 

This is Met 101.

[lee59]

17 minutes ago, psv88 said:

No. The rules say the temp sensor needs to be a certain distance from all objects, including trees. We well know that a canopy of trees leads to cooler weather in the daytime and warmer weather at nightime, as it limits radiational cooling. 

This is Met 101.

Exactly, which is why it would seem to me if they remove the foliage, temps would be higher in the day and lower at night, in general.

[etudiant]

2 hours ago, lee59 said:

I have never seen the site in Central Park but I wonder if they want to keep it somewhat hidden because of possible vandalism. Of course they still can keep it reasonably under control with the overgrowth.

The site is surrounded by a 10' cyclone fence with razor wire on top, so it takes determination to vandalize these instruments.

Actually, the Park is pretty well cared for at the moment, vandalism is down to its lowest levels in decades. However, the tree cover is also at its fullest in decades and surely skews the readings.

I'd not thought of the trades driven by cooling degree days, but there is a very active market in that supporting the natural gas futures.  Possibly there might be a legal liability here.

[psv88]

Point and click for today says 42 and sunny. 

It is currently snowing!

[psv88]

Not to mention the hourly grid says i have a 0% chance of precip right now

[Allsnow]

Light snow here currently 

[Rjay]

Light snow. 40 degrees

[BombsAway1288]

Heavy graupel in northern Bergen County. 

Place looks like a fertilizer truck spilt his load. 

[STORMANLI]

Snow pellet shower now

[psv88]

First accumulations of the season!

 

[lee59]

3 minutes ago, psv88 said:

First accumulations of the season!

 

That is what my area looked like yesterday morning about 7am. It was gone by 8, so you actually might have had the same thing yesterday but if you didn't look out side early, you missed it.

[dWave]

Moderate to occasionally heavy snow in lower Manhattan

[LibertyBell]

1 hour ago, dWave said:

Moderate to occasionally heavy snow in lower Manhattan

wtf is that headed here....42 and snowing here lol

 

how?

 

 

[LibertyBell]

5 hours ago, dWave said:

I've always suspected that is a factor.  If it was out in the open I'm sure someone would mess with it just because. You still can now, its just not very noticeable unless you are looking for it.

who in their right mind would steal weather equipment.....steal cars instead leave weather equipment alone it is of no value to the public

[bluewave]

41 minutes ago, LibertyBell said:

who in their right mind would steal weather equipment.....steal cars instead leave weather equipment alone it is of no value to the public

It was regularly getting stolen in the 1970s. Also notice how they mention that Central Park was warmer than LGA during the summer in the 1970s when the equipment was out in the open. Now it’s hidden underneath the trees and people can’t see it. So while it’s bad for accuracy, at least they don’t have to worry about it getting stolen or vandalized anymore.

https://www.nytimes.com/1977/07/22/archives/vandals-in-central-park-forcing-weather-service-to-seek-new-site.html

Besides taking New York City's temperature and trying to predict when it will go up or down. National Weather Service forecasters are searching for a new place in Central Park to keep the sensitive instruments they use to prepare their hourly reports.

“It's really a sh‐me, but we have to move,” said Harold Gibson, the meteorologist in charge of the New York bureau, as he stepped carefully through the debris at the crumbling Belvedere Castle, where weather data is collected and transmitted electronically to Weather Service headquarters in Rockefeller Center.

Mr. Gibson said he decided to leave the hilltop castle, which is the highest point in the park, because he cannot predict the frequency of break‐ins that interrupt the monitoring of temperature, humidity, sunlight and wind at the unmanned station in the unguarded, city‐owned castle, which is south of the Delacorte Theater at 79th Street on the west side of the park.

Vandalism Disrupts Work

“Mostly we suffer from malicious destruction,” Mr. Gibson said. “The problem up here can be as little as somebody pulling a circuit‐breaker switch that stops the current and halts the measurements. But from our standpoint, that's almost as bad as stealing all the equipment—it disrupts our work.”

The last break‐in occurred two weeks ago. The thermometer was not damaged, but the anemometer, which meastures wind speeds, was stolen, and other equipment has not functioned properly since.

Some of the forecasters work in windowless rooms and cannot tell whether the sun is shining without the Central Park equipment. As a result, visitors to the Weather Service office at Rockefeller Center are sometimes asked what the weather outside is like.

When the devices at the castle are not functioning, the Weather Service substitutes readings from La Guardia Airport. But Mr. Gibson said those readings do not really reflect conditions in the city, because they may be several degrees cooler in summer or warmer in winter than those in Central Park.

During the current hot spell, the Weather Service has used wind and humidity readings from La Guardia in its forecasts. Replacing the Central Park equipment is fairly expensive—an anemometer costs about $2.500, Mr. Gibson said—but the forecasers arc reluctant to install replacements because they fear another break‐in.

“Whoever does this to us is speedy,” Mr. Gibson said, recalling_ one break‐in that had occurred in the morning. By 2:30 P.M. the repairs were completed. No sooner was the 4 P.M. forecast released than the new equipment was stolen.

The police have increased the number of patrols passing the castle, and that has deterred some vandals, Mr. Gibson said. And the Parks Department put steel gratings over the windows after vandals smashed through the concrete blocks that had been installed in place of the semicircular windows.

“Clearly, that's not enough,” said Joseph P. Bresnan, director of historic parks, monuments and restoration. “That building should be used.”

Meanwhile, the stonework at the castle, which was designed by Calvert Vaux, a collaborator wtih Frederick Law Olmsted on the design of Central Park, has been frescoed with graffiti.

A $557,000 project to restore the castle, the top priority item in a 1973 study of Central Park, has been put off indefinitely because of the city's economic problems.

One possible site for housing the sensitive instruments is the roof of the Central Park Precinct station house, which the police have offered. It is only a short distance from the castle, and meteorologists think the climate conditions there are almost identical to those at Belvedere, where weather data have been gathered for 109 years.

“It would be almost criminal to destroy the century‐old data base we have accumulated here at Central Pork.” Mr. Gibson said. “It is one of the best in the United States, or, for that matter, in the world.”

 

[LibertyBell]

1 hour ago, bluewave said:

It was regularly getting stolen in the 1970s. Also notice how they mention that Central Park was warmer than LGA during the summer in the 1970s when the equipment was out in the open. Now it’s hidden underneath the trees and people can’t see it. So while it’s bad for accuracy, at least they don’t have to worry about it getting stolen or vandalized anymore.

https://www.nytimes.com/1977/07/22/archives/vandals-in-central-park-forcing-weather-service-to-seek-new-site.html

Besides taking New York City's temperature and trying to predict when it will go up or down. National Weather Service forecasters are searching for a new place in Central Park to keep the sensitive instruments they use to prepare their hourly reports.

“It's really a sh‐me, but we have to move,” said Harold Gibson, the meteorologist in charge of the New York bureau, as he stepped carefully through the debris at the crumbling Belvedere Castle, where weather data is collected and transmitted electronically to Weather Service headquarters in Rockefeller Center.

Mr. Gibson said he decided to leave the hilltop castle, which is the highest point in the park, because he cannot predict the frequency of break‐ins that interrupt the monitoring of temperature, humidity, sunlight and wind at the unmanned station in the unguarded, city‐owned castle, which is south of the Delacorte Theater at 79th Street on the west side of the park.

Vandalism Disrupts Work

“Mostly we suffer from malicious destruction,” Mr. Gibson said. “The problem up here can be as little as somebody pulling a circuit‐breaker switch that stops the current and halts the measurements. But from our standpoint, that's almost as bad as stealing all the equipment—it disrupts our work.”

The last break‐in occurred two weeks ago. The thermometer was not damaged, but the anemometer, which meastures wind speeds, was stolen, and other equipment has not functioned properly since.

Some of the forecasters work in windowless rooms and cannot tell whether the sun is shining without the Central Park equipment. As a result, visitors to the Weather Service office at Rockefeller Center are sometimes asked what the weather outside is like.

When the devices at the castle are not functioning, the Weather Service substitutes readings from La Guardia Airport. But Mr. Gibson said those readings do not really reflect conditions in the city, because they may be several degrees cooler in summer or warmer in winter than those in Central Park.

During the current hot spell, the Weather Service has used wind and humidity readings from La Guardia in its forecasts. Replacing the Central Park equipment is fairly expensive—an anemometer costs about $2.500, Mr. Gibson said—but the forecasers arc reluctant to install replacements because they fear another break‐in.

“Whoever does this to us is speedy,” Mr. Gibson said, recalling_ one break‐in that had occurred in the morning. By 2:30 P.M. the repairs were completed. No sooner was the 4 P.M. forecast released than the new equipment was stolen.

The police have increased the number of patrols passing the castle, and that has deterred some vandals, Mr. Gibson said. And the Parks Department put steel gratings over the windows after vandals smashed through the concrete blocks that had been installed in place of the semicircular windows.

“Clearly, that's not enough,” said Joseph P. Bresnan, director of historic parks, monuments and restoration. “That building should be used.”

Meanwhile, the stonework at the castle, which was designed by Calvert Vaux, a collaborator wtih Frederick Law Olmsted on the design of Central Park, has been frescoed with graffiti.

A $557,000 project to restore the castle, the top priority item in a 1973 study of Central Park, has been put off indefinitely because of the city's economic problems.

One possible site for housing the sensitive instruments is the roof of the Central Park Precinct station house, which the police have offered. It is only a short distance from the castle, and meteorologists think the climate conditions there are almost identical to those at Belvedere, where weather data have been gathered for 109 years.

“It would be almost criminal to destroy the century‐old data base we have accumulated here at Central Pork.” Mr. Gibson said. “It is one of the best in the United States, or, for that matter, in the world.”

 

why cant they just put it where it cant be accessed?  Like put an electric fence around the area or something.  The crime rate was really high in the 70s, the city was basically a giant slum, it's nothing like that anymore.

 

[donsutherland1]

Dry but cool weather will continue into the middle of the week. A brief push of milder air could occur on Thursday ahead of the next cold front. No Arctic blasts appear likely for the foreseeable future.

First measurable snowfall statistics for select cities:

Allentown: Normal: December 6; 2020-21: December 9
Bridgeport: Normal: December 3; 2020-21: December 16
Islip: Normal: December 10; 2020-21: December 16
New York City: Normal: December 13; 2020-21: December 16
Newark: Normal: December 9; 2020-21: December 9; 2021-22: November 28
Philadelphia: Normal: December 19; 2020-21: December 16

Out West, Denver has yet to see its first measurable snowfall through November 28. The previous record latest first measurable snowfall occurred on November 21, 1934. Phoenix reached 80° for the 24th time this month. That tied the November record, which was set in 1949. That record could be surpassed tomorrow.

Atlantic blocking (AO and NAO) will break down during the first week of December. As a result, temperatures will likely turn milder for at least a time. Although the first 10 days of December will likely average somewhat cooler than normal overall from a lag in the pattern response to the breakdown in Atlantic blocking, the first half of the month overall could wind up near normal or somewhat warmer than normal. Afterward, developments related to the EPO and AO could determine the outcome for much of the remainder of the month. For now, there remains uncertainty about the evolution of the teleconnections.

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 29 4 pm is 16.41".

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 -1.0°C and the Region 3.4 anomaly was -0.7°C for the week centered around November 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.80°C and the ENSO Region 3.4 anomaly has averaged -0.90°C. La Niña conditions will likely persist into at least late winter.

The SOI was -1.72 today.

The preliminary Arctic Oscillation (AO) figure was -0.829 today.

On November 27 the MJO was in Phase 4 at an amplitude of 1.104 (RMM). The November 26-adjusted amplitude was 1.255 (RMM).

Based on sensitivity analysis applied to the latest guidance, there is an implied near 100% probability that New York City will have a cooler than normal November (1991-2020 normal). November will likely finish with a mean temperature near 46.2° (1.8° below normal).

 

[NorthShoreWx]

7 hours ago, psv88 said:

No. The rules say the temp sensor needs to be a certain distance from all objects, including trees. We well know that a canopy of trees leads to cooler weather in the daytime and warmer weather at nightime, as it limits radiational cooling. 

This is Met 101.

It really was a widely used expression.

[bluewave]

1 hour ago, LibertyBell said:

why cant they just put it where it cant be accessed?  Like put an electric fence around the area or something.  The crime rate was really high in the 70s, the city was basically a giant slum, it's nothing like that anymore.

 

They made the decision in the 90s when the office moved to OKX to accept the less accurate readings from Central Park.  
 

But National Weather Service meteorologists say they knew the weather
readings in the park would never be as keenly accurate as the ones at
the airports where guidelines prevent foliage from being within 100 feet
of the station.

[Rjay]

1 hour ago, NorthShoreWx said:

It really was a widely used expression.

I remember.  

[ForestHillWx]

Cold night incoming, clear skies and no winds. 29 currently. 

[SnoSki14]

1 hour ago, ForestHillWx said:

Cold night incoming, clear skies and no winds. 29 currently. 

28F right now. Temps dropping quickly outside urban areas.