March 5-6 Storm Discussion

[Stovepipe]

I have to admit, it's a little exciting to see MRX mentioning thunder snow for east TN tonight.  GFS and Euro agree we might squeeze out an inch in the valley before it's all said and done.  Wish I had a 4x4 and could rationalize a vacation day.  It's going to be fun in the mountains.

[burgertime]

Didn't see it mentioned but Hi-Res NAM has some wrap around making it close to the RDU area....probably won't amount to much but still it might be chance to see a rouge flizzard or two. 

[rosie]

WWA for up to 2" north GA.

[FallsLake]

Looking at the 12z NAM areas north and east of Raleigh could see some snow showers. Maybe .05 qpf around Raleigh increasing to ~.1 in the northern coastal plain; which could see a dusting to a half inch. But this is also spread over a 24 hour period so even a dusting might not be achievable.

[WilkesboroDude]

Steady Sleet to rain here in Wilkes at 39. Not sure if I will hit 54 today.

 

Is this our obs thread now?

 

[burgertime]

For folks in Northern NC (on the eastern side), you want to hope for the RAP to keep coming in stronger with this ULL...if it hits the coast and slow crawls out it gives you guys a good chance to get some better wrap around. 

 

Latest RAP vs. NAM

 

Nam same time frame:

 

 

[WilkesboroDude]

[GreensboroWx]

Steady Sleet to rain here in Wilkes at 39. Not sure if I will hit 54 today.

 

Is there our obs thread now?

 

 

No, the temps won't make it out of the 40s today in NW NC today with the rain starting up, so  bust there. Sort of an in-situ CAD....

[GreensboroWx]

For folks in Northern NC (on the eastern side), you want to hope for the RAP to keep coming in stronger with this ULL...if it hits the coast and slow crawls out it gives you guys a good chance to get some better wrap around. 

 

Latest RAP vs. NAM

 

Nam same time frame:

 

 

 

Man, that's some energy crossing our area...if only it were about 100mi south. 

[ColdRainsStr8cashhomey]

my Western NC forecast (good luck to Met, Don and FranklinNCwx):

 

Heavy snow streamers will develop on western-facing slopes (first - tonight) and this westerly to WNW wind direction will impact Graham, Swain, northern Jackson and portions of Haywood counties more directly tonight (as we have seen before in similar west to west-northwest wind events).  Tomorrow, the wind will switch to more of a NW direction which will impact northwestern-facing slopes in Haywood, Madison, Yancey and Mitchell through the day tomorrow and tomorrow night.  5-7" of snow is possible above 3,000-3,500ft in every one of these counties mentioned with 1-4" of snow expected within the warned area below 3,000ft. I also wouldn't doubt that a few places which get caught with the same wind direction for a longer period of time could see a foot/12" of snow along the highest elevations.

 

Even though a Winter Weather Advisory has been issued for Buncombe and Macon counties, many areas within those two counties will see mostly rain with only high elevation areas seeing more than 2-4" of snow.  Places like Black Mountain, Weaverville, and the mountains in Macon Co. can expect 2-4" of accumulating snow while towns like Asheville and Franklin may not see much more than an inch or so, although areas around and nearby to Franklin COULD be impacted more if that westerly wind sets up longer than expected.

[griteater]

I got one little ole question!  WHERE"S ALL THAT GREAT BLOCKING??? I mean there's no way this thing can go north right? I've heard the word blocking so much I'm sick of it... See the block? double blocking, banana block, rex block, etc.... I have heard all of them mentioned in the last week!!! I think what we really have is a block centered over the southeast.... It's called a snow block.

I wonder the same thing. All these folks talking about a great block was there. What happened? I guess it is just the weather doing what it wants t do.

Yeah what the hell happened to the block? What happened to it can't trend anymore due to the block to the north? I personally didn't think that could happen either.

Don't look at me. I never said there was a block. Remember the discussion a few days ago from GSP calling for nothing but cold rain outside of the mountains? Hey look, they were right again. Isohume for the win. Systems in this area always trend north, drier, and warmer. People need to realize that once and for all.

upper lows aren't as magical and life-altering as they are portrayed a lot of times even though I understand how it's fun to track these systems... the more I forecast them, the more I respect how challenging they are to predict... ultimately, a bunch more people end up with a cold rain than those with accumulating snow, so it's no real surprise a mythical "block" didn't set up northeast of us and change everything for us... as long as the flow isn't favorable west and northwest of us (pacific influence), it doesn't really matter the upstream pattern

A 552 block is not a historic thing. And you have to take into account other things like its orientation, its movement with time, ridging out west, orientation of energy diving into the area, movement of energy around the block, etc. None of those things are going to be modeled accurately 7-10 days out....not even 48 hrs out sometimes.

 

It looks like the block held fine.  These images aren't the best, but I'm using them because they are archived.  1st image below is the 500 mb map from yesterday's (Mar 4) 12z GFS that tracked the upper low along the NC/VA border.  The confluence over the northeast on this 1st image is centered through southern New York state into Connecticut.  2nd image is from last Friday's (Mar 1) 12z GFS that tracked the upper low through the heart of SC.  The confluence over the northeast on the 2nd image is also centered through Connecticut.  You could actually argue that the confluence on the more recent run of the GFS (1st image) is a bit stronger since it extends a bit further west.  Also, if you run the 500 mb loop, as the upper low is located over the Dakotas / MN, you can see how it pinches off and is forced to dive SE underneath the blocking confluence over the northeast.

 

But look out west.  The western ridging behind the upper low is clearly stronger in the 2nd image, with the ridging extending up into SW Canada.  This weakening of the western ridging to me was a key reason for the north adjustment of our upper low.

 

So, at a 5 day lead time, the upper low track adjusted from central SC to the NC/VA border.  That's probably the typical amount of north creep that we generally see with storms in our region in the winter.  I suppose there must be a common bias for models to overplay the strength of upstream ridging / downstream blocking, or some combination of the 2, in the 3-7 day range.

 

 

12z GFS (Mar 4)

 

 

12z GFS (Mar 1)

 

[Tacoma]

raining in asheville and 39 at my house.  don't think we'll see 50 either.

[frazdaddy]

 

Regarding the blocking issue that Frosty and Brick brought up before (i.e. where is all the great blocking?), I think the answer to that is in the word "great". It's all about the adjectives.

Over the past few years (and this seems to get worse every year), there seems to be some sort of contest for labeling modeled things -- blocking, upper lows, surface lows, upper forcing, etc. -- with the most outlandish adjectives to describe them. Words like "historic", "destructive", "rare", "devastating", "huge", "catastrophic", "super strong", etc. are thrown around to describe things that, most of the time, turn out fairly ordinary from a climo perspective. Sandy and the big NE snowstorm are two events that come to mind that were actually worthy of some of those descriptions.

Those words get used in a blog, on TV, in a weather analysis somewhere, and the spread like the plague through the weather community, leaving a path of weenie destruction in their wake when things don't pan out to the "historic" degree that was modeled 7 days out.

It's fun to look at a 7 day model chart and see 20" of snow in your back yard. I love it. And we all get wound up about it and go through all the PBP and get all excited, and then, guess what? Yep, everything normalizes in reality and we're left wondering why it's raining and where the block went and why does winter suck so bad.

A 552 block is not a historic thing. And you have to take into account other things like its orientation, its movement with time, ridging out west, orientation of energy diving into the area, movement of energy around the block, etc. None of those things are going to be modeled accurately 7-10 days out....not even 48 hrs out sometimes.

Part of being on these boards and avoiding disappointment is to understand that the super strong, historically rare, destructively catastrophic things hardly ever pan out. If we get caught up in the adjectives without remaining grounded in that concept, then we will continue to be disappointed and remain without understanding when the historically strong blocking doesn't work out, even though there was a small potential for it to at some point.

As far as DT goes, he's probably going to be wrong again. That's ok because we're all wrong sometimes. His problem is, jerkness aside, is he speaks in absolutes, which is the most foolish thing you can do in weather. I can count at least three times this winter where he said it was physically impossible for a storm to go north, but it did anyway. When you combine his absolute assertions with his childish behavior, you get the result that we see on his FB page. It's unfortunate, because the guy is smart.

Anyway, those are my thoughts for the day. Have a good one everybody, and congrats to any that see snow!

A very well thought out and spot on commentary sir.

[packfan98]

Man, the gfs just went east about 50 miles and takes most of New England out of the heavy precip!  The folks up there will start joining us at the bottom of the cliff.

[NavarreDon]

my Western NC forecast (good luck to Met, Don and FranklinNCwx):

 

Heavy snow streamers will develop on western-facing slopes (first - tonight) and this westerly to WNW wind direction will impact Graham, Swain, northern Jackson and portions of Haywood counties more directly tonight (as we have seen before in similar west to west-northwest wind events).  Tomorrow, the wind will switch to more of a NW direction which will impact northwestern-facing slopes in Haywood, Madison, Yancey and Mitchell through the day tomorrow and tomorrow night.  5-7" of snow is possible above 3,000-3,500ft in every one of these counties mentioned with 1-4" of snow expected within the warned area below 3,000ft. I also wouldn't doubt that a few places which get caught with the same wind direction for a longer period of time could see a foot/12" of snow along the highest elevations.

 

Even though a Winter Weather Advisory has been issued for Buncombe and Macon counties, many areas within those two counties will see mostly rain with only high elevation areas seeing more than 2-4" of snow.  Places like Black Mountain, Weaverville, and the mountains in Macon Co. can expect 2-4" of accumulating snow while towns like Asheville and Franklin may not see much more than an inch or so, although areas around and nearby to Franklin COULD be impacted more if that westerly wind sets up longer than expected.

 

Sounds about perfect Andy! Weaverville obs 37.9° with light rain.

[HurricaneTracker]

raining in asheville and 39 at my house.  don't think we'll see 50 either.

 

It's pretty raw out there.  Warm front about to lift into the region, so upper 40s still likely before the front passes later this evening.

[burgertime]

Man, that's some energy crossing our area...if only it were about 100mi south. 

 

Yep these past two winters we haven't been able to buy a good trend.    Just a hundred mile shift would probably have put many in central NC in the game.

[Cold Rain]

It looks like the block held fine. These images aren't the best, but I'm using them because they are archived. 1st image below is the 500 mb map from yesterday's (Mar 4) 12z GFS that tracked the upper low along the NC/VA border. The confluence over the northeast on this 1st image is centered through southern New York state into Connecticut. 2nd image is from last Friday's (Mar 1) 12z GFS that tracked the upper low through the heart of SC. The confluence over the northeast on the 2nd image is also centered through Connecticut. You could actually argue that the confluence on the more recent run of the GFS (1st image) is a bit stronger since it extends a bit further west. Also, if you run the 500 mb loop, as the upper low is located over the Dakotas / MN, you can see how it pinches off and is forced to dive SE underneath the blocking confluence over the northeast.

But look out west. The western ridging behind the upper low is clearly stronger in the 2nd image, with the ridging extending up into SW Canada. This weakening of the western ridging to me was a key reason for the north adjustment of our upper low.

So, at a 5 day lead time, the upper low track adjusted from central SC to the NC/VA border. That's probably the typical amount of north creep that we generally see with storms in our region in the winter. I suppose there must be a common bias for models to overplay the strength of upstream ridging / downstream blocking, or some combination of the 2, in the 3-7 day range.

Good post. Illustrates the importance of another feature besides the block as an influence on our system.

And thanks Fraz and Cash. Grit's post is a great example of the fact that there are so many variables that go into these things besides the ones with the most sensational descriptors in front of them.

[Buddy1987]

Gfs still juicy for SW VA looking at total QPF output. Hopefully it's not all the rain before it switches over tonight.

[kvegas-wx]

Saw 47 for a flash here in kvegas but as soon as the rain started we dropped back to 45. No way we hit 50 in the triad now.

[Bevo]

It looks like the block held fine.  These images aren't the best, but I'm using them because they are archived.  1st image below is the 500 mb map from yesterday's (Mar 4) 12z GFS that tracked the upper low along the NC/VA border.  The confluence over the northeast on this 1st image is centered through southern New York state into Connecticut.  2nd image is from last Friday's (Mar 1) 12z GFS that tracked the upper low through the heart of SC.  The confluence over the northeast on the 2nd image is also centered through Connecticut.  You could actually argue that the confluence on the more recent run of the GFS (1st image) is a bit stronger since it extends a bit further west.  Also, if you run the 500 mb loop, as the upper low is located over the Dakotas / MN, you can see how it pinches off and is forced to dive SE underneath the blocking confluence over the northeast.

 

But look out west.  The western ridging behind the upper low is clearly stronger in the 2nd image, with the ridging extending up into SW Canada.  This weakening of the western ridging to me was a key reason for the north adjustment of our upper low.

 

So, at a 5 day lead time, the upper low track adjusted from central SC to the NC/VA border.  That's probably the typical amount of north creep that we generally see with storms in our region in the winter.  I suppose there must be a common bias for models to overplay the strength of upstream ridging / downstream blocking, or some combination of the 2, in the 3-7 day range.

 

Eventhough - as CR also pointed out - there are so many variables that go into to this madness we have chosen to follow, The origins of winter life for the last two seasons have been the Pacific.  It hath giveth and it hath taketh.  Really it's been mostly taketh, but you get the point...

[burgertime]

I said it in the pattern thread when this threat first became legit, you just never know with ULLs. Like this one they often 5 days out end up in a totally different spot. Just think if the ridging out west was really sharp folks in NC would miss out and GA would be huge winners. Just the name of the game with these systems...they are an even bigger gamble to put your faith in. 

[Buddy1987]

Hey Burger not sure if anyone will answer me in the Ma thread busy times over there. Do you have access still to see what the QPF output was on the Euro run from last night it was basically the model yesterday still giving me some decent accumulations for overnight tonight.

[Brick Tamland]

Yep these past two winters we haven't been able to buy a good trend.    Just a hundred mile shift would probably have put many in central NC in the game.

 

But there was a lot of talk this winter about great looking patterns, great blocking, the players on the field look great, etc. I guess the main thing to get out of all of this is don't believe the hype.

[calculus1]

But there was a lot of talk this winter about great looking patterns, great blocking, the players on the field look great, etc. I guess the main thing to get out of all of this is don't believe the hype.

 

Or, don't hype things in your own mind when other people just discuss possibilities.  Possibilities do not equate to certainties.

[franklin NCwx]

my Western NC forecast (good luck to Met, Don and FranklinNCwx):

Heavy snow streamers will develop on western-facing slopes (first - tonight) and this westerly to WNW wind direction will impact Graham, Swain, northern Jackson and portions of Haywood counties more directly tonight (as we have seen before in similar west to west-northwest wind events). Tomorrow, the wind will switch to more of a NW direction which will impact northwestern-facing slopes in Haywood, Madison, Yancey and Mitchell through the day tomorrow and tomorrow night. 5-7" of snow is possible above 3,000-3,500ft in every one of these counties mentioned with 1-4" of snow expected within the warned area below 3,000ft. I also wouldn't doubt that a few places which get caught with the same wind direction for a longer period of time could see a foot/12" of snow along the highest elevations.

Even though a Winter Weather Advisory has been issued for Buncombe and Macon counties, many areas within those two counties will see mostly rain with only high elevation areas seeing more than 2-4" of snow. Places like Black Mountain, Weaverville, and the mountains in Macon Co. can expect 2-4" of accumulating snow while towns like Asheville and Franklin may not see much more than an inch or so, although areas around and nearby to Franklin COULD be impacted more if that westerly wind sets up longer than expected.

good post I agree with the more westerly wind component at the onset. Thst should really benefit the southern mtns.

[Brick Tamland]

Or, don't hype things in your own mind when other people just discuss possibilities.  Possibilities do not equate to certainties.

 

I know, but some folks tend to hype things by the way they deliver their message. They might not even know they are doing it, though.

[NCSNOW]

Man, the gfs just went east about 50 miles and takes most of New England out of the heavy precip!  The folks up there will start joining us at the bottom of the cliff.

 Hopefully packbacker from Apex who worships the GFS and thinks it owns the Euro will see this. Doesnt matter he'll be right back on the train claiming the GFS nailed this and that. Which I wouldn't  mind if it was correct.

[Brick Tamland]

 Hopefully packbacker from Apex who worships the GFS and thinks it owns the Euro will see this. Doesnt matter he'll be right back on the train claiming the GFS nailed this and that. Which I wouldn't  mind if it was correct.

 

I thought the GFS had done pretty well this winter.

[packfan98]

I thought the GFS had done pretty well this winter.

 

I think the GFS and EURO go back and forth on their performances in certain situations.  One of the downsides to the GFS I think is that it runs 4 times per day.  In the longer term, one might think that it is flopping around more than the EURO simply because there are twice as many runs to analyze.  Statistics can be made to sound however the presenter wants to shade them (ala DT).  I don't have an agenda and don't care which one is correct.  I really don't think someone can say that one is clearly the BETTER model.  Too subjective.