November 14th Possible first flakes for some!!

Hey Frank , was asking because everyone was talking about possible snows and temps below 40 . Just saw your explanation on the other thread thanks for the input

Artechmetals wrote:Hey Frank , was asking because everyone was talking about possible snows and temps below 40 . Just saw your explanation on the other thread thanks for the input

One thing to keep in mind, and that goes for everyone, is when myself or Sroc or anyone else posts model images and they show cold temps or snow, it does NOT mean A) we are forecasting it and B) that's how it's going to play out. Models are used to compliment forecasting. They're not to be taken verbatim

After looking at all the models we are going to have a strong upper air disturbance or short wave energy which is very cold passing over us. the surface temps are going to be warm probably in the forties at the beginning. However a lot of cold air further up in the atmosphere. so my thinking is that if we are to get snow its going to have to come down pretty hard to bring the cold air down to the surface. after looking at the trends today this seems likely. I believe it can happen anywhere in our area but the timing has to be just right. good thing is that it's happening in the early morning hours so if it does come down hard enough chances are It could stick. obviously for the areas away from the coast have a better chance.

algae888 wrote:After looking at all the models we are going to have a strong upper air disturbance or short wave energy which is very cold passing over us. the surface temps are going to be warm probably in the forties at the beginning. However a lot of cold air further up in the atmosphere. so my thinking is that if we are to get snow its going to have to come down pretty hard to bring the cold air down to the surface. after looking at the trends today this seems likely. I believe it can happen anywhere in our area but the timing has to be just right. good thing is that it's happening in the early morning hours so if it does come down hard enough chances are It could stick. obviously for the areas away from the coast have a better chance.

Warm air is pretty shallow so it wont take much to cool the surface once precip gets going and 850s continue to crash. But you need the 850s to cool fast enough. Seeing the NMM and ARW due that is worrying but we will see how models trend tonight with temps.

Frank , guess between getting excited about the winter ahead and with you being so accurate I think I'm spoiled lol !

Quietace wrote:

algae888 wrote:After looking at all the models we are going to have a strong upper air disturbance or short wave energy which is very cold passing over us. the surface temps are going to be warm probably in the forties at the beginning. However a lot of cold air further up in the atmosphere. so my thinking is that if we are to get snow its going to have to come down pretty hard to bring the cold air down to the surface. after looking at the trends today this seems likely. I believe it can happen anywhere in our area but the timing has to be just right. good thing is that it's happening in the early morning hours so if it does come down hard enough chances are It could stick. obviously for the areas away from the coast have a better chance.

Warm air is pretty shallow so it wont take much to cool the surface once precip gets going and 850s continue to crash. But you need the 850s to cool fast enough. Seeing the NMM and ARW  due that is worrying but we will see how models trend tonight with temps.

I don't think 850's are the problem. The 850 mb temps are going to be -5 to -7*C before the Precip moves in. What I am not liking for the immediate jersey coast and LI is the dew points. When examining the surface temps during the time frame when the Precip is moving through we are looking at surface temps at mid to upper 30's at best. Even some lower 40's. The dew points along the coast look to be low to mid 30's. So even with evaporative cooling it is going to be hard for those small light flakes to not melt, even if only passing through a small surface layer of above freezing temps. Relative humidity along the coast looks to be in the upper 60's and 70's throughout much of the event which also is more suggestive of rain at the surface given the forecasted surface temps.

What does all this mean many of you may ask. Well you can get snow even if the surface temps are above freezing. First you need the mid layers to be cold enough so the Precip starts as snow. If the 850's are above freezing your almost guaranteed not to get snow. Two basic rules you can use to gauge the probability of snow with above normal surface temps. First if you take the halfway point or the avg of the dew point and surface temp and it is at or below freezing chances go way up that you see snow to the surface. The other way to do it is to take the relative humidity of a location and compare it to the surface temp. There is a complex equation for that but I use this simple site to do it. This site is just for fun and there are other variables to consider but can be used as a general guide. http://www.sciencebits.com/SnowProbCalc

NAM saying a bit wetter for Friday morning - the NAM of course!

0z Hi-Res NAM total snowfall

0z NAM gives me something as well in NERN VT

NAM which was dry seems to have trended toward .1-.25", however with surface temp profiles looking to begin around 40 in some areas falling to mid to lower 30s at best its a rain/snow to snow or all wet snow event. However in any case I don't anticipate temps being favorable enough for sticking but it'll be nice just to see the first flakes fly which I'm pretty sure most of us know is all this will likely amount to.

0z GFS Coming in Juicy for Thursday Night-Friday

Southern NE and NYC/LI do well here

2m temps don't get to freezing in NENJ until the morning, about 9 am, halfway through the precip event so not expecting much

models keep trending wetter. and all ncep models now showing snow for us. nws updated disco...

FCST ON TRACK FOR TNGT SO NO MAJOR CHANGES MADE. 00Z NAM DOES
SHOW A SWATH OF LGT SNOW ACCUMS THU NGT...ESPECIALLY CT INTO THE
HUDSON VALLEY AND NERN NJ. THE SREF AND 18Z GFS ALSO SUGGESTED THE
POTENTIAL FOR A COATING TO AROUND AN INCH OF SNOW WITH THE SYS.
look for 1st nws snow map in the morning. btw who has nov 14 as getting our first flakes in winter weather contest?

Thinking there's a good chance most of us could see a period of steady snowfall even though it won't stick. Maybe to grassy surfaces where half an inch could accumulate. Will be interesting to see how this unfolds. Don't think I'm going to change my snow map, but will make a final decision tomorrow around 12 pm.

Euro not as enthused as gfs, but still solid for long island.

Ukmet, my new favorite model, shows pretty much what the gfs has. Thus could be fun

Here is my final call snowfall map. I expanded the area expected to see snow. I still think the immed. coast and LI will see some flakes, but I just don't see anything sticking unless there are brief bursts of moderate snowfall. Even then it will be very short lived. ie: gone in an hr or two after the precip stops. Like Tom said above it will be nice to see the first flakes fly. Those just off the coast I can def see very light accumulations for you guys.
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Noaa for Brooklyn

Tonight: Rain before 1am, then snow. Low around 35. Wind chill values between 25 and 30. Northwest wind 7 to 14 mph. Chance of precipitation is 90%. New snow accumulation of less than a half inch possible.

Al,

I have nov 15th!! Anyway, I will take a grass and car coating this early anytime. If this was dec 14 th then it would really put us all in the mood for Xmas!!

Zoo it will stick on the mountain up the block from you - Mugs's house!! Hahaha

Rgem snow map

Nam came in with .25 to .5 qpf. wouldn't be surprised if some areas picked up to 3 inches of snow out of this.

mugs is the contest price is right rules who ever is closest without going over or just whoever is closest? If it is price is right rules then by that fact you would be over and lose, if not then you may win that one.

Al that would be awesome hope its cold enough here to give us a inch or more : ) And I am still hoping for next week, hey this one trended wetter maybe that one will trend colder, who knows the models are kinda all over.

According to the wxbell NAM snow map, we basically get nothing. Its all rain. I don't know if they are still useless this close to an event but if this verifies it stinks.