ChescoWx

We had some light rain earlier with more just entering the county from the south. We should see a few rounds of rain some heavy through tonight into tomorrow morning. Many spots could pick up at least 1" to 2" of rain - higher amounts are possible. With the rain temps will be a bit below average (83 degrees) today. We dry out and heat up again by Sunday. Chester County records for today: High 104 degrees at Phoenixville (1936) / Low 45 degrees also at Phoenixville (1945) / Rain 4.02" at KMQS Coatesville Airport (2013)

Thanks Charlie I am still not clear is the above the NCEI adjustments to the data for the entire county or for Coatesville? I have not found the individual station adjustments yet. If the above is just for Coatesville can you send me the link to that site? . I would like to see the bias adjustments for Phoenixville and West Chester etc. individually for comparison purposes and adds to my data set. Thanks!

LOL Charlie and I have been doing this for years! If folks don't like it let's start another thread....or just ignore me (could be best solution)

It's more a passion than a job for my team! My human resource team includes a checkbox on the intake form that actually asks the following question (this is directly lifted from the form) Do you believe in climate change (yes) (no) If they answer no and are a self identified climate denier - my HR Director immediately puts them in the left pile (left does not move forward in the process) We refuse to hire climate deniers as climate change is real and of course a stone cold fact!!

Would you like to join our growing team Tim???

The we represents the entire Chester County Weather Team including our statisticians, IT team to support the website and FB page etc.

All about (plural) accuracy (plural) and in plurality of stations (plural) LOL!!!!!

Maybe I run out there with ice packs and wrap the station to chill the thermometer????

My rooftop (poorly sited) Tempest weather station also completely defies diurnal temperature trends and consistently stalls or drops a couple degrees between noon and 1pm see below for July 10th

Can you show me the exact bias adjustment made to the Coatesville obs (not for all of Chester County) if there was a cool bias....why did NOAA with their adjustments for Chester County take the temperature lower than all stations in the county for many of those years?? Wouldn't they have adjusted the temps up for the cool bias??

At 8am is not a big deal as we have shown before....minor to no issues.....6pm for 3 years....no big deal

Max sun and then the 24-hour Davis VP2 Fan Aspiration Radiation Shield kicks in for maximum accuracy

Here in East Nantmeal we picked up 0.17" of needed rain overnight. We see sun return again today with a few degrees cooler than the last several days. Temps should stay in the upper 80's with maybe a few lower spots touching 90 degrees. Rain chances increase by tomorrow PM through Saturday morning - fingers crossed! The local farmers and lawns could surely use a bit more rain. While we are still 1.70" above normal with rain and melted snow so far this year....we are 4.03" below normal through yesterday here in East Nantmeal. Chester County records for today: High 106 degrees at Phoenixville (1936) / Low 45 degrees at Coatesville way back in 1898/ Rain 4.53" at Phoenixville (2019)

Here in East Nantmeal we picked up 0.17" of needed rain overnight. We see sun return again today with a few degrees cooler than the last several days. Temps should stay in the upper 80's with maybe a few lower spots touching 90 degrees. Rain chances increase by tomorrow PM through Saturday morning - fingers crossed! The local farmers and lawns could surely use a bit more rain. While we are still 1.70" above normal with rain and melted snow so far this year....we are 4.03" below normal through yesterday here in East Nantmeal. Chester County records for today: High 106 degrees at Phoenixville (1936) / Low 45 degrees at Coatesville way back in 1898/ Rain 4.53" at Phoenixville (2019)

Below are all 5 sites used and their dates. Overall siting looks pretty consistent over a very short distance. It looks like the "warmest" relative observing site very well might have been the one near the steel mill plant from 1917 to 1930. Overall all of this Coatesville data observation moves clearly did not have much of an impressive material impact on these stations and more importantly on the overall averages for Chester County overall.

Reading's thermometer has been an issue for while....see latest gladstone - red x is not good

You did not answer my question.....

As you should know Charlie one station does not a trend make....So why did Phoenixville's nights chill even more than Coatesville when we compare that same time frame without a station movement there?? Maybe it was just a little chillier in the 1948 to 1960 period??

75.6 for the warm AM low in East Nantmeal. After today we should get a brief break from 90 degree temps till the weekend. Rain chances start to ramp up this afternoon and especially tonight. We are all hoping for some beneficial rains. By early next week the heat returns....it sounds like July!! Stay cool! Chester County records for today: High 111 degrees at Phoenixville but 105 degrees at West Chester (1936) / Low 42 degrees at Devault (1954) / Rain 4.35" at West Chester (1931)

75.6 for the warm AM low in East Nantmeal. After today we should get a brief break from 90 degree temps till the weekend. Rain chances start to ramp up this afternoon and especially tonight. We are all hoping for some beneficial rains. By early next week the heat returns....it sounds like July!! Stay cool! Chester County records for today: High 111 degrees at Phoenixville but 105 degrees at West Chester (1936) / Low 42 degrees at Devault (1954) / Rain 4.35" at West Chester (1931)

Close only counts in checkers....Sounds like a certain pot calling the kettle black....LOL!!!!

Charlie, no need for an apology to anyone as I only analyze the actual NWS data. But since you say I never give you anything beyond stations....well below please find all the deep details for the NWS COOP and MADIS stations in our Chester County PA dataset. Included in the below chart - I also updated your above chart with the correct data inventory dates for all available complete years of record. Data provided below for all historical and currently available NWS COOP/MADIS stations includes station map coordinates, full years of data observations by station and elevation above sea level for each station of record. Some interesting historical and going forward geographic data and station reporting splits. There are 704 complete years of all station historical data available through December 31, 2023. 368 years of total data or 52% of the years have been observed at elevations below 407 FT ASL (relative lower spots) 336 years of total data or 48% of the years have been observed at elevations over 440 FT ASL (relative higher spots) Pre-1990 we have 451 years of historical total station data 256 or 57% of those earlier observations were taken at relative lower elevations 195 or 43% of those earlier observations were taken at relatively higher elevations Going forward we will have a split of 8 stations located below 407 FT ASL and 8 stations above 440 FT ASL That said we only had 55 years of observations at the relatively highest levels above 600 feet prior to 1990. These ongoing observations will include 5 stations (31%) between 620 ft and 685 ft / 5 stations (31%) between 407 ft and 465 ft and 6 stations (38%) reporting data between 105 ft. and 348 ft.

Most spots except the highest stations exceeded 90 degrees...as both West Grove and East Nantmeal reached 89.6 degrees. The warmest station high was the 95.1 at West Chester.However, whether it's 89.6 or 95 degrees....one thing is for sure - It's oppressively hot and humid! The next couple days will again see 90's in most spots. Rain chances do increase starting tomorrow and looks to last through Friday. After tomorrow most spots will fall into the 80's for high temps. We should clear out for the weekend. Chester County Records for today: The all-time recorded PA high based on records was recorded today and tomorrow in Phoenixville at 111 degrees in 1936. This reading has been called into question as both West Chester and Coatesville "only" reported 103 degrees that same day. Highly unlikely there was an 8 degree difference on that day. The record low was 44 degrees also at Phoenixville in 1972. Record rain was the 5.82" at Phoenixville in 1935.

Most spots except the highest stations exceeded 90 degrees...as both West Grove and East Nantmeal reached 89.6 degrees. The warmest station high was the 95.1 at West Chester.However, whether it's 89.6 or 95 degrees....one thing is for sure - It's oppressively hot and humid! The next couple days will again see 90's in most spots. Rain chances do increase starting tomorrow and looks to last through Friday. After tomorrow most spots will fall into the 80's for high temps. We should clear out for the weekend. Chester County Records for today: The all-time recorded PA high based on records was recorded today and tomorrow in Phoenixville at 111 degrees in 1936. This reading has been called into question as both West Chester and Coatesville "only" reported 103 degrees that same day. Highly unlikely there was an 8 degree difference on that day. The record low was 44 degrees also at Phoenixville in 1972. Record rain was the 5.82" at Phoenixville in 1935.

So with the new corrected actual COOP data for Chester County PA that eliminated any ghost/estimate data from the observation database we found the following. From 1893 thru 1927 no change in the data For 86 consecutive years from 1928 thru 2013 each year has now cooled with the elimination of the ghost/estimate data See the actual average annual temperature variance (red with ghosted/estimated data included and blue with the revised clean actual data from 1893 thru 2023) Clearly the elimination of these ghosted averages has further flattened the warming trend lines.....