Member snowfall maps for 12/26/10 storm

[weatherwiz]

I figure instead of clogging the main threads will maps and all we can just place our maps.discussion here and if people have questions or want to say good luck or whatever it can be done here.

[weatherwiz]

Well folks after an incredible start to the winter season in the snowfall department it looks like we will catch up real quick as a very intense coastal storm will impact the region beginning sometime late Sunday morning/early afternoon and lasting through the first part of Monday. This storm will bring lots of snow to the region as well as some VERY strong winds. We can also expect coastal flooding as well. There is alot to cover and still some uncertainties as to where the heaviest snowfall will occur as well as the strongest winds but this should be worked out by tonight or tomorrow morning. There is alot to cover here so let's get into it.

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Technical discussion:

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A weak mid-level disturbance is moving through the Ohio Valley region and is expected to move somewhat southeastward towards the gulf coast states, at the same time an upper level disturbance is moving along the gulf coast states. Sometime this evening these two systems will begin to phase and once this occurs we will begin to see rapid cyclogeneis begin to occur just off the Carolina coast-line. A very strongly negatively tilted trough will lead to further intensification and also allow the developing system to stay further tucked towards the US coast and ride up along the coast towards New England. As this occurs the system is forecasted to continue rapidly deepening all the way to the 40/70 benchmark.

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Over the past several days we have seen tons of model inconsistencies and disagreements, however, this has all changed over the course of the last 24 hours, model consensus is now showing a direct impact to portions of the region with heavy snowfall and very strong winds.

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Right now it's looking very likely that the storm will track close enough to the coast to where most of us see heavy snowfall at some point during the storm, in fact the system may track so close that locations out in the Cape and back a bit further into eastern MA may possibly mix with sleet or even change to rain.

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Forecast:

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Still some details to be ironed out as to where the heaviest snowfall will occur and where the strongest banding will setup but right now I am leaning towards this occurring out across parts of central/eastern MA down into portions of N. RI. Anyone who is exposed to these bands will see periods of extremely heavy snowfall with snowfall rates possibly as high as 2-3'' per hour. Now it's still possible that this banding could set up a further west than what I have highlighted and trends for this will have to be monitored over the course of the next 18 hours.

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Parts of MA (Springfield area) down through portions of CT into Hartford/Tolland counties may experience a bit less in the way of snowfall. Some models suggest that there may be some issues with downslopping which could significantly cut back on the amount of QPF which in turn would decrease the potential snowfall totals. A scenario like this is fairly common for this location and unless the banding mentioned above is further west into these areas downslopping may be an issue, with this I expect totals to be a bit less in this highlighted area (the 5-9'' contour).

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Back across western MA down through western CT looks to be a secondary max of QPF, thus higher snowfall totals can be expected here. All models are showing some pretty high QPF totals to go along with some very high omega values and great snow growth. As much as 8-14'' can be expected although some isolated higher amounts are certainly possible as well.

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Out across the Cape area it appears there will be some mixing issues and some rain issues, therefore, totals out here will be significantly less than the rest of the region.

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The next issue that we will have to contend with are the winds, there is potential to see some pretty serious wind gusts during the height of the storm as a very strong and intense pressure gradient sets up over the region. Winds could potentially gusts as high as 50 mph across much of the region with some isolated gusts up to 60-65 mph, winds this strong coupled with snow falling will make for blizzard conditions and it's becoming rather likely that as good part of the region will see a blizzard. Winds this strong normally lead to downed trees and power lines leading to power issues, this may be enhanced due to the fact that there will be snow falling and sticking. Now this doesn't appear to be a heavy, wet snow, although the further east you go the snow will become a bit more heavier but this could lead to some widespread power outages across the region. This will certainly have to be watched and monitored over the next day.

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With the strong winds and strong coastal storm the threat for coastal flooding will certainly be an issue as well which could be a problem for those living along the coast, waves could be very high as well.

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This is not a final forecast as some details still need to be ironed out and totals could certainly change. Next forecast will be out sometime around 1 AM tomorrow morning.

[OKpowdah]

So ... no snow outside of MA, CT, and RI

[weatherwiz]

So ... no snow outside of MA, CT, and RI

My focus is just on these three states lol.

[OKpowdah]

In all seriousness, great discussion, and your map makes pretty good sense!

... still confused about the sharp cutoff to the west and north though okay, I'll stop

Merry Christmas Paul

[weatherwiz]

In all seriousness, great discussion, and your map makes pretty good sense!

... still confused about the sharp cutoff to the west and north though okay, I'll stop

Merry Christmas Paul

I definitely left soom room in there to potentially bump up totals a bit more, especially around the CEF/HFD area but the potential for downslopping is a concern for me.

Merry Christmas to you as well

[weatherwiz]

With the 18z runs if the 0z runs are THIS wet I'll certainly have to up my totals in CT.

[CCPSUSuperstorm2010]

Major Nor'easter to impact SNE with blizzard conditions over central and western areas, with rain/snow mix expected at the immediate coastline. Expect totals to exceed 2'+ in the black zone. This is a very dangerous snowstorm, travel will be greatly impacted, shut down of major state highways and airports is expected by Sunday evening/Monday morning. Closest passage of the surface low to cape cod will likely turn the snow over to rain, but not before heavy snow accumulates at least 6" as intense lifting and convective parameters offset initial temperature issues in the boundary layer. Someone will likely pick up between 30-40" of snow. Surface analysis shows that the low over the GOM is initially stronger then modeled as of 18z today. This will be an extremely impactful storm system, coastal flooding is expected to become a major concern, especially NE facing beaches.

Please take this storm seriously, this is not a joke, modeled QPF is useless now, just watch this storm unfold. Thundersnows will be likely, especially over eastern SNE before any changeover can occur.

[wiley1]

Major Nor'easter to impact SNE with blizzard conditions over central and western areas, with rain/snow mix expected at the immediate coastline. Expect totals to exceed 2'+ in the black zone. This is a very dangerous snowstorm, travel will be greatly impacted, shut down of major state highways and airports is expected by Sunday evening/Monday morning. Closest passage of the surface low to cape cod will likely turn the snow over to rain, but not before heavy snow accumulates at least 6" as intense lifting and convective parameters offset initial temperature issues in the boundary layer. Someone will likely pick up between 30-40" of snow. Surface analysis shows that the low over the GOM is initially stronger then modeled as of 18z today. This will be an extremely impactful storm system, coastal flooding is expected to become a major concern, especially NE facing beaches.

Please take this storm seriously, this is not a joke, modeled QPF is useless now, just watch this storm unfold. Thundersnows will be likely, especially over eastern SNE before any changeover can occur.

Wow that would be something along the lines of the 1978 storm coastal flooding and all I hope its not that bad especially with all the holiday travellers on the road.

[blizzard00]

this is what i'm thinking

[Tolland Death Band]

this is what i'm thinking

Heavy heavy banding along I-84. NICE!

[CCPSUSuperstorm2010]

Final issuance of my snowfall map, vaild 12z Sunday through 00z Tuesday

I decided to scale back the eastern sections some, including Cape Cod, MA as mixing will become a great issue to deal with. Track still looks good, weakened the pressure for its closest passage to our south, major coastal flooding issues for the Monday morning high tide is probably. High wind warning is in effect for the Cape and Islands, including BID. Coastal flood watch and winter storm watch is up for Barnstable as well given uncertainty of potential mixing.

[weatherwiz]

My final call:

While there are still a few model runs to go from what I have seen transpire over the past several hours I feel confident enough to vastly up my totals across a large chunk of the area. Computer models continue to indicate that a major blizzard is going to impact the region beginning as early as mid morning tomorrow and lasting through perhaps as late as midday Monday.

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The height of the storm is projected to occur during the late evening through the overnight hours into Monday. During this timeframe the heaviest snowfall is expected, possibly exceeding 3-4'' per hours where the strongest banding sets itself up. This is when the winds will be the strongest as well which will create blizzard conditions across much of the region. Winds are expected to gust up to 50 mph with isolated gusts in the 60-65 mph range. Winds of that strength coupled with accumulating snow on trees and power lines will yield to some pockets of tree damage and power outages.

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There is also potential for pockets of embedded thunderstorms, or in this case thundersnow which would heavily increase the probabilities of very strong/damaging winds reaching the surface as well as causing intense snowfall rates of up to 3-4''/hr.

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Due to a very intense possibly sub-970mb low just off the coast near the 40/70 benchmark, high tides occurring during the night, and very strong winds the potential for some serious coastal flooding exists as well, so anyone living near the coastline and exposed to the waters should certainly monitor for this possibility.

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This certainly looks as if it will be one of the biggest storm to impact such a widespread area in over several years, possibly since 2005.

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Below is my final call:

[Quincy]

going with a generalized 8-14 inch snowfall, although 14"+ is likely in the heavier bands and climotologically favored areas. was tempted to go a bit higher, but it's going to come down to banding and ratios, both of which won't be easy to pinpoint.

[40/70 Benchmark]

Major Nor'easter to impact SNE with blizzard conditions over central and western areas, with rain/snow mix expected at the immediate coastline. Expect totals to exceed 2'+ in the black zone. This is a very dangerous snowstorm, travel will be greatly impacted, shut down of major state highways and airports is expected by Sunday evening/Monday morning. Closest passage of the surface low to cape cod will likely turn the snow over to rain, but not before heavy snow accumulates at least 6" as intense lifting and convective parameters offset initial temperature issues in the boundary layer. Someone will likely pick up between 30-40" of snow. Surface analysis shows that the low over the GOM is initially stronger then modeled as of 18z today. This will be an extremely impactful storm system, coastal flooding is expected to become a major concern, especially NE facing beaches.

Please take this storm seriously, this is not a joke, modeled QPF is useless now, just watch this storm unfold. Thundersnows will be likely, especially over eastern SNE before any changeover can occur.

:weenie: :weenie:

[free_man]

Major Nor'easter to impact SNE with blizzard conditions over central and western areas, with rain/snow mix expected at the immediate coastline. Expect totals to exceed 2'+ in the black zone. This is a very dangerous snowstorm, travel will be greatly impacted, shut down of major state highways and airports is expected by Sunday evening/Monday morning. Closest passage of the surface low to cape cod will likely turn the snow over to rain, but not before heavy snow accumulates at least 6" as intense lifting and convective parameters offset initial temperature issues in the boundary layer. Someone will likely pick up between 30-40" of snow. Surface analysis shows that the low over the GOM is initially stronger then modeled as of 18z today. This will be an extremely impactful storm system, coastal flooding is expected to become a major concern, especially NE facing beaches.

Please take this storm seriously, this is not a joke, modeled QPF is useless now, just watch this storm unfold. Thundersnows will be likely, especially over eastern SNE before any changeover can occur.

We're all gonna die.