KamuSnow Posted December 13, 2020 Share Posted December 13, 2020 5 hours ago, ChescoWx said: Paul, are you sure 1989 didn't have snow on the ground at Christmas? In Delco we did, leftover from earlier snows, even though it was gone by New Years. 1 Link to comment Share on other sites More sharing options...
ChescoWx Posted December 14, 2020 Author Share Posted December 14, 2020 1 hour ago, KamuSnow said: Paul, are you sure 1989 didn't have snow on the ground at Christmas? In Delco we did, leftover from earlier snows, even though it was gone by New Years. Kamu! You are 100% correct! I somehow missed 1989....I am going back and reviewing all years - it snowed 3.1 inches in Chesco on the 8th with additional smaller snow events on the 12th/13th/15th and 19th keeping snow on the ground through the rest of the month. I will update and include 1989 - thanks!! Paul Link to comment Share on other sites More sharing options...
ChescoWx Posted December 14, 2020 Author Share Posted December 14, 2020 With KamuSnow's correction - thanks!!- with my miss of 1989....I went back and reran the report with over 1" of snow on the ground in Chester County on Christmas morning - thanks! 1 Link to comment Share on other sites More sharing options...
KamuSnow Posted December 14, 2020 Share Posted December 14, 2020 1 hour ago, ChescoWx said: With KamuSnow's correction - thanks!!- with my miss of 1989....I went back and reran the report with over 1" of snow on the ground in Chester County on Christmas morning - thanks! Thanks for the data! Link to comment Share on other sites More sharing options...
ChescoWx Posted December 17, 2020 Author Share Posted December 17, 2020 With the snowstorm total of 9.3" in East Nantmeal Township in Chester County this storm was the 10th largest snowstorm in December history back to 1894 for the county. The 7.3" of snow yesterday set a new daily record eclipsing the 6.0" that fell in 1973. 1 Link to comment Share on other sites More sharing options...
ChescoWx Posted December 21, 2020 Author Share Posted December 21, 2020 With our 10th largest December snowstorm that fell last week on the 16th -17th (9.3") - what does that potentially mean for the ensuing winter snow season? What about December's with a storm greater than 6" during the year's final month?? Funny you should ask below are some statistical potential answers.... 1 Link to comment Share on other sites More sharing options...
ChescoWx Posted December 22, 2020 Author Share Posted December 22, 2020 An analysis from Dr Joe D'Aleo at WeatherBell - supporting some of the analytics I presented above for here in Western Chester County PA Link to comment Share on other sites More sharing options...
ChescoWx Posted December 29, 2020 Author Share Posted December 29, 2020 So here in Western Chester County PA we have already received 10.2" of snow this December. This is good for a top 25 December snow ranking with records back to 1894. So what does this potentially portend for the following snow season? funny you should ask....see the top snowy December months and the final snow season analysis below. Link to comment Share on other sites More sharing options...
ChescoWx Posted January 2, 2021 Author Share Posted January 2, 2021 December 2020 Climate Summary Link to comment Share on other sites More sharing options...
ChescoWx Posted January 2, 2021 Author Share Posted January 2, 2021 2020 Full Year Climate Summary Link to comment Share on other sites More sharing options...
ChescoWx Posted January 11, 2021 Author Share Posted January 11, 2021 In reviewing out winter (December through March) trends - our last 6 decades here in Western Chester County PA have seen both the 3 coldest decades from the 60's thru 80's to now the 3 warmest decades 1990's thru 2010's - as always weather truly is cyclical - how long will this warming cycle continue before the next cooling cycle we saw through the 80's? Link to comment Share on other sites More sharing options...
ChescoWx Posted January 16, 2021 Author Share Posted January 16, 2021 I went back and updated the analysis for the last 12 decades now including the Philadelphia data from 1900-1949 (this represents raw unadjusted data with no after the fact adjustments) comparing data for the last 120 years from 1900 thru 2019. The key finding is that the suspected rapid PHL heat island impact and problems are growing at an even greater rate than ever imagined....the difference between the heat island near Philadelphia and the burbs using actual NWS observed temps is telling....Just look at how quickly the lines are diverging and you will see where this is going. Just look at that % difference column and you can see the disparity between average temperatures has never been higher and is only getting more pronounced. Link to comment Share on other sites More sharing options...
ChescoWx Posted January 16, 2021 Author Share Posted January 16, 2021 I have gone back and analyzed long running data now for both long term Chester County sites and have now updated to include both West Chester PA and Coatesville PA. Clearly West Chester and Coatesville are well aligned for 12 decades....and almost exactly the same over the last 2 decades....however, PHL is just as clearly demonstrating the heat island problem as they begin to accelerate away - not at all consistent. Link to comment Share on other sites More sharing options...
ChescoWx Posted January 28, 2021 Author Share Posted January 28, 2021 Wxsim with 6z NAM/GFS blend sees snow starting by 630am on Sunday and lasting to some degree or another till 10am on Tuesday AM. Forecast is for 11" to 18" with some ZR/IP mix overnight Sunday included Sunday: Dense overcast. A chance of snow in the morning, then snow likely in the afternoon. High 31. Wind chill around 21. Wind east around 5 mph in the morning, becoming 10 mph, gusting to 18 mph, in the afternoon. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly around half an inch. Snow accumulation 2 to 4 inches. Sunday night: Dense overcast. A mix of snow, freezing rain, and sleet likely in the evening, then a mix of snow, freezing rain, sleet, and rain likely after midnight. Breezy. Low 29, but temperatures rising after midnight. Wind chill as low as 19. Wind east around 13 mph, gusting to 20 mph. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly between 1 and 2 inches. Snow or ice (on ground) accumulation 4 to 6 inches. Above-ground freezing rain accumulation up to 0.2 inches. Monday: Dense overcast. A mix of snow, rain, and sleet likely in the morning, then snow likely in the afternoon. Breezy. High 35. Wind chill around 23. Wind east around 15 mph, gusting to 23 mph. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly between 1 and 2 inches. Snow or ice (on ground) accumulation 5 to 8 inches. Monday night: Dense overcast. Snow likely. Low 31. Wind chill as low as 23. Wind north-northeast around 10 mph, gusting to 19 mph. Chance of precipitation 60 percent. Precipitation (liquid equivalent) mostly less than a quarter of an inch. Snow accumulation about half an inch. Tuesday: Dense overcast in the morning, becoming cloudy in the afternoon. A chance of snow in the morning, then a slight chance of snow in the afternoon. High 33. Wind chill around 24. Wind north around 10 mph, gusting to 17 mph. Chance of precipitation 50 percent. Precipitation (liquid equivalent) mostly around a tenth of an inch. Snow accumulation about half an inch. Link to comment Share on other sites More sharing options...
ChescoWx Posted January 28, 2021 Author Share Posted January 28, 2021 WXSIM with a 12z blend of the NAM/GFS has total snow accumulation now from 17" to 24" Start times for Western Chester County PA - flurries at 7am / Light snow by 11am and S+ by 4pm Sunday: Dense overcast. A slight chance of snow in the morning, then snow likely in the afternoon. High 32. Wind chill around 22. Wind east-northeast around 4 mph in the morning, becoming 9 mph, gusting to 17 mph, in the afternoon. Chance of precipitation 70 percent. Precipitation (liquid equivalent) mostly around a quarter of an inch. Snow accumulation 1 to 2 inches. Sunday night: Dense overcast. Snow likely in the evening, then a mix of snow and rain likely after midnight. Breezy. Low 28, but temperatures rising after midnight. Wind chill as low as 19. Wind east-northeast around 13 mph, gusting to 20 mph. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly between half an inch and one inch. Snow accumulation 3 to 5 inches. Monday: Dense overcast. A mix of snow and rain likely in the morning, then snow likely in the afternoon. Windy. High 34. Wind chill around 21. Wind east-northeast around 16 mph, gusting to 24 mph. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly around 2 inches. Snow accumulation 12 to 16 inches. Little if any freezing rain accumulation. Maximum snow level 300 feet above ground. Monday night: Dense overcast. Snow likely. Breezy. Low 31. Wind chill as low as 22. Wind northeast around 12 mph, gusting to 20 mph. Chance of precipitation 70 percent. Precipitation (liquid equivalent) mostly around a quarter of an inch. Snow accumulation about an inch. 2 1 Link to comment Share on other sites More sharing options...
ChescoWx Posted February 8, 2021 Author Share Posted February 8, 2021 Wxsim with 18z NAM and 12z GFS has a wintry week ahead with 5" to 6" of snow/ice by next Sunday Tuesday: Dense overcast in the morning, becoming cloudy in the afternoon. A mix of snow and rain likely. High 33. Wind south-southeast around 3 mph in the morning, becoming west in the afternoon. Chance of precipitation 60 percent. Precipitation (liquid equivalent) mostly less than a quarter of an inch. Snow accumulation about half an inch. Tuesday night: Partly to mostly cloudy, with scattered light frost possible. Low 23. Wind northwest around 4 mph. Wednesday: Mostly cloudy in the morning, becoming mostly cloudy to cloudy in the afternoon. High 33. Wind northwest around 4 mph. Wednesday night: Dense overcast, with areas of light frost likely. Patchy light fog after midnight. A slight chance of snow in the evening, then snow likely after midnight. Low 26. Wind east-northeast around 2 mph. Chance of precipitation 70 percent. Precipitation (liquid equivalent) mostly around a quarter of an inch. Snow accumulation around 2 inches. Thursday: Dense overcast. Patchy light fog. Snow likely in the morning, then a slight chance of snow in the afternoon. High 30. Wind chill around 22. Wind east-northeast around 6 mph. Chance of precipitation 70 percent. Precipitation (liquid equivalent) mostly between a quarter and half an inch. Snow accumulation 2 to 3 inches. Thursday night: Dense overcast. Patchy light fog in the evening. A slight chance of snow in the evening, then a chance of snow after midnight. Low 28. Wind chill as low as 22. Wind east-northeast around 6 mph. Chance of precipitation 60 percent. Precipitation (liquid equivalent) mostly less than a quarter of an inch. Snow accumulation about an inch. Friday: Cloudy. A chance of snow in the morning, then a slight chance of snow in the afternoon. High 31. Wind northeast around 5 mph. Chance of precipitation 50 percent. Precipitation (liquid equivalent) mostly around a tenth of an inch. Snow accumulation about half an inch. Friday night: Mostly cloudy to cloudy, with moderate to heavy frost. Low 27. Wind northeast near calm. Saturday: Dense overcast. High 30. Wind northeast near calm. Saturday night: Dense overcast, with light to moderate frost. Patchy light fog after midnight. Low 28. Wind east around 2 mph in the evening, becoming northeast after midnight. Sunday: Dense overcast. A chance of a mix of snow and sleet in the morning, then sleet likely in the afternoon. High 31. Wind chill around 21. Wind northeast around 8 mph, gusting to 17 mph, in the morning, becoming 12 mph, gusting to 20 mph, in the afternoon. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly between half an inch and one inch. Snow or ice (on ground) accumulation about half an inch. Sunday night: Dense overcast in the evening, becoming mostly cloudy to cloudy after midnight, with areas of light frost likely. A mix of sleet and snow likely in the evening, then a chance of snow after midnight. Low 29. Wind chill as low as 20. Wind north around 9 mph, gusting to 19 mph. Chance of precipitation 70 percent. Precipitation (liquid equivalent) mostly around a quarter of an inch. Snow or ice (on ground) accumulation about a quarter inch. Link to comment Share on other sites More sharing options...
ChescoWx Posted February 23, 2021 Author Share Posted February 23, 2021 Some snow records for Western Chester County PA (1894 to Present) with the storm total of 5.0" yesterday - 4th snowiest February at 35.9" (snowiest the 69.8" in 1898) - 20th snowiest season 51.4" (snowiest 1898-99 with 95.0" of snow) - 4th time in last 8 years we have surpassed 50" of snowfall in a season (2017-18 last time) - At least 1" of snow has been on the ground for every day of February. If the snow cover lasts through this week it will mark the 7th February with snow observed on the ground every day of the month. This would also be the 3rd February in the 8 years with a totally snow covered February (last 2015) Link to comment Share on other sites More sharing options...
ChescoWx Posted March 2, 2021 Author Share Posted March 2, 2021 February 2021 Climate Summary for Western Chester County PA Link to comment Share on other sites More sharing options...
ChescoWx Posted April 14, 2021 Author Share Posted April 14, 2021 Winter weather analysis for Chester County PA. Dec-March months since 1894. Our current cycle of warming has produced 7 of the warmest winters since 2000...including the top 3. Conversely, it has also delivered 3 of the coldest winters since 2000. When will the next colder cycle start? Link to comment Share on other sites More sharing options...
ChescoWx Posted May 1, 2021 Author Share Posted May 1, 2021 April finished with an average temp of 53.4 in East Nantmeal this is the 22nd warmest April with the top 5 warmest being 1921 - 57.5 / 2017 - 57.1 / 1941 - 56.1 / 1915 - 56.0 and 1942 at 55.6. As you can see in my comparison my Vantage Pro has been consistently running warmer than my other 2 stations and KMQS Airport....The Tempest and Ambient on my property are running virtually the same with 0 variation over the year to date and April for the month. I will keep an eye on this to see if the VP may be in need of replacing. Link to comment Share on other sites More sharing options...
ChescoWx Posted May 2, 2021 Author Share Posted May 2, 2021 https://www.unsettledsciencebook.com/ Interesting new scientific review in the above book is coming out from another scientist. I have already ordered! This will again attempt to correct the "settled science" voices depicted by some....as I always say it is of course not settled. Thought provoking point made in the upcoming liner notes "He dispels popular myths and unveils little-known truths: despite a dramatic rise in greenhouse gas emissions, global temperatures actually decreased from 1940 to 1970. What’s more, the models we use to predict the future aren’t able to accurately describe the climate of the past, suggesting they are deeply flawed. " Link to comment Share on other sites More sharing options...
ChescoWx Posted May 16, 2021 Author Share Posted May 16, 2021 Some analysis below comparing the original Coatesville PA NWS Coop climate averages from 1894 to 1982 (88 years of data) taken at locations between 340ft to 400ft ASL vs. the last 38 years of data 1983 to current taken at over 660 ft ASL. The analysis highlights a small 0.3 degree increase (+0.6%) in annual average temperature with this relative modest change in elevation between the 1st 88 years of data vs. the last 38 years. Biggest variation has been in snowfall with a near 15% increase in annual snow from the old vs new location and precipitation +9.5% at the new location. Of interest the average daily high temperature is lower in 10 of the 12 months (except January and December) at the higher elevation - while the average low temperature has increased in all 12 months Link to comment Share on other sites More sharing options...
ChescoWx Posted May 23, 2021 Author Share Posted May 23, 2021 WXSIM forecast for this week has what it calls a couple "unusually hot" days both today and again Wednesday...that said it still keeps us shy of the 90 degree mark....I suspect we get pretty close to 90 today and eclipse the elusive mark on Wednesday....we shall see WXSIM text forecast for East Nantmeal, initialized at 10:00 AM May 23, 2021 _______________________________________________________________________________ This afternoon: Partly cloudy. Unusually hot. High 87. UV index up to 8. Wind northwest around 8 mph, gusting to 18 mph. Tonight: Mostly cloudy in the evening, becoming cloudy after midnight. A chance of rain. Low 66. Wind north-northwest around 6 mph, gusting to 15 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. Monday: Cloudy in the morning, becoming dense overcast in the afternoon. High 76. Wind east-northeast around 5 mph, gusting to 16 mph, in the morning, becoming southeast in the afternoon. Monday night: Cloudy in the evening, becoming dense overcast after midnight. Low 66. Wind southeast around 4 mph, gusting to 16 mph. Tuesday: Dense overcast in the morning, becoming mostly cloudy to cloudy in the afternoon. Warm. High 79. UV index up to 6. Wind south around 6 mph, gusting to 19 mph. Tuesday night: Mostly cloudy to cloudy in the evening, becoming partly cloudy after midnight. Low 63. Wind south around 5 mph, gusting to 17 mph. Wednesday: Mostly sunny in the morning, becoming sunny in the afternoon. Unusually hot. High 87. UV index up to 10. Wind southwest around 5 mph in the morning, becoming 10 mph, gusting to 20 mph, in the afternoon. Wednesday night: Partly cloudy in the evening, becoming mostly cloudy to cloudy after midnight. A chance of rain. Scattered thundershowers possible. Low 65. Wind west-southwest around 5 mph, gusting to 15 mph. Chance of precipitation 30 percent. Precipitation mostly less than a tenth of an inch. Thursday: Partly to mostly cloudy in the morning, becoming partly cloudy in the afternoon. Warm. High 83. UV index up to 9. Wind west-northwest around 8 mph, gusting to 20 mph. Thursday night: Partly cloudy. Low 63. Wind north-northeast around 7 mph, gusting to 17 mph. Friday: Mostly cloudy to cloudy in the morning, becoming dense overcast in the afternoon. Patchy light fog in the afternoon. A slight chance of rain in the morning, then rain likely in the afternoon. Precipitation showery or intermittent. High 70, but temperatures falling in the afternoon. Wind east-northeast around 9 mph, gusting to 19 mph. Chance of precipitation 80 percent. Precipitation mostly between 1 and 2 inches. Friday night: Dense overcast. Patchy light fog. Rain likely in the evening, then a slight chance of rain after midnight. Precipitation showery or intermittent. Low 62. Wind east around 10 mph, gusting to 19 mph. Chance of precipitation 70 percent. Precipitation mostly around half an inch. Saturday: Dense overcast. Patchy light fog in the afternoon. A slight chance of rain in the morning, then rain likely in the afternoon. Precipitation showery or intermittent. High 66. Wind east around 8 mph, gusting to 20 mph. Chance of precipitation 70 percent. Precipitation mostly between a quarter and half an inch. Saturday night: Dense overcast. Patchy light fog. A chance of rain in the evening, then rain likely after midnight. Precipitation showery or intermittent. Low 62. Wind east-northeast around 6 mph, gusting to 17 mph. Chance of precipitation 80 percent. Precipitation mostly around half an inch. Sunday: Dense overcast. Patchy light fog. A chance of rain. Precipitation showery or intermittent. High 67. Wind northeast around 7 mph, gusting to 18 mph. Chance of precipitation 50 percent. Precipitation mostly less than a quarter of an inch. Sunday night: Dense overcast. Low 65. Wind northeast around 7 mph, gusting to 17 mph. Monday: Dense overcast. High 70. Wind northeast around 7 mph, gusting to 19 mph. Monday night: Dense overcast. Low 65. Wind northeast around 7 mph, gusting to 19 mph. Link to comment Share on other sites More sharing options...
ChescoWx Posted May 31, 2021 Author Share Posted May 31, 2021 For those that like their data raw and without adjustment decades later....some humor.... Link to comment Share on other sites More sharing options...
ChescoWx Posted June 3, 2021 Author Share Posted June 3, 2021 Well first off thanks to my fellow Chesco neighbors Maureen and Tim for the email message both asking me to perform an analysis of Summers in Chester County away from the City - can't believe I never looked at that - thanks guys! So with the summer months (June-July-August) now here I indeed went back through the data set to analyze the Average Summer Temps by Decade since the 1890's here in Western Chester County PA. Some will no doubt be surprised that the top 5 warm decade summers all occurred prior to 1940 Link to comment Share on other sites More sharing options...
ChescoWx Posted June 5, 2021 Author Share Posted June 5, 2021 So below are the warmest summers (June-August) in Chester County recorded history. Of interest 9 of the 10 warmest summers occurred prior to 1944 Link to comment Share on other sites More sharing options...
ChescoWx Posted June 27, 2021 Author Share Posted June 27, 2021 Link to comment Share on other sites More sharing options...
ChescoWx Posted June 28, 2021 Author Share Posted June 28, 2021 Updated Philadelphia PA vs. Chester County PA 1894 to Present - all summer seasons and below that by decades with trend lines overlaid. The heat island impacts really began to widen the gap starting all the way back in the 1930's and of course that gap is accelerating during the most recent years Quote Average Chester County PA Snow at elevations over 660 FT ASL (1983-Present) = 36.3": Snow totals by season: 2020/21 snow (52.2") / 2019/20 snow (5.8" )/ 2018/19 snow (35.1" )/ 2017/18 snow (58.5") / 2016/17 snow (24.0")/ 2015/16 snow (40.8")/ 2014/15 snow = (55.3") /2013/14 snow (80.0") . Heat Island Tracker from 2015 thru 2021 the PHL airport has recorded 215 days at 90 degrees+ while KMQS, KPTW and East Nantmeal combined have seen only 139 such days / 2021 (90+) days to date KPHL (9) / KMQS (2)/ KPTW (2) and East Nantmeal (1) Check out my historical Western Chester County PA website at https://www.chescowx.com and follow me on twitter at https://twitter.com/ChescoWx Link to comment Share on other sites More sharing options...
ChescoWx Posted July 26, 2021 Author Share Posted July 26, 2021 I just started to analyze the West Chester NWS COOP data today - I bumped up the 2 longest running long term weather COOP sites in Chester County - Coatesville and West Chester PA against the Philadelphia long term data for annual average temperatures at all 3 locations (I have scrubbed out any non-comparative years so the comparison below is all years from 1894 to 2016) The Chester County long term sites are nicely aligned and are clearly NOT warming (Blue West Chester and Red Coatesville) (this is not cherry picking of data - I am simply using the longest continuous data sets in Chester County PA with 123 years of data without any missing days for analysis) ....now the overlaid Philadelphia data as you can clearly see is much more supportive of the warming posit and shows clear sharp warming (green trend line) . For full transparency I should mention that on another forum an excellent poster had previously informed me it has been determined that Coatesville had a warm bias earlier in the 20th century and expect I will soon hear that it now appears based on this data that the West Chester PA COOP observer suffered the same fate as the Coatesville observers with similar poor instrument/technical issues that now requires that both the Coatesville and West Chester observations be cooled in the combined pooled data set to better show the true warming trend. Link to comment Share on other sites More sharing options...
ChescoWx Posted July 26, 2021 Author Share Posted July 26, 2021 I clearly have some time on my hands this week....so I dove deeply into the data and as a 1st set of analysis. I have now completed an annual temperature trend analysis of all available NWS Coop sites across Chester County PA. Seven NWS COOP sites were included in the review with the 1st analysis examining the reported average annual temperatures at all locations across the County with a comparison to the annual temperatures and subsequent warming observed with the Philadelphia data set. The NWS COOP sites included in this analysis were Coatesville/Chesco / West Chester / Phoenixville / Devault / Chadds Ford / Honey Brook and Glenmoore observation sites. I have attached all of the analysis and charts below - the clear conclusion 6 of the 7 sites are consistent and well aligned. All sites have at least 60 years of 100% complete consecutive daily obs/data. While the pooled SE PA Observations clearly show warming....we cannot find anywhere close to that degree of warming across the vast majority (85%) of the entire Chester County COOP stations. Some key findings: 4 of the 7 sites (ChescoWx / West Chester/ Phoenixville and Devault show no warming at all over the analyzed period... but actually some slight cooling....these sites are not aligned at all with the warming seen outside of Chester County with the Philadelphia observations 2 of the 7 sites (HoneyBrook and Chaddsford) with the shortest data years (60) show some slight warming but again the degree of warming is nothing like that seen with the Philadelphia data Only 1 site of the 7 observation sites shows warming that is comparable to the Philadelphia obs - that would be the Glenmoore site Link to comment Share on other sites More sharing options...
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