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NNE Winter Thread


dryslot

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Great AFD from the Met in Charge Andy Nash regarding the upslope potential:

12z guidance all in line with developing a closed upper low over
New Brunswick by early Saturday. This upper low will be nearly
stationary and pull in the surface low that is moving into the
Canadian Maritimes this evening. As a result, deep Atlantic
moisture will be able to rotate around that upper low and come
into our region from the northeast. At lower levels, a brisk
northwest flow will develop due to the pressure gradient from
the stalled low that will be to our east. Will result in semi-
breezy conditions Saturday with wind gusting up to 25 mph at
times. This northwest flow, combined with the deeper moisture,
will set the stage for a classic upslope flow event across the
higher terrain of northern New York, and especially northern
Vermont. Even the lower resolution global models have a strong
signal of this upslope event, which lends confidence to the
details that we see in the hi-res models.

The tough part of the forecast is exactly how much QPF, where
that QPF will fall and what will the snow- liquid ratios (SLR)
be. QPF varies widely amongst models, with the BTV 4km showing
some liquid equivalent nearing 1" in the far northern section of
the Greens. Think that`s too high. Took the blended approach
and came up with liquid totals of up to 0.45" at elevations
above 2500ft from Mt Mansfield to Jay Peak, with widespread
0.20-0.30" at lower elevations across northern VT. SLRs are much
more uncertain. Typically we get 25-30:1 type ratios, however it
looks like the temperature profiles will be just a little warmer
than we like to see in the snow growth region. Thinking SLRs
will be more like 15-18:1. Doing the conversion, it does appear
that we`ll see a pretty widespread 3-5" along the western slopes
of the Greens, northern VT and into the northeast Kingdom. The
mountains will do better (8"+ at least). Pattern suggests that
the Jay Peak area will see some hefty totals, probably well
above the point total forecast I came up with. As a result, I`ve
gone ahead and issued a Winter Weather Advisory for the region.
Will probably be some snow covered roads Saturday evening and
overnight, but other than that, I think the majority of people
in the area will be happy to see the snow. Best combo of upslope
lift, deep moisture and upward motion is from late Saturday
afternoon until the pre-dawn hours on Sunday morning. There is
an element of blocked flow that could play a role Saturday
night. Models indicate the Froude number to be down around 0.5,
which would suggest snowfall being pushed westward some from the
crest of the Green Mountains. At the very least, minor
accumulations should occur into the Burlington area.
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BTV snow forecast for the upslope event.

Similar to the big snowstorm for the mountains, ha.  So many of us up here talk about how these are the bread and butter, and even the skiers know that the big "hyped up newsworthy storms" usually do just as much as a good 12-18 hours of moist NW flow.

These are the events though where you ride the Gondola with a family who says, "we were watching The Weather Channel last night in our hotel room and it said a 50% chance of snow showers and no one mentioned a snowstorm.  But yet here we are skiing through half a foot of snow that fell overnight.  Do you know where this came from?"  "Why yes, yes I may have an idea."

W6DqvQ1.png

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I've got 3-6" for Bolton/Stowe/Smuggs and 6-10" for Jay Peak by noon Sunday.

The only negatives for me are the flow turning a bit more blocked throughout the night, especially after midnight Saturday night into Sunday morning.  The flow is unblocked Saturday afternoon/evening and then again during the day on Sunday as the insolation seems to disturb the inversion layer and creates a more freely flowing air over the mountains.  I could see the upslope backing into BTV for a time. 

Other negative is snow growth... I think it'll be ok but not Champlain Powder per se.  Looking at the BTV omega and temps you can see how the low level forced lift is under the DGZ but the lift over the mountains will likely be a bit higher due to the upslope.  Over the Spine, the orographic lift is usually more centered around 850mb.  Might be enough to get 15-20:1 ratios.

b59C8xQ.png

 

Positives are for whatever reason, the overnight time frame seems to be real good for upslope.  Hard to figure out why but these things like to congeal into a more uniform band overnight and then get disrupted into more squally nature during the daytime hours.  Relative Humidity is also >90% in the lowest 5-7kft of the atmosphere, which should allow the 25-35kt winds to push that into the mountains fairly effectively.

whe36cW.png

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23 minutes ago, powderfreak said:

Great AFD from the Met in Charge Andy Nash regarding the upslope potential:

That’s great – I didn’t even know we were getting a Winter Weather Advisory, but they’ve got one up and a headline as well:

09MAR18A.jpg

09MAR18B.jpg

 000
WWUS41 KBTV 092029
WSWBTV

URGENT - WINTER WEATHER MESSAGE
National Weather Service Burlington VT
329 PM EST Fri Mar 9 2018

VTZ003-004-006-016-017-101000-
/O.NEW.KBTV.WW.Y.0014.180310T1800Z-180311T1200Z/
Orleans-Essex-Lamoille-Eastern Franklin-Eastern Chittenden-
Including the cities of Newport, Island Pond, Johnson, Stowe,
Enosburg Falls, Richford, and Underhill
329 PM EST Fri Mar 9 2018

...WINTER WEATHER ADVISORY IN EFFECT FROM 1 PM EST SATURDAY TO
8 AM EDT SUNDAY...

* WHAT...Snow expected. Total snow accumulations of 3 to 5 inches,
with localized amounts up to 8 inches across higher elevations,
are expected.

* WHERE...Portions of northern Vermont that include Orleans,
Essex, Lamoille, Eastern Franklin and Eastern Chittenden
Counties.

* WHEN...From 1 PM EST Saturday to 8 AM EDT Sunday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Be
prepared for reduced visibilities at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
Please allow extra time if travel is necessary.

For more information from the National Weather Service visit
http://weather.gov/btv/winter

Nash

09MAR18C.jpg

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Here’s the north to south listing of available snowfall totals from the Vermont ski areas for Winter Storm Quinn through today.  I’m using 48-hour totals or storm totals if the resorts gave them:

Jay Peak: 13”

Burke: 14”

Smuggler’s Notch: 12”

Stowe: 11”

Bolton Valley: 13”

Mad River Glen: 14”

Sugarbush: 14”

Suicide Six: 16”

Pico: 15”

Killington: 15”

Okemo: 24”

Bromley: 34”

Magic Mountain: 32”

Stratton: 34”

Mount Snow: 35”

These likely represent the final totals for the storm cycle, with a foot or so in the northern half of the state and two to three feet in the southern part of the state.

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Event totals: 0.5” Snow/0.01” L.E.

 

Details from the 11:00 P.M. Waterbury observations:

New Snow: 0.5 inches

New Liquid: 0.01 inches

Snow/Water Ratio: 50.0

Snow Density: 2.0% H2O

Temperature: 30.2 F

Sky: Light Snow (2-8 mm flakes)

Snow at the stake: 9.5 inches

 

This is where it can get really tough to discern where one winter storm/event ends and another begins, especially when something like the surface low of Winter Storm Quinn ends up getting incorporated into the upper level low off to our northeast, but it sounds like this might be a good break point to start a new event post-Winter Storm Quinn.  The BTV NWS indicated that this afternoon/evening’s snowfall activity was from convective snow showers, so I’m going to file this evening's accumulation under that.

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Hopefully the radar looks like this this evening... all the models have a pretty solid gradient between north and south of I89. 

Still looks on track for a fun little upslope event tonight.  Jay Peak is going to get crushed.  This is right in their wheelhouse and the models agree.

20180236_10103353900558260_1225215647_o.

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42 minutes ago, CoastalWx said:

How has the season been so far? I feel like the upslope machine has been idling but should go full tilt later.

Season featured a really good start with with some fun upslope and synoptic events. 

It really seemed to stall out after early January.  January 3rd saw 12" fall overnight in lake effect/upslope combo at the High Road stake, (with more like 14-15" up at 3,500-4,000ft) and that produced the best powder day of the season.  Then January and February despite some good days and systems just couldn't get the ball rolling.  Every time we got a snowfall or two in a row, it would rain the next day or something.  Momentum never really could build up.

February 2017 saw more snow than both January/February 2018 combined but last year was really special to me.  Top snowfall since 2000-01 with 375" and 108" in 22 days from late Jan to mid Feb.  Then there was 52" in the mid-March storm and a couple 10-14" events in April.  The Mansfield Stake even had the second highest reading on record for mid-February (only 68-69 had more) last year before that big thaw around the end of Feb/early March.  So compared to that stuff, this winter is definitely a bit mediocre to say the least, ha.

Right now I'm at 196" at 3,000ft for seasonal snowfall which is below average.  I do think the next 7 days could be very good though for orographic snows.  Just has that overall look and feel of moist cyclonic flow given the upper level pattern and surface pressures.  We do best when maritime air/moisture gets into the flow and wraps back down around...only negative is temps aren't overly cold so snow growth may not be maximized like it sometimes is.

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27 minutes ago, powderfreak said:

Season featured a really good start with with some fun upslope and synoptic events. 

It really seemed to stall out after early January.  January 3rd saw 12" fall overnight in lake effect/upslope combo at the High Road stake, (with more like 14-15" up at 3,500-4,000ft) and that produced the best powder day of the season.  Then January and February despite some good days and systems just couldn't get the ball rolling.  Every time we got a snowfall or two in a row, it would rain the next day or something.  Momentum never really could build up.

February 2017 saw more snow than both January/February 2018 combined but last year was really special to me.  Top snowfall since 2000-01 with 375" and 108" in 22 days from late Jan to mid Feb.  Then there was 52" in the mid-March storm and a couple 10-14" events in April.  The Mansfield Stake even had the second highest reading on record for mid-February (only 68-69 had more) last year before that big thaw around the end of Feb/early March.  So compared to that stuff, this winter is definitely a bit mediocre to say the least, ha.

Right now I'm at 196" at 3,000ft for seasonal snowfall which is below average.  I do think the next 7 days could be very good though for orographic snows.  Just has that overall look and feel of moist cyclonic flow given the upper level pattern and surface pressures.  We do best when maritime air/moisture gets into the flow and wraps back down around...only negative is temps aren't overly cold so snow growth may not be maximized like it sometimes is.

Seems like it has that feel widespread through New England. Maybe a few exceptions. Although I am AN so far, it just has not had that feel. 

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Event totals: 0.7” Snow/0.01” L.E.

 

Details from the 6:00 A.M. Waterbury observations:

New Snow: 0.7 inches

New Liquid: 0.01 inches

Snow/Water Ratio: 70.0

Snow Density: 1.4% H2O

Temperature: 30.9 F

Sky: Mostly Cloudy

Snow at the stake: 10.0 inches

 

It appears that the origin of the overnight snow in the area was independent of the convective snowfall yesterday.  The BTV NWS indicates that it was a combination of shortwave energy and mid-level moisture, so I’m putting it down as its own event.

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I was out at Bolton Valley yesterday, and I’ve got to say, for an event that was only in the range of 1 foot snow/1 inch L.E., it was a fantastic resurfacing of the slopes.  I poked around yesterday on fairly ledgy terrain trying to find the pitch limits of what the snow could support, and I really couldn’t find it.  The combination of that dense snow at the beginning of the event and essentially no wind just put things in place really well without the scouring that affects some areas.  A few shots from yesterday:

09MAR18E.jpg

09MAR18D.jpg

09MAR18F.jpg

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1 hour ago, CoastalWx said:

Seems like it has that feel widespread through New England. Maybe a few exceptions. Although I am AN so far, it just has not had that feel. 

One storm per winter month (NNE calendar), 8" DE, 13" JAN, 9" FEB, 20" (rounding up) this week.  Other than the solstice storm of about 5", nothing else has gone much over 3, and more than usual RA.  I'm within 6" of my full-season average, so I'm guessing it will finish a bit AN, with SDDs ight around my 1,700 average.  Just an odd way t get there.  Front-loaded cold, too, more than any winter since 1989-90.

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Dumping moderate to heavy upslope snow now thanks to a nice lake effect streamer supplying a steady moisture feed into the Greens. Hopefully we can keep it cranking for a while. Measured 5" of new post storm snow this morning at 830 AM that has accumulated over the past 2 days. Probably an additional inch or so since then.

Despite the new snow, we've "lost" snow pack due to settling and compaction. That fronto band I was in Wednesday night was puking 5-6" an hour dendrite fluff. ~27" in 5 hours!! Measured 35" at 1145 PM Wednesday night, I measured 12" at ~640 PM cleared a spot and measured 27" new in that same spot at 1145 PM. It tapered a bit for awhile overnight only to get into another band that nailed us early Thursday morning with another ~10", yielding a total of 45". Who knows how much I would've totaled had I not been lazy and measured every hour! Net gain from the storm was ~36" due to settling, which is likely why most of the reports from this area are around 3'.

Measuring here is an absolute nightmare though. Blowing, drifting, compaction, you name it. I'm still trying to figure out the best location on my property to measure...haha. I lost my snow board somewhere in the snowpack because I neglected to put a marker in. Next winter I'll definitely try to be more by the book. 

Another thing I've noticed too here is that the heaviest snowfall is sometimes a bit downstream of where the radar indicates it, particularly if we're getting dendrites. I was a tad west of the brightest echoes on Wednesday night for much of the time, but I was still puking 5-6" per hour. E and SE winds aloft likely advected those flakes downstream W and NW a few miles since the 0.5° radar beam from ENX is ~4.2K feet above radome level here and the radome is ~1,800' ASL WSW of ALB. Additionally, those fronto bands tend to angle upward toward the W and NW. Downstream advection of dendrites also happens with W and NW flow upslope, they just get carried to the E and SE. 

I may not get as much upslope as up by Jspin of PF, but I feel like I'm in a better position to get in on coastal nor'easters and some nice deform bands. We had several nice 8-12" SWFE earlier in the season (i.e. the Super Bowl day storm) while the Berkshires mix or flip to rain/sleet. Although they're still at or above 2K all the way down to about the north side of Becket, there's an impressive snowfall gradient from here to the crest of the central and southern Berkshires. The Green Mountain spine forms a wide plateau here averaging 2-2.5K with individual peaks between 3 and 4K, but it narrows south of the MA line, so the effect of the terrain is not as significant as it is here.

 

 

 

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5 hours ago, wxmanmitch said:

Dumping moderate to heavy upslope snow now thanks to a nice lake effect streamer supplying a steady moisture feed into the Greens. Hopefully we can keep it cranking for a while. Measured 5" of new post storm snow this morning at 830 AM that has accumulated over the past 2 days. Probably an additional inch or so since then.

Despite the new snow, we've "lost" snow pack due to settling and compaction. That fronto band I was in Wednesday night was puking 5-6" an hour dendrite fluff. ~27" in 5 hours!! Measured 35" at 1145 PM Wednesday night, I measured 12" at ~640 PM cleared a spot and measured 27" new in that same spot at 1145 PM. It tapered a bit for awhile overnight only to get into another band that nailed us early Thursday morning with another ~10", yielding a total of 45". Who knows how much I would've totaled had I not been lazy and measured every hour! Net gain from the storm was ~36" due to settling, which is likely why most of the reports from this area are around 3'.

Measuring here is an absolute nightmare though. Blowing, drifting, compaction, you name it. I'm still trying to figure out the best location on my property to measure...haha. I lost my snow board somewhere in the snowpack because I neglected to put a marker in. Next winter I'll definitely try to be more by the book. 

Another thing I've noticed too here is that the heaviest snowfall is sometimes a bit downstream of where the radar indicates it, particularly if we're getting dendrites. I was a tad west of the brightest echoes on Wednesday night for much of the time, but I was still puking 5-6" per hour. E and SE winds aloft likely advected those flakes downstream W and NW a few miles since the 0.5° radar beam from ENX is ~4.2K feet above radome level here and the radome is ~1,800' ASL WSW of ALB. Additionally, those fronto bands tend to angle upward toward the W and NW. Downstream advection of dendrites also happens with W and NW flow upslope, they just get carried to the E and SE. 

I may not get as much upslope as up by Jspin of PF, but I feel like I'm in a better position to get in on coastal nor'easters and some nice deform bands. We had several nice 8-12" SWFE earlier in the season (i.e. the Super Bowl day storm) while the Berkshires mix or flip to rain/sleet. Although they're still at or above 2K all the way down to about the north side of Becket, there's an impressive snowfall gradient from here to the crest of the central and southern Berkshires. The Green Mountain spine forms a wide plateau here averaging 2-2.5K with individual peaks between 3 and 4K, but it narrows south of the MA line, so the effect of the terrain is not as significant as it is here.

Nice.  I saw some of your pics on Twitter, please post some here too.

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59 minutes ago, powderfreak said:

J.Spin probably getting 1-2"/hr now too there on the county line at the interstate cut through.

I don’t think we were up at that rate of snowfall back then, but I’d say we’re up in that range now.  You can see the returns verging on 30 db in the composite radar image – seeing the flecks of 30 db yellow travel ESE and then disappear as they crash into the spine is pretty cool:

10MAR18A.gif

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