Chester County PA - Analytical Battle of Actual vs. Altered Climate Data

[ChescoWx]

1 hour ago, TheClimateChanger said:

A little deeper dive in the Chester County temperatures over the past 18 years. Maybe @chubbshas an explanation.

 

I calculate a warming trend of 12.64F/century at the U.S. CRN station located at Avondale 2N, a warming trend of 12.13F/century at PHL Airport, a warming trend of 11.14F/century at @ChescoWx's East Nantmeal location. Yet NCEI only reports a warming of 7.99F/century.  According to data supplied by @ChescoWx, other stations he analyzes (varying sites) show a warming of 6.91F/century over this timeframe when averaged together. It looks to me like NCEI is underdoing recent warming, when the gold standard CRN station is showing so much warming, supported by PHL's data and @ChescoWx's high quality backyard data. I suspect actual warming could reach 15-20F/century over the coming decades before plateauing.

 

 

 

Holy cow!!! LOL!! 15-20F over the next century huh?? NCEI better get their act together and let's increase those post hoc altered numbers and ramp up those raw numbers even more than they have in the past!! Let's hope they do that and quick before we all boil!!! 

[TheClimateChanger]

24 minutes ago, ChescoWx said:

Holy cow!!! LOL!! 15-20F over the next century huh?? NCEI better get their act together and let's increase those post hoc altered numbers and ramp up those raw numbers even more than they have in the past!! Let's hope they do that and quick before we all boil!!! 

I think such warming is plausible, especially in the winter. Last 50 years trend is +12.3F/century statewide for January - more in certain areas, especially in the north.

Prior to this year's chilly January, it had been nearing 14F/century. If we reel off a couple of very mild Januarys, it could reach 15F/century soon.

[TheClimateChanger]

I always see people dismiss this analysis and go back to 1895, but that makes little sense. From 1895 to 1970, CO2 went from 294 to 324 ppm, a relatively small 30 ppm increase over 75 years. It's now more than 100 ppm higher than it was 55 years ago. So that's a big change, and there's less cooling sulfur aerosols from industry today. There's certainly nothing to suggest the trendline is going to get less steep with time. In fact, 4 of the past 6 Januarys are above the trend I display above, whereas 6 of the first 7 and 8 of the first 10 are below. This suggests a possible acceleration in the trendline.

[chubbs]

1 hour ago, TheClimateChanger said:

A little deeper dive in the Chester County temperatures over the past 18 years. Maybe @chubbshas an explanation.

I calculate a warming trend of 12.64F/century at the U.S. CRN station located at Avondale 2N, a warming trend of 12.13F/century at PHL Airport, a warming trend of 11.14F/century at @ChescoWx's East Nantmeal location. Yet NCEI only reports a warming of 7.99F/century.  According to data supplied by @ChescoWx, other stations he analyzes (varying sites) show a warming of 6.91F/century over this timeframe when averaged together. It looks to me like NCEI is underdoing recent warming, when the gold standard CRN station is showing so much warming, supported by PHL's data and @ChescoWx's high quality backyard data. I suspect actual warming could reach 15-20F/century over the coming decades before plateauing.

 

 

 

18 years is a short period so there is uncertainty in the individual station slopes. Here are a couple of charts that cover a longer period. Local warming has been roughly 7F per decade for the past 54 years. Warming has sped up over the past 15-20 years globally so higher rates of warming locally recently wouldn't be surprising. But, a longer period of time is needed to say anything definitive. What we can say is that there is no evidence that Chester County is warming any differently than other regional sites. Can also see that the Coatesville station moves in 1946/47 makes raw data before then unusable for climate trend purposes. 

[ChescoWx]

23 minutes ago, TheClimateChanger said:

I always see people dismiss this analysis and go back to 1895, but that makes little sense. From 1895 to 1970, CO2 went from 294 to 324 ppm, a relatively small 30 ppm increase over 75 years. It's now more than 100 ppm higher than it was 55 years ago. So that's a big change, and there's less cooling sulfur aerosols from industry today. There's certainly nothing to suggest the trendline is going to get less steep with time. In fact, 4 of the past 6 Januarys are above the trend I display above, whereas 6 of the first 7 and 8 of the first 10 are below. This suggests a possible acceleration in the trendline.

Still giggling over the 15f to 20f....hardest I have laughed in a long time!! 

[chubbs]

On 7/7/2025 at 1:00 PM, ChescoWx said:

So I have finally completed the analysis of the Ghost Data stations and compared their inputs vs. the actual averages across the County. NOAA has employed techniques like interpolation to estimate temperatures in what they normally would say are data-sparse regions and in other cases this data may be resampled from another grid.  Of note there are seven (7) ghost stations employed across Chester County PA with this estimated temperature data in the period of record from 1895 through 2013. All of these were during the ghost years reporting only precipitation data. Some eventually did begin actual temperature reporting after the ghost years. The Ghost Stations and years of estimated data are Phoenixville (1895-1914) / West Grove (1928-1962) / Coatesville (1948-1955) / Glenmoore (1957-2005) / Honey Brook (1957-2013) / West Chester 2W (1979-1981) and Devault (1988-2004). Overall there are 189 years of ghosted data used to "fill in data gaps". Of note this ghost data was warmer than the actual county records in 101 of the 106 years of ghosted data between 1895 and the "shuttering "of the last remaining ghost station at Honey Brook in 2013.. The largest warming adjustments were unsurprisingly made during the coldest decades of the 1960's and 1970's. Below is an analysis of the impact on average temperature trend lines between the actual raw data and ghost data in the years these adjustments were applied. Some more analysis on this data will follow. 

Thinking about this. The chart tells us more about your method  than it does about "ghost data". The "ghost data" is a simple re-analysis product developed by IEM. There is no bias adjustment. Raw data from available sites is used to back fill for missing data at other stations. So you are plotting raw data vs raw data. Not sure what you did, but guessing that the main difference between the two charts is the station population. Your base analysis, the blue line, starts with a relatively warm station population and transitions to a cool group. Which completely hides local warming. Use a group of stations with less cooling bias and the warming re-appears. Thanks for illustrating how your method distorts our local climate. Of course the red line still underestimates warming because station moves and other station changes are included.

 

 

 

[ChescoWx]

57 minutes ago, chubbs said:

Thinking about this. The chart tells us more about your method  than it does about "ghost data". The "ghost data" is a simple re-analysis product developed by IEM. There is no bias adjustment. Raw data from available sites is used to back fill for missing data at other stations. So you are plotting raw data vs raw data. Not sure what you did, but guessing that the main difference between the two charts is the station population. Your base analysis, the blue line, starts with a relatively warm station population and transitions to a cool group. Which completely hides local warming. Use a group of stations with less cooling bias and the warming re-appears. Thanks for illustrating how your method distorts our local climate. Of course the red line still underestimates warming because station moves and other station changes are included.

 

 

 

At least you stick to the same playlist....

[chubbs]

1 hour ago, ChescoWx said:

At least you stick to the same playlist....

Yes, the facts. Can you list the stations that the red and blue lines were derived from?

[ChescoWx]

1 hour ago, chubbs said:

Yes, the facts. Can you list the stations that the red and blue lines were derived from?

Still finding more of these Ghost Stations and trying to see where they grabbed the data from - but so far Phoenixville (1895-1914) / West Grove (1928-1962) / Coatesville (1948-1955) / Glenmoore (1957-2005) / Honey Brook (1957-2013) / West Chester 2W (1979-1981) and Devault (1894-1950 and again from 1989 thru 2003) 

[chubbs]

32 minutes ago, ChescoWx said:

Still finding more of these Ghost Stations and trying to see where they grabbed the data from - but so far Phoenixville (1895-1914) / West Grove (1928-1962) / Coatesville (1948-1955) / Glenmoore (1957-2005) / Honey Brook (1957-2013) / West Chester 2W (1979-1981) and Devault (1894-1950 and again from 1989 thru 2003) 

How IEM estimates missing values is explained on the IEM site. Likewise NOAA/NCEI's method is explained in peer reviewed articles and other documentation. No sleuthing, no tin foil hat, needed. 

You didn't answer my question about the stations used for your red and blue lines. Wonder why.

[ChescoWx]

3 minutes ago, chubbs said:

How IEM estimates missing values is explained on the IEM site. Likewise NOAA/NCEI's method is explained in peer reviewed articles and other documentation. No sleuthing, no tin foil hat, needed. 

You didn't answer my question about the stations used for your red and blue lines. Wonder why.

Nothing hidden it is what is says the red is ghost and blue is actual raw data...

[chubbs]

5 minutes ago, ChescoWx said:

Nothing hidden it is what is says the red is ghost and blue is actual raw data...

It isn't clear what you did. What stations were used for the red line?  The stations listed in your post: Phoenixville, West Grove, Coatesville, Glenmoore, Honey Brook, West Chester and Devault? If so it's a much different set of stations vs the blue that could easily explain the differences between the two lines.

 

[ChescoWx]

1 hour ago, chubbs said:

It isn't clear what you did. What stations were used for the red line?  The stations listed in your post: Phoenixville, West Grove, Coatesville, Glenmoore, Honey Brook, West Chester and Devault? If so it's a much different set of stations vs the blue that could easily explain the differences between the two lines.

 

Correct! estimate of ghost averages vs actual averages for those years.

[chubbs]

43 minutes ago, ChescoWx said:

Correct! estimate of ghost averages vs actual averages for those years.

So for Phoenixville what is the difference between ghost and actual?