2130  2/7/10
I am hoping the most you are finding the new page to wxrisk.com ‘ s Virginia’s weather fairly easily.

I posted later than I want to because I was busy making changes to the website cleaning up some old files and getting ready to watch the Super Bowl and was pleasantly surprised by the significant win of the saints over the Colts.

The model  data   is has not  showing any real  changes with regard to Tuesday’s weather.   The main issue of contention remains how far to the south and east does this huge of 500 low a real powerhouse of the feature reach as it reaches the middle Atlantic Coast. As I try to make clear earlier when you have a clipper will like this even a Manitoba Maller which is a very powerful type of Alberta clipper… all these significant precipitation always occurs on the north side of the system and about 75 to 100 miles north of the 500 low.

These images from today show the feature. The European model takes the system to WVA and over MD which would spare Washington, DC Northern Virginia and Baltimore from the same and other major snowstorm.    These areas would see some snow but   o eastern portions would see snow going to rain from I-95 East .

Click on Image for Larger map

However the National Weather Service has issued a winter storm watch is for the Washington, DC and Baltimore metro areas and given the amount of snow damage that the last storm last… this is probably a wise course. However speaking strictly from a meteorological point of view I remain quite skeptical that the Clipper Low is going to drop as far south as central Virginia. This is very rarely happens.

In addition keep in mind that with the January 30 snowstorm of central and southern Virginia the forecast models continue to show that the heavy snow will fall from Richmond South… from Roanoke South to the VA/ NC border and into the northern counties of NC. Of course at the last minute there was a significant northward extension of the precipitation shield and the 850 Mb Low came out of the Tennessee Valley much stronger and track 50 miles to the north. Thus the Snow Shield did reach Washington, DC — NWS has 1 ” ..I had 3-5″ and they got 4-7″…. and the heaviest snow was actually from Richmond North towards Fredericksburg…. while along the NC/ VA border saw Sleet mixed in with the snow .

Then on the Saturday FEB 3… the storm that brought the humongous amount of snow over NW and Northern VA into Washington and Baltimore… the rain snow line advance much further to the north than any forecast called for… and this includes my forecasts. Recall that the rain snow line reached as far northwest as Charlottesville and into Fredericksburg. This was not in any of the model data. Again at the last minute the 850 MB low Jump to the north which drove the warm air much further to the north and west of Richmond than originally forecasted.

The point here is that for folks in the snow battle scarred Northwest and Northern Virginia… even though right now the data shows that the system is going to bring much of central and eastern Maryland a significant snowstorm… it is possible that the best nose will fall over Philly and eastern Pennsylvania into central and northern New Jersey and by pass Washington, DC and Baltimore metro areas.

For central Virginia the strong system coming out of the Midwest presents a different sort of problem. At the surface of this is simply going to be a cold front that will sweep through western… central and eastern VA. The air mass might be cold enough for a period of snow over central and western Virginia but it will quickly go over to rain as Southwest winds bring in the warm air. Behind the front a new surge of arctic air moves in as the storm explodes off the New Jersey coast into a monster’s Low for southern half of New England… Northeast PA… northern NJ… NYC … and Long Island.

The midday models show the next system of February 12 13 to be a significant event if you’re along the Gulf Coast and the Deep South area. This is going to be a very unusual and major snowfall for portions of AL GA SC NC. Whether or not the system turns the corner and comes up the coast enough to reach central and southern Virginia is going to depend of course on the position of the New England LOW once it reaches storm southeastern Canada.

Right now as I have been saying the models had been shoving the system too far to the south so when it stalls over southeastern Canada… it is of course still too far to the south. We are just going to have to wait and see whether or not the models make any sort of Lee adjustment. We could be looking at a situation where the data is showing no snow for central and southern Virginia over the next two days and then suddenly on Thursday they show a jump in the track and the snow gets into central and southeastern Virginia. If this sounds all rather uncertain to you and filled with “maybe” s and “could be”s and “possibilities”… well that’s exactly what this is. At this point for the weekend we simply don’t know.

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0945   2/7/10