Showing posts from August, 2015

Already Raining in Eastern MA

It won't rain in Eastern MA until this afternoon (Me-yesterday).  Opps.  Well I blew that one.  Pouring in Middlesex, Suffolk,  and Essex counties.
The combo surface and water vapor satellite shows the front and upper level low in the Northwest Atlantic nicely.  The low is undoubtably helping to feed moisture northward into Southeastern New England as it interacts with the cold front.
Here is the 500 mb chart from 2 AM morning.  The upper level flow is into Quebec and North of Atlantic Canada.  Yet there is convergence from the interaction of the upper level features.  That puts New England in a favorable spot for heavy rain and thunderstorms today.  I should have seen this yesterday.
That said the convergence at the upper levels should subside this afternoon, but a tropical air mass remains in place so thunderstorms capable of flash flooding and lots of lightning will be a threat all day.  The short range high resolution guidance suggests Eastern MA is under the gun for storms un…

Unsettled Weather for the Weekend

I've been stopped several times this week by people lamenting the forecast for rain all weekend.  Yes I expect some rain but not a washout.  I wouldn't recommend any camping trips to Northern New England but hold off on cancelling the cookouts and pool parties.  Summer is almost over so don't give up on a weekend so quickly.

General Overview
A strong trough of low pressure is slowly moving through the Great Lakes.  The system is trying to move towards New England but it is going to be forced up and over the ridge in the Western Atlantic Ocean.  Here is the upper level 500 mb chart.
Temperatures are very fall like in the Midwest.  Going back to 8 am lets see who can spot the cold front.
Fairly easy in this case.  As of noon the front has pushed a little further east and south, though not much.
The water vapor satellite image shows the two major weather players for Southern New England this weekend and early next week.  A large upper level low pressure system is present near …

Tropical Thoughts on Bob and Danny

Happy Hurricane Bob Day! For many it is a not so happy anniversary but it has been 24 years since the tropical cyclone stormed through Buzzard's Day with 105 MPH winds and 12-15 ft of storm surge.  Let's look back at Bob and take a look at Tropical Storm Danny way out in the Atlantic.  Please see my post from Saturday on my overall late August look at the tropics.

Hurricane Bob August 19, 1991
Bob developed in the Bahama's on August 16, 1991.  It was spawned by a cold front that exited the East Coast and degenerated.  The storm quickly intensified and moved north passing about 35 miles east of the Outer Banks.  The forward motion increased as Bob strengthened into a 115 MPH Category 3 Hurricane.  Cool ocean waters south of New England prevented Bob from keeping this strength (note- not the case this year see below).  Still on August 19 Bob roared into SE New England.   East of the center had very little rain but strong storm surge and strong Category 2 strength winds.  West…

Peak of Huricane Season Approaching, Any Action?

The vast majority of tropical cyclones that impact New England occur in August and September.  There have also been a few in October, most notably Sandy in 2012.  We have seen impacts in July and November as well (Arthur 2014, Noel 2007) but the highest potential for a strong storm is now. 
Irene was a tropical storm that dropped tremendous rain on Vermont and its winds knocked down thousands of trees and power lines in Eastern New England.  Power was out for 5 days for many areas in MA/RI.  That was eye opening as the past tells us much stronger storms have impacted the region.  These storms bring a variety of impacts to the region.  The Hurricane of 1938 is the GOAT as it hit without warning, at high tide, moving at 50+ MPH with sustained winds of 120 MPH.
Here is the NWS Boston's overview of the storm put together in 2013 for the 75th anniversary of the storm.  The good news is that nothing in the Atlantic Ocean at the moment is even remotely capable for producing a storm like t…

Hot, Humid Weather for Next Several Days

The calender says mid August but it is still summer time.  The next week looks to be hot and humid with a few chances for thunderstorms.  Despite a soaking rain on Tuesday dry conditions have expanded again and these thunderstorm chances will not put a big dent into the moisture deficit.  The Atlantic basin remains quiet thanks it large part to El Nino, but also relatively cool sea surface temperatures in the tropical Atlantic and a drought in the Caribbean.  First up the upcoming heat and humidity.

General Overview/Short Term Forecast
A weak cold front will push through New England today but in general high pressure will be in charge.
Temperatures today should climb into the upper 80s/near 90.  Dew points will climb into the 60s in Southern New England.  The biggest threat for thunderstorms will start in Southern VT, NH, ME around 1-3 PM.  The threat shifts to Western MA around 4 PM and further east around 5-7 PM.  The steering in the upper atmosphere is weak so the biggest threat wil…

Rain, Thunderstorms for Tuesday

After nearly perfect weather Friday-Monday (my opinion) unsettled weather will move into Southern New England for Tuesday.  A widespread severe weather outbreak like last week doesn't appear likely.  However the rainfall will be widespread and embedded within the rain will be thunderstorms with isolated severe weather.  The Storm Prediction Center currently anticipates a marginal severe weather threat
Here is the SPC outlook chart
Forecasting severe weather is hard.  The SPC does a great job overall but they sometimes struggle in New England as our severe weather outbreaks tend to be atypical.  That threat could jump to slight in the next update.    The system responsible for the active weather is currently in the Great Lakes
In the upper levels the trough is rather shallow, with just a few shortwaves (at the surface the two low pressure systems to the North and South of Michigan) moving under a stronger shortwave in Ontario. 
Temperatures are mild tonight, staying in the mid 60s …

BREAKING: Severe Thunderstorm Watch Issued for Much of New England

A wicked line of thunderstorms roared across Southern New England this morning downing trees, power lines, and ripping up front lawns.  Seriously
Rhode Island and SE MA look like they were painted blue because there were so many wind reports
Now another severe thunderstorm watch is up.
1 PM Update
The atmosphere is ready to explode this afternoon
 There is ample potential energy in and around Southern New England.  The winds are turning with height (ample wind shear)
These parameters (and many others) should lead to supercells and line segments alike this afternoon.  The radar has already popped
Keep an eye to the sky, especially North of MA Pike into S NH, VT, and ME.  The cold front will not pass until this evening so Southern New England (south of Pike, CT, RI) may get another round of storms later, in addition to anything the might pop this afternoon.
-Zack Green