ChescoWx

Do you think folks get a little excited about snow? My Chester County Weather Facebook page has added 1,200 followers since yesterday!!

Good stuff!! really enjoying the research - I have also forwarded all the corroborating data to NCEI - plus still finding even more examples- plenty of food for thought for them!!

HI Birds - you are correct thanks for the kind words! most appreciated. My wife has tolerated my weather hobby for a long time - I tell her there are many worse hobbies a guy could have!!

Agreed!! If you follow the rules it is of course not difficult. All that said - snow measurements are always one of the more difficult numbers to get your arms around.....and the NWS knows this very well. I take a lot of time and effort to be accurate as one of my friends at the NWS Mount Holly Tony Gigi once recommended me for an article for the Inquirer after the big snows of February 2010. The reporter that came to my house for the interview told me they were told - that I was "mighty strong" in my efforts to produce accurate snowfall measurements. I try to live up to those standards!!

LV you of course do not need a newspaper to corroborate reported weather data....since all a local Coatesville paper would have reported would have been what Mr Gordon would have reported to the US Department of Agriculture - Weather Bureau which was the NWS back then....the record is real, validated by high totals in surrounding locations relatively close to the station so time to let this one go my man!! Snowfall measurements are and will continue to be the most variable of weather measurements. We cannot 125 years after the fact try to cancel out what the weather service viewed as valid enough to publish and make part of our climate records because you think the 29" should have been 20.2"

Hi Mike you know how much I love this stuff! I love to dig into all this data. Who knows maybe I should call myself the ChescowxHistorian - I don't know anyone who has done more research and purchased more NWS data then me in the last 25 years focused on Chesco Wx!

HI LV attached is the American Meteorological Society snowfall map for April 1894 published in May 1894. You can clearly see the 33" line of snow entering Chester County PA - clear weather service evidence to support the Coatesville snowfall for April 1894. This is fun!!

Here's the 1st newspaper article mentioning almost 20" of snow in South Central PA in that very April 1894 storm - again clear confirmation it is a reasonable snowfall total for Coatesville - again! https://www.ydr.com/story/news/2018/04/07/snow-april-yes-18-inches-fell-1894-central-pa/494402002/

I assumed you were like I a trained NWS spotter If so I suspect you know but if you need a refresher - "Measure and record the greatest amount of snowfall that has accumulated on your snowboard (wooden deck or ground if board is not available) since the previous snowfall observation. This measurement should be taken minimally once-a-day but can be taken up to four times a day, (every 6 hours) and should reflect the greatest accumulation of new snow observed (in inches and tenths, for example, 3.9 inches) since the last snowfall observation. Snowfall amounts can be measured hourly or at any interval as long as the snow measurement board is NOT cleared more frequently than once every 6 hours. If you are not available to watch snow accumulation at all times of the day and night, use your best estimate, based on a measurement of snowfall at the scheduled time of observation along with knowledge of what took place during the past 24 hours. If you are not present to witness the greatest snow accumulation, input may be obtained from other people who were near the station during the snow event. If your observation is not based on a measurement, record in your remarks that the "snow amount based on estimate". Remember, you want to report the greatest accumulation since the last observation. If snowfall occurred several times during the period, and each snowfall melted either completely or in part before the next snowfall, record the total of the greatest snowdepths of each event and enter in your remarks "snowfall melted during the OBS period". For example, three separate snow squalls affect your station during your 24-hour reporting day, say 3.0, 2.2, and 1.5 inches. The snow from each event melts off before the next accumulation and no snow is on the ground at your scheduled time of observation. The total snowfall for that reporting 24-hour day is the sum of the three separate snow squalls, 6.7 inches, even though the snow depth on your board at observation time was zero."

It clearly highlights the incredible variability within only 9 miles in Chester County. As you move from SE to NW across this county you see wide swings in snowfall totals = with much more (actually equal to Chicago IL on an annual snow basis in Western Chesco) compared to Eastern Chesco. This is part of the reason the NWS a few years back split the zone East and West. Those Coatesville historical obs are clearly accurate and within the realm of variability based on the unique climatology of Chester County

Now LV to put a fine point on this great discussion Recent Annual Actual snow reports by NWS Trained observers - East Nantmeal Twp PA (EN) vs West Chester PA (WC) (only 9.1 miles apart) to highlight some years with great variability over less than 10 miles 2017 - EN 34.9" / WC 15.8" 2013 - EN 32.6" / WC 18.8" 2012 - EN 21.3" / WC 11.2" 2010 - EN 72.4" / WC - 53.0" 2007 - EN 29.6" / WC - 13.6"

It's on the NWS PNS reports still available on the NWS site https://www.weather.gov/phi/eventsummarymain Also in nautical or straight miles my station is precisely 35.1 miles from ABE

Also maybe we should look at why Coatesville's observer Mr Gordon only reported 51.4" of snow in 1895 while West Chester reported a whopping 79.4" - LOL!! The variations are just too great to try and question long standing historical observations!

LV again just to highlight the incredible variability in reported snow totals and highlight how difficult it is to disprove higher totals. Back in February 2010 - ABE airport reported 42.9" of snow for the month - Here in East Nantmeal Twp in Chester County only 35 miles SW of that spot a NWS trained spotter (me) recorded 62.8"of snow a 20" difference over 30+ miles in 1 month - a 48% variance!

LV again just to highlight the incredible variability in reported snow totals and highlight how difficult it is to disprove higher totals. Back in February 2010 - ABE airport reported 42.9" of snow for the month - Here in East Nantmeal Twp in Chester County only 35 miles SW of that spot a NWS trained spotter (me) recorded 62.8"of snow a 20" difference over 30+ miles in 1 month - a 48% variance!

Still you are dead wrong for calling anyone a name. He was a solid long standing reported for the weather service for at least 36 years! show some respect please

LV - it simply points out the variability in snow totals over short distances. I will post some real doozies between here and surrounding locations just in the past 15 years along with the rest of the data I am analyzing. Thanks!

Thanks Mike! I originally ordered Mr. Gordon's hand written obs from the NCDC back in the late 90's for 1894 to 1930 - he was very thorough and we should not disparage his work. I think the fact we are finding 50" plus snow totals for February at the NJ shore is plenty of validation for Coatesville - since we will never be able to review the radar to determine banding and/or if any convective components such as the Christmas 1966 blizzard etc. Thanks!!

Thankfully it is close enough as the crow flies in NMs to validate. I will also be sure to pass the total data set over to the NCEI when done to help them corroborate - good stuff!!

Christmas Eve 1966 - Coatesville 21.2" - West Chester 22" - while the Lehigh Valley and PA only received about 12"

Elevation was between 340ft and 380ft between 1894 to 1983. Since February 1983 elevation has been over 640ft ASL

Always enjoy these data mines!! I have so many examples of huge differences in snow totals across very short distances Any way back to February 1899. While not topping the Coatesville monthly total (heck someone has to be 1st it just is what it is!) here are some other relatively close monthly totals some to help corroborate totals Warrenton VA - 54" Egg Harbor City NJ - 52" Ellicott City MD - 52"

Some more back up for the February 1899 totals - Coatesville's 3 day total was 45.3" - Washington DC reported 34" even Cape May NJ 32" of snow - Easton MD reported over 50" of snow that month!

To start to validate and corroborate some totals - the Washington Post reported that "A storm on April 10, 1894 blocked roads with 2 feet or more of wind-whipped snow throughout parts of Maryland, Pennsylvania, and New York. As usual, however, D.C. was left with only a couple of inches"

There are so many examples of huge differences over short distances in Chester and Berks County - how about the March 19-21, 1958 snow event?? 50 inches at Morgantown while only 12 miles SE of there at Coatesville only 19" and yet then we go just 11 miles east of Coatesville and find West Chester back up to 32". Do we just go back and say Morgantown is wrong because it is an outlier? Good news for that storm is we have photos of the snow depth with trucks trapped at the PA Turnpike entrace. You cannot go back and disprove snow totals they are very very variable and to Mike G's post the set ups are different plus in the absence of any radar data to actually track and validate the banding it is impossible. Revisionist history like wiping data will not change the fact it happened