Winter Storm Stella Set To Deliver Blow To Region

Winter Storm Stella will come together off the Mid-Atlantic coast on Monday and she will deliver a quick hitting strike that will drop over a foot of snow for much of Southern New England.  Snow will begin between 5-7 AM and will continue until late Tuesday evening.  Winds will be very strong on Tuesday and as a result, a *Blizzard Watch* has been issued for parts of the region.  A *Winter Storm Watch* is up for much of the rest of SNE.

NWS Boston AM Headlines 

After reviewing the latest data, I think the blizzard watches may be expanded west to Providence and Worcester and east to include Martha's Vineyard and the Lower Cape.    The dominant feature that will contribute to the coastal development of Stella is moving across the Great Plains today.  IL/IN/OH are all expecting 4-8" of snow as the feature progresses east the next 24-36 hours.

NWS/NOAA/NCEP GOES Water Vapor Satellite 1115 AM

The energy moving off the Carolina coast dropped a bit of snow in the South this morning.  It was nothing major but it's clear that air mass preceding Stella is incredibly cold for March.  Temperatures at 12 PM are in the 20's still for much of the northern 1/3 of the country.

15z HRRR 2 m temps Sunday 12 PM (image Weatherbell)

Temperatures tonight will fall to the upper single digits/low teens.  It will be a little warmer tomorrow when compared to the past few days.  Max temps will rise into the low to mid 30's.  Winds will be light and skies will be sunny tomorrow.  Even a light wind at the bus stop tomorrow morning will give wind chills around 0.  This all sets the stage for Stella.  Here is the forecast surface map tomorrow at 8 PM.

WPC Surface Fronts/Precipitation Monday 8 PM

Snow flies after 3 AM in Western New England and it flies in Central/Eastern Southern New England around 5 AM.  Once it hits it will stick.  This is not like last Friday when the snow did not stick to the roads. The cold this weekend will allow for snow to stick to all surfaces immediately.

12z NAM hires 3 km Simulated Radar Tuesday 5 AM (image Weatherbell)

The worst of the storm is from Tuesday 7 AM to 5 PM.  Winds will gust 40-50 mph while heavy snow falls.   Temperatures will be in the low 20's when the snow begins.  Temps should rise to near 30 by Tuesday afternoon, before falling back into the low 20's.

WPC Surface Fronts/Precipitation Tuesday 8 AM

The center of the storm is forecast to cross near Nantucket.  If the track is a little further offshore, higher snow totals will verify in SE MA.  One signal that is really jumping out to me is the potential for extremely heavy snowfall Tuesday AM.  The commute will be nearly impossible in Southern New England if this is to verify.  Some guidance is suggesting 4-6" of snow by 8 AM in the Blackstone Valley (also most of Metrowest and SE MA).  By 11 AM we are over a foot!  Do the math- it will be snowing at of rates of 2"/hr.

12z NAM 3km sim radar Tuesday 9 AM (image Weatherbell)

The storm will thump all morning and into early afternoon before the intensity begins to wane.  That mix line is very important along the south coast.  It will push inland; how far is the question.  I don't see it getting past Plymouth/Providence.  Tuesday night there will be some backlash snow, but the intensity of this remains in question.  It will likely to be hard to tell at times if snow is falling or blowing Tuesday evening into Wednesday AM, however.

NWS Boston Snowfall Forecast Tuesday-Wednesday

Please don't get too excited about the 18". I think many towns will check in the 12-14" range and a few will be 16-20".  That's something to fine tune as Stella approaches.  The incredible intensity of the initial snow burst will introduce a huge bust potential into the snow totals.  If you miss that band you may miss the high range.   I will post again tomorrow AM with updates to timing, totals, and watches/warnings.  I also think Stella has a surprise or two up her sleeve.

PS- Since everyone is probably heading to the store today/tomorrow, why not pick up some Stella's in honor of the storm?  If you are in that sort of thing, that is.

Alibaba.com

If you went to the store yesterday,

-Zack Green

You Didn't Really Think Winter Was Over, Did You?

When temperatures spiked to 73 in February, did anyone actually believe winter was over?  Oh, you did?  Ha!

A major winter storm will impact the region beginning Tuesday morning.  Confidence in a storm is high but the ultimate track is still being worked out.  There is a high probability of double-digit snow totals for everyone except South Coastal New England.  The final track will likely bring some mixed precipitation/rain to these areas.    They hit the jackpot yesterday as many locations near the South Coast and over to the Cape and Islands reported over 6" snow Friday.  A full list can be found here.

NWS Boston Observed Snow Totals 

Temperatures this morning bottomed out at 6 in Worcester, 10 in Boston and Hartford, and 14 in Providence.  These fall short of record territory but they will set the stage for potentially the lowest high temperature on record for the date.

Current forecasts do indeed break or tie the low max temperatures today.  Worcester will struggle to get back to 15-16 while Boston should get into the low 20's, but no higher than 22.

NWS Max temp forecast Saturday.  Potential record low max temps circled (image Weatherbell)

 One does not need to be a meteorologist to know that it is nasty outside today.  The winds are howling out of the Northwest making a mess of the snow that did fall yesterday.  Wind chills are forecast to remain below zero most of the day.  A *Wind Chill Advisory* has been posted for Northern Worcester County until 10 AM.  A wind advisory may go up this afternoon for wind gusts over 40 MPH.

NWS Saturday AM Headlines

Low temperatures tonight will fall into the single digits.  Worcester and Providence are currently forecast to break/tie their record low temps for the date.  The wind should lessen a little tonight but it will still be very cold.

NWS min temperature forecast Sunday.  Potential record low temps circled (image Weatherbell)

Now let's turn our focus to the real reason you are here for this blog.

Medium Range Forecast
Here is the forecast surface map tomorrow at 8 AM.  Notice the dome of high pressure in Central Canada, the storm coming through the Northern Rockies, and the mess along the Gulf Coast.

WPC Surface Fronts/Precipitation Sunday 8 AM

While high temperatures remain in the 20's in Southern New England tomorrow, the Southern and Northern branches of the jet stream will send energy on a journey that is destined to meet up near the East Coast.  At 8 PM tomorrow night the upper air chart does not look all that impressive.

00z ECMWF 500 mb height anomaly Sunday 8 PM (image Weatherbell)

You'll have to look closely, but there is a notch of upper atmosphere tracking through the Dakota's and another just to the east of Florida.  By Monday morning there will be snow across Illinois and Indiana spreading east into the Ohio Valley.

WPC Surface Fronts/Precipitation Monday 8 AM

By Tuesday AM the energy will combine off the Mid-Atlantic coast forming a large and powerful Nor'easter.  A new upper atmospheric low will close off in the Great Lakes, effectively capturing the new surface low that develops near the Delmarva.

00z ECMWF 500 mb height anomaly Tuesday 8 AM (image Weatherbell)

Here what this looks like at the surface (500 mb is about 18k ft).

WPC Surface Fronts Tuesday 8 AM

As we enter the middle of March, the sun angle plays a big role in accumulation.  This storm is strong enough to overcome the physical limitations that are naturally placed a Spring snowstorm.  That said temperatures in SE MA will be near freezing.  That means some sleet/rain can mix in for a time.  Temperatures look to be in the upper 20's once you get into Central/Western Southern New England.

I'm still working on snow totals, I'll have something out tomorrow.  But you can probably imagine what a major nor'easter that is pretty much all snow will deliver.  Tomorrow I may declare this a "Bread, Milk, and Alcohol" type snowstorm.  If you plow, get ready for a long shift.  If you teach. have a backup plan for Tuesday/Wednesday lesson plans.

So yeah, winter is not over.

- I don't think this is likey, but I can't ignore what some of the computer guidance is suggesting today.  A track over Southern New England would deliver something like this

Friday AM Update

Snow is filling in South of the MA Pike already.  It has yet to stick to the main roads in here in the Blackstone Valley and it may struggle to accumulate on the main roads after dawn thanks to the recent warm temperatures and the high March sun angle.  As of 540 AM

NWS Southern New England Radar 540 AM (image Weatherbell)

The low is still developing over Maryland and Virginia.  The boundary the low will move across is already well established south of New England.

WPC Northeast Surface Analysis Friday 4 AM

The water vapor satellite confirms the easterly movement of this system.  It also shows just how quickly the low will scoot out to sea.  Also, notice the dig coming through the Great Lakes.  There is some potent Arctic air behind it.

NWS/NOAA/NCEP GOES Water Vapor Satellite 415 AM

By 11 AM light to moderate snow will be falling across Southern New England.  The best snow zone will shift from south of the MA Pike to RI/SE MA as the day wears on.

09z HRRR Simulated Radar Friday 11 AM (image Weatherbell)

By 3 PM the snow shield will be more blotchy as the low center pulls away.

09z HRRR Simulated Radar Friday 3 PM

Temperatures this morning begin in the mid to upper 20's but they will rise into the low 30's this afternoon.  However, temps by 10 PM are in the mid 20's again and falling fast.

09z HRRR 2 m temperatures Friday 10 PM (image Weatherbell)

The Arctic boundary will sag across SNE around 1 AM.

WPC Surface Fronts/Precipitation Saturday 1 AM

We are on our way to the single digits.

NWS min temp forecast Saturday AM (image Weatherbell)

The latest high-resolution model is printing out these snow totals over the next 18 hours.  This is a general 3-5", even in NE MA where winter weather advisories should probably be posted.

09z HRRR 18 hour total snowfall accumulations (image Weatherbell)

Now we get to work on this potential beast on Tuesday.

WPC Surface Fronts Tuesday 7 AM

Time to hit the textbook this weekend to study up on past March snowstorms.

The bible for Northeast winter weather

-Zack Green

Light to Moderate Snow Event Tomorrow

(I am going to take this one storm at a time.  It appears a major get the bread and milk winter storm is on its way Tuesday-Wednesday next week.  I'll post on that event tomorrow.  At 120 hours out there is still plenty of time to monitor.) - Zack Green

A wave of low pressure riding along a frontal boundary south of New England will develop a snow shield as it passes the region Friday AM.  Snow will begin before dawn and will taper off in the early afternoon.  Generally speaking, a coating to an inch is possible along and north the MA Pike while 1-3" south of the Pike in Hampden, Worcester, and Norfolk counties.  4-8" will fall in RI and SE MA with perhaps locally higher amounts on the Cape.  Potentially historic cold arrives this weekend.

General Overview

The NWS has issued a *Winter Storm Warning* in pink and a *Winter Weather Advisory* in light purple.  

NWS PM Headlines 

A piece of mid-atmospheric energy is tracking through the upper Midwest.  A surface low will form near the Mid-Atlantic coast tonight.  

WPC Surface Fronts/Precipitation Friday 1 AM

As an aside the strength of the high pressure dropping into the States is impressive.  Snow will begin to stick to grassy surfaces around 5-6 AM.  Here is the future radar for 5 AM tomorrow.

20z HRRR Simulated Radar Friday 5 AM (image Weatherbell)

There will be 1" or less at 7 AM.  Snow should pick up after 8 AM.  The snow is gone early Friday PM as the low races out to sea.  Snow will linger in South Coastal MA.

WPC Surface Fronts/Precipitation Friday 1 PM

The snow gradient is tight tomorrow but radar trends in the morning will tell us whether or not the snow shield is further north (south) than anticipated.  

NWS Most Likely Snowfall

Temperatures will rise into the low 30's tomorrow afternoon before crashing into the single digits by Saturday AM.  Talk to you in the AM.

What's Up, Winter

So far March has been a bit up and down when it comes to temperatures.  Last year the temperature spiked to 77 in Boston on this date while in 2005 the max temp stalled at 24.  In 2007 the low temperature was 5.  Today will be near normal temperature-wise but gusty westerly winds will make it feel colder than it actually is.  The NWS has issued a *Wind Advisory* until 4 PM for sustained winds 20-30 MPH with gusts 40-50 MPH.

NWS AM Headlines

You may be drawn to the *Winter Storm Warning* on the Cape/Islands or the *Winter Weather Advisory* in CT, S Worcester, and Norfolk counties There is a *Winter Storm Watch* in SE MA and RI..  Skies will be mostly sunny today with wind chills in the upper 20's/low 30's.  When the wind is calm it will feel nice because the March sun angle gets higher and higher every day.

WPC Surface Fronts/Precipitation Thursday 7 PM

A front will pass through New England today which will help enhance the wind threat.  This boundary will stall across the Mid-Atlantic, south of Long Island.  Low pressure will ride along the boundary developing a little bit as it reaches the Atlantic.  Snow will break out along the South Coast after 2 AM.  It will reach Southern Worcester County and most regions south of the Pike around 530-6 AM.

06z NAM hires 3 km sim radar Friday 7 AM (image Weatherbell)

It snows steadily until early afternoon.  Snow is gone from the Worcester area around 2 PM, Boston 3 PM, and the Cape and Islands by 5 PM.    Total snow looks like 1-3" from Springfield to Worcester to Boston down to the South MA/RI/CT border.  3-6" in CT, RI and SE MA down to about Middleboro and Taunton and 6-10" across S coastal RI and the Cape and Islands.

NWS Total Snowfall Forecast Through Saturday 7 AM (image Weatherbell)

This whole system has been trending north and higher snow totals so I will issue a PM update tonight.  Temperatures tomorrow are in the low 30's with winds shifting from the Northeast to Northwest at 5-10 MPH.  An Arctic cold front will cross the region tomorrow night.  Another round of snow squalls will be possible.

WPC Surface Fronts/Precipitation Friday 7 PM 

This incoming air mass will deliver mid-winter cold, much like last weekend.  We may again be in record-breaking territory.  Here is the origin of that air mass. 

Another snow threat is developing for Tuesday of next week, but we have plenty of time to watch that one.

-Zack Green

Rain Showers Through Wednesday AM

A massive storm is moving through the Upper Plains into Manitoba.  Warm, moist air is streaming into Southern New England as a result.  The next 24 hours will be wet and/or mild before a return to more winter-like temperatures.

NWS/NOAA/NCEP GOES_Composite Water Vapor Satellite through 515 AM

Although not as large as last week, this system has produced another round of severe weather in the Midwest.  Here is the northeast regional radar loop this AM.  Temps are near freezing north of the MA Pike in the highest elevations so please exercise caution on the roads this AM.

NWS Northeast Regional Radar 548 AM

There is still a lot of dry air in Southern New England so this precipitation is having a difficult time reaching the ground.  Dew points are still in the mid to upper 20's.  Later this afternoon these will rise into the 40's by this evening and into the 50's before the frontal passage tomorrow.  At 1 PM this afternoon the front will be advancing to the east.

WPC Surface Fronts/Precipitation Tuesday 1 PM

Now despite being in the "warm sector", gray skies and off/on rain showers will keep max temperatures in the 40's today.

NWS Max temps Tuesday (image Weatherbell)

Winds are out of the south today 5-10 MPH with gusts up to 20 MPH.  A gradual wind shift is likely to occur overnight first to the southwest and then to the west as the system pushes towards the Atlantic.  A lull in the precipitation as the warm front lifts through will occur this evening, followed by more showers as the actual front passes.  By 7 AM the cold front is nearly offshore.

WPC Surface Fronts/Precipitation Wednesday 7 AM

Although cooling will occur tomorrow afternoon, some sunshine and gusty winds in the late AM/early PM will allow temps to soar into the low to mid 50's.

NWS Max temperatures Wednesday (image Weatherbell)

Near record, Arctic cold returns this weekend.  There will be a few snow chances but the strength of the Arctic air may be so great that the storms pass well to our south.  First chance Friday, second chance Sunday.

-Zack Green

The True Roar Will Be Tomorrow

A nice looking thunderstorm moved across South Coastal New England late this morning and early this afternoon.  I think this will be as good as it gets in Southern New England.  Computer guidance is forecasting a few showers as a strong cold front crosses the region overnight.  It is already windy right now but behind the front, the true lion arrives with wind gusts up to 60 MPH on Thursday.

NWS NEXRAD radar 1140 AM (image NOAA)

The lunchtime rain only made it to about the MA Pike (a few showers north of Worcester).  The current Northeast Regional Radar shows action in Eastern NY moving into Western New England as of 3 PM.  This rain will track east so a few more showers are possible through the evening commute, but it is fading fast.

NWS Northeast Regional Radar Loop

Temperatures are not at record levels in Boston, Worcester, Providence, and Hartford.  That said temps have peaked at 65 in Fitchburg and Lawrence so some parts of the region are warm.  It's only in the 40's on the Cape/Islands.  The rest of us are in the 50's.  To our southwest is where one can find the true spring warmth.

19z HRRR 2 m temps 2 PM (image Weatherbell)

Much cooler air in Canada will slowly make its way to Southern New England.  Temperatures will fall into the mid 30's by dinner time Thursday.  So to get there, we see isolated showers tonight.  By 1 AM the cold front should be crossing SNE.

WPC Surface Fronts/Precipitation Thursday 1 AM

Low pressure entering Quebec is strengthening while high pressure in Central Canada that is descending towards the Upper Midwest.  This is beginning to create the pressure gradient that will deliver strong winds tomorrow.  Some leftover showers will be around in the early AM hours.  Here is the future radar for 4 AM.

18z HRRR simulated radar Thursday 4 AM (image Weatherbell)

At 7 AM, a *High Wind Warning* will go in effect for sustained winds greater than 40 MPH and gusts greater than 58 MPH.  While we may not verify that criteria, it will be close and because of that tree and power line damage is possible.  The ground is rather soft thanks to the snowmelt and recent rains which make uprooted trees more likely.

NWS PM Headlines

The winds will be strongest between dawn and 3 PM.

WPC Surface Fronts/Precipitation Thursday 1 PM

The low departs later Thursday afternoon so the winds die down tomorrow night.  We then come under the influence of a cold Arctic high and a cold winter air mass.  It will feel like winter again on tomorrow and Friday.  A low will pass to our south Friday so we should avoid snow.  The true cold does not arrive until Friday night.  Saturday would not be out of place in mid-January.

-Zack Green