Here is forecast map for snowfall amounts around the tristate:

http://img370.imageshack.us/img370/874/blankmapsf1.png

These are preliminary as there is still alot of inconsistency in models handle this storm. However, the trend has been in the last few days for a weaker and further east storm track. This will decrease precip amounts across the tri-state area, especially north and west of NYC. Snowfall amounts over 3″ appear unlikely this time. Precip types, may vary acros sthe area, as the storm tries to get better organized near us in the upper-levels. Soundings and Bufkit profiles show a warming layer at 900mb to 925mb. This may drag warmer air aloft to mix with or change snow to sleet, freezing rain, for some inland areas, Thurs night and Friday morning cutting down on snowfall amounts. Along coast, enough warm air should come to change the snow to sleet and rain before daybreak Friday. I used a blend of the GFS and GGEM QPF fields for this forecast (.25″ – .50″)

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The clipper going through tonight, I expect a Coating to 1″ for most areas and amounts up to 2″ are not out of the question for areas in North-Central NJ, Orange County in NY, as the low heads right over them and with best lift there. And also over Eastern LI and Eastern Conn, as the storm begins to intensify offshore later tonight.

As for storm on Thurs. night and Fri AM, you’ve seen me discuss it on tri-state, so now you want to know snowfall amounts. I’m actually suprised by the amount of forecasts, already out there even though it is premlinary, give large amount variables there are and changes that can still occur. Anyway, it appears that models have come to an agreement on a track further offshore than earlier this morning. Normally that would bring more snow to the coastal areas, but being that there will be no ridge to the our north to keep cold air and the wind direction coming from the warmer than normal ocean waters, a change to snow to rain is likely along coastal areas.

For now I will put a “Snowfall Potential” map, that will be more of an outlook on how much snow I feel we may get around the tri-state right now. This is NOT a preliminary forecast map and I probably will not put one until sometime tomorrow:

http://img401.imageshack.us/img401/8499/snowfallpotentialzf6.png

To explain in short, I think that 3″ or more is possible over many inland areas away from the coast, where they should not see so much of marine influence and remain mainly snow. Closer to the coast, accumulations are most likely to be under 3″ due to the likely changeover. However, a few questions for me:

1. How much moisture will get back to the west? Will the east trends on the models continue?

2. How fast will the storm move out? Will the most of the precip be over before the changeover along the coast?

3. What about the warming layer that the GFS Bufkit keeps showing at 900mb to 925mb level across the area? There could be a period of freezing rain from some coastal areas, before a complete changeover to rain. Also some inland areas not far the coast may see a mix or changeover to freezing rain as well, cutting down snowfall amounts.

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When these things become clearer to me I’ll put a forecast map.

Forecast Amounts for tonight here:

http://img95.imageshack.us/img95/3822/sundaypmyf7.png

The latest runs of the GFS, NAM, SUNY MM5, have shifted the inverted surface trof axis down to Southern NJ for tonight event. The heaviest amount of snow should occur along and north of that trof axis. For those that don’t understand that, you see how I’ve illstruated here from the latest 6z NAM at 24hrs and 30hrs:

http://img258.imageshack.us/img258/5015/namp06024luq0.gif

http://img227.imageshack.us/img227/2130/namp06030lev5.gif

Although the NAM and MM5 is shows more than a .25″ liquid in Central and Southern NJ, I suspect this may be overdone and the GFS shows far about .10 or less here. So I’ve comprised expecting about .10″ to .20″ across Southern NJ and .05″ to .15″ across SE PA and Central NJ. With snowfall ratios tonight going down from 15:1 to 20:1, I’m expecting to 1″ to 3″ in general places. It is possible that a few spots get up to 4″.The rest of the area will see lighter snowfall amounts as they will be farther away from the surface trof. The models do not show any precip for NYC, LI and areas to the North and East tonight. But decent 700mb Omega on the NAM suggest precip, perhaps unmeasurable, can still could occur. Some very light snow or flurries is possible with little or no accumulation.If the models shift the trof axis back north today, than heavier snowfall amounts, will likely shift back north as well. I don’t really expect this to happen, but this will still be watched.

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