Mid Week Coastal Storm To Approach Southern New England

A strong ocean storm will develop off the East Coast and it looks like it track close enough to New England to produce some effects.  There are still plausible scenario's in which the storm slides out to sea and the impact is minimal.  However given the projected strength of the system let's take a look at it.

Short Term Forecast
Temperatures today warmed into the 50's in Southern New England (SNE) today

5 PM 2 m temps (image Weatherbell)

A surface low tracking through Northern New England and associated warm front allowed for these "warm" temperatures today.  This is short lived however as a strong Arctic high is descending into the Upper Plains

WPC 2 PM Surface Analysis

See the cold front north of Michigan?  That will bring potentially record breaking cold on Monday.  Sunday is not bitter cold, but temperatures in general will max out in the upper 30's outside of SE MA.  SE MA should reach the mid 40's

18z NAM hires 2 m temps 3 PM Sunday (image Weatherbell)

By Monday morning temperatures are in the single digits North and West of Worcester and in the teens for the rest.  Record low temps for Monday via NWS Boston are

• Boston        6 (1874)
• Worcester   6 (1906)
• Springfield   7 (1906)
• Providence  9 (1906)

Record Low Max temps (IE lowest high temp for date)

• Boston       26 (1888)
• Worcester  24 (1940)
• Springfield  29 (1940)
• Providence 28 (1940)

We will challenge these records, but probably fall just short.  The record Low Max temperatures are more likely to fall than the record low min temps.  Here is 5 am Monday

18z NAM hires 2 m temps 5 am Monday (image Weatherbell)

Here is the projected Surface Chart Monday 8 am. 

WPC projected surface analysis 8 am Monday

High temps are in the mid to upper 20's.  Monday night lows are in the teens.  By Tuesday our Arctic high will slide offshore as a coastal low begins to develop off the east coast.

Medium Range Outlook

Here is what I think I know

• A powerful storm will develop Tuesday and track northeast
• Highest impact is in SE MA
• Strong Winds in SE MA

Why a powerful storm?  First of all the computer models are all developing a sub 980 mb storm.  Many are under 970, and a significant number are below 960.  Given this information let's examine the sea surface temperature gradient along the east coast.

NOAA/NESDIS SST Analysis 3.21.14 (OSPO)

The low will generally track long this gradient.  That puts the center south and east of the "benchmark" which is 40/70 (nearly all major New England snow storms track over the benchmark).  This is why I believe SE MA sees the greatest impact.  The rest of Southern New England is still vulnerable to snow.  Here is the 500 mb pattern according to the American GFS model

18z GFS 500 mb heights Wednesday 2 am (image NCEP)

This is actually a low impact event according the GFS as the low does not close off at 500 mb until it is past New England.  I have trust issues with the GFS and the EURO seems to handle these events better, but it foolish to discount a scenario that is still 84 hours away.  The Weather Prediction Center projected surface analysis for Wednesday at 8 am is more in line with my thinking

WPC Surface Forecast Wed 8 am 

This shows a 972 mb low which I actually think is underestimated.  I think a 955-960 low is more likely but we will see.  Here are the impacts I expect

Expected Impacts

Enjoy your Saturday, I'll keep evaluating data tomorrow.  

-Zack Green