ChescoWx

Only for counties that may be impacted by the IVT

...WINTER STORM WARNING IN EFFECT FROM 4 AM TO 10 PM EST FRIDAY... * WHAT...Heavy snow expected. Total snow accumulations of 5 to 6 inches. * WHERE...Portions of northern Delaware, southern New Jersey and southeast Pennsylvania. * WHEN...From 4 AM to 10 PM EST Friday. * IMPACTS...Travel could be very difficult. The hazardous conditions could impact the morning or evening commute. * ADDITIONAL DETAILS...Temperatures will rapidly drop into the teens late Friday night. Any untreated roads will become icy and dangerous.

It's amazing how many folks are weather nerds - I was asked to do a write up on the Norlun Trough yesterday on the FB page - non nerds want to know!!! I have welcomed almost 300 people since yesterday and the chatter has been nonstop over there! As our friend Ben Franklin said "some are weatherwise and some are otherwise"

Whatever happened to DT? I used to enjoy arguing with him....did not take much before he started to drop the f bombs....good times!

That last run of the 3km NAM makes be think that red circle will come in further south then that....we shall see - it will probably move further north again next run

If I was making a forecast that sounds solid in my view.....but what do I know!!

Latest 3km NAM now brings the enhanced band to south of the M/D line - in line with what Bernie Rayno predicted yesterday

I have also seen in these situations some enhancements as moisture is lifted into the modest hills as you move N and W of the fall line - glad I am not a professional forecaster. Feel like trying to predict exact t-storm totals....

HRRR 3km aligns has modeled relative highest snow totals running from NW Chester County over to Central NJ

Based on latest SREF potential for 3" or more highest probabilities run across much of NW Chester County - Montgomery County and over to Central NJ. With a pretty quick reduction in % chances as you get up to the Lehigh Valley and over to NW NJ

Temperatures have started to rebound across the area with clouds on the increase after a low of 14 degrees at 330 this morning. A cloudy day today with temps remaining below freezing across most of Chester County for the 4th consecutive. The below freezing streak looks to continue across the area until Monday at the earliest. Light snow should arrive toward daybreak tomorrow and continue much of the day tomorrow. Snow totals should range from 2" to 4" across SW Chester County to 3" to 5" as we move NE through Chester County and into Montgomery and Bucks counties. We could see a little blowing and drifting snow later Friday night into Saturday and temps will struggle to get much above the teens with wind chills near or below zero. A warming trend gets underway next week as we get our January Thaw. Records for today: High 66 (1973) / Low 4 below (1994) / Rain 1.15" (1915) / Snow 6.0" (1930)

Temperatures have started to rebound across the area with clouds on the increase after a low of 14 degrees at 330 this morning. A cloudy day today with temps remaining below freezing across most of Chester County for the 4th consecutive. The below freezing streak looks to continue across the area until Monday at the earliest. Light snow should arrive toward daybreak tomorrow and continue much of the day tomorrow. Snow totals should range from 2" to 4" across SW Chester County to 3" to 5" as we move NE through Chester County and into Montgomery and Bucks counties. We could see a little blowing and drifting snow later Friday night into Saturday and temps will struggle to get much above the teens with wind chills near or below zero. A warming trend gets underway next week as we get our January Thaw. Records for today: High 66 (1973) / Low 4 below (1994) / Rain 1.15" (1915) / Snow 6.0" (1930)

agreed! That's why I like the 3k more than the 12k NAM

NBM creeping up though...

3km NAM says it's 12km brother has been drinking....let's cut those figures in half!!

NBM

18z ICON

18z Euro

18z GFS

Found this Norlun in the area from 2016. Here in East Nantmeal we ended with 7.3" - long duration event with the heavy period of snow falling in the late afternoon of February 9th

Some Chesco climate data for today

Solid thoughts IMO thanks Kevin!

I suspect this one will impact folks further south and east from the Lehigh Valley with the relative higher amounts....that said the ratios will be good so should not take a lot of precip to get us to similar snow totals to the last storm for most locales...

18z NAM looks very close to what is in the current NWS Forecast with a little less snow north and west and the focus of snows ( IVT?) over the I95 corridor.

Updated NWS Point and Click have 1.5" to 2.5" for most of Eastern PA from Allentown down through most of the Philly burbs with up to 3" possible over toward Phily - seems not buying what above Hrrr is selling...