Tuesday, December 21, 2010

Somebody wake up Bing Crosby--

When the NWS says "likely" 5 days before an event-- take notice. I'm sure part of the extreme lead time is the
nature of the holiday season so everyone has a chance to make and adjust plans, while the other reason is we have great agreement from every model that we see at least SOME snow.

BTW, here is a nice link to the NWS office in Blacksburg.

http://www.erh.noaa.gov/er/rnk/

You just click on your location and it gives you a forecast. The folks our office do a fine job forecasting for our region.

The storm that is beating California to pulp as we currently sleep begins to move east and holds together well. Cold air is firmly entrenched in our region while another piece of energy dives down from Canada into our Christmas low pressure.

The models diverge a little where some (GFS) takes a little while to get the low cranking while losing the storm from Cali and we just a nice 1-3 inch snowfall but Philly North and East get more of a 6-10 inch event (and then some). The ECMWF is a little slower bringing the energy out of the SW, the storm "Phases" a little sooner and we end up with a 4-8 inch event. However, the ECMWF is known to hold energy a little to long in the southwest--so this could be an error as well. COLD storm-- temps down in the 20's.

This looks like a event to be shared by all from Carolina to New England...


This is the QPF(Quanitative precipitation forecast) output from the GFS-- the light green is .10 to .25 liquid
For comparisiong, the shades of blue are a half inch and the pink is an inch and  a half. As always, the QPF maps are the least accurate on some levels for actual forecasting at this time frame, but very helpful is showing what a model is indicating.


The ECMWF model (not allowed to post QPF maps) has a more defined low near FL as its slowed and the northern energy is involved sooner.



That explodes as it moves up the coast-- Goes from 1008 MB to 978 in a day, which is rather impressive.





If you notice over MN--there is a high pressure over MN-- High pressure moving in from the west and storm just to our east means WIND!


Summary--
Snow is likely-- at this point, I'd suggest a snowfall of 2-4 inches for Christmas day over most of our region. The fast solutions bring us less snow and snow starts overnight Christmas eve into Christmas day, while the slower models are not bringing in snow until Christmas day afternoon lasting into the 26th.Windy and VERY cold--so if Santa is bring your kids a sled, make sure he sends gloves and a scarf as well.

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