Friday, January 30, 2015

Friday Morning: Preliminary Forecast on Late Weekend Snowstorm

Good morning everyone. I have looked at enough data to put out my preliminary forecast for Sunday into Monday. At this time it looks very probable that a moderate to significant winter storm is on the way for the region. Unlike the last storm, this should be a little easier to hone in on due to the fact its set up is not as complex. Regardless, this is still a preliminary forecast and will be updated this weekend to the final forecast.

This storm will not be nearly as deep (pressure level) at the surface as the last storm, however it is going to carry a lot of moisture with it. An area of low pressure will develop in the Ohio/Tennessee valley on Sunday morning as slide just south of the area as we head into Monday morning.  The worst part of this storm should be between the hours of 1-7am. However, snow should break out by Sunday late afternoon for many areas. This will be a cold storm to the north meaning the ratio of liquid to snow will be higher. I expect ratios up to 15:1 for Northern NJ into southern New England. This will enhance snow totals. To the south ratios will be a little lower. 

For the Balt/Wash area, I expect snow to break out Sunday afternoon but then turn to a mixed bag of precipitation as we approach later Sunday night. This will cut down accumulations. Regardless, you can still expect a moderate accumulation especially just to the northwest of those cities. 

Here is my initial Impact map:



This is just an initial estimate and like I mentioned will be tweaked as we approach the event.  I am basing this prediction on the decent consistency I see with the GFS,European and their ensemble models. The Canadian model is more south of that guidance but based on it's ensemble seems to be too far south.

Here is the model spread:

GFS:



Canadian:


Canadian ensembles suggest this is too far south based on their spread to the north..



European is similar to the GFS which I do not have an image of.

Biggest risks to this forecast:

The biggest risk I see to this forecast is a sudden trend north with this system. I think the risk to a northern movement is greater than a southern movement at this time. If that was to occur the whole snow map would be adjusted north and the  mixed precipitation could extend all the way into central NJ. That is not my forecast at this time.

I will have a video update tonight at 7pm. Stay tuned!


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