Extreme Cold, Snow & Sleet: SECS 1/24 - 1/26

[Stormlover74]

Nam came south a bit with the mix line at 18z

[nycsnow]

Don’t see how the city and Long Island don’t hit double digits. Absolutely ripping and not even in the big stuff yet 

[EasternLI]

Yeah, that looks a tick cooler on the 12z nam

[nycsnow]

Just now, Stormlover74 said:

Nam came south a bit with the mix line at 18z

Looks like well the short range meso models that started this last night 

[jm1220]

4 minutes ago, eduggs said:

Ugh, the HRRR has sleet in here by 1-2pm. It has continuously shifted north since it's been in range. And sleet actually started to mix in in VA earlier than the HRRR showed. The northern edge of mixing might oscillate or battle back to snow but that's quite the warm tongue surge now modeled.

Heavy snow rates=warm air advection. Not surprising to me, we just have to max out what we can while we have the cold enough mid level air. It’s a SWFE and these type of storms will always behave accordingly when we have retreating confluence. Enjoying the heavy snow and closing in on 2”. Should end up with 8” at least before sleet which should add up to a couple more inches. A little freezing drizzle to freeze it all up and weenies here will be happy for a long time. 

[nycsnow]

Just now, jm1220 said:

Heavy snow rates=warm air advection. Not surprising to me, we just have to max out what we can while we have the cold enough mid level air. It’s a SWFE and these type of storms will always behave accordingly when we have retreating confluence. Enjoying the heavy snow and closing in on 2”. Should end up with 8” at least before sleet which should add up to a couple more inches. A little freezing drizzle to freeze it all up and weenies here will be happy for a long time. 

I don’t see how the island don’t hit double digits. It’s puking snow in Nassau

[BxEngine]

7 minutes ago, eduggs said:

Ugh, the HRRR has sleet in here by 1-2pm. It has continuously shifted north since it's been in range. And sleet actually started to mix in in VA earlier than the HRRR showed. The northern edge of mixing might oscillate or battle back to snow but that's quite the warm tongue surge now modeled.

Soundings at 2 just south of nyc are still all snow. 

[nycsnow]

Nam is gonna be completely wrong with snow totals for nyc area 

[nycsnow]

1 minute ago, BxEngine said:

Soundings at 2 just south of nyc are still all snow. 

I posted last night. Happened in the south a lot can’t go off the precip maps a lot of the pink was actually snow and soundings supported snow despite the pink 

[eduggs]

2 minutes ago, nycsnow said:

Don’t see how the city and Long Island don’t hit double digits. Absolutely ripping and not even in the big stuff yet 

I think we have about 4 hours at least to do it. Although sleet could add another inch+ thereafter. Might be able to do it.

[Astoriaweather]

1 minute ago, nycsnow said:

Nam is gonna be completely wrong with snow totals for nyc area 

You think?  Don’t you  think city will fiip to sleet by 3 pm? That is only 5 more hours.

[eduggs]

2 minutes ago, BxEngine said:

Soundings at 2 just south of nyc are still all snow. 

 

I'm extrapolating when areas further south started mixing with sleet relative to the HRRR. The mid-level surge is really strong. 

[North and West]

Changeover line is in southern DE.

Keep it there.


.

[NJwx85]

I have over 3” here in Rockland already. Plow just went past.

[North and West]

The mix line is through the the DCA area. The graphics for the colder models (e.g., UKMET) had it well south of there at this time. The snowier models (ECM-AI etc) that showed 10"+ down that way are not likely to verify. Most reports are around 6" or less of pure snow. They should get a few inches of sleet on top, however (which Pivotal claims not to count as snow).

are you rooting for rain?


.

[BxEngine]

2 minutes ago, eduggs said:

I'm extrapolating when areas further south started mixing with sleet relative to the HRRR. The mid-level surge is really strong. 

Extrapolating is subjective. The objective soundings on the hrrr support snow in the entire subforum north of 78 at 2. Whether its correct or not is a separate argument. But the comment that the hrrr shows sleet by 1 or 2 is incorrect.

[SnowGoose69]

I think there will be many 7s-8s-9s but getting over that unless rates go to 2-3 inches an hour after 15Z will be hard 

[RU848789]

Here's a PSA for snowfall measurement: clear the board after the change to sleet and sum the snow and sleet measurements together; otherwise you'll likely get some compaction.  This is from a great article on snow measurement in The Conversation based on NWS guidelines.  Or maybe we'll get lucky and get no sleet, lol.  

More complicated cases of measurement
So, let’s consider three common scenarios. Here in the eastern U.S., we often have to deal with snow that changes to rain during the course of a storm. Imagine 6.0 inches (15 cm) of snow falls, then an inch (2.5 cm) of sleet which compacts the snow to a 4-inch (10-cm) depth. Then, on top of that falls an inch of freezing rain which further compacts the snow to 2.6-inch (6.6-cm) depth by the end of the observation period. What should be listed as the daily snowfall? The snow depth?

In this situation, when the snow transitions to sleet, the snow board should be cleared and the maximum depth of snow recorded – 6 inches (15 cm) in this case. Do the same with the sleet and this will add an inch (2.5 cm) to the snowfall – technically, “solid precipitation” – total. Freezing rain is never added to the daily snowfall total because it is in liquid form when it reaches the ground. Thus, the daily snowfall is 7.0 inches (measured to the nearest tenth of an inch) (17.8 cm), while the snow depth at observation is rounded up from 2.6 inches (6.6 cm) to 3 inches (7.6 cm).

https://theconversation.com/how-is-snowfall-measured-a-meteorologist-explains-how-volunteers-tally-up-winter-storms-175628

 

[nycsnow]

1 minute ago, Astoriaweather said:

You think?  Don’t you  think city will fiip to sleet by 3 pm? That is only 5 more hours.

Yea some places were almost at 2 inches over an hour ago in nyc nam has the total at 5-7 we’re gonna be in 1-3 inch per hour rates til it mixes

[nycsnow]

https://x.com/bradybgwx/status/2015415124677308705?s=46

[eduggs]

Just now, North and West said:

are you rooting for rain?


.

Who likes rain in the winter, are you crazy? I'm obviously rooting for snow and only snow. I'm heading outside now to enjoy it. It's perfect out right now. I'm not looking forward to sleet this afternoon.

[North and West]

I don’t see how the island don’t hit double digits. It’s puking snow in Nassau

not ripping?


.

[Astoriaweather]

DC was also forecast for 6 to 10 and seems to have busted a bit low. Think that is also a sign the warmth may make it here before we would like in NYC

[eduggs]

3 minutes ago, BxEngine said:

Extrapolating is subjective. The objective soundings on the hrrr support snow in the entire subforum north of 78 at 2. Whether its correct or not is a separate argument.

That's fair, but here's 3pm near Newark. That's a sleet sounding. So presumably sleet started before this time period. Obviously the further north you go, the later this sleet. But it definitely looks like it's coming quickly. That's why I'm heading outside now to enjoy it.

[SnowGoose69]

LGA and NYC had .12 and .10 liquid past hour.  LGA now reporting 3 on the ground 2 last hour 

[nycsnow]

6 minutes ago, North and West said:

not ripping?


.

No it is… I meant like I don’t see how they don’t have double digits it’s ripping snow

 

[SACRUS]

2 minutes ago, SnowGoose69 said:

LGA and NYC had .12 and .10 liquid past hour.  LGA now reporting 3 on the ground 2 last hour 

25:1 ratios here as well more or less

[Stormlover74]

Hrrr a touch colder but still a flip between 2 and 3 here. About an hour after the nam

[jm1220]

5 minutes ago, eduggs said:

That's fair, but here's 3pm near Newark. That's a sleet sounding. So presumably sleet started before this time period. Obviously the further north you go, the later this sleet. But it definitely looks like it's coming quickly. That's why I'm heading outside now to enjoy it.

Doesn't look like it's moving north all that fast over DE and hitting some resistance over DE Bay. I'm sure it's still coming but time to watch the radar and the CC line from here IMO. And heavy enough rates can overcome a very shallow warm layer a little above freezing which is probably what the HRRR is showing with the fighting back and forth. 

[CPcantmeasuresnow]

3.2 inches as of 9am.