NWS Zones Philadelphia / Mount Holly Specific Climate Data Analytics (Stay Away from this thread if you dislike debate!!)

[ChescoWx]

I thought I would start a unique thread specific to the Philadelphia Mount Holly Zone for those of you that have any interest in this kind of long term climate data. That said I wanted to respect those of you who wish to avoid this kind of long term climate analysis which due to our limited years of data will often lead to debate you may wish to avoid!

If this kind of longer term Climate Data Analytics is not your cup of tea...please avoid this thread as many on both sides of the debate view this topic sort of like a religion!

But if you like so many folks on this forum seem to enjoy and learn from this kind of real world climate data and analytics please feel free to post here.

But please if you post here....be sure to come forward with your data to support your position as folks on this thread are more interested in facts over what you feel the climate might be perceived to be doing here in the Philadelphia / Mount Holly Zone !!  Thanks to all of you!!!

[ChescoWx]

Let's start this baby off for those of you interested in actual factual climate for our area!! Thanks again!!!

Below is a chart splitting the Chester County PA Climate Period between almost down the middle since 1895. We have 64 years climate averages by month from 1895 thru 1959 with a comparison to the most recent average temperatures for the 63 year period from 1960 thru 2023. The top (Grey) includes all 27 Chester County stations (even those introduced with modest relative elevation increases). The next section (Yellow) shows the adjusted NOAA/NCEI Altered Adjusted Data. The bottom (green) only includes the 17 stations at a similar relatively lower elevation. Not surprising across all of the actual data there has been essentially no change in our average annual temperatures over the last 63 years vs. the prior 64 years. The only way we get any warming (+1.2 degrees) at all to appear is to apply the post observation adjustments to the data (as shown in the altered data in yellow). Of most interest overall Januaries have trended colder and Decembers warmer but all other months only show slight variations over the split climate periods of record.

[ChescoWx]

Below is an analysis of 100 degree days by Decade. Not surprisingly about 50% of these extreme hot days all occurred between the 1930's through 1950's. We have noted a sharp decline in these type of extreme heat days across the County. So far in the 2020's only one such day here in Chesco back on August 23, 2021.

[ChescoWx]

I was asked to also look at hot days >95 degrees over the same time frame. Plus I added in the average number per station as the number of stations have changed by decade with a dramatic increase in stations in the 2010's . Again the hottest decades were the 1930's thru 1950's.

[ChescoWx]

So are the nights getting warmer in the Philly burbs (I actually thought they would show this) but as with all of the temperature analytics - very cyclical with a cooling trend in excessively high nighttime lows over the last 2 complete decades.

[ChescoWx]

Below is the by decade split of average temps for complete decades since the 1950's sorted by elevation above sea level. Low stations are below 450 feet above sea level. As we typically have seen the temperatures have been very cyclical in nature with cooler decades followed by warmer rinse and repeat. The lower elevations during the 2010's were within 0.2 degrees of the 1950's....both the higher and lower spots have actually cooled a bit since the 1990's peak warmth.

[ChescoWx]

Here in the Philly burbs of Chester County PA June 2023 was only good for the 15th warmest June since 1893. More interesting is 13 of the 20 (yellow highlights) warmest June's occurred prior to 1980. Back before our current warmer cycle....

[ChescoWx]

Below is the average July temperatures by decade for complete decades in Chester County since 1900. The actual averages are in blue and in red you can see the machine adjusted NOAA/NCEI revised averages. These adjusted averages as we have noted before are continuing with their consistent chilling of older decades and now the warming of our most recent decades. Of note in just the last 3 years 2020-2023 they have already adjusted the July average temperature up by 0.7 degrees for this decade of the 2020's...this includes the massive 1.1 degree warming they applied to July 2022.

[ChescoWx]

Hey guys thanks to Charlie (Chubbs) I was just able to figure out how to find detailed NCEI adjustments for individual stations in Chester County. I am starting with the original Coatesville 1SW station . Below is an analysis of the actual/raw average annual temperature data vs. the NCEI altered data for Coatesville 1SW from 1894 thru 1982. As discussed before NCEI has multiple reasons stated to support these adjustments. (Time of observation/ station moves/ equipment or siting issues etc.) But of interest the chilling adjustments were consistently applied to the first 71 years (1894 thru 1971) The greatest chilling adjustments were applied to the oldest data with at least 2 degrees F adjustments made from 1897 thru 1922 along with 1931-35 and 1941-45. The end result with the altered data (red) flips what the raw data (blue) clearly shows as cooling trend during those years....to now a clear warming trend. The greatest overall chilling adjustments were made to the October thru December months. But 100% of all months for all years were chilled for April through October. February had the least number of months chilled with 75 of the 89 months while January and March both saw chilling adjustments to 78 of the 89 months on record.

[ChescoWx]

Below is the average summertime (June thru August) average temperatures by decade for Chester County since the 1890's. The hottest complete decades were back in the 1930's and 1940's. We are only 3 years in to the 2020's but so far we are tied for 2nd warmest decade but plenty of years left to work on this decade.

[zenmsav6810]

I don't mean to be rude, but are you having a debate with yourself? Lol. I dont know to much about NCEI adjustments but I'd enjoy seeing some of your temperature data presented with average windspeed and humudity too. My friend who is spent some time as a climate physicist seemed to take uncorrected wet bulb as the most important measurement. 

[zenmsav6810]

On 7/13/2024 at 11:06 AM, ChescoWx said:

Hey guys thanks to Charlie (Chubbs) I was just able to figure out how to find detailed NCEI adjustments for individual stations in Chester County. I am starting with the original Coatesville 1SW station . Below is an analysis of the actual/raw average annual temperature data vs. the NCEI altered data for Coatesville 1SW from 1894 thru 1982. As discussed before NCEI has multiple reasons stated to support these adjustments. (Time of observation/ station moves/ equipment or siting issues etc.) But of interest the chilling adjustments were consistently applied to the first 71 years (1894 thru 1971) The greatest chilling adjustments were applied to the oldest data with at least 2 degrees F adjustments made from 1897 thru 1922 along with 1931-35 and 1941-45. The end result with the altered data (red) flips what the raw data (blue) clearly shows as cooling trend during those years....to now a clear warming trend. The greatest overall chilling adjustments were made to the October thru December months. But 100% of all months for all years were chilled for April through October. February had the least number of months chilled with 75 of the 89 months while January and March both saw chilling adjustments to 78 of the 89 months on record.

It would be interesting to see this data correlated with forest cover data too. It could help describe some of the discrepancies as most of the area was clear cut.  

[ChescoWx]

On 7/17/2024 at 12:19 PM, zenmsav6810 said:

I don't mean to be rude, but are you having a debate with yourself? Lol. I dont know to much about NCEI adjustments but I'd enjoy seeing some of your temperature data presented with average windspeed and humudity too. My friend who is spent some time as a climate physicist seemed to take uncorrected wet bulb as the most important measurement. 

Hi zenmsav - not rude at all. I suspect you are correct with the self debate LOL! Hopefully folks not interested just ignore this....which most but not are seem to be doing! I do not have average windspeed and humidity for all stations....but I may add those in to my dataset for those that have that data.. Thanks!

[ChescoWx]

Do you think there is a problem with the KRDG Thermometer? Further north in Berks County -  higher elevation yet now consistently warmer than the lowest and warmest somewhat urban location in Chester County - Phoenixville. At this rate KRDG might approach KPHL levels soon.

[zenmsav6810]

8 hours ago, ChescoWx said:

Do you think there is a problem with the KRDG Thermometer? Further north in Berks County -  higher elevation yet now consistently warmer than the lowest and warmest somewhat urban location in Chester County - Phoenixville. At this rate KRDG might approach KPHL levels soon.

I would say not. Reading is surrounded by tall hills which probably amplifies the heat island effect which is something Philly does not contend with. Could the steel mill and power plants in Reading be interfering too? Its also a much more compact layout than Philly. Plus I would think the heat capacity of the old brick buildings in Reading is greater than modern steel, concrete and asphalt structurers in Philly. Philly rivers and waterfrontage (and likely forested and park areas) are much larger too when compared to Reading. 

[ChescoWx]

14 hours ago, zenmsav6810 said:

I would say not. Reading is surrounded by tall hills which probably amplifies the heat island effect which is something Philly does not contend with. Could the steel mill and power plants in Reading be interfering too? Its also a much more compact layout than Philly. Plus I would think the heat capacity of the old brick buildings in Reading is greater than modern steel, concrete and asphalt structurers in Philly. Philly rivers and waterfrontage (and likely forested and park areas) are much larger too when compared to Reading. 

The last 8 week analysis of the temperature at KRDG indicates per the below a possible radiation shield problem for why they are reading so high.

[ChescoWx]

Below is a great illustration of how the post observation NOAA/NCEI adjustments are skewing the analysis. They are continuing to warm even the current decade - following the chilling adjustments made to the hottest summer decades back in the 1930's thru 1950's. If you believe the red NCEI trends we are warming pretty quickly....if the actual raw blue data is viewed....almost flat! No summer warming here in Chester County PA....

[wkd]

I missed a lot of posts but I was wondering if you consider your location as representative of global temperature trends?

[ChescoWx]

On 8/1/2024 at 9:51 AM, wkd said:

I missed a lot of posts but I was wondering if you consider your location as representative of global temperature trends?

Absolutely not! It has nothing to do with global temperature trends. It is exclusively about the actual climate of Chester County PA

[ChescoWx]

We finished July across Chester County with an average temperature of 76.9 degrees. This is the 19th warmest July since 1893 - the warmest being July 2011. The first 7 months of 2024 with an average temperature of 54.8 degrees is the 4th warmest start to a year- the all time warmest being way back in 1921 . The warmest temperature in July 2024 was the 99 degrees at Phoenixville (16th) and the lowest was the 52.9 degrees at Warwick Twp. (2nd). The wettest spot during July was at Spring City where 5.04" of rain fell the least rain fell at KOQN Brandywine Airport where only 1.70" of rain fell.

Ranking below:

[ChescoWx]

Below is an analysis of the actual average annual Chester County PA temperatures over the last 100 years from 1924 through 2023. We have been in our current warming cycle since the 1990's but have to date still failed to reach the warmth we experienced in the 1930's. Will we get as warm as then before our next cooling cycle??

[TheClimateChanger]

On 7/23/2024 at 10:01 AM, ChescoWx said:

Below is a great illustration of how the post observation NOAA/NCEI adjustments are skewing the analysis. They are continuing to warm even the current decade - following the chilling adjustments made to the hottest summer decades back in the 1930's thru 1950's. If you believe the red NCEI trends we are warming pretty quickly....if the actual raw blue data is viewed....almost flat! No summer warming here in Chester County PA....

This is actually surprisingly easy to debunk. Chester County is part of what is known as the Southeastern Piedmont climatological region of Pennsylvania.

In August 1975, the mean of 19 stations was 74.6F.

In August 2022, the mean of 21 stations was 77.2F.

If you pull up the current divisional data from NCEI, you'll see August 1975 is 73.0F. Looks pretty damning - that's a drop of 1.6F over what was reported. But then turn to August 2022, the value is 76.3F, or 0.9F cooler than reported. It's important to note that the values reported in the publication are simply the arithmetic mean of the station data, while the means shown on NCEI are areal averages factoring in topography/elevation etc. As long as processed in the same manner, the suite of stations can change and still produce a comparable value. In any event, there is no systematic warming of recent data like these guys frequently show - the opposite, in fact. You're welcome to do this with any time period, any month, any region since they started using the current climatological divisions and the result.

That's why it's important, as @ChescoWx always says, to look at the raw data!

 

 

[TheClimateChanger]

NCEI reports August 2022 was 3.3F warmer than August 1975 in the Southeastern Piedmont region of Pennsylvania. Is this reasonable?

One way of looking at this would be to compare stations for which data is available in both periods - unfortunately, I see only two such stations - Philadelphia International Airport and Phoenixville. Looking at these two, PHL was 4.7F warmer in August 2022 relative to August 1975. Phoenixville was 4.4F warmer, albeit with some missing data in 2022. Additionally, the Franklin Institute site (2022) is very near to the 23rd & Market site (1975) in Philadelphia. It was 4.3F warmer in 2022 versus 1975 at those two sites. 

Overall, if anything, the NCEI figures look cooler than the comparative data might suggest. This looks like more hullabaloo over nothing.

[ChescoWx]

19 hours ago, TheClimateChanger said:

This is actually surprisingly easy to debunk. Chester County is part of what is known as the Southeastern Piedmont climatological region of Pennsylvania.

In August 1975, the mean of 19 stations was 74.6F.

In August 2022, the mean of 21 stations was 77.2F.

If you pull up the current divisional data from NCEI, you'll see August 1975 is 73.0F. Looks pretty damning - that's a drop of 1.6F over what was reported. But then turn to August 2022, the value is 76.3F, or 0.9F cooler than reported. It's important to note that the values reported in the publication are simply the arithmetic mean of the station data, while the means shown on NCEI are areal averages factoring in topography/elevation etc. As long as processed in the same manner, the suite of stations can change and still produce a comparable value. In any event, there is no systematic warming of recent data like these guys frequently show - the opposite, in fact. You're welcome to do this with any time period, any month, any region since they started using the current climatological divisions and the result.

That's why it's important, as @ChescoWx always says, to look at the raw data!

 

 

First off my analysis is certainly not for any climate division as PHL/NE PHL/Marcus Hook are part of the Atlantic Coastal Plain and not in the Piedmont no matter how the above is grouped. The land geography changes to rolling hills west of philly. The raw data for Chester County PA stands and of course is the actual data specific and exclusively for Chester County. Pooling non related data from another county and topography like multiple Philadelphia stations and Marcus Hook is not represent the actual Chester County data.

[ChescoWx]

Some updates to the Chester County climate data set. Below is a great illustration of how the NOAA altered data has resulted in a more pronounced (but still not scary) warming trend in the Philly burbs of Chester County PA. However the unaltered and un-adjusted raw NWS data clearly shows almost no warming at all in Chester County PA since 1895 . Now with those little post hoc chilling of the old and warming of the new.....FYI - NOAA has now chosen to warm each and every year for the last 25 years!! That red line sure looks a wee bit different!! Reminder this is only for Chester County PA and does not reflect any world data...(but I am starting to wonder if there might be a climate fence around our fair Chester County PA???)

 

1

[ChescoWx]

I thoughts I would split down the middle the entire Chester County PA data set. With an annual average temperature analysis of the first 66 years of data from 1893 thru 1957 vs. the last 65 years from 1958 thru 2023.

The average temperature from 1893-1957 was 53.0 degrees

The average temperature from 1958 - 2023 was 52.6 degrees

[ChescoWx]

I have updated the climate data base for Chester County to add additional stations. See the total list below. These include some that record all weather types (temperature, rain and snow), some just rain and snow and a few just rainfall amounts. This brings the total current and historical network up to 34 NWS COOP/MADIS/AWOS stations to 34. You will note I have included the mapping coordinates. The approximate midpoint latitude in the County is at 39.8 degrees - we have 18 stations north of there and 16 stations in Southern Chester County

[ChescoWx]

Updated Chester County Average Temperatures by Decade 1890's thru 2020's (only 4 years) IF we don't start to see some cooling over the remainder of the decade we have a chance that the 2020's could be the warmest complete decade since reliable climate data began to be recorded in the 1890's. So far in the 2020's we are running 0.6 degrees warmer than our warmest full decade - the 1930's.

[ChescoWx]

Below is a bit of a busy slide but for the first time it shows all 30 NWS stations (color coded if you wish to follow your favorite station) with each stations average annual temperature history plotted individually since 1893 thru 2023. The red trend line shows the overall average of all stations. As we have shown before here in Chester County we have seen nearly flat average temperature trends over the last 130+ years.

[ChescoWx]

Below is an analysis of the average fall (September - November) temperatures across the Philly burbs of Chester County PA since 1893. The data shows our falls are actually getting cooler over the last 130+ years.