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Spring Banter - Pushing up Tulips


Baroclinic Zone

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Pretty intense gusts for the past hour--have to be pushing 50-60mph. Lost 2 downspout gutters that detached and a birch snapped. I'm in kind of sheltered area too, haven't seen much wind at all since I moved here in NOV.

You are in a prime SE downslope wind spot there on the west slope. Up here all those towns that get great west side upslope usually get a couple severe SE wind events throughout the year.

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If you're along the western slopes of the Greens as your location icon suggests, you're in a prime SE-downslope zone.

 

 

You are in a prime SE downslope wind spot there on the west slope. Up here all those towns that get great west side upslope usually get a couple severe SE wind events throughout the year.

Thanks guys, I guess that explains it. Its been pretty severe for a few hours now.

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Why are the SE events produce damaging winds but NW flow doesn't do the same on the east side? SE events have stronger llvl jets?

Could it be that the Mtns are steeper to the west so there is less interference in the downward flow?

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Wind gusts so far in the 50s in the Burlington suburbs and west slope communities.

... Chittenden County...

1 ENE Underhill Center 56 mph 0208 PM 04/20 44.52n/72.87w

Nashville 1 E 53 mph 1223 PM 04/20 44.45n/72.93w

Huntington 52 mph 0232 PM 04/20 44.29n/72.97w

Burlington Intl Airport 47 mph 0330 PM 04/20 44.47n/73.15w

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I was wondering that, but the Greens are pretty steep on both sides no?

They are but there's secondary ridgelines so maybe that's what stops it? Like from Mansfield it drops to 700ft but then goes back up to 3,500ft on the Worecester ridge...all within the town of Stowe from west to east. So the air maybe doesn't have time to mix fully before it has to lift again?

I guess the west slopes can provide much "cleaner" down/up slope flows...but it is interesting how that works. And it seems to happen better on SE winds rather than pure easterly flow or NE flow. Even in strong nor'easters, you don't hear about 60kts at H850 out of the NE causing downslope wind events. But 60kts out of the SE and there's damaging 50+ mph gusts.

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They are but there's secondary ridgelines so maybe that's what stops it? Like from Mansfield it drops to 700ft but then goes back up to 3,500ft on the Worecester ridge...all within the town of Stowe from west to east. So the air maybe doesn't have time to mix fully before it has to lift again?

I guess the west slopes can provide much "cleaner" down/up slope flows...but it is interesting how that works. And it seems to happen better on SE winds rather than pure easterly flow or NE flow. Even in strong nor'easters, you don't hear about 60kts at H850 out of the NE causing downslope wind events. But 60kts out of the SE and there's damaging 50+ mph gusts.

 

There have to be some static stability issues at play too I would imagine.

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Drove down to my folks place in Albany, NY and they live 2 miles away from where a massive landslide took place today (at least 200 yards across). It is now blocking the Normanskill River, which is flooding the golf course upstream...water downstream has come to a stop. It's very odd to drive over the bridge separating Albany and Bethlehem and see no water, but that's what's happening haha.

http://timesunion.com/news/article/Normans-Kill-blocked-by-collapses-bank-flooding-6211387.php

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Why are the SE events produce damaging winds but NW flow doesn't do the same on the east side? SE events have stronger llvl jets?

 

You do get them to an extent. During some of the northwest flow events you'll see the MPV ob along with some Johnson and Stowe obs (I think you've noted it a few times too) have some pretty strong gusts in the 30-40 mph range.

 

But they'll just never get to the intensity of the SE downslope winds, likely because of:

 

1.) Intensity of the LLJ, its not terribly uncommon to see 50-90 knot low level jets out of the SE. I think we were pushing 70 knots today, but luckily for those western slope communities, those strongest winds were above the inversion. You'd be really hard pressed to ever find a NW LLJ over 50 knots.

2.) The orientation of the terrain is much more conducive for the western slopes in the same it is for upslope. That is a sharp barrier on the western side, rather than the more varied terrain leading up the east side.

3.) The location of the low level jet in relation to the inversion and sharp mountain gradient that is necessary for downslope winds and mountain wave breaking. The best downslope winds also tend to happen in WAA regimes due to the increased stability and, especially locally because there's a critical level above mountain top where the winds veer to south (parallel the mountain, which is a critical level for mountain wave breaking).

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You do get them to an extent. During some of the northwest flow events you'll see the MPV ob along with some Johnson and Stowe obs (I think you've noted it a few times too) have some pretty strong gusts in the 30-40 mph range.

 

But they'll just never get to the intensity of the SE downslope winds, likely because of:

 

1.) Intensity of the LLJ, its not terribly uncommon to see 50-90 knot low level jets out of the SE. I think we were pushing 70 knots today, but luckily for those western slope communities, those strongest winds were above the inversion. You'd be really hard pressed to ever find a NW LLJ over 50 knots.

2.) The orientation of the terrain is much more conducive for the western slopes in the same it is for upslope. That is a sharp barrier on the western side, rather than the more varied terrain leading up the east side.

3.) The location of the low level jet in relation to the inversion and sharp mountain gradient that is necessary for downslope winds and mountain wave breaking.  The best downslope winds also tend to happen in WAA regimes due to the increased stability and, especially locally because there's a critical level above mountain top where the winds veer to south (parallel the mountain, which is a critical level for mountain wave breaking).

 

It's long but NWS WDTB has a good pdf on downslope winds:

 

http://www.wdtb.noaa.gov/courses/winterawoc/documents/color_PDFs/IC8_Lesson1.pdf

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