Winter Wx

Snowstorm 2/15/14

Miguel Pierre Forecasts, Winter Wx

Models have been trending stronger and NW this system. Particularly with closing off 700mb and 850mb lows near our area. The GFS has been leading way in these trends. The 0z run tonight back a little bit from it’s 18z run. Which would given NYC around 6″ of snow and  LI and CT 6-12″ of snow. But it still more amplified than the 12z run. The 0z UKMET and ECMWF has also come in further west tonight. So my forecast will follow the 0z GFS closely. Note that initially BL temps may be warm enough for some mixing or melting at the start. Especially over LI. So this may cut-down to the low-end of these ranges.


Snowfallmap21514

Winter Storm for the Tri-State Area 2/03/14

Miguel Pierre Forecasts, Uncategorized, Winter Wx

This is a forecast discussion is for the NYC-PHL Tri-State area.

A cold front will move across the region tonight, with some rain showers. Then a wave of low pressure will track up front offshore. As it turns it colder rain showers will change over to snow showers and become steadier and heavier tomorrow morning. Snowfall could be falling at the 1″-2″ per hr. Especially over Parts of NJ, NYC and LI. Snow should begin to taper off and end late Monday afternoon.

Models have the best UVVs going over parts of SE PA and CNJ tomorrow. This where I’m predicting highest snowfall total  Extreme SNJ/DE will have more warm to overcome tomorrow morning.
18zgfsNE_500_vvel_018QPF totals on the models and ensembles range anywhere from .50″ to 1.00″ the area, expect farthest northern suburbs. It’s possible these totals too high, due progressive moving on the storm. But this system unlike past system, this system in picking more moisture out the Gulf.

The main concern here is with temperatures. Especially in the boundary layer. Today many places around NYC where in low and mid 50s. Several degrees higher than guidance suggested. If the column doesn’t cool off as fast as modeled, early tomorrow morning, than snowfall totals will be less than predicted.

12zGFSNYCsoundingOn the other hand, if this farther north with stronger forcing, we could see higher totals, more dynamic cooling and heavier precip. We are right-rear exit region of a 250mb  upper-level streak. 500mb vorticity has all trending stronger today on all the models. So this isn’t out of the question.

18zgfsUS_250_spd_021namNE_500_avort_027

Here’s is the snowfall total forecast:


Snowfallmap2