ThanksgivingNorEaster2914

Final for this Storm:

Shrewsbury received 6.2″ of snow/IP

Steve

ThanksgivingNorEaster2914

Bullseye for Shrewsbury, MA

— Winter Storm Warning in effect until 7 AM Tomorrow —

Shrewsbury Area Weather for Today, 11/26/2014 (see disclaimer at bottom)…
0700 11/25 fcst

Today (Wednesday)
Dew Point ~29°F, High T ~39°F, Low T ~30°F, Winds N @ 4 – 10 MPH Gusting to ~20 MPH
Precip: Rain/Mixed Precip ~8:00 AM; Heavy Snow ~10 AM to ~3PM; Mixed Precip ~3PM to ~8PM; Snow ~8PM to 3AM

Tomorrow (Thanksgiving)
Dew Point ~26°F, High T ~34°F, Low T ~25°F, Winds N – WNW @ 2 – 10 MPH Gusting to ~20 MPH
Precip: Chance of flurries throughout the day

Total Snow Accumulation: ~4.5″ to ~6.8″, higher totals at higher elevations (up to ~10″ possible)

Details:
As you can see, I have decreased the total totals for snow accumulation, however this precip profile is actually worse for travel…

Precip will arrive a bit later than originally anticipated a couple of days ago, and will be a rain/mix. We will have a very abrupt changeover to snow with heavy snowfall rates mid-morning. This is because the precip will entrain cold air from aloft and pull it right down to ground level. (In other words, the precip will be falling uninterrupted as it changes from rain to snow – expect roads to be difficult when the changeover takes place.) Snow will continue until the coastal front moves in from the west and crosses/stalls over our area and delvers a mix of sleet/ice pellets and freezing rain. Later in the evening, the coastal front will recede back towards Boston and we will finish up as snow.

SO, the storm track as moved west which give us a warmer solution. There was an indication last night from one model that suggest the warm air intrusion from the coastal front, and all the models picked up on it earlier this morning. So, we are in for a very messy early-season Nor’ Easter.

Numerous cancellations and early closures have already been announced, so plan accordingly. Be especially careful driving on secondary roads as the transition to snow will be abrupt and will result in slick driving conditions.

I will send another update this afternoon.

Happy Thanksgiving!

Steve
On Tue, Nov 25, 2014 at 8:27 PM, Stephen Daukas wrote:
— Winter Storm Warning in effect from 7 AM Tomorrow to 10 AM Thursday —

Shrewsbury Area Weather for 11/26/2014 (see disclaimer at bottom)…
2000 11/25 fcst

We are on track in terms of the Nor’Easter hitting the benchmark, but I am revising my QPF downward by a bit taking into account the shift in timing for the storm as well as a slower-than expected traverse of the cold front from the Great Lakes…

Total Snow Accumulation: ~5.6″ to ~7.0″ with higher amounts at higher elevations to our west.

Considering the warm air aloft in the middle atmosphere overnight, and the recent warm ground temps, I expect accumulations to begin ~9 AM with much less accumulation on paved surfaces. Secondary roads will experience accumulating snow starting ~Noon, with primary roads (highways) remaining mostly wet until ~2 PM…

Otherwise, the storm is basically on track… Heavy snow for tomorrow with basically a ~6″ son storm, followed by clear and cold conditions on Thanksgiving day.

Next update tomorrow morning.

Steve
On Tue, Nov 25, 2014 at 12:45 PM, Stephen Daukas wrote:
— Winter Storm Warning in effect 7 AM Wednesday to 10 AM Thursday —
— High Wind Watch for East Coast, Cape & Islands —

Shrewsbury Area Weather for 11/26/2014 (see disclaimer at bottom)…
1300 11/25 fcst

Tomorrow (Wednesday)
Dew Point ~29°F, High T ~35°F, Low T ~29°F, Winds W – N @ 3 – 7 MPH Gusting to ~20 MPH
Precip: Rain/Mixed Precip ~9 AM, Heavy Snow ~10 AM ending ~Midnight

Thursday (Thanksgiving)
Dew Point ~26°F, High T ~33°F, Low T ~25°F, Winds N – WNW @ 2 – 6 MPH Gusting to ~20 MPH
Precip: Snow Showers/Flurries early

Total Snow Accumulation: ~6.6″ to ~8.4″ with higher amounts possible and isolated areas of ~12″ possible

Details:
You can disregard my last update, it was based on bad data that essentially flipped the storm… So, rather than run everything remotely, I am at home in the DWC for lunch validating my forecast…

The above forecast is the correct forecast. There is a slight shift in timing to a later solution with rain transitioning to snow ~9:30 AM, followed by heavy snow. Otherwise, nothing else has changed…

I will send an updated forecast this evening…

Steve

On Tue, Nov 25, 2014 at 8:52 AM, Stephen Daukas wrote:
— Winter Storm Warning in effect from 7 AM Wednesday to 10 AM Thursday —

Shrewsbury Area Weather for 11/26/2014 (see disclaimer at bottom)…
0700 11/25 fcst

Tomorrow (Wednesday)
Dew Point ~29°F, High T ~35°F, Low T ~29°F, Winds W – N @ 3 – 7 MPH Gusting to ~20 MPH
Precip: Heavy Snow ~8 AM ending ~11 PM

Thursday (Thanksgiving)
Dew Point ~26°F, High T ~33°F, Low T ~25°F, Winds N – WNW @ 2 – 6 MPH Gusting to ~20 MPH
Precip: Snow Showers/Flurries linger until ~12 Noon

Total Snow Accumulation: ~6.6″ to ~8.4″ with higher amounts possible and isolated areas of ~12″ possible

Details:
Colder air will move into our area this afternoon and a coastal Low will develop off the Carolinas setting the stage for a Nor’ Easter tomorrow. The central Low of this system looks to make a direct hit on the 40/70 benchmark, which translates into plenty of snow for the greater Shrewsbury area…

I expect we will start off with some light rain/mixed precip ~4AM from the northernmost shield of the storm as it approaches from the south. Precip will changeover to light snow ~6AM. Then, the main event will take place with snow rapidly increasing after ~8 AM approaching rates of ~1″ per hour… Mesoscale snow banding is expected… Areas affected by banding will see snowfall rates approaching 2″ per hour with higher snow accumulations topping out at ~12″… Those ~12″ totals are more likely at higher elevations where banding occurs…

Winds will become backing from the NW which will setup a coastal front… Snow totals will fall off rapidly east of the Rt 128 corridor. A low-level jet streak will cross over RI and Cape Cod bringing winds in the vicinity of ~60 MPH to that general area during tomorrow afternoon into the late evening.

Expect a major impact to Thanksgiving travel plans. For those travelling by car, you should plan to arrive at your destination in this area by ~6 AM. Travel after that time becomes risky because of the rapid increase in snowfall rates. Travel after ~8 AM is not advised!

Expect numerous delays and cancellations tomorrow!

All in all, our first winter storm comes in earlier than is typical. While the details of the forecast are likely to change a bit over the next 12 hours, plan on a sizeable winter storm tomorrow and a white Thanksgiving!

I will send another update this evening…

Steve

On Mon, Nov 24, 2014 at 9:32 PM, Stephen Daukas wrote:
— Winter Storm Watch in effect from Wednesday morning through Thursday morning —

Shrewsbury Area Weather for 11/26/2014 (see disclaimer at bottom)…
2000 11/24 fcst

I am updating my forecast and taking a close look at the models as we speak…

I wanted to give everyone a heads-up that it looks like the central Low may will hit the 40/70 benchmark and we could well be looking at a Nor Easter with accumulations between ~6″ and ~12″ of snow on Wednesday, running from ~8 AM to ~8 PM, with lingering light snow into Thanksgiving…

I will be sending a full forecast tomorrow morning, and lets hope the storm track changes between now and then!

Steve

On Mon, Nov 24, 2014 at 8:59 AM, Stephen Daukas wrote:
— Winter Storm Watch in effect from Wednesday morning through Thursday morning —

Shrewsbury Area Weather for 11/26/2014 (see disclaimer at bottom)…
0600 11/24 fcst

Tomorrow (Tuesday)
Dew Point ~54°F down to 29°F, High T ~56°F, Low T ~37°F, Winds SW – W @ 3 – 10 MPH
Precip: None

Wednesday (Wednesday)
Dew Point ~29°F, High T ~35°F, Low T ~32°F, Winds W – NNE @ 3 – 10 MPH
Precip: Snow Possible…

Total Snow Accumulation: ~3″ to ~10″ (PRELIMINARY)

Thursday (Thanksgiving)
Dew Point ~27°F, High T ~35°F, Low T ~28°F, Winds NNE – W @ 3 – 7 MPH
Precip: Snow Showers/Flurries linger through the AM…
Details:
Models are having a hard time arriving at consensus on this storm’s track and, as we know, storm track determines temp profiles up though the atmosphere, which impacts how much precip as well as the type of precipitation, etc., etc. What follows is a best-guess based on available data as of early this morning…

Right now, the East-West extent of the storm track ranges from well to the East of Cape Cod and Nantucket to inland over Pennsylvania. This variance, as you might guess, brings in entirely different forecasts depending on where the track settles. Looks like we have a 70% probability of the main axis of precip from Shrewsbury to Hartford. However, the possible area of storm track does include the storm hitting the 40-70 benchmark (~100 miles off Nantucket), which would translate into a pretty big storm for our area.

My current QPF places us anywhere from ~3″ of snow to more than ~12″, although I do believe we will be closer to ~3″. Also, ground temps have remained warm so the amount of snow that falls does not equate to accumulation on the ground. It looks likely that areas west of I-95 will see mostly snow with most of the accumulation (possibly approaching ~6″) over the Worcester Hills and into northern CT. The timing of the storm looks to be between 10 Am and 8 PM, with lingering light snow into Thanksgiving morning.

Again, this is by no means a solid forecast. I’m anticipating higher confidence in my forecasts later tonight and tomorrow.

Bottom line: Prepare for a typical early-winter snow event. Get your shovels and snow blowers ready, top-off your windshield washer fluid and gas tanks, and try to travel on Tuesday to avoid whatever comes our way.

I will send an update forecast later today.

Disclaimer:
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. –