WINTER STORM WARNING Mon-Tues 2/12 - 13

Friday Feb 9th

I'm keeping an eye on Monday night and Tuesday. At this time, the signal is too messy for a confident forecast, but it looks like mostly rain with some snow at the end.

The models are throwing off wildly over-amped snow maps. The algorithms don't handle rain-to-snow conversions really well in generating these maps. There are several underlying conditions that argue caution (current warm air mass in place, lack of a blocking high pressure) in predicting significant snow, but I certainly think 2-3" is possible.

Timing is also varying run to run and between the models, and that could effect snow totals, too.

Unless there is a sudden burst of confidence in massive snowfall tomorrow, check back Sunday for an update.

Predicting snow this winter has so far been akin to threading a needle. So after this “Indian summer” we will be back in the middle of winter come next week? 

Sunday Feb 10

Winter storm Monday night into Tuesday, rain likely changing to snow in the morning.

This has shaped up to be another Orange County Special, with a sharp edged snow line at or just north of the MAPSO area. The models have stabilized showing 1 - 4" here, most likely coming in the form of wet mixed rain and snow and then wet snow Tuesday morning. A slight southward shift in the storm track could significantly increase snow depth.

Precipitation starts as all rain Monday, most likely after midnight. Rain becomes heavy and likely transitions to snow Tuesday morning. If snow starts accumulating it could be a messy commute. The wind also picks up for a while Tuesday, with some gusting possible in the 30mph range.

There is a reasonable chance of this being all rain, but there is also an upside potential of heavier snow. Temperatures could very well remain above freezing the entire event.

I know this one is even more confusing than normal. I would say the best bet is prepare for 1 - 4" by lunchtime Tuesday but don't be surprised if it just rains.

This is quite the difficult forecast. Models are windshield wipering every run. 

Confidence in any totals remains low, but probably not a bad idea to start preparing for an impactful snow event. 

I have my milk, eggs.... and a bit of Naan bread. Not quite the French toast triplet, but maybe close enough.

People rushing to get milk when snow is in the forecast is a running joke between me and wife.  Have all supermarkets ever been closed the day after a snow storm?  And if you think the world is coming to an end because of snow, wouldn't you stock up on water and not milk?

bub said:

People rushing to get milk when snow is in the forecast is a running joke between me and wife.  Have all supermarkets ever been closed the day after a snow storm?  And if you think the world is coming to an end because of snow, wouldn't you stock up on water and not milk?

Yes they have. In January 1996 there was a storm that dumped three feet of snow on Northern NJ. People were stuck in their homes for a few days, and if you were a parent of young kids, running out of milk and eggs was challenging. 

There have also been major power outages in this area due to weather which have made grocery shopping more difficult. 

But at this point it’s kind of a self-fulfilling prophecy. 

Monday Feb 12

The NWS has issued a WINTER STORM WARNING for our area for tonight and Tuesday.

Over the last 24 hours the models have shifted the storm track south, and with it the rain/snow line. We are now expecting 4 - 6" and are fairly close to the 6 - 8" line.

Likely rain, starting around midnight, changing over to snow and becoming heavy around 7 or 8 in the morning Tuesday. Accumulating snow probable for most of Tuesday morning with temps near the surface at or near freezing. Snow should end in the early afternoon without changing back to rain, and temps will drop below freezing Tuesday night.

Expect more snow north and west of our area.

The main rain/snow line still presents a sharp line south of us. While the models have been quite consistent for the last few runs, a shift either way could still have an outsized effect on snow depth even though the amount of precipitation will stay about the same.

Winter Storm Warning

URGENT - WINTER WEATHER MESSAGE
National Weather Service New York NY
303 AM EST Mon Feb 12 2024

CTZ009>012-NJZ004-104-105-NYZ071-122115-
/O.EXA.KOKX.WS.W.0002.240213T0600Z-240213T2300Z/
Southern Fairfield-Southern New Haven-Southern Middlesex-
Southern New London-Eastern Passaic-Eastern Bergen-Western Essex-
Southern Westchester-
303 AM EST Mon Feb 12 2024

...WINTER STORM WARNING IN EFFECT FROM 1 AM TO 6 PM EST TUESDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 7 to
  10 inches. Winds gusting as high as 35 mph.

* WHERE...Portions of southern Connecticut, northeast New Jersey
  and southeast New York.

* WHEN...From 1 AM to 6 PM EST Tuesday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning or evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency.

Check local Department of Transportation information services for
the latest road conditions.

While I'm not yet going full eggs and milk, I think it would be prudent to plan for a noticeable snow event tomorrow morning

Kids, do your homework tonight. If you want a snow day you can’t assume a snow day will happen. 

While I’m not excited about the prospect of clearing 6-8” of snow, I’m looking forward to a nice snow storm. It’s February in NJ!  Let’s have a blanket of white for a more than a few days!

max_weisenfeld said:

While I'm not yet going full eggs and milk, I think it would be prudent to plan for a noticeable snow event tomorrow morning

Four to six inches? 

TL;DR: Snow likely, probably 6-8" with higher accumulations possible but higher than normal bust potential. 

Pros for heavy snow:

• Strong upper-level dynamics
• Moisture generally already in place
• High liquid equivalent almost a guarantee; lots of precip, whether rain or snow
  
• Good model consensus
  

Cons for heavy snow:

• Warm temperatures need to be overcome by a lot of radiational/evaporative cooling
  
• Storm will be moving quickly
  

While both local NWS offices continue to paint an 6-12" picture for most of the area, this storm screams boom or bust to me. I think we could see anything from all rain to 15", though I think the likelihood of a full rain event is less than 20%. It is noteworthy that model guidance is very consistent in bringing heavy, accumulating snow to the area and has been trending this way run after run for a day now. This trend can not be ignored this close to the event. 

That said, it remains warmer outside than one would like to see for a robust accumulating snow event. Much of the accumulation potential will be driven by evaporative cooling, i.e., the cooling of the atmosphere as precipitation evaporates while falling. We can quantify this by looking at something called the wet bulb temperature -- the temperature that the air achieves once it reaches saturation and no more evaporation can occur. As of this writing, the wet bulb temp sits around 39º, which is simply too warm for accumulating snow. I do expect this will come down as we lose sunlight and some radiational cooling occurs, but we will need a lot of evaporative cooling to occur during the early period of precipitation in order for a robust changeover to snow to occur. This storm does look like it will produce pretty wicked precip rates, on the order of 2-3" of snow per hour for some periods, which should allow for quite a bit more evaporative cooling. Given this, I do think that significant accumulating snowfall is probable/likely, however given how quickly this storm will move through we simply can not count out a pretty big bust here.

WxNut2.0 said:

TL;DR: Snow likely, probably 6-8" with higher accumulations possible but higher than normal bust potential. 

Pros for heavy snow:

• Strong upper-level dynamics
• Moisture generally already in place
• High liquid equivalent almost a guarantee; lots of precip, whether rain or snow
  
• Good model consensus
  

Cons for heavy snow:

• Warm temperatures need to be overcome by a lot of radiational/evaporative cooling
  
• Storm will be moving quickly
  

While both local NWS offices continue to paint an 6-12" picture for most of the area, this storm screams boom or bust to me. I think we could see anything from all rain to 15", though I think the likelihood of a full rain event is less than 20%. It is noteworthy that model guidance is very consistent in bringing heavy, accumulating snow to the area and has been trending this way run after run for a day now. This trend can not be ignored this close to the event. 

That said, it remains warmer outside than one would like to see for a robust accumulating snow event. Much of the accumulation potential will be driven by evaporative cooling, i.e., the cooling of the atmosphere as precipitation evaporates while falling. We can quantify this by looking at something called the wet bulb temperature -- the temperature that the air achieves once it reaches saturation and no more evaporation can occur. As of this writing, the wet bulb temp sits around 39º, which is simply too warm for accumulating snow. I do expect this will come down as we lose sunlight and some radiational cooling occurs, but we will need a lot of evaporative cooling to occur during the early period of precipitation in order for a robust changeover to snow to occur. This storm does look like it will produce pretty wicked precip rates, on the order of 2-3" of snow per hour for some periods, which should allow for quite a bit more evaporative cooling. Given this, I do think that significant accumulating snowfall is probable/likely, however given how quickly this storm will move through we simply can not count out a pretty big bust here.

I’m thinking I-78 is the defining line. We’re right in the zone. Sussex county could get 12 inches. Monmouth county could get one inch and rain. Plus the high tomorrow should be around 40 degrees. 

Jaytee said:

WxNut2.0 said:

TL;DR: Snow likely, probably 6-8" with higher accumulations possible but higher than normal bust potential. 

Pros for heavy snow:

• Strong upper-level dynamics
• Moisture generally already in place
• High liquid equivalent almost a guarantee; lots of precip, whether rain or snow
  
• Good model consensus
  

Cons for heavy snow:

• Warm temperatures need to be overcome by a lot of radiational/evaporative cooling
  
• Storm will be moving quickly
  

While both local NWS offices continue to paint an 6-12" picture for most of the area, this storm screams boom or bust to me. I think we could see anything from all rain to 15", though I think the likelihood of a full rain event is less than 20%. It is noteworthy that model guidance is very consistent in bringing heavy, accumulating snow to the area and has been trending this way run after run for a day now. This trend can not be ignored this close to the event. 

That said, it remains warmer outside than one would like to see for a robust accumulating snow event. Much of the accumulation potential will be driven by evaporative cooling, i.e., the cooling of the atmosphere as precipitation evaporates while falling. We can quantify this by looking at something called the wet bulb temperature -- the temperature that the air achieves once it reaches saturation and no more evaporation can occur. As of this writing, the wet bulb temp sits around 39º, which is simply too warm for accumulating snow. I do expect this will come down as we lose sunlight and some radiational cooling occurs, but we will need a lot of evaporative cooling to occur during the early period of precipitation in order for a robust changeover to snow to occur. This storm does look like it will produce pretty wicked precip rates, on the order of 2-3" of snow per hour for some periods, which should allow for quite a bit more evaporative cooling. Given this, I do think that significant accumulating snowfall is probable/likely, however given how quickly this storm will move through we simply can not count out a pretty big bust here.

I’m thinking I-78 is the defining line. We’re right in the zone. Sussex county could get 12 inches. Monmouth county could get one inch and rain. Plus the high tomorrow should be around 40 degrees. 

It's very hard to say where any line will be because it will be completely dictated by how much evaporative cooling occurs.

WxNut2.0 said:

TL;DR: Snow likely, probably 6-8" with higher accumulations possible but higher than normal bust potential. 

Pros for heavy snow:

• Strong upper-level dynamics
• Moisture generally already in place
• High liquid equivalent almost a guarantee; lots of precip, whether rain or snow
  
• Good model consensus
  

Cons for heavy snow:

• Warm temperatures need to be overcome by a lot of radiational/evaporative cooling
  
• Storm will be moving quickly
  

While both local NWS offices continue to paint an 6-12" picture for most of the area, this storm screams boom or bust to me. I think we could see anything from all rain to 15", though I think the likelihood of a full rain event is less than 20%. It is noteworthy that model guidance is very consistent in bringing heavy, accumulating snow to the area and has been trending this way run after run for a day now. This trend can not be ignored this close to the event. 

That said, it remains warmer outside than one would like to see for a robust accumulating snow event. Much of the accumulation potential will be driven by evaporative cooling, i.e., the cooling of the atmosphere as precipitation evaporates while falling. We can quantify this by looking at something called the wet bulb temperature -- the temperature that the air achieves once it reaches saturation and no more evaporation can occur. As of this writing, the wet bulb temp sits around 39º, which is simply too warm for accumulating snow. I do expect this will come down as we lose sunlight and some radiational cooling occurs, but we will need a lot of evaporative cooling to occur during the early period of precipitation in order for a robust changeover to snow to occur. This storm does look like it will produce pretty wicked precip rates, on the order of 2-3" of snow per hour for some periods, which should allow for quite a bit more evaporative cooling. Given this, I do think that significant accumulating snowfall is probable/likely, however given how quickly this storm will move through we simply can not count out a pretty big bust here.

Thank you so much for introducing a ray of hope into the forecast.

joan_crystal said:

WxNut2.0 said:

TL;DR: Snow likely, probably 6-8" with higher accumulations possible but higher than normal bust potential. 

Pros for heavy snow:

• Strong upper-level dynamics
• Moisture generally already in place
• High liquid equivalent almost a guarantee; lots of precip, whether rain or snow
  
• Good model consensus
  

Cons for heavy snow:

• Warm temperatures need to be overcome by a lot of radiational/evaporative cooling
  
• Storm will be moving quickly
  

While both local NWS offices continue to paint an 6-12" picture for most of the area, this storm screams boom or bust to me. I think we could see anything from all rain to 15", though I think the likelihood of a full rain event is less than 20%. It is noteworthy that model guidance is very consistent in bringing heavy, accumulating snow to the area and has been trending this way run after run for a day now. This trend can not be ignored this close to the event. 

That said, it remains warmer outside than one would like to see for a robust accumulating snow event. Much of the accumulation potential will be driven by evaporative cooling, i.e., the cooling of the atmosphere as precipitation evaporates while falling. We can quantify this by looking at something called the wet bulb temperature -- the temperature that the air achieves once it reaches saturation and no more evaporation can occur. As of this writing, the wet bulb temp sits around 39º, which is simply too warm for accumulating snow. I do expect this will come down as we lose sunlight and some radiational cooling occurs, but we will need a lot of evaporative cooling to occur during the early period of precipitation in order for a robust changeover to snow to occur. This storm does look like it will produce pretty wicked precip rates, on the order of 2-3" of snow per hour for some periods, which should allow for quite a bit more evaporative cooling. Given this, I do think that significant accumulating snowfall is probable/likely, however given how quickly this storm will move through we simply can not count out a pretty big bust here.

Thank you so much for introducing a ray of hope into the forecast.

All rain is low probability scenario! But most welcome

When might the snow begin? Later this evening into the early morning, or more likely after 5am.

WxNut2.0 said:

All rain is low probability scenario! But most welcome

Anything under 4 inches of snow would be a relief.  Maplewood just issued an alert saying we were getting 7 to 10 inches of snow from this event.

Monday Evening Update 2/12/24

The NWS has issued a WINTER STORM WARNING for our area for tonight and Tuesday.

A difficult forecast hasn't gotten any easier today, as you can see by the fact that although we agree on the actual forecast WxNut and I have diverged on the snow totals.

The forecast track for the storm has been shifting south all day, and with it the snow forecast has been shifting as well. Right now I want to hold at 4 - 6" but please know that I am lowballing a little because I think the trend will hold up (actually what I am doing is weighting the forecast towards the Euro and the high-res NAM and away from the GFS but I like to make it sound like I shoot from the hip). If you take a peek at the NJ map below, though, you will see that we are uncomfortably close to where the NWS had the 6 - 8" line. For that matter, we are close to the 2 - 4" line as well.

Some things I can say with a bit of confidence:

* Whatever snow falls will be wet, heavy, sticky and probably persistent for a day or two.

* Temps of around freezing will continue to frustrate efforts to predict snowfall in inches, but at least 1 - 1.5" of water will fall in some form or other, with most of it likely to be snow or mixed snow and rain.

* Icing during the storm is quite unlikely.

* There will be periods when the snow could get ahead of the DPW crews. Try not to travel tomorrow morning.

So with all those caveats, here is my best try at a forecast:

Rain, light at the outset, should overspread the area tonight, most likely after midnight.

Precipitation will probably start to change over through mixed snow and rain and become all snow between 5 and 7am. Snow will have difficulty accumulating at first but once the column cools down snow will accumulate steadily. The harder the rain/snow is falling in this early morning period, the sooner the air will cool and the snow will start to bulk up.

Snow should end in the early afternoon. Temps will rise briefly as the snow stops but not enough to melt any significant accumulation. Temps will not get to be appreciably above freezing again until Thursday afternoon.

Snow is likely, heavy at times, all morning. There is a possibility of thundersnow. Wind is likely to pick up mid morning as well, with gusts into the 30s. Snow on the ground will not be too likely to drift but falling snow could swirl and whiteouts might briefly occur. Travel is likely to be difficult all morning.

I'll check in tomorrow morning but by that time it will be all nowcasting (Radar and looking out the window) so make your plans now.

dano said:

When might the snow begin? Later this evening into the early morning, or more likely after 5am.

Changeover from rain looks to be in the early morning, right now I would say between 4 and 6.

It remains quite a bit warmer than you'd expect the night before a big snowstorm. Could delay the changeover and make it a bit more of a slushy mess than a big snow event. Time will tell. 

SOMA school district is closed tomorrow. I predict a bust. 

mrincredible said:

SOMA school district is closed tomorrow. I predict a bust. 

I’ll take it (a bust)

Looks like we’re gonna get dumped on pretty good. I have to double my prediction from 4 ~ 6 to 6 ~ 10 inches.  
It started snowing earlier and it’s coming down steadily. 

There is snow on sidewalks and in the streets this morning and it is still coming down. I plan to get out when it gets light to assess the situation.  Weather report on  ABC shows us right in the middle of the 4-8 inch band.  

Heavy heavy heavy snow out there. Not much but it is going to be a workout shoveling that heavy slushy white stuff. Be careful!

PeterWick said:

Heavy heavy heavy snow out there. Not much but it is going to be a workout shoveling that heavy slushy white stuff. Be careful!

just have to go out often and push it out of the way with the shovel. Like every two to three inches of accumulation. 

Peter I think I live near you and I'm not seeing heavy snow right now.  I can barely make out any precip.