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.

[LibertyBell]

4 minutes ago, CPcantmeasuresnow said:

Things have changed since this morning. Projected highs have gone up three degrees since then from 31 to 34. I'll take it you can keep any ice storms, no use for it.

I feel like it's going to be down to nowcasting where the freezing line sets up.

 

[RU848789]

Most of the 12Z models a bit snowier and further south (including the Euro) with at least minor snow and with more snow to the north too, before the changeover to rain (and probably ice then rain well to the north).  As long as we don't see a much faster changeover to sleet, like the two recent mixed events.  Potential for a few inches even in CNJ/NYC before the rain, although with borderline temps during the day, accumulation might only be on colder surfaces, especially if rates aren't that high (there is always a sun angle issue - it's just at a minimum at the solstice and continually increases away from the solstice).  

[LibertyBell]

16 minutes ago, RU848789 said:

Most of the 12Z models a bit snowier and further south (including the Euro) with at least minor snow and with more snow to the north too, before the changeover to rain (and probably ice then rain well to the north).  As long as we don't see a much faster changeover to sleet, like the two recent mixed events.  Potential for a few inches even in CNJ/NYC before the rain, although with borderline temps during the day, accumulation might only be on colder surfaces, especially if rates aren't that high (there is always a sun angle issue - it's just at a minimum at the solstice and continually increases away from the solstice).  

the sun angle is much more of an issue for urbanized areas though-- we wouldn't have this issue if we didn't have concrete and asphalt pollution.

[Stormlover74]

Nam looks like a nice hit with temps around freezing at 21z

[wdrag]

My guess is WS watches will post  tomorrow morning for much of the I84 corridor roughly Noon Sat-Noon Sunday and they'll hold advisories till sometime tomorrow adjacent to the watches.  We'll see how they'll handle based on internal greater data resources/expertise and collaboration,  which is a time consuming process. 

[SnoSki14]

1 hour ago, MJO812 said:

Seriously 

Sun Angle isn't a problem until after 1st week of March. It certainly won't be an issue in February. 

[forkyfork]

1 minute ago, SnoSki14 said:

Sun Angle isn't a problem until after 1st week of March. It certainly won't be an issue in February. 

if you're worried about sun angle it's not much of a storm to begin with

[RU848789]

Haven't seen updated maps yet, but the NWS-Philly AFD is predicting more than this morning. 

Area Forecast Discussion National Weather Service Mount Holly NJ 336 PM EST Thu Feb 13 2025 SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... To start the day Saturday, a large area of low pressure will be centered near Oklahoma with the systems warm front extending well north and east into Indiana and Kentucky. As the warm front approaches, expect clouds to quickly lower and thicken with precipitation developing over the area west to east most likely through the early to mid afternoon timeframe. This is a slightly later onset than previous thinking as it will take some time for dry air in the low levels to become saturated enough for precip. While the inland track of the low will ultimately put the area on the systems warm side, indications are there will be enough cold air at the onset for a front end "thump" of snow that could affect areas even as far south as the I-95 corridor. As such, expect that the urban corridor will see precipitation start as snow Saturday afternoon with the potential for an inch or two of accumulation before a change to rain occurs here from south to north through the late afternoon into the evening. Farther north, there will be greater concerns for wintry precip lasting further into Saturday night. Getting up towards the I-78 corridor, expect snow to mix with and change to sleet and freezing rain into Saturday evening with the potential for several hours of a wintry mix before an eventual change to rain. It is this zone and areas northward where 2 to 4 inches of snow and sleet is expected with the potential for a tenth to a quarter in of ice accretion to follow.

[RU848789]

8 minutes ago, forkyfork said:

if you're worried about sun angle it's not much of a storm to begin with

Think that's always been the case for this one, at least south of 78 or even south of 80.  Just want to see a few more inches and get the seasonal count up...

[weatherpruf]

This ain't it. These storms may sometimes bring us even up to 3 inches, then crap out to rain and mostly wash away. That's probably our best case scenario; a thump that gives a temporary wintry feel, then over to rain. Seen it lots of times. Well, Costco has the gardening stuff out. Time to plan the garden. 

[RU848789]

12 minutes ago, SnoSki14 said:

Sun Angle isn't a problem until after 1st week of March. It certainly won't be an issue in February. 

Sun angle matters any time of year - it just matters less the closer one is to the solstice, as there is a continuum of melting rates as the sun angle increases continually away from the solstice. I've always guesstimated melting rates (on grass at midday, for example at 32F) as follows: from very low (<0.05"/hr?) within 1 month of the winter solstice to moderately low for 1-2 months away from the solstice (0.05-0.1"/hr?) to moderate for 2-3 months from the solstice (0.1-0.2"/hr?) to fairly high for 3-4 months from the solstice (0.2-0.3"/hr)?, i.e., from late March thru late April. These rates are likely doubled for pavement.

It's not like I've measured these formally, but these are my guesstimates from close observations over decades and they could be off significantly, although directionally they make sense. High snowfall rates can always overcome any melting rate through when snow is likely to fall (late April), even on pavement and remember, once snow starts accumulating, melting rates drop substantially, since the melting before accumulation is coming from the sun's UV rays warming the ground, while after accumulation starts, subsequent snowfall is falling on 32F snow, by definition, greatly decreasing melting rates (there is a minor melting component from the air temp if above 32F, but heat transfer from the air is about 23X less than from a liquid or solid).

[jm1220]

4 minutes ago, weatherpruf said:

This ain't it. These storms may sometimes bring us even up to 3 inches, then crap out to rain and mostly wash away. That's probably our best case scenario; a thump that gives a temporary wintry feel, then over to rain. Seen it lots of times. Well, Costco has the gardening stuff out. Time to plan the garden. 

This’ll be a stat padder near the coast, I don’t expect any of what falls to stay unless you’re well NW and have a period of sleet/ZR instead. If I get 3” I’ll have 20” for the season. So there’s that. 

[Brian5671]

1 minute ago, jm1220 said:

This’ll be a stat padder near the coast, I don’t expect any of what falls to stay unless you’re well NW and have a period of sleet/ZR instead. If I get 3” I’ll have 20” for the season. So there’s that. 

Or hope that by the time the rain gets here, most of the precip is done which does happen sometimes....

[RU848789]

3 minutes ago, Brian5671 said:

Or hope that by the time the rain gets here, most of the precip is done which does happen sometimes....

Most forecasts call of an inch or more of rain after the changeover from snow and temps climbing into the 40s or even 50s on Sunday, at least for the 95 corridor and SE of there.  

[Brian5671]

3 minutes ago, RU848789 said:

Most forecasts call of an inch or more of rain after the changeover from snow and temps climbing into the 40s or even 50s on Sunday, at least for the 95 corridor and SE of there.  

yeah if that happens even the existing snowback will go....still have 3-4 inches here even after today's dampness and low 40's

[LibertyBell]

2 minutes ago, RU848789 said:

Most forecasts call of an inch or more of rain after the changeover from snow and temps climbing into the 40s or even 50s on Sunday, at least for the 95 corridor and SE of there.  

It's getting close to 50 even today here, as soon as the sun popped out just before 4, the temperature has been off to the races.  It really feels like a spring sun with it so bright so late in the day

[LibertyBell]

Just now, Brian5671 said:

yeah if that happens even the existing snowback will go....still have 3-4 inches here even after today's dampness and low 40's

getting close to 50 here with the bright sun out now

[Brian5671]

6 minutes ago, LibertyBell said:

getting close to 50 here with the bright sun out now

Still overcast here---42

[psv88]

Long Island will have no snow on the ground by Sunday 

[RU848789]

37 minutes ago, RU848789 said:

Haven't seen updated maps yet, but the NWS-Philly AFD is predicting more than this morning. 

Area Forecast Discussion National Weather Service Mount Holly NJ 336 PM EST Thu Feb 13 2025 SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... To start the day Saturday, a large area of low pressure will be centered near Oklahoma with the systems warm front extending well north and east into Indiana and Kentucky. As the warm front approaches, expect clouds to quickly lower and thicken with precipitation developing over the area west to east most likely through the early to mid afternoon timeframe. This is a slightly later onset than previous thinking as it will take some time for dry air in the low levels to become saturated enough for precip. While the inland track of the low will ultimately put the area on the systems warm side, indications are there will be enough cold air at the onset for a front end "thump" of snow that could affect areas even as far south as the I-95 corridor. As such, expect that the urban corridor will see precipitation start as snow Saturday afternoon with the potential for an inch or two of accumulation before a change to rain occurs here from south to north through the late afternoon into the evening. Farther north, there will be greater concerns for wintry precip lasting further into Saturday night. Getting up towards the I-78 corridor, expect snow to mix with and change to sleet and freezing rain into Saturday evening with the potential for several hours of a wintry mix before an eventual change to rain. It is this zone and areas northward where 2 to 4 inches of snow and sleet is expected with the potential for a tenth to a quarter in of ice accretion to follow.

NWS-NYC updated with increased snowfall, but NWS-Philly hasn't updated yet (even though their AFD discusses increased snowfall)...

[cleetussnow]

Where I'm at, I have ~19 inches so far, about half of normal.  Not terribly exciting except I've had pack/cover for most of the winter.  That is the most positive aspect of the this season and should not be discounted.

For this weekend - I'm thinking I get 3 to 4 inches of snow until the changeover, and unless I get dry slotted for a bunch of the rain, this pack is toast on Sunday.  I figure I'd have 5 to 6 inches OTG before the rain. If any snow remains, it will be a glacier by Monday, but it's not likely to sustain the rain and warmth. 

As far as next week - I think its a scraper.  It'll put something down, so maybe I will be at 25 inches for the season by the end of it with this weekend's snow.  Hard to see how I get to 40 this season if next week just scrapes.  Again, if we get a couple inches out of that, it will be OTG for a week or so. Snow OTG for most of the winter, that's what I'm experiencing.  Not bad.  

[LibertyBell]

25 minutes ago, psv88 said:

Long Island will have no snow on the ground by Sunday 

It will be gone Saturday night.  The key is what falls during the day Saturday will be snow so at least we will get to see some snow falling during the day time.

[MJO812]

Gfs still looks nice for the front end snow

[LibertyBell]

18 minutes ago, MJO812 said:

Gfs still looks nice for the front end snow

Good to be able to see it fall during the day time :-)

[Allsnow]

 

[Allsnow]

 

[EastonSN+]

Stats padder.

[LibertyBell]

4 minutes ago, EastonSN+ said:

Stats padder.

It's going to look pretty on Saturday, it can do whatever it wants at night, I don't look outside at night anyway lol.

 

[RU848789]

1 hour ago, RU848789 said:

NWS-NYC updated with increased snowfall, but NWS-Philly hasn't updated yet (even though their AFD discusses increased snowfall)...

Finally got the NWS-Philly map update showing increased snowfall across the board, matching the increases seen for the NWS-NYC snowfall map above.  I'd be pretty happy with 2" more snow, as per the map, even though I know it's going to get washed away - just fun to see and nice to add to the seasonal total.  Still 42 hours until the precip starts, so we know more changes are likely; as the 2/8 and 2/11 mixed events, I'm concerned about getting more sleet/less snow than forecast.  

[wishcast_hater]

For Areas way North:

 

Eventually, the cyclone over the Great
Lakes closes off up to 850-700hPa with the warm nose surging
northward and advancing into our southern zones by Sunday
morning. This should support a change over from snow to sleet
from south to north. Just how far north the warm nose reaches is
still uncertain as a secondary coastal low may develop to our
south/east which could pinch off the warm nose and maintain
snow/sleet p-types longer into the day on Sunday. Should this be
delayed, a changeover to freezing rain is possible, especially
for areas along and south of I-90 daytime Sunday.