ChescoWx

Steady snow continues as it has all day temp has dropped to 16.7 down from high of 17.6 continues to accumulate slowly certainly over an inch (over performer) here will measure shortly when snow ends as back end is approaching

Continues to snow at a steady pace here in NW Chesco in East Nantmeal Townshhip with just slightly under an 1" of snow call it 0.9" so far - already more than expected - no doubt excellent ratios

Temp up to 17.5

Here in East Nantmeal I would say almost moderate snow now - heaviest by far of the day - temp up to 14.0 - will measure shortly but looks to be near 0.5" or so

Snow picking up a bit in intensity with visibility coming down a bit - also snowing down in Sea Isle City NJ (see webcam)

East Nantmeal Twp PA

Light Snow all surfaces covered

Temp 9.6

RH 80%
DP 4.7

Rare to see snow here with single digits

Well we did it made it down to 4.8 degrees below zero (see below) - the lowest temperature in almost 23 years since the 5 below recorded back on February 6, 1996 and a new daily record low for the date beating the old record low set way back 114 years ago when it hit 4 below zero on this date in 1905. It looks some lower spots nearby like in Elverson are at 11 below and at lake level at Marsh Creek almost 10 below. Impressive cold for sure! 

Very unlikely and difficult in the relatively higher spots in this area to record below zero readings....We usually need strong cold air advection and never get any benefit of radiational cooling. To highlight here in NW Chester County at 650 ft ASL we have only experienced 3 days with a below zero readings in the last 23 years since 1996. Below are the only 3 days we have touched below zero.

1/24/11 - (1-2)

1/7/14  - (1.6)

1/22/14 - (1.0)

That said at 10:18 pm local we are already down to 2.5 above zero with a DP of 8.6 below zero - with an almost 4" snow cover so it is certainly possible but I would not be surprised if we stay just barely above zero by tomorrow AM - I will call the low at 0.2 above

0.5" of new snow in East Nantmeal with a high wind gust of 20mph so far temp is down 8 degrees to 20 since 1pm high of 28.4

Watching my cams from my plane on the way to San Francisco - dumping snow now with the driveway already re-covered

AM low so far is our current 10.4 - of interest the 3.5" of snow yesterday melted down to 0.44" of liquid. Not surprising as all of the accumulation came with the temperature at about 33-34 degrees. Wxsim has the snow squall through here around 130-2pm with about 0.3" of snow then temps falling to single digits by 11pm with an AM low tomorrow of 1 below. That would be our 1st below zero reading here since February 24, 205. Wxsim then shows snow developing on Friday AM ending by 3pm with 1" to 2" of additional accumulation with temps holding in the teens.

Final total for East Nantmeal Chester County PA of 3.5" - for the MTD we are at 6.9" (same amount as last January) which is 3.6" below normal through today. For the 2018/19 season to date we stand at 14.2" which is 2.7" below normal.

East Nantmeal Township looks like last heavy band moving through now 3.3" as of last measurement at 6:30pm - temp still at 32.9 above freezing for almost all of the accumulation today - on all surfaces - shows you do not always need below freezing temps to have snow accumulate. Will take final measurement after this ends.

Out to plow/shovel now!

As of 5pm at 2.8" of snow in East Nantmeal Township and still moderate snow falling with a temp at 33.2 - 0.5" of snow since last obs (driveway and road covered see attached)

Heavy Snow and 33.3 here in East Nantmeal now up to 2.3" of snow and looks to continue for at least a couple more hours 1" in last 45 minutes. All roads are covered. Yet 200 feet lower and 6 miles south of here still nothing on the ground

Heavy Snow have not measured but over an inch and accumulating quickly all roads are covered....however just 200 feet lower and 5 miles away on the road to Exton there is nothing on the ground at all - elevation is certainly a factor with this one so far. Temp 33.7 but accumulating

Heaviest snow of the day here temp still holding at 34.1 but accumulating on all surfaces even the main road as of 2pm 0.5" of snow here in East Nantmeal Township

31 minutes ago, JMcCaughey42 said:

What is Wxsim?

www.wxsim - it's a personalized forecasting software program that makes in your backyard forecasts using the GFS and NAM and your home weather station 

Wxsim with 12z data has moderate snow becoming heavy by 230pm with moderate snow toward 5pm and light snow continuing through 830pm with a total accumulation of 3" to 4" 

Wind has shifted to the NE across NW Chesco after SE all A< - snowing moderately with all surfaces even blacktop getting covered.

Snow has really picked up over last 20 minutes or so - things are whitening up quickly temp peaked at 35.0 now down to 34.1 but it is sticking even on paved surfaces

Here in NW Chester County PA - Just a few flakes with a lull in precip temp up to 33.7 - looks like another band moving this way from  SW 

12z GFS pretty similar to 6z general 3" to 4" across NW Chesco....NAM vs GFS

Snow picking up here in NW Chesco all surfaces are covered Temp 31.0 /RH 86%/ DP 27.3 Wind SE 3 gusts to 9mph

1 hour ago, Ralph Wiggum said:

Wxsim says 3-5" with periods of heavy snow....NAMs say intermittent snow showers c to not even an inch up there. Going to be interesting to see if the wxsim can outdo the pro guidance. Radar looks meh. Gl.

Remember it will come down to reality next forecast as it is simply a blend of the NAM/GFS - so go with the pro guidance

Wxsim spot on as the light snow started at 9am - temp up to 29.9