ChescoWx

The latest ChescoWx study is live on the website. The question we posed that many in our area have asked is below. Plus how much has NCEI adjusted for any UHI impacts? The study design and supporting charts are available in greater detail on the site below. https://chescowx.com/phl-airport-vs-neighbors/

The latest ChescoWx study is live on the website. The question we posed is below. Plus how much has (if at all) NCEI adjusted for any UHI impacts? The study design and supporting charts are available in greater detail on the site below. https://chescowx.com/phl-airport-vs-neighbors/

Today we should see highs from low 60's in ridge locations to the mid 60's in valley spots with lows tonight in the upper 30's to mid 40's. Highs will peak on Wednesday with highs in the low 70's which is around 10-12 degrees above normal before we return to near normal over the weekend. We should see a pronounced pattern change during the upcoming weekend with temperatures by Sunday falling to below normal levels for November with temperatures later next week getting no higher than the lower 50's. It has been a while since our last rain but our best chance of rain is Friday with around 0.68" according to the ChescoWx model. Of note 165 years ago today back in 1861 the Chester County Area was at the start of a storm that left as much as 2.04" of rain at Pocopson. This was an unnamed tropical storm which tracked within about 140 miles of the county.

Today we should see highs from low 60's in ridge locations to the mid 60's in valley spots with lows tonight in the upper 30's to mid 40's. Highs will peak on Wednesday with highs in the low 70's which is around 10-12 degrees above normal before we return to near normal over the weekend. We should see a pronounced pattern change during the upcoming weekend with temperatures by Sunday falling to below normal levels for November with temperatures later next week getting no higher than the lower 50's. It has been a while since our last rain but our best chance of rain is Friday with around 0.68" according to the ChescoWx model. Of note 165 years ago today back in 1861 the Chester County Area was at the start of a storm that left as much as 2.04" of rain at Pocopson. This was an unnamed tropical storm which tracked within about 140 miles of the county.

October Climate Summary - Chester County Area. See details and overall rankings since 1890 below. We were slightly warmer than normal +0.8 and about average regarding precipitation. Through the 1st 10 months of the year we are running at 0.5 degrees below normal temperatures.

October Climate Summary - Chester County Area. See details and overall rankings since 1890 below. We were slightly warmer than normal +0.8 and about average regarding precipitation. Through the 1st 10 months of the year we are running at 0.5 degrees below normal temperatures.

oday back in 1950 Phoenixville 1E hit 86 degrees and the county as a whole averaged 84.7 for a high...this followed the warmest Halloween ever recorded across the entire USA. That date here in Chester County was the warmest November 1st since records began in 1890. Today we should see highs from near 60 degrees in ridge locations to the low 60's in valley spots with lows tonight in the mid 30's to low 40's. Our warmest day this week will be Wednesday with highs not far from 70 degrees! We turn progressively chillier starting Thursday and by next Sunday morning we should see lows in the mid 30's to low 40's, not far from freezing in the colder valleys! It has been a while since our last rain but our next soaking rain looks to arrive Thursday into Friday with around 1.8" possible according to our ChescoWx model.

Today back in 1950 Phoenixville 1E hit 86 degrees and the county as a whole averaged 84.7 for a high...this followed the warmest Halloween ever recorded across the entire USA. That date here in Chester County was the warmest November 1st since records began in 1890. Today we should see highs from near 60 degrees in ridge locations to the low 60's in valley spots with lows tonight in the mid 30's to low 40's. Our warmest day this week will be Wednesday with highs not far from 70 degrees! We turn progressively chillier starting Thursday and by next Sunday morning we should see lows in the mid 30's to low 40's, not far from freezing in the colder valleys! It has been a while since our last rain but our next soaking rain looks to arrive Thursday into Friday with around 1.8" possible according to our ChescoWx model.

Both Delaware https://chescowx.com/raw-vs-ncei-delaware/ and New York State https://chescowx.com/raw-vs-ncei-new-york/ are now up and availabe with raw vs anomaly vs NCEI figures charts and trends.

I was asked to compare PHL Airport vs East Nantmeal Twp. In the western philly burbs of Chester County PA for climate since 2004. (see full panel below) Summer afternoons: PHL’s highs run 5.4–6.3°F warmer from June through September. Against the whole county the gap was mainly at night; against East Nantmeal it’s mainly in the daytime. That fits what the siting check found: my fan-aspirated Davis VP2 records cooler highs. Elevation adds to it. Overnight lows: PHL is warmer every month, from 2.8°F in April to 5.1°F in August. Rain and snow: Precipitation: East Nantmeal gets 50.35" a year to PHL’s 45.56". It’s wetter in most months, especially July (5.62" vs 4.66"). Snow: East Nantmeal averages 35.8" a season against 22.7" at PHL, about 58% more. EN had more snow than PHL in all 22 seasons. February shows the biggest difference: 13.4" vs 8.4". Is the temperature gap widening? Yes. It has grown about 0.46°F per decade, mostly in daytime highs (+0.64). PHL warmed about 1.0°F per decade over these 22 years, against 0.55 at East Nantmeal. I will post up Chester County as a whole later. Let me know if any questions. Thanks!

I was asked to compare PHL Airport vs East Nantmeal Twp. In the western philly burbs of Chester County PA for climate since 2004. (see full panel below) Summer afternoons: PHL’s highs run 5.4–6.3°F warmer from June through September. Against the whole county the gap was mainly at night; against East Nantmeal it’s mainly in the daytime. That fits what the siting check found: my fan-aspirated Davis records cool highs. Elevation adds to it. Overnight lows: PHL is warmer every month, from 2.8°F in April to 5.1°F in August. Rain and snow: Precipitation: East Nantmeal gets 50.35" a year to PHL’s 45.56". It’s wetter in most months, especially July (5.62" vs 4.66"). Snow: East Nantmeal averages 35.8" a season against 22.7" at PHL, about 58% more. EN had more snow than PHL in all 22 seasons. February shows the biggest difference: 13.4" vs 8.4". Is the temperature gap widening? Yes. It has grown about 0.46°F per decade, mostly in daytime highs (+0.64). PHL warmed about 1.0°F per decade over these 22 years, against 0.55 at East Nantmeal. I will post up Chester County as a whole later. Let me know if any questions. Thanks!

I was asked to compare PHL Airport vs East Nantmeal Twp. In the western philly burbs of Chester County PA for climate since 2004. (see full panel below) Summer afternoons: PHL’s highs run 5.4–6.3°F warmer from June through September. Against the whole county the gap was mainly at night; against East Nantmeal it’s mainly in the daytime. That fits what the siting check found: my fan-aspirated Davis VP2 records cooler highs. Elevation adds to it. Overnight lows: PHL is warmer every month, from 2.8°F in April to 5.1°F in August. Rain and snow: Precipitation: East Nantmeal gets 50.35" a year to PHL’s 45.56". It’s wetter in most months, especially July (5.62" vs 4.66"). Snow: East Nantmeal averages 35.8" a season against 22.7" at PHL, about 58% more. EN had more snow than PHL in all 22 seasons. February shows the biggest difference: 13.4" vs 8.4". Is the temperature gap widening? Yes. It has grown about 0.46°F per decade, mostly in daytime highs (+0.64). PHL warmed about 1.0°F per decade over these 22 years, against 0.55 at East Nantmeal. I will post up Chester County as a whole later. Let me know if any questions. Thanks!

So far this year through yesterday.

So far this year through yesterday.

Happy Halloween to all of you!! Today we should see highs from upper 50's in ridge locations to the low 60's in valley spots. The NWS has issued a frost advisory for tonight for Eastern Chester County with temperatures just above freezing in valley locations while the ridge tops mainly across Western Chesco stay in the low 40’s. Temperatures will be near normal through Monday but by Tuesday we warm to the upper 60's which is 4 to 8 degrees above normal. It has been a while since our last rain but our next soaking rain looks to arrive Friday with around 1.6" possible according to the ChescoWx model. Of note 160 years ago today back in 1866 the Chester County Area was on the last day of a 3 day storm that left as much as 2.10" of rain at Pocopson. This was the remnants of an unnamed tropical storm which tracked within about 130 miles of the county.

Happy Halloween to all of you!! Today we should see highs from upper 50's in ridge locations to the low 60's in valley spots. The NWS has issued a frost advisory for tonight for Eastern Chester County with temperatures just above freezing in valley locations while the ridge tops mainly across Western Chesco stay in the low 40’s. Temperatures will be near normal through Monday but by Tuesday we warm to the upper 60's which is 4 to 8 degrees above normal. It has been a while since our last rain but our next soaking rain looks to arrive Friday with around 1.6" possible according to the ChescoWx model. Of note 160 years ago today back in 1866 the Chester County Area was on the last day of a 3 day storm that left as much as 2.10" of rain at Pocopson. This was the remnants of an unnamed tropical storm which tracked within about 130 miles of the county.

Of note on this date back in 1946 Phoenixville 1E hit 85 degrees and the county as a whole averaged 83.3 for a high...making it our warmest October 30th since records began in 1890. Nothing like that today but it will be very mild for the end of October with highs from upper 60's in ridge locations to the low 70's in valley spots. This is about 7 degrees above normal with lows tonight in the upper 30's to near 40. By Sunday morning we should see lows in the mid 30's to low 40's, not far from freezing in the colder valleys! Temperatures will be near normal this weekend but by Monday we warm to the upper 60's which is 3 to 8 degrees above normal. It has been a while since our last rain but our next soaking rain looks to arrive Thursday with around 1.2" possible according to the ChescoWx model.

Of note on this date back in 1946 Phoenixville 1E hit 85 degrees and the county as a whole averaged 83.3 for a high...making it our warmest October 30th since records began in 1890. Nothing like that today but it will be very mild for the end of October with highs from upper 60's in ridge locations to the low 70's in valley spots. This is about 7 degrees above normal with lows tonight in the upper 30's to near 40. By Sunday morning we should see lows in the mid 30's to low 40's, not far from freezing in the colder valleys! Temperatures will be near normal this weekend but by Monday we warm to the upper 60's which is 3 to 8 degrees above normal. It has been a while since our last rain but our next soaking rain looks to arrive Thursday with around 1.2" possible according to the ChescoWx model.

"needs" to be "corrected" with estimated homogenization adjustments

The state of Delaware study findings are now up and available at https://chescowx.com/raw-vs-ncei-delaware/

Agree 100% the actual data is clear and consistent across the entire USA not just Yellow Medicine or Chester County.

Since this concerns the impact of Climate Change across the entire USA and not just one individual county - I am happy to share the below study of Actual raw temperature data vs. the NCEI adjusted data for the entire Continental USA. Please find the below combined US 48 state findings (PA and NY are already posted an online). For the full reports and individual state and county findings as they are released over the next 46 days please check out https://chescowx.com/raw-vs-ncei-state-by-state/ THE MAIN STUDY FINDINGS FOR THE CONTINENTAL USA The NWS raw trained observer temperature record shows no significant warming at all in the contiguous 48 states since 1895!! (+0.01 °F per decade). In fact the temperature trend lines across the entire USA are basically flat from 1895 through 2026! However by contrast NCEI's adjusted temperatures show significant warming in the contiguous 48 states since 1895 (+0.18 °F per decade). That difference between the two trend lines is statistically significant. Combining the 48 statewide records of actual readings, each weighted by the state's land area, gives +0.01 °F per decade from 1895 to 2025 (95% range -0.04 to +0.05), about +0.1 °F in total. NCEI's published contiguous-U.S. series gives +0.18 °F per decade (range +0.12 to +0.23), about +2.3 °F in total. Of note NCEI's adjusted temperatures are lower than the actual readings in every single decade from the 1890s through the 1990s. To dig deeper into these continental US wide findings including please check out https://chescowx.com/raw-vs-ncei-co ntiguous-us/

Our 2nd state in the Nationwide Actual Raw vs. NCEI Adjusted Study for New Jersey is now available for review and download. For much more detail including study design, by decade breakdowns, county by county maps and breakdowns for all State Counties that compare actual vs NCEI trends for each NJ county please go to https://chescowx.com/raw-vs-ncei-state-by-state/ The main finding The NWS raw trained observer temperatures show significant warming in New Jersey since 1895 (+0.15 °F per decade). NCEI's adjusted temperatures show about twice as much warming (+0.31 °F per decade). That difference between the two trend lines is statistically significant. Averaging what New Jersey's observers actually recorded, county by county and weighted by county area, gives +0.15 °F per decade from 1895 to 2025 (significant), about +2.0 °F in total. NCEI's published statewide series gives +0.31 °F per decade (significant), about +4.1 °F in total. NCEI's series runs 1.4–1.7 °F below the actual readings in every decade from 1895 through the 1940s; 0.7–1.1 °F below them in the 1950s to 1970s; 0.4–0.6 °F below them in the 1980s and 1990s; within 0.2 °F of them from 2000 on. NCEI's adjusted temperatures are lower than the actual readings in every decade from the 1890s through the 1990s.

I really can't remember such a great stretch of weather in a long time! The GFS for East Nantmeal keeps us mild through the first week of November

Today we should see highs from low 60's in ridge locations to the mid 60's in valley spots with lows tonight in the low to mid 40's. Highs will reach well into the 60's to near 70 degrees through Friday which is 5 to 9 degrees above normal before we chill down a bit to near normal by Saturday for the trick or treaters, but by Sunday we warm to the mid 60's which is 4 to 8 degrees above normal. It has been a while since our last rain but a chance of a shower or two next Wednesday according to the ChescoWx model. Of note 14 years ago today back in 2012 the Chester County Area was at the start of a 3 day storm that left as much as 6.97" of rain at the Nottingham DEOS. This was the remnants of Hurricane Sandy which tracked within about 20 miles of the county.