Friday, July 29, 2016

Rain Lingers Over SE MA, Weekend Forecst

Some rain is better than no rain and that's what most of Southern New England received this morning.  It was exactly the type of rain needed in that it was a steady rain and not a torrential downpour from a thunderstorm.  Still it could have been more if not for a blow up of convection in the waters south of New England.  That convection essentially "robbed" moisture from SNE.  Here is the radar as of 10 AM
NWS Northeast Regional Radar 
As of the 915 visible satellite loop you can see this convection blow up in the Atlantic.  But you can also see clearing in Upstate New York.  That will work its way into New England over the next few hours.  SE MA will be the last to clear.  Another 1-2 inches are possible from Plymouth to Middleboro to New Bedford and areas east.
NOAA GOES-East visible satellite loop
That means temperatures this afternoon will climb to near 80.  Some places like the CT River Valley and Merrimack River Valley will surpass 80 while others like Worcester probably fall a few degrees short.
NWS NDFD 2 M max temp forecast Friday (image Weatherbell)
We also have to keep an eye out for a few showers/brief thunderstorms this afternoon in interior MA such as Worcester, Hampden, Hampshire and Franklin counties.  For example here is 4 PM.  The storms are weak and have nothing to sustain them so they will rain themselves out quickly but keep an eye out for them.
13z HRRR Simulated Radar 4 PM (image College of Dupage WxCenter)
Weekend Forecast
Saturday is looking terrific to start.  The cold front will push far enough offshore for high pressure to take control.  The high will be centered in Canada so we get a break from the 90s and high dew points.  A sea breeze will form at the coast tomorrow afternoon but elsewhere highs should be in the low to mid 80s.  We will have to watch for an isolated shower Saturday afternoon/evening but the chance is low.
NWS NDFD 2 m max temps Saturday (image Weatherbell)
By Sunday a upper level feature will work into the region.  Timing is a bit of an issue but low pressure will again form south of New England.  Another feature of rain looks likely to move into Western New England.  Some guidance speeds this up and works it into New England later Saturday although I doubt this.  The set up look similar to today just a slower mover.  So periods of showers and thunderstorms are likely in Southern New England.  This may linger into Monday.  Here is the forecast surface chart Monday AM.
WPC Surface Forecast Monday 8 AM
Monday happens to be August 1.  Although Hurricane season starts on June 1 (this year we had Alex in January!) it peaks August-October.   Right on time some waves near Africa are showing signs of organization.  No I don't believe these make it anywhere near the east coast but its time to pay attention.
National Hurricane Center 5 day forecast outlook
There is plenty of fuel in the Atlantic.  August 19 marks the 25th anniversary of Hurricane Bob, the last hurricane to directly strike New England.  Sure we have felt impacts, even significant impacts from Floyd, Irene and Sandy but no storm has hit at hurricane intensity in 25 years.  Are we due?  Yes and no.  Odds say yes but the atmosphere does what the atmosphere wants.  It could spin up two hurricanes in two weeks (1954), 6 hurricanes in 22 years (1938-1960) or no hurricanes in 25 years.  
Atlantic Sea Surface Temperatures (Image Weatherbell)
I will try and post an update tomorrow before taking a few days off to head to the beach.  

-Zack Green

Thursday, July 28, 2016

Heavy Rain Likely Tomorrow....For Some

Like a good snowstorm the cutoff between beneficial rain and nah will be a matter of miles tomorrow.   The National Weather Service has issued a flood watch for SE MA, RI and CT.  That doesn't include Worcester County has the bulk of the moisture will be closer to the South Coast.
NWS Boston Headlines
Here is the current radar for the entire Northeast.
NWS Northeast Regional Radar Loop
  The activity in Northern New England is from an approaching cold front.  A surface low has formed in the Mid Atlantic.  This will track Northeast and link up with the northern front that will stall near the South Coast.
WPC Surface Analysis 2 PM
Now extremely tropical moisture will be in place.  Our wind is out the Southwest.  On this water vapor satellite loop (which tracks the amount of moisture in the atmosphere) track the flow from the Atlantic and Gulf of Mexico into the Eastern United States.
NOAA GOES_East Water Vapor Satellite Loop
Showers will break out ahead of the cold front later this evening in Western MA/CT and work east after midnight.  By daybreak areas south of the Pike will be raining.  Now does the rain make it all the way to the Mass Pike?  That is questionable.  Sometimes these systems blow up in the Mid Atlantic and the stronger low pulls the available moisture from Southern New England into itself.  Some models show this.  Here is the forecast surface chart for tomorrow at 8 AM
WPC Surface Forecast 8 AM Friday
Here is one simulated radar image (there are many that all show slightly different outcomes)
19z HRRR Parallel Simulated Radar 9 AM (Image Weatherbell)
Notice the brighter colors over Long Island?  There could be some stronger thunderstorms near the center of this low.   Severe weather parameters are quite high for the South Coast/Cape and Islands.  A brief tornado or waterspout is possible.  We really need this rain.  According to the Whitinsville Water Company we are now nearly 13" below normal dating back to January 2015.  June and July have been bone dry as well with less than 4" of rain combined.   That has lead to a Drought Watch.

Drought Watch Issued
A drought watch has been issued for out region as of July 1.  Most towns around us already had issued water bans but until today Sutton and Northbridge had not.
MWRA Drought Status
As a result the Whitinsville Water Company has issued a Stage 1 Water Restriction.  From the press release
The water restrictions will be effective Friday July 29th.  A Stage 1 Water Restriction  entails a voluntary restriction on all non-essential outdoor water to odd/even days.  This means that if your house number is an even number (ends in 0,2,4,6,or 8) , we would ask that you only water on even dates either before 9am or after 5pm on that day.   And if you house number is an odd number (ends in 1,3,5,7 or 9), we would ask that you only water on odd dates either before 9am or after 5pm on that day.   If you have a shared irrigation system, we ask that you set the timer to run only on even days either before 9am or after 5pm.
Examples of “Nonessential” outdoor water uses include:
  • irrigation of lawns via sprinklers or automatic irrigation systems;
  • washing of vehicles, except in a commercial car wash or as necessary for operator safety; and
  • washing of exterior building surfaces, parking lots, driveways or sidewalks, except as necessary to apply surface treatments such as paint, preservatives, stucco, pavement or cement.
Examples of water uses that may be allowed:
  • irrigation to establish a new lawn and new plantings during the months of May and September;
  • irrigation of public parks and recreational fields by means of automatic sprinklers outside the hours of 9 a.m. to 5 p.m.; and
  • irrigation of lawns, gardens, flowers and ornamental plants by means of a hand-held hose.
Examples of water uses NOT subject to mandatory restrictions:
  • for health and safety reasons;
  • by regulation;
  • for the production of food and fiber;
  • for the maintenance of livestock; or
  • to meet the core functions of a business (for example, irrigation by golf courses as necessary to maintain tees, greens, and limited fairway watering, or irrigation by plant nurseries as necessary to maintain stock).
The reason for watering before 9 AM and after 5 PM is simply because the process of evaporation in the peak heating hours does more damage to whatever it is one is trying to water by adding extra energy.  So please follow these guidelines.    Here is the updated drought monitor.
MA Drought Monitor 
Like I said we really need this rain tomorrow but there is no guarantee we get enough to make a difference.  Sing it Luke!

Monday, July 25, 2016

Heat Advisory Until 6 PM

A Heat Advisory has been issued until 6 PM for inland areas away from the coast.  The Merrimack, Connecticut and Blackstone River valley's are all included in this.
NWS Boston headlines/hazards 









There is also a risk of severe thunderstorms to our west.  A severe thunderstorm watch has been posted for parts of NY/PA/NJ/CT.   
SPC severe thunderstorm watch
Wind gusts greater than 60 MPH is the biggest threat with these storms to go along with frequent lightning.  If you look at the graphic above you see two main lines of thunderstorms.  The first is getting ready to enter Berkshire County in MA and Litchfield/Fairfield counties in CT.    Most computer guidance takes these storms east south east into CT.  Areas east of Springfield and Hartford should see little from this cluster.  However given the available energy in SNE right now its possible it holds together a little longer than currently forecast.

The second line looks rather potent.  Using a future radar here are the storms at 7 PM
17z HRRR Simulated radar 7 PM (image Weatherbell)
It does weaken as it loses some instability.  Here is the line at 9 PM
17z HRRR Simulated radar 9 PM (image Weatherbell)
Finally by 11 PM its nearly off the coast and just a batch of showers as more stable ocean air does a number on the line.
17z HRRR Simulated radar 11 PM (image Weatherbell)
Bottom line- limit outdoor activities this afternoon and if you are outside when thunder roars head indoors.

-Zack Green

Saturday, July 23, 2016

Friday Storms Rip Across SNE

Friday evening was wild across Southern New England.  Although we could see lightning and hear thunder most of the Blackstone Valley was spared the strongest thunderstorms.  A severe storm ripped through Worcester, Grafton, Westboro, Southboro and Framingham (among others).  Another severe storm tore through Northern Rhode Island and treated us to one hell of a light show last night.
The damage reports are numerous across the region.  Here is the radar image from 749 PM last night
NWS Boston Radar 749 PM 7/22/2016 (image via RadarScope App)
 That nasty looking cell in Worcester produced this damage in Southboro (images thanks to the National Weather Service Skywarn Spotter Network facebook page)
Clifford Road Southboro- John Mauro
Codarville Road Cemetary Southboro - John Mauro
Breakneck Hill Road Southboro - John Mauro
A lot of weather enthusiasts root for severe weather but it is important to remember the power of these storms and the destruction they can cause.  For many folks across the commonwealth today is not a fun day.   That said the power of mother nature is second to none.    A threat of thunderstorms also exists this afternoon and tonight.

General Overview
The surface chart this morning shows high pressure in control to our Southwest and a cold front to the northwest.
9 AM Northeast Surface Analysis (College of Dupage WxCenter)
You might not believe me if you step outside but we are actually a bit less humid today compared to yesterday thanks to our position on the backside of an upper level trough in the atmosphere.  Notice the dew points in the 70's stop just south of New York City and then compare the position of the upper ridge and trough
8 AM 500 mb vort, heights (College of Dupage WxCenter)
That doesn't make it cool- we don't live at 18,000 ft.  In fact it is already 91 in Boston!  The record if 100 set in 1952.   The city will probably settle around 97-98 but this is an impressive start.  Most weather stations in the Blackstone Valley are reading close to 90 as well.  With all this heat and an upper level feature expected to cross the region this afternoon expect another round of showers and thunderstorms.
SPC Thunderstorm Outlook Saturday
Here is the simulated radar as of 6 PM.  This is not meant to be exact- just a representation of where the model thinks convection will fire later.  In this case it makes sense that most of the action is in Northern New England closer to boundary.  It isn't a great Saturday afternoon at the Northern New England beaches.  Hopefully Roger Goodell is home. Some of this action will spill into Southern New England.
14z HRRR Simulated Radar 6 PM (Image College of Dupage WxCenter)
These should struggle to get south of the Pike.  If they do it will be this evening.    Lows tonight fall into the mid 60's.  We rebound to around 90 (give or take) Sunday with mostly sunny skies.  It will still be hot Monday and extremely humid.  A warm front will lift through Monday AM leaving the region in the "warm sector".  A cold front will approach from the west with a strong line of thunderstorms.  Keep an eye on the forecast if you have outdoor plans Monday evening,

Have a great Saturday

-Zack Green

Thursday, July 21, 2016

Severe Drought Expands in Southern New England

Dry conditions continue across Southern New England.  The area of moderate and severe drought continues to expand.  The dryness started in 2014.  Hurricane Arthur helped dent the conditions in July of 2014.  The heavy snow of January-March 2015 was rather dry and fluffy so that did not do much to alleviate the problem.  After some relief in June of 2015 (Tropical Storm Bill) we went right back to dry.  I decided to do some research and I've found a lot of information.

1) The meteorological cause of the current drought

2) Impacts on the region

3) Historical Droughts in Southern New England  

Here is the Northeast Regional Drought Monitor,
US Drought Monitor Northeast Region 7-19-2016
Percent of Normal Precipitation 1/1/16 to 6/30/16 (CPC)
The first chart shows the latest drought monitor.  Severe and moderate drought has conquered more area with this update.  The second chart shows the percent of normal precipitation for the first half of 2016.  We are running around 75% in Southern New England.  We ran about 80-90% in 2015.   So why exactly has this happened?  

There are two main reasons.  The current reason is the general jet stream set up.  It features a trough off the Pacific Northwest Coast and a trough off the East Coast.  Normally that means cooler and wet but we are on the dry western side of the trough.  Also we are close enough to the ridge every few days we are getting close to 90.  That ridge however takes most of the storms and pushes them to our south.  So West Virginia has had bad flooding and plenty of rain.  Virginia and Maryland have as well.  Last night's upper air chart shows this pattern well. 
00z NAM 500 mb vort, heights Wednesday 8 PM (image NCEP)
The ridge in the Atlantic subsequently weakens cold fronts as they head towards New England.  So the patterns allows for disturbances to ride above the ridge but by the time they get to the Northeast they are rather weak.  That means scattered thunderstorms which don't really help the drought.  It rains hard for a half hour and we might pick up a half inch of rain but it runs off into the storm drains without being able to soak into the ground.  

As for the Atlantic it seems like it is in a period of transition.  From 1995 until 2012 or so the basin was hyper active with tropical cyclone activity.  All oceans do through phases where a warm or cold state is favored.  They also transition to these phases.  One Atlantic transition from warm to cold occurred in the 1960's.  The Atlantic was active from 1925-1965 (give or take) but it began to transition in the later part of the 1950's.  Interestingly enough a rather severe drought began in 1961 that continued through 1969 (Harkness et al, 1986 pg 30).  The drought peaked in 1965-66 (Copeland 1966).  This period of dryness really began in 2014 so history tells us this could (but likely will not) last awhile.  

The Quabbin reservoir fell to 45% capacity in 1967.  Communities faced water restrictions and watering bans.  The Quabbin was built after the 1929-1932 drought.  In fact several towns were moved in order to create the the water supply.  Eastern MA communities were hit hard in the early 30's and they needed to create more water supply.  The Quabbin can hold 416 billion gallons of water and it services over 18 communities.  So how is the Quabbin doing today?

The Quabbin is 90% full as of July 1.  So despite a severe drought the water supply is fine.   Here is the summary off the Massachusetts Water Resources Authority website.
MWRA Quabbin summary
 We have a long way to go to worry about drought warnings and emergencies.   But remember this is on the Whitinsville Water Company web page

State Of Massachusetts Mandatory Annual Water Restrictions

Until Further Notice, There Will Be Mandatory Restrictions On All Non-Essential Outdoor Water Use From 9am To 5pm Every Day Be Between May 1st And September 30th.  This Will Be In Effect Every Year.  Further Information Is Can Be Found At Water Restriction Notice

I reached out to WWC to find out how filled our reservoirs are and I am waiting to hear back.   My guess is we are doing okay .  Uxbridge water (despite the E. Coli issue and the contaminated soil near the water supply) looks to be nearly full (UPDATE 7/22/16 Uxbridge has a water ban more on this Sunday).  So our lawns are turning brown, its dusty and fire danger is elevated but our water supply is in good shape,  This is obviously something to pay attention to going forward because I don't see the pattern changing anytime soon.  We could use a tropical system but we don't want to go from drought to flood and then right back to drought.  All in all this nothing compared to the issues in California but we don't live in California.  

Another note I found interesting was that there was a drought from 1980-1983.  It was before my time but I was told the gypsie moths were horrible in 1981 and 1983.  That makes sense because the fungus that keeps the caterpillar population in check grows best in moist conditions,  Unless we turn things around next winter get ready for more caterpillars and moths in 2017.   This is a topic that has really got my attention so be on the look out for more posts on this topic if you've found it educational/interesting.

-Zack Green

Wednesday, July 20, 2016

Summer Heat Across The US

A rather common summertime pattern is setting up across the United States bringing with it lots of heat and thunderstorms.  This pattern hasn't really developed since the super warm summer of 2012 and as a result many locations in the Central US are forecast to see their highest temperatures since then.  Here in Southern New England we will be largely spared that type of heat.  In fact yesterday and today are in the low to mid 80's with dew points in the 40's/50's.  The National Weather Service has issued a statement warning of elevated fire danger today.



If you are one to complain about that then there is nothing we can do for you as a human being.  The heat and another chance for thunderstorms will return Friday.

General Overview
First lets start off at the surface.  High pressure is currently onshore in the Northeast and building in the Rockies.  Both will slide east over time
WPC Surface Analysis 11 AM
The boundary draped across the Carolina's through Kentucky and into Missouri and Iowa is keeping the heat and humidity away from the Northeast.  Here are temperatures as of 12 PM
RTMA 2 m temps 12 PM
Some showers and thunderstorms are keeping temperatures down in Illinois and Iowa but these will pass and temps will sky rocket this afternoon there.  The upper atmosphere shows 1 upper trough off the Pacific Northwest and one off of New England.  The rest of the country is under the influence of a ridge.
12z NAM 500 mb vort, heights 2 PM (image NCEP/NOAA)
Because of this configuration the storm track is largely through Cali and then up into the upper plains then through the great lakes.  The advancing ridge (the warm front) is also producing storms.  Here is the US water vapor satellite.
GOES_Composite Water Vapor Loop (Image NOAA)
As hot as it will be in the South/Central/West US there shouldn't be too many record high temperatures set.  Here is tomorrow's NWS highs with potential records circled
NWS Forecast temps Thursday-record highs circled (image credit Weatherbell)
Getting back to New England high pressure moves offshore so tonight is a bit warmer than last night.  The humidity will also be a bit higher but it will not be unbearable.  High temps will again be in the mid to upper 80's.  Urban areas should push closer to 90.  If you plan on heading to the beach there will not be much of a sea breeze.  It is a good day to hit the shore.
NWS Northeast High Temps Thursday (image Weatherbell)
Some more active weather is possible Friday.  First here is the upper air chart for Friday 2 PM
12z NAM 500 mb vort, heights Friday 2 PM
There is a disturbance tracking through Southern Ontario.  At the surface we see an approaching cold front.
WPC Surface Forecast Friday 8 AM
It will be much more hot and humid Friday in New England.  Some models are forecast dew points near 70 which is unbearable.  Here is the forecast high temps for the Northeast
NWS max temps/records Friday (image Weatherbell)
Although it will be much hotter in the Mid Atlantic they should be protected by the ridge.  New England on the other hand will have to deal with this cold front passage.  As a result the Storm Prediction Center (SPC) has already placed New England in a severe thunderstorm risk area.
SPC Friday severe thunderstorm outlook 
The thunderstorm coverage should be scattered like it was on Monday.  That means not everyone will get severe storms or even rain.  At this range it is difficult to pinpoint where the highest risks are.  It will depend on AM cloud cover and atmospheric stability.  Northern New England is closer to the cold front/low so they should see more coverage.

The cold front will sweep off the coast overnight Friday into Saturday.  Temperatures do not cool off however.  Saturday is mostly sunny with a high near 90.  Sunday will have a chance of PM thunderstorms but most of the day looks good.  High temperatures also near 90.  We are in the heart of summer.

-Zack Green

Tuesday, July 19, 2016

Recapping Monday's Severe Weather

Although the Blackstone Valley was spared yesterday severe weather ripped through Southern New England causing extensive damage in Haverhill, Weymouth, Jamaica Plain and other local communities.  The storm that caused the damage south of Boston formed near Worcester.  I expected a squall line to form but it never did.  I placed my faith in the high resolution computer models and they let me down in my home area.  Two weeks ago we were hit hard in the Blackstone Valley when everyone else missed out.  This time it was us- that is severe weather.  One complex of storms near the MA/NH border seemed to draw a lot of energy from MA into it and results were damage like this in S NH.
Paula in Merrimac, NH via Fox 25
The storm that formed in Worcester left an even greater trail of destruction.  Here is damage in Quincy, MA
Nick P in Quincy via Fox 25
This damage is from a Microburst (although the storm south of Boston might be a Macroburst- larger area of damage).  What is a microburst?  Check out this diagram from the NWS Boston
NWS Boston microburst diagram
A microburst forms when rain cooled air rushes to the surface.  They differ from tornadoes in that damage occurs in a straight line not in a circular motion.   This is how NWS storm teams determine what hit a given location.  Here is the northeast region storm reports.  There was 1 tornado in the United States yesterday and it was near Caribou, ME
July 18, 2016 preliminary storm reports
We will have another chance of thunderstorms on Friday.  A strong ridge of high pressure will develop over the Central US so most of the country will see extreme heat.  In the northeast we will be above average but in general in the upper 80's and low 90's.  Perhaps next week the heat will shift to the east coast as the Bermuda high sets up offshore.  As for today high pressure in the Great Lakes keep us 10 degrees cooler than yesterday with dewpoints 20 points less.
WPC Surface Forecast Tuesday 2 PM
Temperatures gradually rise and humidity will increase as the high moves offshore later this week.  Enjoy the low 80's today and tomorrow- it doesn't get much better than that in July.

-Zack Green

Monday, July 18, 2016

Strong Thunderstorms Possible Today

A cold front approaching from the west will fire off strong to severe thunderstorms this afternoon and evening.  Ahead of these storms we will find temperatures in the low 90's.  Add in the humidity and it will feel closer to 100.  The storms will first impact the Berkshires/western MA between 2-3 PM, Worcester County/Hartford 3-6 PM and Boston/Eastern MA 4-730 PM,  Damaging winds are the number one threat today along with frequent lightning.  Hail and an isolated tornado (especially Western MA and into New York) are also possible.

General Overview
The SPC has issued a slight risk for Western New England and a marginal risk for Central/Eastern New England
SPC Day 1 Severe Weather Outlook
Here is the cold front as of 2 AM.  As the warm front lifts through to our west it will help to re-enforce the heat and humidity providing fuel for the thunderstorms.
WPC Surface Analysis 2 AM
High temperatures today are low 90's although some places in Eastern MA may hit the mid 90's.
NWS NDFD max temps Monday (image Weatherbell) -click to enlarge-
The cold front is on the move and by 2 PM thunderstorms will be firing well ahead of the actual front.
WPC Surface Forecast Monday 2 PM
Here is the simulated radar for 2 PM
09z HRRR simulated radar 2 PM (image College of Dupage WxCenter)
4 PM
09z HRRR Simulated radar 4 PM (image College of Dupage WxCenter)
It will be a great beach day along the South Coast up until the storms arrive so if you are planning a quick trip to the shore that will be the place to go.  We stay mostly dry until Friday after this so hopefully we can receive some beneficial rain.  After all we still have this
US Drought Monitor MA 7-12-16
If possible I'll try to live stream a video as the storms roll through.

-Zack Green

Biggest Snow Storm Of The Season Heads To Impact Region Tonight

The National Weather Service (NWS) in Norton, MA has issued a * Winter Storm Warning * from 7 PM tonight until 10 AM Wednesday.  A widesprea...