ChescoWx

Wednesday: Mostly cloudy to cloudy in the morning, becoming dense overcast in the afternoon. A slight chance of snow in the morning, then snow likely in the afternoon. High 35. Wind chill ranging from 19 to 26. Wind east-northeast around 7 mph, gusting to 16 mph, in the morning, becoming 10 mph, gusting to 18 mph, in the afternoon. Chance of precipitation 70 percent. Precipitation (liquid equivalent) mostly between a quarter and half an inch. Snow accumulation 2 to 3 inches. Wednesday night: Dense overcast. Patchy light fog after midnight. Snow likely. Breezy. Low 28. Wind chill as low as 18. Wind east-northeast around 14 mph, gusting to 20 mph, in the evening, becoming 11 mph, gusting to 20 mph, after midnight. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly around 2 inches. Snow accumulation 15 to 20 inches. Thursday: Cloudy. A chance of a mix of snow and sleet in the morning, then a slight chance of snow in the afternoon. High 30. Wind north-northeast around 9 mph, gusting to 18 mph, in the morning, becoming 5 mph in the afternoon. Chance of precipitation 60 percent. Precipitation (liquid equivalent) mostly less than a quarter of an inch. Snow or ice (on ground) accumulation about an inch.

WXSIM with 18z GFS NAM has 13" to 18" of snow for Western Chesco.....it has 850's warming to 30.6 at 2am at their warmest....hence the inflated totals..... Wednesday: Cloudy in the morning, becoming dense overcast in the afternoon. A slight chance of snow in the morning, then snow likely in the afternoon. High 35. Wind chill ranging from 21 to 25. Wind northeast around 7 mph, gusting to 15 mph, in the morning, becoming 11 mph, gusting to 19 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. Wednesday night: Dense overcast. Snow likely. Breezy. Low 29. Wind chill as low as 18. Wind northeast around 14 mph, gusting to 21 mph. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly around 2 inches. Snow accumulation 12 to 16 inches.

Of note In 126 years of December records in Chester County only 26 storms have exceeded 6" only on average once every 5 years! Only 2x has a December storm exceeded 20" - six times 12" plus and only 8 times 10" or more....climo argues against a major snow event....but of course that does not mean it cannot happen....just rare!

Gonna be dicey IMO for most on here unless N and W of MDT - RDG - ABE line.......

I always like to start looking at the NAM for the profiles at this juncture....growing pretty confident the 850's get to over 0c over much of the area for a time on Wednesday night before crashing SE again....with that in mind thinking a early thump of snow to IP for a while and back to snow before ending with a solid 6" to 9" of snow/concrete snow in my area of NW Chesco.....the all snow zone will be from around MDT to just N of RDG to just N of ABE and NE from there.....but allow me the option to change my forecast by game time!

WXSIM backing off a bit on totals with 12z runs only 14" to 19" now.... Wednesday: Cloudy in the morning, becoming dense overcast in the afternoon. A slight chance of snow in the morning, then snow likely in the afternoon. High 33. Wind chill around 21. Wind east-northeast around 8 mph, gusting to 16 mph, in the morning, becoming 11 mph, gusting to 18 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. Wednesday night: Dense overcast. Snow likely. Breezy. Low 29. Wind chill as low as 18. Wind east-northeast around 14 mph, gusting to 22 mph. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly around 2 inches. Snow accumulation 12 to 16 inches. Thursday: Dense overcast. Patchy light fog. Snow likely in the morning, then a chance of snow in the afternoon. High 30. Wind chill around 22. Wind northeast around 6 mph, gusting to 16 mph. Chance of precipitation 70 percent. Precipitation (liquid equivalent) mostly around a quarter of an inch. Snow accumulation about an inch.

Snowing almost moderately temp down to 34.4 on VP and 32.9 on Tempest...ground whitening quickly now

Rain Snow mix here in NW Chesco at 685ft temp 38.2 on VP and 36.9 on tempest....

I do not see this at all as a Miller B or any type of hybrid B system....there is no primary going up well west with a 2nd low developing on the coast

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!

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

WXSIM much more enthused about tomorrow's initial event than my NWS point and click is.....WXSIM sees a mix of rain and snow becoming all snow and briefly heavy after 230pm with 2" to maybe 3" accumulating. It has "backed off" a bit on the Wed event starting around 2pm with 19.4" of snow accumulating....

WXSIM with 6z data shows 850s getting to 32.7 by 11pm Wed night with a mix of heavy snow and sleet.....still spits out 26.8" of snow and sleet - on top of the 2" or so tomorrow PM.... Wednesday: Cloudy in the morning, becoming dense overcast in the afternoon. Snow likely in the afternoon. High 35. Wind chill around 23. Wind east-northeast around 8 mph, gusting to 18 mph, in the morning, becoming 12 mph, gusting to 19 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. Wednesday night: Dense overcast. Snow likely in the evening, then a mix of snow and sleet likely after midnight. Breezy. Low 30. Wind chill as low as 20. Wind east-northeast around 13 mph, gusting to 23 mph. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly around 3 inches. Snow or ice (on ground) accumulation 20 inches or more.

12z NAM shows 4" of snow tomorrow PM......

There will be a couple more of these 18z type runs - details to be ironed out....when the EPS is honking I am buying at least a significant snowstorm (over 6") for many from the I95 corridor N and W....keep in mind major 10" + storms are very rare in this area. I will be posting top 10 shortly for Western Chester County PA shortly

No doubt this will happen....WXSIM went off the deep snow end with the 6z models - says 20" or more on Wed....the actual amount of snow it forecasts on the ground by Thursday AM is 29.3" Monday: Dense overcast. Patchy light fog. A mix of rain and snow likely in the morning, then a mix of rain, sleet, and snow likely in the afternoon. High 37. Wind northeast around 2 mph in the morning, becoming north around 6 mph in the afternoon. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly around an inch. Snow or ice (on ground) accumulation about an inch. Wednesday: Cloudy in the morning, becoming dense overcast in the afternoon. A slight chance of snow in the morning, then snow likely in the afternoon. High 32. Wind chill around 22. Wind east-northeast around 6 mph, gusting to 16 mph, in the morning, becoming 12 mph, gusting to 21 mph, in the afternoon. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly between half an inch and one inch. Snow accumulation 4 to 6 inches. Wednesday night: Dense overcast, with areas of light frost likely. Snow likely. Breezy. Low 28. Wind chill as low as 18. Wind east around 14 mph, gusting to 22 mph, in the evening, becoming north-northeast after midnight. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly around 3 inches. Snow accumulation 20 inches or more.

Latest WXSIM with 18z data up to 6" to 10" on Wednesday - just flurries on Monday at this point Wednesday: Dense overcast. Snow likely. High 33. Wind chill around 24. Wind northeast around 11 mph, gusting to 20 mph. Chance of precipitation 80 percent. Precipitation (liquid equivalent) mostly around an inch. Snow accumulation 5 to 8 inches. Wednesday night: Dense overcast in the evening, becoming cloudy after midnight. Patchy light fog after midnight. Snow likely in the evening, then a slight chance of snow after midnight. Low 28. Wind chill as low as 22. Wind northeast around 10 mph, gusting to 20 mph, in the evening, becoming 6 mph after midnight. Chance of precipitation 70 percent. Precipitation (liquid equivalent) mostly around a quarter of an inch. Snow accumulation 1 to 2 inches.

WXSIM timetable for potential snow event on Wednesday the 16th for Western Chester County PA Snow arrives by 930am temp 31.5 Heavy Snow by 10am temp 30.2 Moderate Snow at 4pm temp 31.7 with 5" to 6" of snow so far Snow winding down by 10pm with total accumulation of 6" to 8"

Some elevation will help....

Still snowing lightly 0.3" with our 2nd "winter" event of the season - now 0.6" for the season still 2.6" below normal through today