Friday, January 11, 2008

A LATE WEEKEND STORM THREAT ! FOR RAIN, CHANGING TO ACCUMULATING WET SNOW SUNDAY NIGHT INTO MONDAY AM.

Discussion: 1/11/08
Friday @ 6:00 PM
Ruggie Weather

A very interesting coastal storm will play a big part in my forecast, and our weather later this weekend. A strong cold front moved through the region this afternoon, bringing a line of showers and Thunderstorms, some which were quite heavy. This front will move offshore tonight, and cooler air will begin filtering tonight and tomorrow. Temperature will remain above normal, in the low 50's for Saturday, but much cooler than this past week's Blowtorch, and record breaking warmth of the 50's and 60's. We are in the beginning stages of a gradual pattern change, that will likely lead to a much colder and stormy pattern as we head into the second half of January. (Please See my previous mid range call, and Blog writeup on this topic)

As we head into Sunday, colder air will begin to bleed into the region, from the North and Northwest, as High Pressure sets up near the Great Lakes into SE Canada. Temperature will be even colder for Sunday and will reach the low to mid 40's for Highs.

Now comes the good stuff for later this weekend. A storm system will begin to develop along the Carolina coast on Sunday. I've been watching this coastal low, and following it for several days now. The Computer models have been very consistent in showing this storm, but uncertain and waffling with it's track. Some too far offshore and a miss, while at times showing the storm to close to the coast or even inland. Also the models have been having problems in a phasing solution, and where the Upper Level energy set's up. It appears there's now much more agreement as we are now getting closer to the event. The latest GFS and NAM runs are now showing a favorable storm track, for a colder solution and Wet Snow, in where our storm moves NE from the Carolina's, and stays far enough offshore (about 200 to 300 miles)

This is a classic setup for the Delaware Valley, Especially for extreme Eastern PA, most of NJ and Northern DE. Upper Levels Temperatures at 850 and 500 Mb's will support wet Snow during the height of the storm, for later Sunday evening into Early Monday morning. However, Surface temperatures will be marginal, in the low to mid 30's during this time frame, so this would equate to a heavy wet snowfall. A nice thump of Accumulating snow is likely if the latest trends and models are correct.

The 2 most critical things I'll be watching over the next 24 to 36 hours in taking a shot at possible snowfall amounts, will be the track of this storm, and the surface temperatures. If all lines up, and this storm stays 200 to 350 miles off the NJ Coast later Sunday night, we could be looking at several inches of Wet Snow. If surface temps are slightly cooler than progged and more cold air is worked into the system, then a general 3" to 6" snowstorm for much of the Delaware Valley is possible.

I'll have more on this storm later Saturday or early Sunday morning, so check back and stay turned. I should have a much better handle on this system tomorrow, So I'll take a stab at possible snow Accumulations, and my overall forecast for the Region at that time.

Take Care,
Ruggie

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