Wednesday Storm Update: Rain to the South, Ice to the NW, Snow to the Far North

 Good morning. I have updated my forecast for tomorrow afternoon into Friday morning's storm system below. Overall I did not change much for where the rain changing to ice will occur. I did however hone in on where the heaviest snow will fall to the far north. This storm system arrives tomorrow morning and lasts till Friday morning. The ice zones do not change to ice till very late tomorrow night or early Friday morning.

Here is my updated forecast:

Summary:

• Storm moves in as light rain tomorrow morning/early tomorrow afternoon as rain for all areas outside blue zones

• Snow starts falling in the mountain areas of New England and will be accumulating throughout the day

• By late Thursday night/early Friday morning the rain will pick up in intensity then change to freezing rain and then sleet for the pink zone west to east. 
• This is where we need to watch for ice accretion especially over the higher terrain of NW NJ NE PA etc.
• To the southeast I think surface temperatures will over just above freezing and stay plain rain

• For the green zone this is a rain storm 
• Areas on the NW fringes can see some ice at the tail end of the storm
• Very cold air rushes in Friday afternoon so need to watch for flash freeze potential

• Storm tapers off by early Friday afternoon

In terms of models some are colder than others, but I believe my map is the best representation of what happens. There will be a final forecast released tomorrow morning. 

Our storm system exists of a setup that involves a mild southwest flow of moisture rich air and cold air pressing from the northwest due to strong high pressure...

By Thursday morning the mild air moves in with rain and snow to the northwest...

The changeover to ice is then debated by the models. Some have the rain holding on longer than others. As of now I like this changeover to occur just after midnight for many in the pink zone...

This will be in the form of freezing rain then sleet towards the end of the storm. The freezing rain could start to accumulate on non treated surfaces. Ice forecasting is extremely difficult so I have up to 0.25" as of now. 

By late morning you can see even the warmer models show the ice line just off the coasts...

This then ends by early Friday afternoon with very cold arctic air moving in by Friday night. Need to watch for freezing areas of water...

Yes those greys are sub zero by Saturday morning. 

Stay tuned, will have some updates tonight and a final forecast out tomorrow.