1.5" OTG as of 11:30 am, so 1/2" in the last 90 minutes - been mostly light to moderate. 14Z HRRR only had me at 1.5" at this point and 12Z NAM had me around an inch or so, which is pretty impressive actually, although HRRR only has me at about 9" at the end and NAM at almost 11", which would be fine, but maybe a little disappointing, given the forecast of 10-15" (and 12-18" for awhile yesterday).
NWS-Philly updated map from 10:40 am - mostly unchanged (NB actually up from 14 to 15"). Obviously, they're seeing things differentl from many others - we'll know who was right in about 12 hours. Here's their thinking...
National Weather Service Mount Holly NJ
1106 AM EDT Wed Mar 21 2018
NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030AM update: Increased snow amts N central NJ through ptns of
e central and se PA down thru e MD and
srn-central DE, and then
tonight coastal NJ Atlc
nwd.
WSW is out. 1030 AM STS is posted
and reminder...only 8A today to 8A Thursday. We know its struggling
to snow snow north of I80 and we haven`t changed amts there and
sweat it out as models insist it will snow pretty good there
this
aftn/early tonight. We have not changed PHl
amt at all
until we know the reality at 230 PM.
2.5" OTG as of 1:00 pm and 2.0" OTG as of 12:30 pm, so 1" per hour the last half hour - coming down moderately to almost heavily. 32F. Streets getting covered again. Beautiful dendrites - this must be at least 10:1 ratio snow. NWS-Philly still holding fast to forecast, as is NWS-NYC just recently.
National Weather Service New York NY
1151 AM EDT Wed Mar 21 2018
NEAR TERM /UNTIL 6 PM THIS EVENING/...
Precipitation type is mainly snow across the region with a few
inches of snow already reported in different parts of Northeast
New Jersey and in New York City to Western Long Island. Snow is
mostly moderate to occasionally heavy and this is expected to
continue into this afternoon.
Upper low continues to march toward the east coast, with
coastal low still east of the Delmarva.
With an expected track of the
sfc low near the 40N/70W
benchmark along with strong deep lift and banded precip, the
stage is set or a major winter storm for the area. Colder and
drier air is in place when compared to previous events.
Colder air will be pulled down from the north as the storm
deepens.
NYC
metro including NE NJ, the lower Hudson Valley and into SW
CT, would typically be in the bulls eye of heavier snow
conceptually. Always hard to pinpoint any potential bands, but
generally expect 12 to 18 inches across these locations if
everything pans out as expected (track,
thermal profiles, etc).
Temps in the lower 30s remain steady or fall as the heavier
snow commences. Snow ratios look to be at least 10 to 1, and
even 13 to 1 or 15 to 1 is possible for the interior.
The western extent of the precip shield should keep amounts well
NW down slightly, but a foot or more is possible even up across
those locations.
Winds will be quite gusty, with 40+ mph at times possible.
Blizzard conditions are possible at times, just not quite enough
confidence for that upgrade to the hazard.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
As the slow moving storm begins to pull away, heavier snow will
taper from west to east late tonight. Once again, 7-12 inches
possible well NW, 12-18 around NYC
metro and into SW CT, and
slightly lower totals are expected east, and lower snow ratios.