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OT: Significant (CNJ) to Major (Along/N of 78) Winter Storm Likely on Tuesday (2/12-13; much less uncertainty on outcome)

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Title from 1/31 through 2/11: OT: Winter Storm Mon Night/Tuesday (2/12-13) - HUGE Uncertainty on Outcome

Been discussing this event in the pattern thread, linked below, for a few days and now that we're only 4-4.5 days away and have some indication that this could be a minor snowfall, after some rain for 95/coast and a moderate to significant snowfall N of 78 and especially NW of 80/287 (after some initial rain), figured a thread was worthwhile. Like many storms in the Philly-NJ-NYC region, uncertainty on precip amounts, precip type, timing of precip and any changeover from rain to snow, as well as uncertainty on how much snow that falls will actually accumulate, is pretty high this far out, but it's probably even greater than usual given what we're seeing in the models, so far.

https://rutgers.forums.rivals.com/t...a-possible-colder-and-snowier-pattern.273234/

I don't think anyone has a handle on a storm that models are showing could give New Brunswick, for example, anything from all rain to mostly rain with an inch or two of snow/slush to moderate rain then a few inches of snow to some rain and several inches of snow (with 6" or more on the table if the GFS is right), with probably mostly rain followed by an inch or two of snow being most probable. Like most storms around here, it's looking like NW areas are most favored for snow (colder temps) with 95/coast most favored for mostly rain (warmer), but the track and intensity of the storm could easily shift 100+ miles, such that huge changes are still possible and it should also be noted that some models are showing heavy, high intensity precip (over 1" of QPF - total precip on a liquid basis) while others are showing much less precip (<1/2" QPF).

I could probably stop right here and just say to check back in in 2 days when we'll hopefully have a consensus, but that's not how I roll, lol. So, below is a summary of what we've seen for yesterday's 12Z models (using 7 am data inputs) and tonight's 0Z models (using 7 pm data inputs). Overall we kind of have 2 camps: the GFS/Euro with significant snowfall for much of our area vs. the CMC/UK with minor to no snowfall for most of our area (and much less precip overall). Definitely not worth attaching all the snowfall maps as the model runs will change - maybe as we get closer.
  • Tonight's 0Z GFS shows a general 6-10" snowfall for our entire region (mostly falling from 7 am to 4 pm Tuesday, while the 12Z GFS showed a significant snowstorm south of 276/195 (minor/moderate north of there)
  • The 0Z Euro shows 6-10" N of 78 and several inches from 195/276 to 78, falling from about 4 am to 10 am, after 1/2-3/4" of rain late Monday into Tuesday morning, while the 12Z a significant snowstorm N of 78 and minor/moderate snow south of there.
  • The 0Z UK shows a few inches of snow for areas S of 78 after 1/2" or so of rain (but very little snow or precip overall N of 78), while the 12Z UK showed only an inch or two in spots N of 78 after about 1/4" of rain for most. It's just been a drier model.
  • And tonight's 0Z CMC shows maybe 1/4" of rain for everyone followed by a couple of inches of snow, largely N or 78, while the 12Z CMC only had snow along/N of 90 (yes 90 in NY/MA), so it made a huge jump southward in precip towards our area.
  • Lastly, the NBM (model blend), which the NWS follows closely, went from about an inch or so to 2" N of 78 at 12Z to 2-4" N of 78 and 1-3" between 78 and 195/276 at 0Z tonight, a modest increase.

Still, so much can change, but the likelihood of a complete miss is pretty low. However, having confidence in a mostly/all rain vs. mostly/all snow or somewhere in between (and where the heaviest precip/snow/rain is) outcome is extremely low at this point. It's also likely that even if there is significant snow falling from the sky, it could have a hard time accumulating with temps likely at or just above 32F and some of the snow falling during the day, unless intensity is fairly high. Fortunately, with the main pieces of energy now being over land (they were over the Pacific or far north with sparse data inputs leading to higher uncertainty) and given that we're closer to the event, when the error bars shrink, hopefully we'll start seeing more consensus by tomorrow night or Saturday. For now, stay tuned.

Not sure what the NWS is going to do with the current wildly varying model depictions of the storm, but they did at least move towards a possible snowier outcome with their 4 pm discussion today, after dismissing snowfall chances yesterday morning. Specifically, this morning, they were only calling for a chance of snow well NW of 95 with rain for 95/coast, but as per the part in bold, they're acknowledging that a plowable snow is possible all the way down to 95 (the fall line). Below are the usual links to the NWS and the AmericanWx thread and I also included a link to a fantastic summary of the synoptic setup by brooklynwx (a well-respected met) highlighting the things that might still go wrong, but showing that some accumulating snow for even 95/coast is possible.

https://www.weather.gov/phi/
https://www.americanwx.com/bb/topic...m-potential-rain-snow-mix-on-feb-1314/page/2/
https://www.americanwx.com/bb/topic/59981-february-2024/?do=findComment&comment=7200829

LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Unsettled weather on tap for the start of the new work week as
a developing storm system impacts the Northeast and Mid-
Atlantic. However, there are numerous inconsistencies among the
models that leads to a low confidence forecast.

A deep upper trough over the West Coast ejects into the
southern Plains, and the base of the trough pinches off into a
closed upper low over the Southern Plains and Gulf Coast states
Sunday night. Surface low pressure develops out ahead of it and
moves towards the Mid-Atlantic on Monday.

This is where the models go awry. The 12Z/08 ECMWF has the low
passing through southern New Jersey and Delmarva Monday night,
and then the low intensifies off the New Jersey coast as the H5
trough follows behind it Tuesday morning. This system then
departs Tuesday afternoon. In terms of sensible weather, the
predominant ptype will be rain on Monday, changing to snow over
the southern Poconos and northern New Jersey Monday night and
Tuesday as colder air filters into the region behind the
departing low. A plowable snow is possible for those areas, and
possibly even down to the Fall Line.


The surface low is faster in the 12Z/08 CMC, with rain moving
into the region earlier on Monday, and has the low over eastern
Long Island by Tuesday morning. The storm is then gone Tuesday
afternoon before the cold air filters into the region. This
results in minimal snow accumulation.

The outlier, though it has been a consistent outlier, is the
12Z/08 GFS. The storm is much slower, with the low still over
North Carolina and Virginia Tuesday morning, and then passes
through Delmarva during the day Tuesday before departing Tuesday
night. With high pressure building in from the north, cold air
advection will be underway, and temperatures drop to below
freezing across much of the region. This results in at least a
plowable snow across much of southern New Jersey and into
Delmarva.

The NBM snow probabilities have a less than 10 percent chance
for 4 inches of snow or more in 24 hours ending at 00Z Wednesday
for most areas south of the Fall Line, and up to 25 percent
chance for 4 inches of snow or more in the 24 hours ending at
00Z Wednesday for the southern Poconos and northern New Jersey.

Due to the low confidence in the forecast, opted to follow the
NBM guidance closely. This results in likely PoPs for Monday
afternoon and Monday night, and chance PoPs for Tuesday morning.
Opted to keep slight chance PoPs continuing into Tuesday
afternoon, mainly due to the GFS being slower.
 
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This should be an interesting thread !

In Monmouth County, it appears rain was forecasted 1-2 days ago and now it appears to be a mix.

The good news : weather won’t interfere with NW game on Thursday
 
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Tuesday's potential winter storm. Some now hinting at the snow coming as far south as Long Island/NYC.

426808948_789593386537940_1008055691810832223_n.jpg
 
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Tuesday's potential winter storm. Some now hinting at the snow coming as far south as Long Island/NYC.

426808948_789593386537940_1008055691810832223_n.jpg
I know you mean well, but this is already outdated as the 12Z GFS came north quite a bit, as per below - it's the 3rd in the series showing the trend north on the GFS and I included the zoomed in versions with 10:1 snow/liquid ratios and Kuchera ratio, which is less than 10:1, due to above 32F surface temps/melting. IMO, posting maps when they're all over the place, ie., the 12Z CMC shows moderate to significant snow mostly along/SE of 95 (minor/moderate NW of there) in a big shift from last night and the UK barely shows any snow after minor rain and the Euro just came out and is a bit less snowy, with the 2" line around 195/276 and the 5" line around 78 (and more N of 80). However, both the Euro and GFS ensemble mean snowfall did not move north, so it's possible the Euro/GFS Op runs were off a bit. Anyway, in these situations, the only model probably worth posting is the NBM (model blend), which shows minor/moderate snow for most.

trend-gfs-2024020912-f108.sn10_acc-imp.us_ma.gif


cA0apRB.png


DAMm8jD.png



wNRtlEv.png
 
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These early trends aren't giving me the happy feels. Large shift northward.
 
These early trends aren't giving me the happy feels. Large shift northward.
Not sure what you're talking about...2 days ago (see the pattern thread from 2 days ago) nearly every model was all rain for 95/coast with only a bit of snow N of 80 on a couple of models. Yes, there was a bit of a shift northward today on the GFS and Euro, but the ensemble mean snowfall axis was unchanged for the GFS and Euro, which as you know is some indication that the Op runs might be a bit off in some way. Also, there was a big shift southward on the CMC and the UK appears to be out to lunch.
 
NWS-Philly will probably put out its first maps Saturday morning, about 72 hours before the heaviest precip, but they did put out the AFD below, which follows the NBM (model blend) pretty closely, discussing 6" or so for the Poconos/Sussex and 2" from about Philly over to the NJ coast (I think they mean for about the Parkway and west, based on the NBM); this would put NB in the 3" area, as per the NB map I posted above.

This actually dovetails reasonably well with Lee Goldberg's initial map, which is slightly less snowy than the NBM/NWS AFD, as he has the 2" line from about Washington Crossing to Woodbridge and a 4" line from about Belvidere to Mahwah with 4-8" NW of that line. These are initial guesses, as so much can still change in this very sensitive setup. So far the 18Z models look a bit more bullish for snow, including the GFS which has a 6" line (at 10:1) near 195/276 and a 12" line N of 80/NW of 287. The GFS remains the most bullish model, but has been remarkably consistent for days which is unusual and other models have been moving towards it's evolution, but we'll see if that continues.

Area Forecast Discussion
National Weather Service Mount Holly NJ
316 PM EST Fri Feb 9 2024

LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
There continues to be model disagreement, but models are coming
more in line, at least compared to 24 hours ago. Low pressure
moves into the Mid-Atlantic as high pressure builds in from the
north. This low intensifies as the upper trough follows behind
it. At least through Monday evening, the predominant ptype will
be rain for all but the southern Poconos, where snow is
expected. As colder air filters in to the region as the low
departs, cold air advection will be underway into most of the
region. For areas generally north of I-80, and even down to
I-78, snow will develop, possibly becoming heavy at times. That
rain/snow line will track farther south through Tuesday morning
before precip finally ends by Tuesday afternoon as the low
departs.

Confidence remains low, as there are timing and placement
uncertainties among the models, but the trend is for significant
accumulating snow across the southern Poconos and northern New
Jersey, but this may extend down to the Fall Line. Minimal
accumulations are then possible for the I-95 corridor and for
areas south and east Tuesday morning.

Latest NBM snow probabilities indicate a 35 percent chance for
6 inches of snow or more in the 24 hour period ending 7pm
Tuesday for Carbon, Monroe, and Sussex (NJ) counties. Latest NBM
snow probabilities also indicate a 35 percent chance for 2
inches of snow or more in the 24 hour period ending 7pm Tuesday
for areas down to the I-95 corridor, including Philadelphia and
surrounding suburbs, extending towards coastal New Jersey.


03ybIhP.png
 
So another dud? I’m up to two 2 inch “blizzards”, hit the 20s once or twice and a lot of cold rain. Give me feet and single digit day time temps.
 
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Its a wet 2 inches which means grassy surfaces 2 inches

Upton isnt biting with coating to an inch for nyc and metro

1-3 N and W

And its an early call..could still be nothing but white rain as surface temps are in mid 30s
There is no cold air to work with
 
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Bold move creating this thread, I can already hear the executioner sharpening his sawzall
Nah, the threat is real, so the thread was warranted IMO. If it fizzles, it fizzles and I'll get some grief (but I'll get that even if we get a big snowstorm so that's a given) and we'll move on. Same thing with the pattern thread. Anyway, a threat of significant snow for at least a decent part of the region (nearby EPA/NJ/SENY) is worth a thread and the threat is quite significant (4" or more) for folks N of 78 and especially along/N of 80 and while the NWS and others aren't biting yet on more than a slushy 1-2" for most of CNJ, 3 of the 4 major global models right now show a range of 3-5/4-8" of 10:1 snow or 2-5" of lower ratio snow. Doesn't mean that will be the outcome, but the potential is there.

And if the Euro/GFS are correct with high intensity snow for 6-8 hours, it will accumulate pretty well even with surface temps of 33-35F along 95 (and even maybe toward the coast) during the day (we see it all the time in March and even April), since once the projected 1"/hr rates hit, they'll overcome the melting rate easily and once there's a snow layer on the ground, the ground is now 32F, not 33-35F, such that subsequent snowfall accumulates much more easily as 33-35F air only has 1/20th the heat transfer coefficient of water/ground, meaning melting rates go way down. But if we don't get that kind of intensity or if the track is further north and there's a lot more rain, obviously, it'll be mostly wet.

To be clear, 3.5 days out I am not calling for 4-8" for 95 as that would be just dumb, since so much can still change with the synoptic evolution that could result in a lot less precip (like the UK) or a lot more rain or a lot less intensity of snowfall over a longer time, all of which would lead to maybe a slushy inch or two for 95 and less for the coast. In fact I wouldn't make any forecast before seeing more of a model consensus, but that doesn't mean I can't point out the potential of this system. Long way to go.
 
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NWS-Philly will probably put out its first maps Saturday morning, about 72 hours before the heaviest precip, but they did put out the AFD below, which follows the NBM (model blend) pretty closely, discussing 6" or so for the Poconos/Sussex and 2" from about Philly over to the NJ coast (I think they mean for about the Parkway and west, based on the NBM); this would put NB in the 3" area, as per the NB map I posted above.

This actually dovetails reasonably well with Lee Goldberg's initial map, which is slightly less snowy than the NBM/NWS AFD, as he has the 2" line from about Washington Crossing to Woodbridge and a 4" line from about Belvidere to Mahwah with 4-8" NW of that line. These are initial guesses, as so much can still change in this very sensitive setup. So far the 18Z models look a bit more bullish for snow, including the GFS which has a 6" line (at 10:1) near 195/276 and a 12" line N of 80/NW of 287. The GFS remains the most bullish model, but has been remarkably consistent for days which is unusual and other models have been moving towards it's evolution, but we'll see if that continues.

Area Forecast Discussion
National Weather Service Mount Holly NJ
316 PM EST Fri Feb 9 2024

LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
There continues to be model disagreement, but models are coming
more in line, at least compared to 24 hours ago. Low pressure
moves into the Mid-Atlantic as high pressure builds in from the
north. This low intensifies as the upper trough follows behind
it. At least through Monday evening, the predominant ptype will
be rain for all but the southern Poconos, where snow is
expected. As colder air filters in to the region as the low
departs, cold air advection will be underway into most of the
region. For areas generally north of I-80, and even down to
I-78, snow will develop, possibly becoming heavy at times. That
rain/snow line will track farther south through Tuesday morning
before precip finally ends by Tuesday afternoon as the low
departs.

Confidence remains low, as there are timing and placement
uncertainties among the models, but the trend is for significant
accumulating snow across the southern Poconos and northern New
Jersey, but this may extend down to the Fall Line. Minimal
accumulations are then possible for the I-95 corridor and for
areas south and east Tuesday morning.

Latest NBM snow probabilities indicate a 35 percent chance for
6 inches of snow or more in the 24 hour period ending 7pm
Tuesday for Carbon, Monroe, and Sussex (NJ) counties. Latest NBM
snow probabilities also indicate a 35 percent chance for 2
inches of snow or more in the 24 hour period ending 7pm Tuesday
for areas down to the I-95 corridor, including Philadelphia and
surrounding suburbs, extending towards coastal New Jersey.


03ybIhP.png

So let's talk about the 0Z models, which are coming in. Note that the snowfall amounts I discuss are at 10:1 ratios, which are unlikely to verify, except N of 80/NW of 287. The Kuchera numbers are about 70% of those numbers and should be easily achievable if we get the 1-1.5" per hour rates that some models are showing, but if we get less intensity, we may only get ratios of 50-60% of 10:1.
  • The 0Z GFS continues to show a significant rain and then snowstorm for 95/CNJ and north of there with most of the snow falling from about 7 am to 1 pm Tuesday, with the 6" line being around 276/195 and 10" or more along/N of 78/NW of 287 (at 10:1 ratios).
  • The CMC moved back north a bit and looks fairly close to the GFS, except for having the 6" line further south, i.e., roughly from Philly to Toms River with 7-10" amounts (at 10:1 ratios) from 276/195 up to 84.
  • Finally, the UK, the last holdout not showing much/any snow, has caved to the other models and is now showing 6" or more (at 10:1), with a 6" line from about Philly to Toms River and another 6" line along 80 (with a bit less N of 80 - less precip).
  • The 0Z NAM and RGEM (which only run 84 hrs and are beyond their useful range by the end) are both showing the start of heavy snow through 7 am Tuesday with a few to several inches by then for much of the area.
  • The GFS ensembles look quite snowy for almost everyone with the 4" line from Philly to Toms River and up to 6" north of there past 84
  • And the Euro came in further south and snowier with the 3" line from Philly to Toms River, the 6" line from Trenton to Sandy Hook and 6-10" (or more) north of that line to well N of 84. The Euro was the coldest model with temps getting down to 31-32F by 7 am and staying there for the rest of the storm, which is why the Kuchera isn't much lower than 10:1 for 95 and is 12:1 or more well inland.
Given that this is the snowiest model suite so far and that we no longer have any model outliers with little to no snow, I'd expect to see the NWS and others significantly raising their snowfall forecasts, probably to something like 3" between Mt. Holly and Belmar and 6" along 78 and more than 6" N of 78. Or they might raise them a bit less to something like the NBM, below with a 2" line from Mt. Holly to Belmar and a 4" line along 78 and more N of there, waiting to see if we see continuing consensus on significant snowfall, especially along and SE of 95.

Digging in to the possible thermal issues, the GFS shows surface temps in the 34=35F range at 7 am when the changeover starts, then the ridiculous 7-10" of 10:1 snow falls over the next 6 hours with surface temps shown as 32-33F at 7 am, but back up to 35-36F as the precip is lightening up. The other models all now have similar heavy intensity for a 6-10 hour period with surface temps along/SE of 95 generally being a little above 32F. So, we're really relying on dynamic cooling here and if we get the intensity, the column will cool a few degrees, as shown and we'll get good accumulation at 1.5"/hour rates, but relying on all of that is a very low confidence place to be with very little margin for error, such that lower intensity or warmer temps aloft could easily lead to only a slushy inch or two (on grassy surfaces) despite snow falling for hours or from a changeover to rain, especially along/SE of 95. But anywhere we do get 6-10"+ of heavy wet snow sticking to everything the power outages are likely going to be substantial.

https://www.americanwx.com/bb/topic...-potential-rain-snow-mix-on-feb-1314/page/12/

O8Kk23j.png
 
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Euro crushes us. Close to a foot in the immmediate nyc. Doubt that will be the final outcome but wow, crazy to see.

Just one run, obviously, but things looking real for a plowable event around here.
 
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Euro crushes us. Close to a foot in the immmediate nyc. Doubt that will be the final outcome but wow, crazy to see.

Just one run, obviously, but things looking real for a plowable event around here.
Yep, Euro crushed us and the EPS (ensembles) did too. As per my note above, based on this model suite's consistency, gun to my head I'd guess 2-3" along a line from Trenton to Sandy Hook (with 1-3" for Philly/SNJ excluding SENJ) and snow increasing northward to about 5-6" along 78 and then increasing to 8-10" from 78 north to 80 and being 8-10" N of 80/NW of 287 in NJ/PA and N of 287 in NY. This is only about 1" or so more than what the conservative NBM is showing for CNJ and maybe 2-3" more than the NBM N of 80.
 
6Z NAM is much colder and had a bit less precip, but still puts down 5-8" for the whole Philly-NJ-NYC region, including the coast from 4 am to 10 am on Tuesday. No idea if it's right, but a colder and less intense solution (below 32F the whole time it's snowing and no rain) gives a much greater floor, but a bit lower ceiling - and probably avoids power outages.
 
NWS has the Monmouth/Ocean border at 37 degrees with rain and snow and no accumulation. Not seeing where Goldberg is getting this from.
Many models have you getting several inches. And it was a really bad move by the NWS (Philly and NYC offices) to only include half of the storm in their maps this morning (through 7 am Tuesday when much of the snow/precip comes after that) - either forecast for all of it or don't bother - this is misleading as some will think this is for the whole storm. 6Z models mostly hold course with a significant snowfall for most of the area, including the 95 corridor. See y'all after the RU game (disc golf, then the game, so I'll be AWOL).
 
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Just to confirm, this is a Tuesday day event so flights out of EWR should be good Wednesday morning right?
 
Yea I can’t see how it would stick with these high temps the past few days
not so much that but the air mass itself doesnt have a lot of cold air to work with. Temps are marginal even on the coldest models. Other models are in the mid 30s. You need a really good rate of precipitation to overcome that. If you dont you get alot of compaction and melting. That the thread over there is missing the best mets chiming in with positive thoughts says alot. Its not just about what clown maps are showing.
 
And the latest GFS model is mostly rain for a large part the state with the low north of us….

As always just gonna be a tough forecast.
 
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Euro run north too. Now joins the GFS with a more northern storm meaning less snow/more rain.

Is it a trend or just a blip?
 
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So let's talk about the 0Z models, which are coming in. Note that the snowfall amounts I discuss are at 10:1 ratios, which are unlikely to verify, except N of 80/NW of 287. The Kuchera numbers are about 70% of those numbers and should be easily achievable if we get the 1-1.5" per hour rates that some models are showing, but if we get less intensity, we may only get ratios of 50-60% of 10:1.
  • The 0Z GFS continues to show a significant rain and then snowstorm for 95/CNJ and north of there with most of the snow falling from about 7 am to 1 pm Tuesday, with the 6" line being around 276/195 and 10" or more along/N of 78/NW of 287 (at 10:1 ratios).
  • The CMC moved back north a bit and looks fairly close to the GFS, except for having the 6" line further south, i.e., roughly from Philly to Toms River with 7-10" amounts (at 10:1 ratios) from 276/195 up to 84.
  • Finally, the UK, the last holdout not showing much/any snow, has caved to the other models and is now showing 6" or more (at 10:1), with a 6" line from about Philly to Toms River and another 6" line along 80 (with a bit less N of 80 - less precip).
  • The 0Z NAM and RGEM (which only run 84 hrs and are beyond their useful range by the end) are both showing the start of heavy snow through 7 am Tuesday with a few to several inches by then for much of the area.
  • The GFS ensembles look quite snowy for almost everyone with the 4" line from Philly to Toms River and up to 6" north of there past 84
  • And the Euro came in further south and snowier with the 3" line from Philly to Toms River, the 6" line from Trenton to Sandy Hook and 6-10" (or more) north of that line to well N of 84. The Euro was the coldest model with temps getting down to 31-32F by 7 am and staying there for the rest of the storm, which is why the Kuchera isn't much lower than 10:1 for 95 and is 12:1 or more well inland.
Given that this is the snowiest model suite so far and that we no longer have any model outliers with little to no snow, I'd expect to see the NWS and others significantly raising their snowfall forecasts, probably to something like 3" between Mt. Holly and Belmar and 6" along 78 and more than 6" N of 78. Or they might raise them a bit less to something like the NBM, below with a 2" line from Mt. Holly to Belmar and a 4" line along 78 and more N of there, waiting to see if we see continuing consensus on significant snowfall, especially along and SE of 95.

Digging in to the possible thermal issues, the GFS shows surface temps in the 34=35F range at 7 am when the changeover starts, then the ridiculous 7-10" of 10:1 snow falls over the next 6 hours with surface temps shown as 32-33F at 7 am, but back up to 35-36F as the precip is lightening up. The other models all now have similar heavy intensity for a 6-10 hour period with surface temps along/SE of 95 generally being a little above 32F. So, we're really relying on dynamic cooling here and if we get the intensity, the column will cool a few degrees, as shown and we'll get good accumulation at 1.5"/hour rates, but relying on all of that is a very low confidence place to be with very little margin for error, such that lower intensity or warmer temps aloft could easily lead to only a slushy inch or two (on grassy surfaces) despite snow falling for hours or from a changeover to rain, especially along/SE of 95. But anywhere we do get 6-10"+ of heavy wet snow sticking to everything the power outages are likely going to be substantial.

https://www.americanwx.com/bb/topic...-potential-rain-snow-mix-on-feb-1314/page/12/

O8Kk23j.png
So after the 6Z models continued with fairly snowy outcomes, the 12Z models crushed the souls of snow lovers everywhere, lol. The GFS and Euro both moved north, bringing in warmer air and more mixing up through 95 reducing snowfall by at least half (but still significant snow N of 78), the CMC was all snow but much lighter (several inches for most vs. 6"+ for most) and only the UK got a bit snowier (6"+ for everyone); also the NAM went from 6"+ for most at 6Z to just several inches for most at 12Z (less precip), while the RGEM went from 4-7" for most to maybe 2-4" for most (also drier). The one thing many still point out is that the GFS and Euro ensembles didn't move nearly as far north as their op runs (with the EPS still showing 3-6" for CNJ/95 and the GEFS still showing 4-7" for those areas), implying it's possible those op runs were out of step with the overall setup, but that's a bit of guesswork.

So, is this a trend that will be confirmed with the 18Z runs and 0Z runs tonight or was it more of a blip? We're closer to the event so the models should be more accurate, but with this fragile setup who knows. Time for more watching and waiting, but I would expect most forecasters to at least cut back on snowfall somewhat based on the 12Z models; there's always plenty of time to increase them again if the models trend back snowier.

I'll leave folks with the latest from the 18Z NAM. It looks a lot more like the snowy 6Z NAM (and not the low precip 12Z), as it shows a 5" line along 276/195 and 5-8", generally, north of there to 84. In addition, there is some rain on the front end, but most of the precip is snow as temps crash and the cold conveyor belt gets going, dynamically cooling the column, with surface temps in the 32-33F range for most of 95/CNJ from 4 am to 10 am when 90% of the snow falls. Will the other 18Z models trend back? Again, no clue, but will be interesting to watch as always.

Anyway, back to fun stuff. Had a great round of disc golf this morning and how about those Scarlet Knights opening up a can of whoop ass on the Badgers (JWill is a revelation)? Off shortly to a nice dinner at the Frog and the Peach with 3 other couples then likely going to see a couple of bands locally. So, if the snow threat dwindles further, I'll live, lol. Will check back in late tonight.
 
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One more thing. It turns out the NWS did publish a snowfall map this morning for the whole event, but took it down - but WaltDrag somehow found it and posted it on AmericanWx. Based on last night's models this was likely underdone, but based on 12Z models this probably looks pretty good. Willl be interesting to see if they change it.

6HGdGQo.png



Edit: here's the updated NWS map - surprised they didn't decrease snow for areas S of 78/along 95 given their AFD. Big jumps north of 78 and especially 80.

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