New Year's Total Snow

— Winter Storm Warning in Effect through 10 AM Tomorrow —
— Wind Chill Adviory in Effect until 11 AM Tomorrow —
— Blizzard Warning in effect for SE MA through 11 AM Tomorrow —
Shrewsbury Area Weather for New Year’s 2014 (see disclaimer at bottom)…
2100 1/2 fcst 
Snowfall at 9 PM: ~4.75″
Total Accumulation: ~10″ of Snow, higher amounts possible
The storm is progressing as expected, with the worst of the storm hitting south and east of our area.  The challenge of forecasting snow totals for this storm are the cold temps and the wind.  Frigid air increases the snow ratio dramatically…  At these temps, snow ratios could be 20:1 or 30:1 or even as high as 40:1, as opposed to our normal ratios around 10:1.  Wind is more of an obvious issue in general, more particularly with light snow, in that you have to find just the right location to measure to avoid measuring a blowout or a drift.
Measured amounts at my location (Shrewsbury Center) at 9 PM are running ~4.75″ so my earlier forecast for ~10.0″ of snow remains unchanged.
As noted in my previous forecast, the low temps, wind and blowing snow make this a dangerous storm.  You should avoid going out in this storm tonight and early tomorrow morning.  Expect a difficult commute tomorrow morning despite the numerous school and business closures.  Gov. Patrick has told non-emergency State employees to stay home tomorrow.  If you can, avoid travel tomorrow morning!
The good news is that the storm will shut down rapidly ~Noon.  The better news is that we will be pushing 40°F by the end of the weekend into Monday
I will send an update tomorrow morning.


On Thu, Jan 2, 2014 at 7:08 AM:

— Winter Storm Warning in Effect through 10 AM Tomorrow —
— Blizzard Warning in effect for SE MA through 11 AM Tomorrow —
Shrewsbury Area Weather for New Year’s 2014 (see disclaimer at bottom)…
0600 1/2 fcst 
Snowfall at 6 AM: ~1.0″
Total Accumulation: ~10″ of Snow, higher amounts possible
The DWC-MU1 (her newly adopted designator that she prefers to “she who must be obeyed”) reports that only a few major secondary roads have been plowed/treated at 05:30 this morning.  WIthout traffic, those road surfaces are still slick in spots for driving.  Snow hitting paved surfaces is sticking instantly due to the very cold temperatures, so treated/plowed surfaces will remain slick for the duration of this storm.  However, the majority of secondary roads have not yet been plowed/treated (especially in Worcester) and care should be taken when driving this morning…
Mid-level dry slot midday today looks to cap the potential accumulation of snow from this storm system for our area.  Accordingly, I have dropped my forecast totals by 1.0″ to ~10.0″.  This is a complex storm to forecast because pockets of higher amounts will take place, however the central Low for this storm will develop far enough out to sea such that the majority of snow will fall to our south and east…
The bullseye for this storm is south coastal zones where blizzard conditions are expected resulting from bombogenesis (rapid, deep intensification) of the Low as it passes southeast of the 40/70 benchmark…  Long Island, Cape Cod, and SE coastal MA are under a blizzard warning.
Temps are a major concern as windchill values will run approximately -15°F with steady winds running ~20 MPH accompanied by higher gusts.
There have already been multiple school closings for today and tomorrow, with additional business dismissals and closings expected.
This is a dangerous storm given single-digit temps, increasing winds, sub-zero wind chills, and the potential for a foot of snow.  If you have to drive during this storm, make sure you have a full tank of gas, shovel, blanket, etc., and dress for bitter cold.  Allow for plenty of extra time to reach your destination.  Continue to monitor weather reports as the snow totals could change during the day.  Tune your NOAA All Hazards Wx Radio (that you all have, of course) to Channel 7.  If you have a scanner or radio app for your smart phone and live in or near Worcester County, tune to 146.970 MHz for NWS SKYWARN reports.
I will send updates at the storm evolves.
On Wed, Jan 1, 2014 at 4:45 PM

— Winter Storm Warning in Effect through 10 AM Friday —
— Expect Additional Watches & Warnings to be Issued —
Shrewsbury Area Weather for New Year’s 2014 (see disclaimer at bottom)…
1600 1/1 fcst 
Total Accumulation: ~11″ of Snow
Warm air advection in advance of the main event will result in frontogenesis that will start delivering light snow ~midnight tonight between the I-90 and Rt. 2 corridors.  This light snow will continue throughout the day Thursday, slowly accumulating to a few inches just in time for the evening commute.  This accumulation will add to the snow from the main event resulting in storm totals approaching ~12″ for our area.  However (there is always a “however”), coastal zones to our E and SE will see significant enhancement from onshore winds delivering a possible additional ~4″ of snow inside I-495/I-95.  Since we are rather close to I-495, local pockets of higher snow totals for our area are possible.
Having said that, I am also looking at very inconsistent precip patterns with a lull in precip midway through the day Thursday and high-resolution models that have some annoying variability.  My excel-based model for forecasting snow runs from between 7.1″ and 15″ with some hourly rates varying by ~0.5″ or more.  My final numbers may have more variability than I like on an hourly basis, but overall numbers look reasonable because we have no issues with any warm air or mixed precip.  My forecast is for ~11.0″ of snow for this storm.
My hourly Breakdown:
Inline image 1
Here are a few frames from the short-range ensemble forecast that show the storm system coming together off the southern coast of Nantucket:
The first image shows the frontogenesis to the north of the main storm that will deliver light snow on Thursday.  The second shows the storm developing later on Thursday, and the third shows the storm intensifying before it is ejected into the Gulf of Maine later on Friday…
Inline image 2          Inline image 3Inline image 4
Expect a difficult commute and numerous early closings Thursday, followed by a difficult commute and numerous cancellations on Friday from this storm.  Because of the impact to travel, you should continue to monitor local weather outlets and tune your NOAA All Hazards Wx Radio to channel 7 for the the Shrewsbury area.  Also, be prepared for dangerous cold weather, especially on Friday when wind chills will be at or below zero.
I will continue to update my forecast and send updates as the storm develops.
On Tue, Dec 31, 2013 at 10:00 AM

Shrewsbury Area Weather for New Year’s 2014 (see disclaimer at bottom)…
0600 12/31 fcst 

New Year’s Eve (Today)
Dew Point ~14°F, High T ~25°F, Low T ~12°F, Winds WSW @ 5 – 13 MPH
Precip: Potential for some flurries

New Year’s Day
Dew Point ~14°F, High T ~24°F, Low T ~16°F, Winds W @ 4 – 12 MPH
Precip: None

Dew Point ~7°F, High T ~14°F, Low T ~3°F, Winds NNE @ 10 – 20 MPH
Precip: Snow
Dew Point ~-13°F, High T ~6°F, Low T ~-2°F, Winds NNW @ 20 – 10 MPH
Precip: Snow
Unlike the previous storm that left, when all the snow and rain was over, ~1″ of slush/concrete for folks to our north and west, this storm will be all snow, and it will be a “fluffy” snow.  The questions is how much…
It is still a bit too early to forecast specifics, but we are looking at a widespread ~6″ of snow with an upside of as many as ~12″ of snow.  Don’t let the higher numbers get you too excited…  The arctic air mass that will be emplaced by Thursday will make for high “snow ratios”, meaning a very light fluffy snow that will give higher accumulations than what is typical for our area.  The one problem is the frigid temps and snow combine to make driving difficult (as we saw in previous storms).
At the current time, the best interpolation of the models has the storm center trending to the SE of the 40/70 benchmark.  If that track holds, the heavier areas of snow will fall to our SE towards the Cape and Islands.  Other models track the storm closer to the benchmark, meaning more snow for our area.  (One models suggested more than 1 foot.)
The timing of the storm will begin with a precursor light snow that will begin ~Midnight Thursday and continue throughout the day making the evening commute difficult.  The snow will then intensify overnight and continue well into Friday as the storm proper arrives.
We are still ~72 hour out, so I will be updating my forecast later today and again tomorrow.  The models should settle down once we get inside the 36 hour window, but you should prepare for ~12″ of snow and expect a difficult commute and numerous early closings on Thursday, followed by a difficult commute and numerous cancellations on Friday from this storm.
My forecasts should not be used for anything other than general information.  You should not send my forecasts to others without this disclaimer attached  so that there is no chance of misinterpretation by others.  Thanks!Steve
– Civilization exists by geological consent, subject to change without notice. –