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Napril Fools? Pattern and Model Discussion . . .


HimoorWx

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2 minutes ago, ORH_wxman said:

It's because our warning criteria for icing is really high. Half an inch of accretion. That's very rarely reached. I think the last time anyone reached it was the dec 2008 storm...outside of maybe some very isolated occurances. The criteria should probably be a quarter inch because you start getting a few power outages at a quarter inch and then it really ramps up around 1/3rd to 3/8ths or so. 

12/23/17 was really close to that here, we had at least .40".

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It's actually even possible that the models are under-doing the amount of "tuck" and related to that.. .the depth of the cold.  The NAM actually drops the sleet transition over to snow into Essex Co between 9 and 12z overnight ...  If that is the case, there may be bullets along 135 more so than actual liquid water... 

As an avid runner/cyclist, there is a difference between being caught out in solid H2o as opposed to liquid relative to temperature.  

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Not to be a dink and or confrontation (really) but ...no one really should be surprised at the colder profiles coming in... 

I was trying to hit on this issue the other day (I think Will engaged in the conversation) but, doing a standard deviation relative to the pattern is just as important as the pattern its self ? 

And what I mean by that is... it is not uncommon for one of two things to take place with Lakes Cutters (particularly in spring...):

1  ... the warn from that subtends eastward of said low might and more often than not, ..will slump back SW as a BD

2  ... more than merely slump because the low is transitively causing more confluence N-E over southern/SE Canada, which feeds back on generating more high pressure --> adding to the pressure pattern and really drills the front BD or N-door with raging abandon.  

This is the #2 variety...and, #2 tends to be the colder of the two.

That said... enters the relative to pattern:  This thing has top dawg cold supply with it... For whatever reason, it's got cryo paste air involved in the low levels ... We could have the same timing and amount of wind and pressure patterning ...and end up with 50 F out of these messes...but this one is executing the same evolution at some 20 F colder (or more..).   

It's interestingly just related to the tenor of the late winter through this mid spring cold N/A thing.  It's alike anything that gestates and goes through life cycle will profile colder than it normally does, including this thing over the weekend.  That's certainly what it seems like - and much of this is just my observation.  

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1 hour ago, dendrite said:

NAM is pushing the cold enough south that SW ME dries out and warms up into the low 30s on Sunday while interior SNE rots in the 20s.

Just like 2 years ago - ORH near 20 (with SN+, not this time) while my area had dim sun and near 30.  Lots of April upside-down in recent years.

As for marathon wx (and I've never run competitively - my track events were discus/shotput), I think that RA- and 50 could be fine, but RA+ and 38 would be dangerous, due to both the cold and the serious puddles/pavement-rivers.

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12 minutes ago, Typhoon Tip said:

It's actually even possible that the models are under-doing the amount of "tuck" and related to that.. .the depth of the cold.  The NAM actually drops the sleet transition over to snow into Essex Co between 9 and 12z overnight ...  If that is the case, there may be bullets along 135 more so than actual liquid water... 

As an avid runner/cyclist, there is a difference between being caught out in solid H2o as opposed to liquid relative to temperature.  

Definitely a very good point - and if it were earlier in the season I would totally be in favor of that happening. As y'all know, often times in these situations the magnitude of the cold is underdone and the tendency to displace/modify it is overdone.

Having said that, it is tough to find any cons for this set-up other than the fact its mid April! 

Some of pros:

-Nearly ideal wind direction for low lvl CAA from the N/NE, also at like 20-30 kts just above the surface 

-Strong High pressure situated in a great spot in Quebec that is nosing into Maine - nice CAD signature 

-Advecting in dp in the 0s and 10s from Maine throughout the day Sunday .. has to be one of the more impressive low dp feeds I've ever seen in an icing situation 

Honestly would't surprise me if it took until later in the morning Monday to really dislodge the sub freezing air nw of 495/90 

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I'm sorry but I have to elucidate... there is not going to be anymore significant snowfall. I still check the models yes but we have to take that all with a grain of salt. Don't let it obfuscate you there are many slanted readings on the models. We must not be perfunctory when reading the models and not jump to conclusions. I know many of us hope for snowfall but unfortunately it has pretty much packed up for the season. I do predict a chilly summer ahead however. Just stop stressing and embrace the warmer weather... I know everyone is suffering a malaise about the winter season ending. The summer readings can be quite scintillating as well and I will be on here all year long with simply a passion for any and all weather patterns. Let us all see it as it comes

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2 minutes ago, Weatherexpert said:

I'm sorry but I have to elucidate... there is not going to be anymore significant snowfall. I still check the models yes but we have to take that all with a grain of salt. Don't let it obfuscate you there are many slanted readings on the models. We must not be perfunctory when reading the models and not jump to conclusions. I know many of us hope for snowfall but unfortunately it has pretty much packed up for the season. I do predict a chilly summer ahead however. Just stop stressing and embrace the warmer weather... I know everyone is suffering a malaise about the winter season ending. The summer readings can be quite scintillating as well and I will be on here all year long with simply a passion for any and all weather patterns. Let us all see it as it comes

Sorry...Saturday night through Monday morning is sub-freezing there regardless of what the calendar says. Enjoy your sleet bullets and ZR. 

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5 minutes ago, Weatherexpert said:

I'm sorry but I have to elucidate... there is not going to be anymore significant snowfall. I still check the models yes but we have to take that all with a grain of salt. Don't let it obfuscate you there are many slanted readings on the models. We must not be perfunctory when reading the models and not jump to conclusions. I know many of us hope for snowfall but unfortunately it has pretty much packed up for the season. I do predict a chilly summer ahead however. Just stop stressing and embrace the warmer weather... I know everyone is suffering a malaise about the winter season ending. The summer readings can be quite scintillating as well and I will be on here all year long with simply a passion for any and all weather patterns. Let us all see it as it comes

Do you really live in Waterville, VT?  North of me in the northern Greens snowbelt?  

Post a picture of your front yard on Sunday morning please.

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1 hour ago, ORH_wxman said:

It's because our warning criteria for icing is really high. Half an inch of accretion. That's very rarely reached. I think the last time anyone reached it was the dec 2008 storm...outside of maybe some very isolated occurances. The criteria should probably be a quarter inch because you start getting a few power outages at a quarter inch and then it really ramps up around 1/3rd to 3/8ths or so. 

Given the NWS method of measuring accretion, 1/2" is huge - I've only seen it in 1953 (NNJ) and 1998, maybe in Dec. 1983 in Ft. Kent.  Of course, I think that method is problematic (assuming I understand it correctly), in that it appears to assume that accretion builds equally on top, sides, and bottom of a branch, which is not reality.  For a hypothetical example, consider a very efficiently accreting event of 1" LE, such that the top of a 1" diameter branch has that full inch, the sides just a glaze, and the bottom remains dry.  The way I understand the measurement method, that would just barely reach the 1/2" threshold.  IMO, the ice atop the surface should be the criteria.

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9 minutes ago, powderfreak said:

Do you really live in Waterville, VT?  North of me in the northern Greens snowbelt?  

Post a picture of your front yard on Sunday morning please.

Born and raised in the VT area. If you would like to see my yard i can take a photo - however most of the snow has melted at this point which exposes my extremely damaged yard - grass is ripped up and it is in extremely bad somewhat embarrassing shape. There are also scraps of plastic scattering the yard from some sleds that had been ripped up due to a phenonemon. here is a photo taken a couple months back. my yard still looks like this. 

weatherexpertsyard.JPG

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21 minutes ago, tamarack said:

Given the NWS method of measuring accretion, 1/2" is huge - I've only seen it in 1953 (NNJ) and 1998, maybe in Dec. 1983 in Ft. Kent.  Of course, I think that method is problematic (assuming I understand it correctly), in that it appears to assume that accretion builds equally on top, sides, and bottom of a branch, which is not reality.  For a hypothetical example, consider a very efficiently accreting event of 1" LE, such that the top of a 1" diameter branch has that full inch, the sides just a glaze, and the bottom remains dry.  The way I understand the measurement method, that would just barely reach the 1/2" threshold.  IMO, the ice atop the surface should be the criteria.

Agreed on the difficulty of measuring...it should probably just be the max accumulation on the surface.

In the 2008 ice storm, we had unusually high winds for an icing event. So the ice actually became deformed at times...the below picture I took shows the phenomenon...you can certainly tell which direction the wind was blowing:

 

 

028_downsized.jpg

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24 minutes ago, Weatherexpert said:

Born and raised in the VT area. If you would like to see my yard i can take a photo - however most of the snow has melted at this point which exposes my extremely damaged yard - grass is ripped up and it is in extremely bad somewhat embarrassing shape. There are also scraps of plastic scattering the yard from some sleds that had been ripped up due to a phenonemon. 

There's still got to be a ton of snow in N VT, perhaps not in your yard but in the woods in your hood.  Even down here in Central NH there is lots of snow in the woods.  Maybe your yard is bare but Im sure your area has lots of snow.  I just don't understand your post that there can't be measurable snow in New England on 4/14.   I have had snow on Memorial Day weekend.  

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36 minutes ago, ORH_wxman said:

Sorry...Saturday night through Monday morning is sub-freezing there regardless of what the calendar says. Enjoy your sleet bullets and ZR. 

Waterville is a well known snow spot... western slope between Mansfield and Jay Peak and all those towns up there from Eden on the east slope to Belvidere on the west side.  Bakersfield is the spot that always pulls 30"+ totals in big upslope events.

Waterville is the marker...guy probably gets similar snow to J.Spin.

Untitled.jpg.579badd57689e30db900a08a720613cd.jpg

 

29 minutes ago, Weatherexpert said:

Born and raised in the VT area. If you would like to see my yard i can take a photo - however most of the snow has melted at this point which exposes my extremely damaged yard - grass is ripped up and it is in extremely bad somewhat embarrassing shape. There are also scraps of plastic scattering the yard from some sleds that had been ripped up due to a phenonemon. 

I'm just joking with you about a photo... I just think your yard will be covered on Sunday morning with some frozen material. 

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Just now, powderfreak said:

Waterville is a well known snow spot... western slope between Mansfield and Jay Peak and all those towns up there from Eden on the east slope to Belevidere on the west side.

Waterville is the marker...guy probably gets similar snow to J.Spin.

 

 

 

I had no idea how far north he was...yeah hes getting more snow...not just sleet and ZR. His post deserves multiple buns.

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2 minutes ago, dendrite said:

GFS is all snow here from about 39-60hrs. Of course the NAM usually wins those H75 temp battles.

i know i mentioned this already a while ago ... but more signs/clues perhaps that there's a bit more of a colder correction in terms of depth and profile to this ordeal... 

maybe not, but... the NAM 'tucked' snow ptype into Essex for several hour near dawn on Monday ... and now your seeing that... makes me wonder if we just keep adjusting - to what ends? who knows -

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1 minute ago, dendrite said:

GFS is all snow here from about 39-60hrs. Of course the NAM usually wins those H75 temp battles.

The low levels are so ridiculously cold that there will prob a lot of snow grains and pixie dust in your 'hood and even possibly down to the pike region. Putting up -9C and -10C at 900-950 below the warm layer is no joke. That's like arctic airmass during overrunning in Jan/Feb 1994 type stuff. It's so weird to see it in April, but if the guidance keeps showing it, then it is what it is...gotta forecast for it.

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