More Cold and Snow for Next Week into March

February 21, 2014February 21, 2014 Miguel Pierre Uncategorized

This is an update to the previous post on the cold & storm pattern in late February and early March

First, the model guidance now the Polar vortex drop further south in SE Canada. This is due the 500mb heights increasing around North Pole. This is similar pattern evolution we saw in the last two weeks of January So there is now more potential for more extreme cold for late February and early March. You may have to wear you big coats again. The GEFS shows this potential for very anomalous negative 500mb height and surface temparture departures, near end of the next week.

Another minor stratospheric warm event is occurring. The EP vectors are forecast shift more to right (poleward) by ECMWF. This would means that warm would be downwell in higher latitudes. Possibly resulting more west-based blocking over Greenland/Davis Strait.

The MJO still forecast by GFS and ECMWF ensembles to head in through phases 7 and 8. These forecasts are a little less than reliable. But they have been fairly consistent this week. There is more support for progression by westerly vector wind anomalies being shown at 200mb and 850mb, over the Central Pacific.

More later…

Updated Snowfall map 2/03/14 Winter Storm

February 3, 2014February 19, 2014 Miguel Pierre Forecasts, Uncategorized, Winter Wx

Based on latest guidance and observations. I’ll discuss more soon:

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

February 2, 2014February 19, 2014 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.
QPF 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.

On 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.