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Potential widespread snow event for Wednesday Night through Thursday.

CoastalWx

By CoastalWx,
in New England

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ORH_wxman

ORH_wxman

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Bump for Will.

Probably the biggest thing that the '07-'08 winter taught me is the model biases in SWFE...usually too heavy on qpf, too slow with the precip, and too slow with the mid-level warming. However the caveat is that it was a +NAO pattern. If there is a big block, then obviously a lot of that stuff flies out the window. But most of those events do not have a big block.

One of the reasons we downplayed the Feb 1-2 event...classic setup where modeled QPF was going to be too much.Its usually hard to get over an inch of qpf from a SWFE. So those 20-25" totals looked very dubious.

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CoastalWx

CoastalWx

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Probably the biggest thing that the '07-'08 winter taught me is the model biases in SWFE...usually too heavy on qpf, too slow with the precip, and too slow with the mid-level warming. However the caveat is that it was a +NAO pattern. If there is a big block, then obviously a lot of that stuff flies out the window. But most of those events do not have a big block.

One of the reasons we downplayed the Feb 1-2 event...classic setup where modeled QPF was going to be too much.Its usually hard to get over an inch of qpf from a SWFE. So those 20-25" totals looked very dubious.

Alright..we're thinking on similar terms.

I don't know what it is..but I have some sick fascination with those stupid SWFE. Maybe it's the challenge they provide...I don't know..but I always find them intriguing. They always seem like a good learning experience for winter forecasting. I mean yeah sure, lows going over the BM are fun to forecast, but lets face it...many times it's an easy forecast with amounts and ptype. SWFE bring all sorts of problems to the table, but I find that they help fine tune the winter forecasting skills. At least imo.

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ORH_wxman

ORH_wxman

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Alright..we're thinking on similar terms.

I don't know what it is..but I have some sick fascination with those stupid SWFE. Maybe it's the challenge they provide...I don't know..but I always find them intriguing. They always seem like a good learning experience for winter forecasting. I mean yeah sure, lows going over the BM are fun to forecast, but lets face it...many times it's an easy forecast with amounts and ptype. SWFE bring all sorts of problems to the table, but I find that they help fine tune the winter forecasting skills. At least imo.

They are definitely the hardest storms to forecast because you can have situations like Dec 16, 2007 where a couple hours makes the difference between 4-5" of snow and 10" of snow. Luckily I didn't bust too bad in that storm since most of my forecasts were for N ORH county which was favored to hold onto the mid-level cold longer. I think I went 4-7 and we got 8-9". Bust, but not an epic one.

The biggest disappointment of that winter was the 12/30-31/07 event. My biggest bust of the season that was otherwise very good. That one just wouldn't stop trending north...usually those SWFEs would trend north from about 96h out to roughly 48h out and then stabilize. This one didn't, it just kept trending north. I recall on Dec 29, the 15z SREF was mostly whiffing us to the south and so was the usually better GFS (at least in SWFE it was far superior to the cold-biased NAM). The models at 00z on the night of the 29th (00z 12/30 runs) came north and absolutely smoked all of us. They were giving 8-12" of snow. They bumped north yet again the next morning so we then knew there would probably be mixing but still very solid accumulations.

We ended up with snow, then sleet, then back snow and 3-4"...qpf also busted too. There was a pretty bad dryslot in the middle of the qpf shield. The south coast was getting heavy rain and SW NH was getting pretty heavy snow while we were stuck in the middle with a shredded precip shield.

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ORH_wxman

ORH_wxman

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BTW..I was just weenie-ing out at some old obs..and you're not kidding about how hard it snowed on 4/28/87.

METAR KORH 282100Z 05008KT 1/16SM +SN FG OVC001 00/M01 A2989 RMK 0 /72045 90409 SNOINCR 3/6/9

3" per hour.

21z in the afternoon. Already 9 inches on the ground. Pretty remarkable for a sun angle thats a month later than now.

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CoastalWx

CoastalWx

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21z in the afternoon. Already 9 inches on the ground. Pretty remarkable for a sun angle thats a month later than now.

BOS actually fell to freezing and S+. That's just incredible. I would have loved to see an old radar image, even though they weren't the best.

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CoastalWx

CoastalWx

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They are definitely the hardest storms to forecast because you can have situations like Dec 16, 2007 where a couple hours makes the difference between 4-5" of snow and 10" of snow. Luckily I didn't bust too bad in that storm since most of my forecasts were for N ORH county which was favored to hold onto the mid-level cold longer. I think I went 4-7 and we got 8-9". Bust, but not an epic one.

The biggest disappointment of that winter was the 12/30-31/07 event. My biggest bust of the season that was otherwise very good. That one just wouldn't stop trending north...usually those SWFEs would trend north from about 96h out to roughly 48h out and then stabilize. This one didn't, it just kept trending north. I recall on Dec 29, the 15z SREF was mostly whiffing us to the south and so was the usually better GFS (at least in SWFE it was far superior to the cold-biased NAM). The models at 00z on the night of the 29th (00z 12/30 runs) came north and absolutely smoked all of us. They were giving 8-12" of snow. They bumped north yet again the next morning so we then knew there would probably be mixing but still very solid accumulations.

We ended up with snow, then sleet, then back snow and 3-4"...qpf also busted too. There was a pretty bad dryslot in the middle of the qpf shield. The south coast was getting heavy rain and SW NH was getting pretty heavy snow while we were stuck in the middle with a shredded precip shield.

Well as you said..perhaps we get another season of those if we have a multi-year nina. It was a fun time for SNE...those events and experience taught me a lot.

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ORH_wxman

ORH_wxman

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Will, how is the new map coming? Or do you wait until May or so to start (I guess it would not make sense to start if there is any chance of snow)

And do you know how much Princeton has received? One of the lift guys last night said Wachusett had gotten about 90-95" at the summit this year...so far

I don't start the map usually until at least mid April. Princeton probably has around 90"...they started off slower than here but they were catching up through February. Maybe slightly less than 90". I'll have their figure at the end.

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Damage In Tolland

Damage In Tolland

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Will, how is the new map coming? Or do you wait until May or so to start (I guess it would not make sense to start if there is any chance of snow)

And do you know how much Princeton has received? One of the lift guys last night said Wachusett had gotten about 90-95" at the summit this year...so far

Why would he do a final map with a major snowstorm on the horizon next week?

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dendrite

dendrite

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I don't know..It looks like Phil started a thread and then they moved it and deleted it..I don't understand why and am wondering where it is and who did it

I wasn't around at the time, but it looks like he wanted it deleted.

We're almost at the end of the winter threats so it'd be nice if everyone could just play together nicely for a couple more weeks.

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nzucker

nzucker

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BTW..I was just weenie-ing out at some old obs..and you're not kidding about how hard it snowed on 4/28/87.

METAR KORH 282100Z 05008KT 1/16SM +SN FG OVC001 00/M01 A2989 RMK 0 /72045 90409 SNOINCR 3/6/9

3" per hour.

Wow, that's literally white-out conditions in late April, unreal. That 1/16SM reading looks look something you'd see in the Dakotas, though I guess it's similar to what happened in Boxing Day here. Did any snow make it to NYC metro or the Poconos from that storm? It's interesting how much we talk about the late-March sun angle as an unfavorable factor, but then we look at these storms like 4/28/87 and 5/10/77 and realize that it's all about the strength of the upper-level cold pool and precipitation rates, which can easily overcome even a summertime sun if you have a bit of elevation. Wasn't there a big one in the Whites on 5/28-29 one year?

What caused the dendrites to be "hooked together" in the December 1997 storm? Was that a product of how close together they were being formed by the intense condensation in that type of storm, so they just got stuck like aggregates but except dry? I've never seen a radar image like that except when it's bright-banding; I think the hardest snows I've seen here are around 40dbz like during the Snowicane and then the band that went over NYC late in the evening of the 1/27 storm.

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