ChescoWx

32 minutes ago, J.P. said:

Paul, does wxsim use 3km nam data or just 12km nam? 

 

I can't tell it just says NAM.....

Latest Wxsim with 6z data - not too much wintry once past Tuesday AM... rush not bad at all

Sunday night: Cloudy in the evening, becoming dense overcast after midnight. A
 slight chance of snow in the evening, then a chance of snow after midnight. Low
 28. Wind south-southwest near calm in the evening, becoming southeast after
 midnight. Chance of precipitation 40 percent. Precipitation (liquid equivalent)
 mostly less than a tenth of an inch. Little or no snow accumulation expected.
 
 Monday: Dense overcast. A slight chance of snow in the morning, then a chance of
 a mix of snow and sleet in the afternoon. High 37. Wind east-northeast around 4
 mph. Chance of precipitation 40 percent. Precipitation (liquid equivalent)
 mostly less than a tenth of an inch. Little or no snow or ice (on ground)
 accumulation expected.
 
 Monday night: Dense overcast. Sleet likely in the evening, then a mix of
 freezing rain and sleet likely after midnight. Low 30. Wind chill ranging from
 21 to 27. Wind east-northeast around 8 mph in the evening, becoming 12 mph,
 gusting to 17 mph, after midnight. Chance of precipitation 80 percent.
 Precipitation (liquid equivalent) mostly around half an inch. Ice (on ground)
 accumulation about a quarter inch. Above-ground freezing rain accumulation up to
 0.1 inches.
 
 Tuesday: Dense overcast. A mix of rain and freezing rain likely in the morning,
 then rain likely in the afternoon. Breezy. High 43. Wind east-northeast around
 14 mph, gusting to 21 mph, in the morning, becoming 10 mph, gusting to 18 mph,
 in the afternoon. Chance of precipitation 80 percent. Precipitation (liquid
 equivalent) mostly around 2 inches. No ice (on ground) accumulation expected.
 Above-ground freezing rain accumulation up to 0.1 inches.

Latest Wxsim with 6z data has a mainly sleet fest starting as snow on Monday evening with heavy sleet falling from around 1130pm thru 10am Tuesday AM with total snow accumulation of 3" to 5" before changing to ZR with 2.35" of w.e. falling before temps rise above freezing by 4pm on Tuesday PM. Then rain thru about 8pm....this will of course change with the 12z data

1 hour ago, Ralph Wiggum said:

Not a huge fan of seeing wxsim signaling mixing even well n and w with elevation. Expectations tempered severely for now. Yeah models look ok....just ok honestly. It's a fine line. And being 6 days out still there is ALOT that can go wrong to muck up the fragile setup we r seeing.

Agreed 100%

Latest Wxsim with 6z data shows 0.81" of rain later today and tonight and then a couple of potential winter events early next week. Current WXSIM shows up to 2" snow on Sun Night into Mon Am and then a bigger storm with a combo of Snow and Sleet for Tuesday night into Wed AM with between 4" to 6" of accumulation here in Chester County PA

High today in East Nantmeal was 62.4 - our warmest day since the 68.9 back on November 2nd. Nowhere near the record for today of 66.0 set back in 1991. Of interest down the shore in Sea Isle City we were able to overcome the sea breeze unlike yesterday where the chilly 36 degree ocean won out and kept temps in the 40's. Today we reached 61.6 at the beach. Hope all enjoyed the last couple days....reality returns and liking some snow prospect for the next Mon-Wed time frame

1.3" total snow in East Nantmeal Twp. Chester County PA with 5.3" of snow in the last 4 days. Seasonal Snow is now up to 16.0" only 1.6" below normal for the season to date.

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"