Tuesday 12/6 Snow Event Discussions & Observations

Peeps,

Looks like another N& W event incoming tomorrow later day night.

Light Rain to a dump of white gold to light rain

850's are cooling into CNJ



NAM - of course the amounts are slightly overdone BUT nonetheless it is there

This is an interesting system. Cold air damming has NW winds driving cold air into PA and N&W parts of NYC later in the day. It could start as snow, but most likely I think many start as rain then change to snow.

Maybe I will put a snow map out for this system when I get home. This one could drop more than 2".

Here's my first call:

Start: 4-8pm Tuesday, southwest to northeast
End: 12-3am Wednesday, southwest to northeast



Very similar to this most recent event, although we will now be working with more concentrated, albeit fracturing mid-level energy AND jet help. I also think that there is a little room for this to trend slightly northward, which would bring the best advective forcing further into the interior and heavier precipitation. This is also concerning, though, because it may allow more warm air to surge northward earlier and further, especially if the energy doesn't fracture as fast as I think it's going to and remains a more stout shortwave embedded in the flow. In all, I like where I stand right now with this.

^^ RB I like where you are at now - watch this trend colder IMO may have to jog that R/S line down about 25 miles in a SE direction.

And again on Thursday

This appears to be a good elevation storm. Southern NY will be a tough forecast. Will analyze when I get home. EURO matches pretty close with Ray's map.

Rayno's take on this next storm - IF only we had teh HP sliding down from Canada and not up from teh Midwest we'd be in business

http://www.accuweather.com/en/videos/accuweather-experts/snow-tuesday-across-northeast-late-week-cold-front/2430839568001

DEAR GOD THE NAM 4K!!!!!!

amugs wrote:Rayno's take on this next storm - IF only we had teh HP sliding down from Canada and not up from teh Midwest we'd be in business

http://www.accuweather.com/en/videos/accuweather-experts/snow-tuesday-across-northeast-late-week-cold-front/2430839568001

I completely agree with his thinking, I just think he's too low, personally. Look at your PWAT anomalies.....1-1.5 stdev. which is significant in winter.

amugs wrote:^^ RB I like where you are at now - watch this trend colder IMO  may have to jog that R/S line down about 25 miles in a SE direction.

And again on Thursday

Idk, Mugsy. There are only two ways in which I think that will happen. 1) The entire system trends south and/or weaker, allowing less warm advection into our region, but also less precipitation. 2) We are able to condense a lot of water out of the atmosphere, which is also possible given the look of the PWAT anomalies, and it can wet bulb/dynamically cool the column just enough for snow further south. Both of which are certainly possible and plausible, but are unfortunately things that we'll have to wait for tomorrow as we watch it develop haha

I do have to say that I am a little concerned with how far south most of the guidance is still bringing this. I'd like to see the H5 energy track more over the Delmarva, even Philly in a setup like this, to ensure the PVA is over our entire region. This can still change, though.

I decided against issuing a snow map after evaluating guidance further. This system has a lot working against it. For example, 925's and 850's are above freezing as the heart of the precipitation moves in. There is a retreating High Pressure, southerly flow, above freezing dew points, a disorganized surface low, and sheared out 500mb energy. I believe accumulations of 2 to 4 inches are likely in higher elevations of Pike County in PA and northern parts of Orange and Sullivan Counties in NY. Then an area of 1" to 3" S&E of there to NW NJ. Then a thin C-2" S&E of there to counties just north of NYC.

The rest of us may see a brief period of snow, but most likely we'll be all rain from the get-go. 

00z NAM is mostly rain for anyone south of 84.

Final call to be issued around mid-day, expect some changes mainly in Connecticut, Massachusetts, and the Hudson Valley.

30 degrees here in Binghamton, NY. Awaiting the chilly rain to begin this afternoon. We may mix and change to snow for a time with a possible 1-3" but I'm leaning against it at this point. I think an inch or less

Here's my final call:
Start: 3-7pm this evening from southwest to northeast
End: 12-4am tomorrow morning from southwest to northeast

Note that the red box depicts where the changeover times are applicable.

Please be aware that the snow could fall heavily at times, especially in the dark blue regions, where rates could reach or even exceed 1"/hr, mainly between about 7-11pm.

Potential "bust" factors:
1. Warm air is able to make it further northward earlier than expected, which would limit snowfall accumulations, but potentially increase the sleet/freezing rain accumulations. Neither are expected to be significant at this time.
2. Models are under-representing precipitation rates this evening, which would make amounts end up in the high end of, or exceed, my prediction. I would say that I am leaning 60/40 (60 for factor 2, 40 for factor 1, as factor 2 could combat factor 1 if the precipitation is heavy enough) with respect to which is more likely cause a bust in the forecast.

^^ Good call may I share with friends?

amugs wrote:^^ Good call may I share with friends?

Absolutely!! Thanks! Yours is good too. It looks like you're betting on a slightly warmer and/or lower precipitation event? Also, why is PA greyed out? lmao totally just curious haha

rb924119 wrote:

amugs wrote:^^ Good call may I share with friends?

Absolutely!! Thanks! Yours is good too. It looks like you're betting on a slightly warmer and/or lower precipitation event? Also, why is PA greyed out? lmao totally just curious haha

Ray,
I took that map from a met offline - HAHAHA!
I am not as advanced in making such, i should but it would be more like my son when colored with crayons!!!
What program do you use to make these maps?
Thanks again and appreciate you taking the time to do this and offer yuor expert and in depth analysis.

amugs wrote:

rb924119 wrote:

amugs wrote:^^ Good call may I share with friends?

Absolutely!! Thanks! Yours is good too. It looks like you're betting on a slightly warmer and/or lower precipitation event? Also, why is PA greyed out? lmao totally just curious haha

Ray,
I took that map from a met offline - HAHAHA!
I am not as advanced in making such, i should but it would be more like my son when colored with crayons!!!
What program do you use to make these maps?
Thanks again and appreciate you taking the time to do this and offer yuor expert and in depth analysis.

LMFAOOOO Don't worry, your secret is safe with me ahaha you should make maps; it's fun!!!

The map itself is actually one that I created myself using QGIS, which is a free version of GIS software. The contours for the snowfall amounts and rain were added with an online program that's equivalent to Microsoft Paint, but it just produces a higher quality image, and then the red box, text, and legend boxes were created in Microsoft PowerPoint. I use the basemap that I created with QGIS and load it into the online paint program. Then, I manually draw in and color-fill the snow amounts on the image using the online program, save it as a new image on my computer, then load that newly saved image with the color scheme on a PowerPoint slide as the background and add the rest. It's actually a really simple process. The hard part is figuring out where I want to draw the contours and what snow amounts I want to use. That makes up probably 80% of my process lmfao

currently 42f and cloudy here.

44* and cloudy it looks like it wants to snow out

33° and flurries just started.

37* and cloudy here. NWS now has all rain for Binghamton