December 17th "Front-End Thump" Storm Discussion & Observations

I know our main focus is the snow and ice but holy damn look at sundays 850mb winds (sustained!), I think gusts will exceed 60mph at one point possible, 100+ mph 850s wow.

Dunnzoo wrote:Looking at the soundings, the RAP and HRRR have freezing rain for Teterboro for 3 hours, 9 am- noon!

Yep looking like a rather rare ice event for a large area, not sure how much of it gets in here north of NYC, the RGEM doesnt really show the pink there but NJ damn. Still going by what mugs and Frank said though that north of NYC, and that pivotal weather (where is that is it free? Ice map isn't joking.

After MUCH deliberation, I have decided to leave my forecast alone. I am sticking with the reasons mentioned in my video, which can be seen by clicking this link:

https://drive.google.com/open?id=0Byod2Sk27yNYMG5zZlJCNEVnODA

I am adjusting the timing though, mainly on the back-end:

Start: 11pm Friday-3am Saturday
End: 10am-2pm Saturday



Admittedly, I may be a little too low for the eastern half of LI and into southeastern CT, central RI and southeastern Mass, but in my honest opinion I feel I would be splitting hairs if I moved my 1-3" border southeastward by those 15 or 20 miles. If I do miss low in those areas, I feel it would only be by a half-inch, maybe an inch at absolute most. We shall see!

^^^ Yuo are going to need a bigger boat my man

For those wondering, I completely disregarded the RGEM on this one, as I do not like the look of its precipitation field AT ALL. It has a tremendous bullseye in a steep valley in Pennsylvania, and a valley which severe downsloping is likely to occur in this event. The WRF and NAM suites, while closer to my snowfall gradient locations, appear too wet before the change-over, while the EURO and GFS ensembles seem to agree pretty well with my train of thought. The GFS Parallel aligned very well with my first call, but the Operational seems displaced a bit too far to the south with the higher totals for my liking. Again, I did not change anything from my first call, but if I was going to make another map, it would have likely followed the GFS Ensembles/Parallel and EURO suite.

amugs wrote:^^^ Yuo are going to need a bigger boat my man  

I don't follow lol

So models have trended colder or just the hrrr model showing that?

rb924119 wrote:

amugs wrote:^^^ Yuo are going to need a bigger boat my man  

I don't follow lol

me neither.....

http://www.tropicaltidbits.com/analysis/models/namconus/2016121700/namconus_asnow_us_7.png

My reference is to Jaws with Capt. Quinn when they see Jaws and are thrown .

0z 3k Nam has 4+ for the whole area

amugs wrote:My reference is to Jaws with Capt. Quinn when they see Jaws and are thrown .

Well I know the reference, but I'm not seeing how it applies haha I'm "missing the boat" so to speak

Recent runs of the HRRR look to be falling much more in line with me now......that's a slight relief. Although seeing the NAM holding its ground is equally unnerving; then again, it IS the NAM lmao

I know it's only 9:30 but the radar looks completely horrendous. Actually non-existent. Not a good sign for us when we want the moisture here ASAP before the cold air gets scoured out.

rb924119 wrote:Recent runs of the HRRR look to be falling much more in line with me now......that's a slight relief. Although seeing the NAM holding its ground is equally unnerving; then again, it IS the NAM lmao

you would be the only member of this board my friend to be hoping that the models trend to less accumulations. *  I for one hope your forecast busts low.

syosnow94 wrote:

rb924119 wrote:Recent runs of the HRRR look to be falling much more in line with me now......that's a slight relief. Although seeing the NAM holding its ground is equally unnerving; then again, it IS the NAM lmao

you would be the only member of this board my friend to be hoping that the models trend to less accumulations. *  I for one hope your forecast busts low.

My fault for not elaborating: I truly hope that I don't bust, and at the same time I hope am too low. If I do bust, I'd rather be in the situation that I am now, where if I'm wrong, I'm too low. I'd be a lot less upset, and a lot happier, if we end up with more than what I think, versus if we get less haha it's a double-edged sword

rb924119 wrote:Recent runs of the HRRR look to be falling much more in line with me now......that's a slight relief. Although seeing the NAM holding its ground is equally unnerving; then again, it IS the NAM lmao

Well rb the latest hrrr has 3 to 5" for most of Long Island

Hey sroc, where did you find the blank map that you use for your snowfall maps? Unfortunately I lost the one I used to use and can't seem to find any others.

Anyway, temp is sitting at 22 here currently. Radar showing lots of virga popping up to the west.

Looking at the radar I would say no way the start time will be anywhere near before or after midnight, but maybe it fills in?

algae888 wrote:

rb924119 wrote:Recent runs of the HRRR look to be falling much more in line with me now......that's a slight relief. Although seeing the NAM holding its ground is equally unnerving; then again, it IS the NAM lmao

Well rb the latest hrrr has 3 to 5" for most of Long Island

Haha I saw that, don't worry :p My personal feeling is that many of those areas will see sleet and/or snow grains for most of the burst of heavier precipitation before it goes to rain. So when you look at the model and it shows the darkest blues between 12-15/16z, I think that ends up verifying as sleet and/or the snow grains and not snow, but counts the qpf that falls as those p-types as snow. Again, my own interpretation lol the model does have 4" amounts through central LI and southwestern Connecticut, though, you're right.

The GFS has to be counting sleet as snow. There's no way it's snowing beyond 12z in southeastern Pa when 850s are +2C and higher ahaha zero chance

I'm headed to bed, and I'll see what we have in the morning. This storm has completely tired me out trying to figure it out haha 'night all!

I'm way to excited for a potential 3-6 that may change to rain

2004blackwrx wrote:I'm way to excited for a potential 3-6 that may change to rain

lol me too (it WILL change to rain thats a for sure) guess cuz we may not get a lot of chances, interested to see how bad the icing event may b too.

rarely see icing that is as bad as forecasted

Wow, thats some dayumm heavy freezing rain for a big area, only lasts a few hrs but thats enough to cause major trouble.