Discussion for a probable 2 or 3 winter storms/events between Tue Feb 11 - Sat Feb 15. OBS threads for each will be added as needed.

[nycsnow]

3k looks good as well 

[NJwx85]

3k NAM ticked North from 12z. Snow into Orange County vs Bergen County at 03z.

[Allsnow]

1 hour ago, winterwarlock said:

hrrr keeps cutting back with each run

It had nothing for us for the last 24 hours 

 

its wrong 

[TJW014]

NAM with over 0.5" qpf over me

[NJwx85]

The 18z NAM 12k is weaker with the precip than 12z. Double digit snows in VA cut back to 6-8”. Philly went from 6 to 4.

[NJwx85]

It’s snowing now in DC at the White House.

[nycsnow]

Winter Weather Advisory now in effect for Nassau and Suffolk
Counties 9pm this evening through 7am Wednesday morning.

Low pressure beginning to develop over the southeast this
afternoon and will push ENE off the southern Middle Atlantic
this evening into tonight. The region will continue to lie on
the northern periphery of the precip shield. The latest model
trends all support a bump up in liquid equivalent with around a
few hundredths well inland, around a tenth southern portions of
the Lower Hudson Valley and coastal CT, 0.15-0.20" in the NYC
metro, and around 0.25" across Long Island. The NAM still
appears to be the wettest of the guidance across the area,
especially across the southern half with as much as 0.3" in NYC
and 0.4" across eastern Long Island. Much of the 12z CAMs have
come into better agreement and have been noting slow trends in
the HRRR to slowly increase precip amounts across the area. The
HRRR in past lighter events on the northern periphery has run a
bit too low, so this has been factored into the latest forecast.

There are several key ingredients that support the trend upward
including a stronger 700mb frontogenesis signal combining with
strong upper divergence from a 170-190 kt departing polar jet
streak to our north. Models do tend to struggle with the
combination of these features and have seen several past events
over perform with lift accompanying a strong upper jet. The
other factor is the majority of the model suite is indicating
enhancement of the precip shield from Southern NJ up into the
area tonight as the coastal low emerges off the coast. Thermal
profiles are also supporting an all snow event. Soundings also
indicate deep ice saturation within the dendritic growth zone
for several hours tonight, especially across Long Island and
portions of the NYC metro. The strongest lift appears to occur
between 10pm and 2am with a decrease the rest of the night.

The snow will begin to overspread from the south tonight between
7-9pm, becoming steady and continuing through the early morning
hours. There is a period between about 10pm and 2am where
snowfall rates could run between 0.25-0.50" per hour. There is
even a low probability snowfall rates could briefly approach 1"
per hour across Long Island from around 11pm-1am as the
strongest forcing and deepest moisture combine. Snowfall rates
will drop off from west to east from 3am to 5am. Some flurries
may linger towards day break, but accumulating snow should end
before sunrise.

Snow to liquid ratios look higher with this event given we are
on the northern periphery of the low and soundings show more of
an ice saturation signal over one with deeper supercooled water
saturation signal. For these reasons have gone closer to a
12-13:1 ratio.

Updated snow totals in the are around 3 inches with potential of
a few spots approaching 4 inches. Elsewhere across the NYC metro
and much of NE NJ and coastal CT, generally 1-2 inches are
forecast. Locations closer to the south shore in Staten Island
and southern Brooklyn and southern Queens could see up to 3
inches. Amounts across the interior will be lower and generally
less than an inch.

Have also issued a Special Weather Statement for areas outside
the advisory where 1-2 inches is expected to account for
potential of slick conditions tonight.

 

[LibertyBell]

1 minute ago, nycsnow said:

Winter Weather Advisory now in effect for Nassau and Suffolk
Counties 9pm this evening through 7am Wednesday morning.

Low pressure beginning to develop over the southeast this
afternoon and will push ENE off the southern Middle Atlantic
this evening into tonight. The region will continue to lie on
the northern periphery of the precip shield. The latest model
trends all support a bump up in liquid equivalent with around a
few hundredths well inland, around a tenth southern portions of
the Lower Hudson Valley and coastal CT, 0.15-0.20" in the NYC
metro, and around 0.25" across Long Island. The NAM still
appears to be the wettest of the guidance across the area,
especially across the southern half with as much as 0.3" in NYC
and 0.4" across eastern Long Island. Much of the 12z CAMs have
come into better agreement and have been noting slow trends in
the HRRR to slowly increase precip amounts across the area. The
HRRR in past lighter events on the northern periphery has run a
bit too low, so this has been factored into the latest forecast.

There are several key ingredients that support the trend upward
including a stronger 700mb frontogenesis signal combining with
strong upper divergence from a 170-190 kt departing polar jet
streak to our north. Models do tend to struggle with the
combination of these features and have seen several past events
over perform with lift accompanying a strong upper jet. The
other factor is the majority of the model suite is indicating
enhancement of the precip shield from Southern NJ up into the
area tonight as the coastal low emerges off the coast. Thermal
profiles are also supporting an all snow event. Soundings also
indicate deep ice saturation within the dendritic growth zone
for several hours tonight, especially across Long Island and
portions of the NYC metro. The strongest lift appears to occur
between 10pm and 2am with a decrease the rest of the night.

The snow will begin to overspread from the south tonight between
7-9pm, becoming steady and continuing through the early morning
hours. There is a period between about 10pm and 2am where
snowfall rates could run between 0.25-0.50" per hour. There is
even a low probability snowfall rates could briefly approach 1"
per hour across Long Island from around 11pm-1am as the
strongest forcing and deepest moisture combine. Snowfall rates
will drop off from west to east from 3am to 5am. Some flurries
may linger towards day break, but accumulating snow should end
before sunrise.

Snow to liquid ratios look higher with this event given we are
on the northern periphery of the low and soundings show more of
an ice saturation signal over one with deeper supercooled water
saturation signal. For these reasons have gone closer to a
12-13:1 ratio.

Updated snow totals in the are around 3 inches with potential of
a few spots approaching 4 inches. Elsewhere across the NYC metro
and much of NE NJ and coastal CT, generally 1-2 inches are
forecast. Locations closer to the south shore in Staten Island
and southern Brooklyn and southern Queens could see up to 3
inches. Amounts across the interior will be lower and generally
less than an inch.

Have also issued a Special Weather Statement for areas outside
the advisory where 1-2 inches is expected to account for
potential of slick conditions tonight.

 

3-4 inches sounds nice it could match the last storm with no taint....

an inch per hour from 11 pm to 1 am....

[TJW014]

Coastal Jersey should see some ocean-effect enhancement with the ENE winds. 

[SnowGoose69]

Both the 12 and 3km NAM have snow into JFK by 0030z now, even the HRRR has 0130z

[Roger Smith]

Wondering if there could be a narrow band of heavy snow tonight-Wed similar to what happened last winter? Focus would be the secondary arctic front stalling south of EWR-JFK. 

 

[nycsnow]

Precip looks to be creeping north in southern Jersey 

[jm1220]

There’s often a heavy snow band that develops on the north side of these in the 700mb fronto max zone, and usually has high ratios. NAM still looks the most impressive in developing that frontogenesis zone and moving it across NYC/LI. 

[winterwarlock]

1 hour ago, NJwx85 said:

Why are people looking at the HRRR at this range? It’s useful once it actually starts snowing to pick out banding features. I wouldn’t worry about it unless the NAM caves this next run.

why do people only love the nam when it gives the most snow

[NJwx85]

2 minutes ago, winterwarlock said:

why do people only love the nam when it gives the most snow

I don’t favor the NAM, exactly the opposite. The HRRR is completely out of range.

[Brasiluvsnow]

2 minutes ago, winterwarlock said:

why do people only love the nam when it gives the most snow

in fairness most weenies my self included love EVERY model when they show snow ,,,,,,with the exception of Snowman and a few others ,,,,that said enjoy the snow you guys that get it as us up here north of the Tappan Zee bridge we can cheer you on and only beg

[dseagull]

Im declaring a new p-type with this report. 

 

35.4F

28.5 DP

67 RH

... sporadic "pixie graupel"

 

Central Barnegat Bay

[SACRUS]

 

[SnowGoose69]

I am starting to think coastal NJ and parts of LI see more snow from this than places such as NRN MD/NRN DE and SE PA

[LibertyBell]

42 minutes ago, Roger Smith said:

Wondering if there could be a narrow band of heavy snow tonight-Wed similar to what happened last winter? Focus would be the secondary arctic front stalling south of EWR-JFK. 

 

Looking for that here, we had a 4 and 6 inch event at JFK last year around this same time!

 

[LibertyBell]

Just now, SnowGoose69 said:

I am starting to think coastal NJ and parts of LI see more snow from this than places such as NRN MD/NRN DE and SE PA

ground zero from Coney Island to JFK to Oceanside to Long Beach to Jones Beach to Fire Island?

 

[weatherpruf]

17 minutes ago, SACRUS said:

 

You can see where the bands are setting up, and it ain't looking like much above Monmouth Co 

[nycsnow]

2 minutes ago, weatherpruf said:

You can see where the bands are setting up, and it ain't looking like much above Monmouth Co 

Super early for up here

[Allsnow]

5 minutes ago, weatherpruf said:

You can see where the bands are setting up, and it ain't looking like much above Monmouth Co 

Super early for that type of post..

 

snow won’t start until after 7pm earliest 

[winterwarlock]

did we have a huge storm 4 years ago on this day

[weatherpruf]

4 minutes ago, Allsnow said:

Super early for that type of post..

 

snow won’t start until after 7pm earliest 

Yeah maybe, thought I heard something pinging outside. Didn't see anything yet. But these storms often kinda stop around that area; when they are getting a foot, we get a lot less. So with 3-4 or so on the table, could leave us with an inch or less. But every storm is different.

[nycsnow]

Clear push north on radar last few frames 

[MJO812]

HRRR slowly catching on

[winterwx21]

18z RGEM looks fine. Gets 2 inches about up to our area. 

[winterwx21]

1 minute ago, MJO812 said:

HRRR slowly catching on

The 20z run still only gives us a dusting. Crazy if it's gonna be this far off. We're only several hours away from the start of the event, so it's not as if it's long range for the HRRR. It's going to be an embarrassment for that model to miss this badly if it's wrong.