Not a Repeat; Flood Watch AGAIN

For the third time in a week the National Weather Service in Taunton has issued a Flood Watch for all of MA, RI, and CT except for the Cape and Islands

NWS Boston Hazards

A strong area of low pressure is working across NE Ohio, Western PA, and Western NY State

SPC Mesoanalysis 6 am MSLP, radar

The visible satellite captures the storm well; heck you can even see breaks of sun in parts of Southern New England

GOES_East Visible Satellite 645 am

The regional radar shows a well defined vortex and squall line that will reach Philly, Baltimore, and Washington later this morning

NWS Northeast Regional Radar 658 am

This leading edge of the rain will work across the region this morning.  I expect Worcester/Providence to be raining by 10 am, Boston by 1130 am.  We will stay out of the severe weather, though isolated thunderstorms are certainly possible.  I suppose SW CT could see a rogue severe cell.

SPC Day 1 Convective Outlook

Here is the current surface chart.  Notice the stationary boundary the low will try to follow towards the coast.  

WPC Surface Analysis 500 AM 

Here is the surface forecast for tonight; notice where the WPC believes the low pressure will be

WPC surface forecast 8 PM 

The WPC however is unimpressed with precipitation totals across most of Southern New England.  I'm not sure why they believe that as the majority of the guidance I am reviewing shows a general 1-2 inches with isolated higher amounts. In fact this morning's NAM hires likes a general 2-4 inches across Western MA, CT, Southern RI and coastal SE MA

06z NAM hires total precip through Sat 2 PM (image weatherbell)

Here is one of the short range models total precipitation during the next 18 hours

11z RAP total precipitation (image weatherbell)

So that leads me to question this forecast from the WPC.  I believe it is underdone

WPC 2 day precipitation totals

None the less by tomorrow morning the low will morph into a Nor'Easter and move south and east of New England

WPC surface forecast 8 am Fri

High pressure dropping into the Great Lakes will help kick this system out and the weekend looks great.  More on that later, I hate triple OT.