Welcome Rain Monday

After temperatures in the 80s today high pressure will slide offshore and a front will bring welcome rains to the region overnight tonight into tomorrow.  Warm temperatures return Tuesday with the threat of thunderstorms, although the greatest potential appears to be in Eastern NY and Western MA/NW CT.  As the week progresses a weak tropical system will likely impact the Texas coast.  It will be embedded in the jet stream and may enhance precipitation in our region late this weekend.

WPC surface analysis 11 am, issued 1230 PM

Temperatures as of 1 PM were in the upper 70s/low 80s

RTMA 2 m temperatures 1 PM (image Weatherbell)

Light rain will break out around 10-11 PM from west to east.  Heavy rain will arrive just in time for the lovely Monday morning commute.

12 z Hi res NAM simulated radar 7 am Monday (image Weatherbell)

Anyone who has to use our wonderful interstate system to go to work knows what the combination of Monday, heavy rain, and rush means.  Give yourself extra time.  Here is the projected surface chart at 8 am.

WPC projected surface chart 8 am Monday

 Notice the red warm front to the southwest of New England.  High temperatures tomorrow will struggle to reach 60 in a lot of areas.  Thankfully this is short lived.  Notice the 90's in Central NJ, 50's in MA! Also notice the low in the Gulf of Mexico.

12z Hi Res NAM 2 m temps 2 PM Monday (image Weatherbell)

 The low in the Gulf of Mexico may become a tropical depression or a weak tropical storm.  It doesn't really matter because whatever it is it has a deep tropical connection and it is expected to bring heavy rain to parts of Texas that do not need it.  I don't expect a repeat of Tropical Storm Allison in 2001 but there could be more serious flooding in SE Texas northward up into Oklahoma.  The disturbance is not terribly impressive at the moment

GOES_east IR rainbow satellite image 145 PM (image NOAA)

But by Tuesday morning it should be near the Texas coast and should be a little better organized.

WPC projected surface chart 8 am Tuesday

Rain in Southern New England ends tomorrow late afternoon/evening.  The heaviest rain is over early afternoon.  1-2 inches of rain is likely regionwide.

48 hour rainfall ending 8 am Tuesday (image WPC)

Now this is where it gets interesting.  The storm prediction center (SPC) suggests a isolated risk of severe weather on Tuesday.  I don't buy it for Southern New England except maybe the far western counties of MA and CT.  I believe the threat is more PA/NY/NJ.

SPC Day 3 severe thunderstorm outlook Tuesday

Wednesday is around 80 and sunny, Thursday a chance of showers, Friday and Saturday look ok.  Sunday could be questionable as the leftovers of the tropical system (probably named Bill) will be close.  I have a very important forecast on Saturday as my cousin Kate is getting married (to a Bill no less).  I told her 83 and partly cloudy so Tropical Storm Bill will not be welcome.  7 day rain totals

WPC 7 day rain totals ending Sunday 7 am

We need it.  Last weeks rain dented the drought but it did not erase it.

US drought monitor issued June 9, 2015 (NOAA)

Sing it Luke

Have a good Sunday

-Zack Green

UPDATE 320 PM-Severe Thunderstorms Possible Today

 The Storm Prediction Center in Norman, OK has issued a SEVERE THUNDERSTORM WATCH for Central and Western New England

Severe Thunderstorm Watch 280 (SPC)

The cold front is pushing east and is entering a somewhat favorable environment for thunderstorms.  A strong line of storms has exploded in the Hudson River Valley heading towards Western MA/VT/NW CT

NWS Northeast regional radar loop 248 PM

Damaging wind and isolated severe hail will be the main threats.  Perhaps a micro-burst or two with the warm moist environment that is in place.  The best threat looks to be Springfield to Worcester to Nashua, NH north and west.  Keep an eye to the sky as it may impact areas like the Blackstone Valley and Merrimack Valley.  Boston should be fine. The threat relaxes early this evening (8 PM latest). 

Previous discussion below
On this date 62 years ago the worst tornado in New England history ripped through Worcester, MA.  94 people lost their lives.  A separate tornado ripped through Sutton, Northbridge, and Mendon.  Thankfully the towns were not as densely populated (specifically Northbridge) in 1953 as they are today and no one was killed.  I can't see anything like that happening today but we will face the threat of severe weather, especially outside of 495.

NWS Northeast regional radar through 630 am

As of 630 there was solid rainfall in upstate New York and parts of Northern New England.  Warm and muggy air is present ahead of this cold front heading through Western PA and NY.

WPC 5 am surface analysis

Temperatures are not bad, most of Southern New England is in the mid 60's as of 6 am and climbing

6 am 2 m temperatures

Dew points are also in the 60's

11z HRRR 7 am dew points (image weatherbell)

 Dew points will rise into the mid 60's as the front approaches this afternoon.  Temperatures should rise into the upper 70's and maybe low 80's if we can get some sunshine.   If we do get sunshine the threat if severe weather will increase.  As of now Northern CT and Western MA face the greatest risk of severe storms.

SPC 2 am thunderstorm outlook

The front will clear tonight leaving temperatures around 80 and dew points in the upper 50's tomorrow.  Another threat of thunderstorms exists for Thursday as a another cold front approaches from the Great Lakes.

WPC surface forecast Wednesday 8 am

I'll update with any severe weather watches this afternoon.

-Zack Green

Tornado Watch for Portions of Western New England

A tornado watch has been issued by the Storm Prediction Center in Norman, OK for Berkshire County in Western Massachusetts and Bennington County in SW Vermont. 

Tornado Watch 274

A surface low pressure system is moving across Ontario with a trailing cold front and a leading warm front.  The tornado threat is in between the warm and cold front.

WPC Northeast surface analysis 11 am

As of 1 PM temperatures were a good 5-10 degrees warmer in NY and PA

RTMA 2 m temps 1 PM

Short range, high resolution guidance is showing the potential for a nasty round of storms from Albany towards Pittsfield, MA. 

17z HRRR simulated radar 6 PM est (image weatherbell)

These will fall apart as they head east so no worries in Southeastern New England from any severe weather (at least today).  Although I believe Western New England has the greatest chance of severe weather tomorrow there could be isolated storms further east.

Day 2 SPC thunderstorm outlook valid 8 am Tuesday

 I'll post in the morning with the latest.

-Zack Green

Cold and Damp Through Tuesday

On Patriots Day in April a soaking steady rain fell.  Until yesterday that was the last appreciable precipitation event.  We do need it so this is welcome

24 hour precipitation 8 am Sunday-8 am Monday (NWS/NOAA)

Even if temperatures like this are more like early April than June 1.  Many of us woke up to temperatures in the upper 40's. 

2 m temps 7 am (image weatherbell)

We are going to do much better as the day goes on.  Rounds of rain are expected to move across a stalled frontal boundary to our south. 

WPC Northeast Surface Analysis 5 AM

The low in PA is responsible for this mornings round of showers.  We should see a let up in the late morning early afternoon hours.  The air mass is unstable so isolated showers and thunderstorms will develop but they will not be as widespread.  The widespread rainfall threat will resume this evening and into tomorrow.  For this reason a Flash Flood Watch is in effect for much of CT and N RI.

NWS Boston Hazards 6/1/2015

We are looking at as much as 2-3 additional inches of rain through 8 am tomorrow.

WPC 24 hour precipitation forecast

CPC 1-2 week precipitation anomaly forecast

This will wipe out the drought in some places (although its certainly possible that it returns later this summer).  I did mention the drought could linger through the summer but the short term (1-2 weeks) is looking like above normal precipitation.   High temperatures tomorrow will struggle to get out of the 50s.  New England weather is funny.  Four years ago today we experienced a tornado outbreak that killed 3, including the infamous Springfield tornado that was rated as an EF-3.

Tornado Watch 411, June 1, 2011 from SPC

Here is the National Weather Service event summary.  It is a reminder that we can get all types of weather in New England.  

Thanks for reading

-Zack Green

Weekend Forecast and General Weather Thoughts

The upper level disturbance that brought a round of severe weather to New England yesterday has moved offshore and it has taken the humidity with it.  It left a mark in Methuen as a microburst (a real confirmed one) with 70 mph wind gusts  uprooted 20-30 trees.

Tree, Utility damage in Methuen, MA (image credit Boston Globe)

Emery Street, Methuen, MA (image credit Morgan Murphy/CBS Boston)

Overall there were many wind reports in New England and even a few hail reports.

5/28/2015 SPC preliminary storm reports

Temperatures this morning are in the 70's, on the way to low 80's inland and mid 70's near the coast.

2 m temps 10 am (image weatherbell)

Here is the surface chart as of 8 am.  Notice the cold front to the south of the region and also the front in the upper Midwest.  High pressure is in control over the interior northeast.  This is temporary

WPC Surface analysis 8 am

 At 500 mb

12z NAM 500 mb vorticity 8 am (image NCEP)

 By later this evening the high will slide offshore and the front from the Midwest will slowly move east.  Dew points will rise into the 60's again tomorrow, but not before a nice evening in which temperatures will not drop out of the 60's in Southern New England.  Up north temperatures will fall into the 50's.

WPC surface forecast 8 PM tonight

As the high moves offshore Southwesterly flow will resume so tomorrow will easily reach the mid 80s.  The atmosphere will be unstable tomorrow but with the front well to the west and temperatures warm aloft (mid levels) it will be difficult to get thunderstorm formation.  A few pop up storms are possible especially in the Northwestern half of New England (if we slice from Caribou to Stamford).  Therefore if you are in the Lakes region keep an eye to the sky especially late afternoon.

SPC Day 2 (Saturday) Thunderstorm outlook

Saturday night is fine as any convection should die down as we lose the heating of the day.  Sunday looks to be unsettled region wide.  While not anticipating a total washout the threat of rain will linger all day and into Sunday night.  Temperatures are around 70 (will get warmer with any breaks of sun) and dew points in upper 50's/low 60's.

GENERAL WEATHER THOUGHTS
As you may have noticed much of Southern New England is experiencing a moderate drought.  Some have asked how is this possible after all the snow this winter?! The answer is that we didn't receive as much precipitation as you might think.  Since it was so cold the snowfall ratio's were on the order of 20-25-1.  That means for every 1 inch of precipitation we got 20-25 inches of snow.  Normally we see a 10-1 ratio.

US Drought monitor, released 5/28/2015 (NOAA)

Yesterday's storms really didn't help much

24 hour observed rainfall (AHPS precipitation analysis)

While a soaking rain is possible on Monday the long term outlook is not positive.  The Climate Prediction Center is forecasting these conditions to continue through August.  Hurricane season begins on Monday so we may have to hope for a tropical system to replenish our water supply.

CPC seasonal drought outlook (NOAA)

Speaking of hurricanes the seasonal forecasts are out and by all reputable accounts we are in for a "down" season.

NOAA, Colorado State, and Weather Channel predictions (image Weather Channel twitter)

 While this appears to be good news the truth is it does not mean much unless you are someone like me who gets excited to track a tropical storm near the Canary Islands.  Given that our already quite low to impacted by a tropical system a down season does not do much to decrease ours odds.  In fact in 1991 which was a down year Hurricane Bob blasted SE New England and the perfect storm battered the coast late in the season.    The reason for the down forecasts? Perhaps you have heard of El Nino.

OSPO Sea Surface Temperature Anomaly 5.28.15

This is a sea surface anomaly chart.  Please notice the red/orange along the equator in the Pacific Ocean near Central and South America.  This is abnormal as usually the warmest water relative to average in the pacific is in the Western Pacific.  Basically trade winds blow east to west across the Pacific.  There are two ocean currents, one on each side of the equator that also flow east to west.  As these currents move west they are heated by the sun and tend to pool water in the West Pacific.   For comparison here is 2013, a "neutral" year

OSPO Sea Surface Temperature Anomaly 5.30.2013

Along the equator there is a weaker current that moves west to east.  At times this current becomes stronger as the trade winds weaken.  The warm water sloshes back east and thus we have an El Nino.  Due to this constant wind the Western Pacific sea surface sits a few meters higher than the east.  This evens out during warm events.  But why does this cause a disruption to the Atlantic Hurricane season?  All the warm water in the eastern Pacific allows for favorable thunderstorm growth in that region.  With all the rising air there it creates a ripple effect of stronger than normal winds in the eastern Atlantic and higher pressures than normal in the Caribbean Sea.  Those factors suppress thunderstorm development.

 WHAT DOES IT ALL MEAN?
It means that we are looking at a warm dry summer!  That's what the odds say.  Every El Nino behaves differently.  A particular interest of mine in college was how El Nino and La Nina's behave.  In 2009
the Pacific was also bringing on an El Nino event.  The summer of 09 was horrible in New England; rain and cool.   The oceans and atmosphere are different this time around so if you work in an industry that is dependent on water be aware that this will likely get worse before it gets better.

Have a good weekend and thanks for reading

-Zack

UPDATE 12 PM- Severe Thunderstorms Possible Today

 As anticipated, the Storm Prediction Center in Norman, OK (SPC) has issued a Severe Thunderstorm Watch for most of New England (and parts of NY, NJ)

SPC Severe Thunderstorm Watch 233, valid uptil 7 PM EST

 The Southern New England radar is quiet for now

NWS Boston radar 1130 am

But to the northwest storm coverage is increasing.  Nothing is severe...yet

NWS Burlington radar 1202 pm

With temperatures expected to max in the mid to upper 80s and clear skies

GOES-EAST visible satellite 1115 am (NOAA)

I feel scattered thunderstorms will develop.  Boston-Worcester-Hartford north and west has the greatest chance to see a severe storm, though the Blackstone Valley and Eastern CT are not out of the woods.  Keep an eye on weather.gov/box or NWSBoston on twitter for severe thunderstorm warnings.  Facebook is not reliable during severe weather.

-Zack

PREVIOUS DISCUSSION BELOW


Welcome back to the blog.  A severe thunderstorm watch was issued for the northwestern half of New England yesterday.  The primary hazard was wind and this verified

5/27/15 preliminary storm reports

Offshore high pressure has introduced a southwesterly wind in Southern New England.  With this comes warm and humid temperatures.  Dew points are already in the mid 60's

11z HRRR 2 m dew points valid 8 am (image weatherbell)

All our atmosphere needs is a trigger with heat and humidity already in place.  As we look at the surface chart we see our trigger moving through the Great Lakes

WPC 5 am surface analysis

This is not the main front but rather a trough in the upper air pattern.

06z NAM 500 mb vorticity valid 11 am (image NCEP)

This mean that we will stay in the warm in muggy pattern until the main cold front can sweep through the area Sunday or Monday.  Today highs will climb into the mid 80's

11z HRRR 2 m temps 2 PM (image weatherbell)

The storm prediction center (SPC) has most of New England at risk for severe thunderstorms.Yellow indicates scattered severe storms possible, green indicates isolated severe storms possible.

SPC day 1 severe weather outlook

The greatest threat other than heavy downpours and dangerous cloud to ground lightning will be the possibility of wind damage

SPC day 1 severe wind outlook

Small hail will be possible in the strongest cells.  Storms will fire around 12-1 PM out west and to the north.  They will move east throughout the afternoon most likely screwing up the evening commute.

11z HRRR simulated radar coverage 1 PM (image weatherbell)

By 4 PM solid coverage from Maine to SW CT is likely

11z HRRR simulated radar coverage 4 PM (image weatherbell)

I will update this post when any severe weather watches are posted.

-Zack