ChescoWx

Based on the current forecast it appears likely this will be a top 10 coldest Christmas Eve and Christmas Day in Chester County PA history with data back to 1894. If the current forecast verifies it would be the 9th coldest Christmas Eve and the 6th Coldest Christmas Day. See the Top 20 coldest for each day below.

Our stretch of chilly weather looks to continue for most of the remainder of 2022. In fact December looks likely to finish as our coldest December since at least 2017 and possibly the coldest since 2010! Dry weather should continue before snow arrives on Thursday morning before quickly changing to rain. A strong arctic cold front will sweep through from west to east on Friday afternoon dropping temps from the 50's at 1pm to below freezing by 8pm. High temperatures on Christmas Eve day and Christmas Day may struggle to reach the low to mid 20's. The record high for today is 62 degrees set in 1929. The record low is 1 above zero from 1951. The daily rain record is the 1.30" that fell in 1934. Our daily snow record I remember well as 15" of snow fell today back in 2009. It started at 5am and was over by 10pm. There was still 4" of snow on the ground on Christmas morning which was our next to last White Christmas - with our last such one 10 years ago in 2012 when we had 2" of snow on the ground that fell on Christmas Eve 2012.

Great info!! It looks like they reached their peak steel production in 1953. They are still in production today - even making some of the steel for the new WTC in NYC! An interesting idea - and no doubt it may have contributed a bit to the warming...but since the same pattern of cyclical warming and then cooling was seen at all of the other Chester County observation locales in West Chester, Phoenixville and Devault during that 1930's through early 1950's time frame. It provides some additional support for the observations at all the chesco spots.

Sorry Steve -I should have clarified - I am of course only looking at all of the Chester County NWS COOP sites for my local suburban Philly county, With the cyclical flow of my analysis of only Chester County PA (see below). We have a clear history at least here in Chester County PA of multiple decades of warming (1930's thru 1950's) followed by multiple decades of cooling (look at those 60's through 80's decades).... now followed by our recent decades of warming - so I am extremely confident we should see multiple decades of cooling as that is what the historical records show us. I am a big believer in the cyclical nature of climate and a huge believer in predictable normal climate change. I understand a lot of folks think warming will continue unabated but I just can't find any actual real world data to support this hypothesis. I am a fact based data guy and I just can't find any long term historical data points outside of heat island locations like PHL airport that support this. Does this make sense?

Of note today will be our 10th of 18 days that have been below normal. Looking ahead regarding temps we are well on our way to only our 3rd below normal December in the last 12 years as we look to be starting the next cooling cycle of our local climate.

Yes Virginia if the NBM were to verify we may see a change to snow before ending and we would see our 1st White Christmas in 10 years! Need a festivus miracle!! Or technically a little anafront action!!

As has been the case for this early winter season here in Chester County it appears we will see below normal temperatures for the upcoming week but then a brief but sharp warm up just in time to turn any brief snow at the start to a heavy rain on Thursday. For those who want snow we need these low pressure systems to track off the coast to our east to keep the cold air locked in. After the storm we will turn sharply colder by Friday PM with our coldest weather of the season so far on tap for Christmas weekend. Christmas eve day may struggle to escape the low to mid-20's for high temps.

Yep lock that up a White Christmas in Chester County...

Some interesting climate data analysis by month for Western Chester County PA. I wanted to see the differences in our local county climate comparing NWS coop observations taken at 340 ft above sea level (ASL) which were recorded from January 1894 through 1982 (89 years) vs. the observations that have been recorded now for the last 40 years at over 660 ft ASL. Some results that might be surprising to some. Overall very little change in our average temperatures since the 1890's +0.7%. However, somewhat cooler warm season months and warmer cold season months. The biggest differences have been in increased precipitation +9.7% and increased snowfall by 14.1%.

Quiet but seasonably chilly stretch of weather on the way through Wednesday. Then as the National Weather Service is saying this morning "Stay tuned for changes to the forecast, and our area should prepare for anything from heavy rain and gusty winds with some coastal flooding to snow and ice Thursday into Friday, with a very cold airmass likely to follow for next weekend." Lots of model disagreements but expect to gain a bit more consensus by Tuesday AM. The record high for today is 62 degrees from 2000. The record low is 1 below zero from 1910. Daily rain record is 2.99" from 2000. The daily snow record is the 7.5" that fell in 1932.

climate has of course not changed....climate cycles change and we have gone from a cold to a warmer and now I suspect we are trending into another colder cycle. We have been in a much snowier cycle during the last 2 decades....it will return again. Patience!

The EURO does not look right at all!! A bomb to lakes does not make sense....this will shift east in future runs although not saying it will be enough to bring a SECSy finish!!

as expected Euro follows - the ex-US models. Still nice to see some relative high level consensus at this range as I am sure we will see some more big swings over the next 6 days! Buckle up!!

It should likely follow the ICON and GEM at this range - it will not be showing a hit IMHO - at least with this run.

A great song there with a weather influence....my personal weather inspired song is Rain by the Beatles....maybe the earliest rock song inspired by mind altering agents

How tired would my snowblower be if it shoveled model snow output?

GFS snow by 7am Christmas Eve morning

Rain will end this AM. We have picked up 1.51" of rain and melted snow so far along with the 0.3" of snow/sleet yesterday. Of note with this event we have now exceeded our normal annual rainfall here in Chester County of 50.21". It looks likely we will now have colder than normal weather to close out 2022. The exception could be if the east coast storm next week tracks like the latest European model is showing. In that case we would have a brief warmup and change any brief snow to rain next Thursday into Friday. The models will change again many times before then. The record high for today is 67 degrees set in 1971. The record low is also the earliest seasonal record of a below zero reading as on this date in 1917 we fell to 1 degree below zero. Record rain is the 1.80" today in 1902. Our record snow was just 2 years ago when we received 7.3" of snow.

Still raining so far 1.51" of rain and 0.3" of snow from event

Suspect many on this forum would sign up for the 12z GFS if you wish for our 1st White Christmas in 10 years

Still moderate ZR here in NW Chesco temp up to 31.7 - evergreens a bit droopy with some ice accretion

Starting to change to all freezing rain - 90% ZR and 10% IP temp up to 29.9 Just measured 0.3" of sleet/snow here in East Nantmeal

Remember the GFS is famous for suppression of east coast snow events...often up till 3 days before the event.

Snow starting to mix back in with the moderate sleet looks like this will be our 1st measurable snow/sleet of the season. All surfaces covered temp at 29.8

Over 30 accidents now reported on the Route 30 Bypass here in Chester County. Still snow and sleet mix all surfaces coated with a temp down to 29.9