Are You Ready For a Snow Day?

Submitted by TheCloudBoy t3_118e2ux in newhampshire

As expected, our next winter storm Thursday is a mess both with forecast uncertainty & what falls from the sky. I've seen several atrocious maps floating around that were lazily created from a single model forecast, here's what to take away:

  1. A high impact winter storm is imminent Thursday for central & northern NH, particularly north of Concord. The majority of snow & sleet falls before the Thursday morning commute
  2. A band of heavy snow (1-2"/hour rates) is expected to set up across the Upper Valley & Lakes Region, though the exact north/south placement of this is still uncertain. Travel overnight under this band will become extremely hazardous.
  3. Warm air will punch in from the south, change snow to heavy sleet & freezing rain south of Concord, and drastically reduce snow totals. If this warm nose is very robust, this changeover likely occurs even further north into the Lakes Region.
  4. My snow forecast accounts for remaining uncertainty; a north/south shift of the warm front will have notable impacts for the Upper Merrimack Valley & Lakes Region.
  5. The majority of ski resorts will face issues with wind on Thursday as the approaching temperature inversion creates Bernoulli acceleration of low-level winds. Numerous lift holds and closures are possible.

https://preview.redd.it/q44ep1soklja1.png?width=1920&format=png&auto=webp&v=enabled&s=2e2adce1bc44210962bcef57d728025af269d04e

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Comments

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Emeleigh_Rose t1_j9gpycn wrote

Thanks for the update. I'm in the Lakes Region and hoping for a snow day.

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rmarkham t1_j9gq38s wrote

Commuting from Hooksett to Chelmsford between 6-7am on Thursday… would I be better off leaving earlier? Will it be bad or just wet?

Bless you cloudboy ❄️

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movdqa t1_j9h3tso wrote

I'm in southern NH and so I guess I can manage 1-2 inches.

I've lived in New England since the early 1960s so I should be able to handle anything that comes this week.

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ennature t1_j9h78en wrote

when I comb through the 2 weather apps and 2 weather bookmarks I use, this is all I'm really looking for. Thanks.

and a pre-thanks for the sailing winds forecasts this summer... ;)

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benduker7 t1_j9h79xf wrote

I moved out of NH a couple years ago to Maine, so I appreciate you making a forecast for more states now!

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Killbro_Fraggins t1_j9h855b wrote

Bring on the snow. I need school to get cancelled so I can get some time to deep clean class rooms.

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TheCloudBoy OP t1_j9h8bup wrote

Replying to ennature (#1,908,260)

I'm glad the post is useful! This is the serious drawback of weather apps, it's info (usually a garbage, single model forecast) compressed into a few numbers and icons. My company is working out ways to bridge this gap, seeing how folks on Reddit respond to posts like this is helping.

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TheCloudBoy OP t1_j9h8xcg wrote

Replying to rmarkham (#1,906,236)

If anything leave a few hours later if you can! I'm expecting sleet, freezing rain, and rain to dominate that stretch of roadway, so it'll be smart to give MassDOT extra time to treat roadways.

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jenkemeater619 t1_j9hcv4t wrote

Ugh, I was hoping for it to dump on Merrimack. Looks anticlimactic for us

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Cullen7777 t1_j9hf2ye wrote

What is the reason for lesser snow amounts over haverhill and littleton?

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doublejpee t1_j9hgh5w wrote

I have an 8am flight out of Boston on Thursday. This makes me extremely concerned. Probably a good idea to get to Boston tomorrow night and not chance it on Thursday morning, but do flights get canceled for the lesser amount of snow that Boston’s expecting?

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timecoyote t1_j9hix35 wrote

You're great Cloud Boy, but is there any way to make the map a little more clear for us colorblind folks?

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Y-DNA t1_j9hn2bl wrote

Awesome! Gotta catch a flight out of Logan at 7 am. A little concerned about driving down from the Seacoast.

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-RYknow t1_j9hnd1v wrote

Hope your right about 2-4 in Claremont. I'd take that over the foot + others are predicting.

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Scubakim13 t1_j9hru0c wrote

Cloudboy is loved by all. Thanks for the update! We are looking forward to it.

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Viking603 t1_j9hto8p wrote

We have whiskey and Bacon, so yes we are ready! 😎

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perfectbebop t1_j9hv0ag wrote

Thanks for this, when can I start to import your forcasts/weather data into Carrot now that Dark Sky is no more haha

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TheCloudBoy OP t1_j9hxoae wrote

Replying to blogthisisyours (#1,910,656)

I thought about this exact issue as I was selecting colors from a trusty color palette I refer to often. I think one of my Python libraries has a colorblind friendly palette, I'll leverage that next time

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TheCloudBoy OP t1_j9hxv4d wrote

Replying to perfectbebop (#1,911,207)

My company does run a bias-corrected superensemble forecast system that generates forecasts at 2.5 km resolution, or ~1.55 mi. How does Carrot ingest data and what data are you looking for?

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TheCloudBoy OP t1_j9i0jgv wrote

For those curious about the NWS forecasts: it is eye-opening how different the latest NWS Gray NDFD snowfall forecast grids look compared to their afternoon package. Compare their forecast to mine, you'll notice it looks similar but 12 hours behind mine.

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[deleted] t1_j9i0l2h wrote

Trashua dodges the bullet again!

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Nydelok t1_j9i4k72 wrote

Already started snowing down here in Claremont during the school day, I am very ready for a snow day.

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Different_Ad7655 t1_j9i4ryw wrote

I think it's funny in this day and age that it even makes news or is part of a forum. How times have changed in our sprawled urbanized landscape where nobody walks to their job School or church and is So weather dependent. I'm 70 and have seen how this has changed over the decades. But everybody now lives somewhere else, shops at the malls drives drives drives so a flake makes a concern for everybody. I did road service, winter service, snow plowing for 40 years so I've seen all the conditions and all of the absurd driving..

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EmeraldMoose12 t1_j9ir3tu wrote

Leaving work in Lebanon at 11 pm Wednesday night and driving 20 miles down 89 is going to be fun as the snow starts getting heavier.

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petrockdog t1_j9j9upp wrote

I’m just excited because our classes were cancelled at Plymouth State lol

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akmjolnir t1_j9jopma wrote

My prediction is that we'll get less, overall, than people are predicting, and it's not going to last very long, unfortunately.

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KrissaKray t1_j9k8rl3 wrote

Give me 8" or I'm gonna cry. please. lol

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Different_Ad7655 t1_j9kmo18 wrote

Replying to TheodoeBhabrot (#1,921,497)

That's why it's required for you is a property owner to do your due diligence and clear your walkway. Everything can't fall to the city although the city does the send a plow sidewalk plow through eventually and Sands. This belongs to the same mentality, I'm taking care of the curb and grassy Street planting which some homeowners strangely ignore even though they tend their property on the other side of the Walk. I'll never understand this. Living in a city brings many advantages but requires shared responsibility

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scajjr29 t1_j9ksumx wrote

WMUR at noon is still sticking to 3-6" across SE NH. Probably should have stopped typing after WMUR ;)

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TheCloudBoy OP t1_j9l5qgs wrote

Replying to scajjr29 (#1,922,860)

Lol I've seen that map and find the 3-6" gradient across SE NH is an absolute joke, I'm sorry. Telling anyone south & east of Concord that they can potentially see the high end of that range (6") is absolutely wrong. My "expect this much" range for Concord, Manchester, Londonderry, Exeter, Portsmouth, Nashua, & Durham is 3-4"

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MrEtrain t1_j9lkly0 wrote

Do we have a Weds. PM update? Wunderground, which has been reliable of late, saying ~9" or so for Upper Valley- no changeover from snow to less desirable precipitation.

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CrowmanVT t1_j9lmho3 wrote

Replying to Cullen7777 (#1,909,205)

When I lived up that way I used to listen to VPR's Eye on the Sky. They often referenced that area of the Connecticut River Valley as being in a shadow area between the mountains that reduced the precipitation generally. I'm very curious to see if our personal weather guru u/TheCloudBoy has a similar or alternate theory.

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exhaustedretailwench t1_j9m4gnw wrote

"the approaching temperature inversion creates Bernoulli acceleration of low-level winds"

you have no idea how sexy that is

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perfectbebop t1_j9me7op wrote

Replying to TheCloudBoy (#1,911,567)

Looking at the options it provides (iOS) theres either preset weather services like Foreca/Apple Weather/AccuWeather etc or personal weather stations (Netatmo/Tempest/PWSweather). Unfortunately I'm guessing none of those would allow for a more custom data feed.

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