March 5-6 Storm Discussion

[downeastnc]

The wind has been perfect all day today to really blow it out in the sounds, so on our end its actually approaching or exceeding record lows and out on the OBX the sound side of the Pamlico is experiencing pretty significant flooding with lots of roads closed, vehicles in the water etc. 

 

Washington NC hydro showing the water is actually closing in on 3 ft BELOW normal water level and a 4 ft drop in 12 hrs outside of a hurricane thats pretty damn impressive. In fact I just checked and this is the second lowest water level on record at this location

 

 

And here is a soundside obs showing where all that water went

 

[franklin NCwx]

An EPIC Fail for anyone inside the DC Beltway. IT is raining now, washing away the mere .2 inch we received earlier.

reading the mid Atlantic thread after playing in half a foot of snow is a great way to end the day. What epic comedy going on in that subforum. I would pay to see nchighcountrywx post one of his "its a geeat day in the nc highcountry to get out and enjoy the snow" in the mid Atlantic thread!

[Teru Teru Bozu]

Just an observation but... 90% of my snow this winter has been with temps above freezing. Sometimes like 10f above.

 

For real. I stopped counting the number of times I saw the precip type change during that semi-event back in February. It was either slushy snow or clumpy rain, back and forth, all day. 95% of which did not accumulate, of course.

 

But since I am a lady I will say something nice about this past winter. We had thundersnow. For like a minute or so back in January. But it was pretty cool.

[deltadog03]

WOW!!!  Not gonna lie, I would be PISSSSSSED If I lived and forecasted for DC.  What an E P I C fail.......this is where I LOVE to tell the haters (ie. people that say we can be wrong so much and keep my job) to see if they want to switch jobs, and listen to the pissed people that it didn't snow.

[LithiaWx]

Why in the name of all that is holy did someone create that graphic using nautical miles?

[WilkesboroDude]

Why in the name of all that is holy did someone create that graphic using nautical miles?

 

Clovers this time of year? 

 

Doubt that...everything is dead here.

[mackerel_sky]

I've got clover alive and well imby! This storm was a total fail for the big cities. I'm glad it wasn't us watching Gastonia get a foot with rain in Belmont !!

Clovers this time of year?

Doubt that...everything is dead here.

[Jaydog]

I saw that a few times while I was there.  You can actually walk across the river bottom in Washington under the HWY 17 bridge when it gets low.  Lots of neat things also emerge as the water reveals the riverbed.

The wind has been perfect all day today to really blow it out in the sounds, so on our end its actually approaching or exceeding record lows and out on the OBX the sound side of the Pamlico is experiencing pretty significant flooding with lots of roads closed, vehicles in the water etc. 

 

Washington NC hydro showing the water is actually closing in on 3 ft BELOW normal water level and a 4 ft drop in 12 hrs outside of a hurricane thats pretty damn impressive. In fact I just checked and this is the second lowest water level on record at this location

 

pamn7_hg.png

 

And here is a soundside obs showing where all that water went

 

hcgn7_hg.png

[beanskip]

By the way ONCE AGAIN a large segment of folks on AmericanWx just decided to ignore the obvious BL issues that existed with this storm and now are wondering what happened. I wish I understood the "it's too early to worry about BL" line that I read over and over on these boards? WHY is it too early? Why do we just assume that because there is a big bowling ball low that -- like magic -- models will be wrong and temps will be not be 34-37 as soundings show, but closer to or at freezing? When a model shows 850s too cold, it's perfectly acceptable in this community to talk about how the models doesn't sustain snow, but the minute someone gets on the north side of the 850 0c line, all the sudden it's aumotically a snowy model run, even if the 10m 0c line is somewhere in the Northwest Territory.

 

That's twice this year I got shouted down for EVEN BRINGING UP boundary layer as just a CONCERN. And that's twice that those who did so were just wrong.

 

HOW MANY TIMES do we get burned on this before BL becomes a legitimate topic of discussion 3, 4, 5 days before a storm?

[Cold Rain]

By the way ONCE AGAIN a large segment of folks on AmericanWx just decided to ignore the obvious BL issues that existed with this storm and now are wondering what happened. I wish I understood the "it's too early to worry about BL" line that I read over and over on these boards? WHY is it too early? Why do we just assume that because there is a big bowling ball low that -- like magic -- models will be wrong and temps will be not be 34-37 as soundings show, but closer to or at freezing? When a model shows 850s too cold, it's perfectly acceptable in this community to talk about how the models doesn't sustain snow, but the minute someone gets on the north side of the 850 0c line, all the sudden it's aumotically a snowy model run, even if the 10m 0c line is somewhere in the Northwest Territory.

 

That's twice this year I got shouted down for EVEN BRINGING UP boundary layer as just a CONCERN. And that's twice that those who did so were just wrong.

 

HOW MANY TIMES do we get burned on this before BL becomes a legitimate topic of discussion 3, 4, 5 days before a storm?

I think it's relevant to look at boundary layer temps, but by the same token, I don't think you can just look at a 10m temp that's above freezing (not saying that's what you are doing) and assume there still can't be a good snowstorm. Dynamics matter/precip rates. Dew points matter. Depth of the above freezing layer matters. Magnitude of the positive above freezing differential matters. Any warm nose present matters. Maybe you mean all of that when you say "boundary layer".

One thing I noticed is that this system sort of acted as a Miller B. That always makes me suspicious of snow. I don't know if any warm air aloft worked in as a result of that process with this system, but that's always a concern of mine with a Miller B. I don't know if this was a true Miller B or not, but it seemed to have some of those characteristics.

[downeastnc]

I saw that a few times while I was there.  You can actually walk across the river bottom in Washington under the HWY 17 bridge when it gets low.  Lots of neat things also emerge as the water reveals the riverbed.

Me and my brother were duck hunting near the mouth of Tranters one year on a day much like today it was maybe a year or two after Floyd and as that cove on the right as you enter the creek  blew out it exposed a coffin stuck in the mud on the bottom. I assumed it was one of the ones that floated during the flood anyways we called the sheriff but they couldnt get to it cause the mud was so deep as far as I know its still there 

 

 

Looks like -3.57 is gonna do it might get a touch lower winds starting to wind down just a bit still looks to be #2 all time 

 

Low Water Records

(1) -3.70 ft on 01/04/1989

(2) -2.79 ft on 02/12/2012

(3) -2.66 ft on 01/16/1992

(4) -2.62 ft on 12/25/2002

(5) -2.23 ft on 02/01/2013

 

 

[jshetley]

By the way ONCE AGAIN a large segment of folks on AmericanWx just decided to ignore the obvious BL issues that existed with this storm and now are wondering what happened. I wish I understood the "it's too early to worry about BL" line that I read over and over on these boards? WHY is it too early? Why do we just assume that because there is a big bowling ball low that -- like magic -- models will be wrong and temps will be not be 34-37 as soundings show, but closer to or at freezing? When a model shows 850s too cold, it's perfectly acceptable in this community to talk about how the models doesn't sustain snow, but the minute someone gets on the north side of the 850 0c line, all the sudden it's aumotically a snowy model run, even if the 10m 0c line is somewhere in the Northwest Territory.

 

That's twice this year I got shouted down for EVEN BRINGING UP boundary layer as just a CONCERN. And that's twice that those who did so were just wrong.

 

HOW MANY TIMES do we get burned on this before BL becomes a legitimate topic of discussion 3, 4, 5 days before a storm?

I'd agree about that for sure. Those BL issues can mess things up for sure. Temps can cool quickly due to dynamics, but it does not happen often around here. Another thing that usually goes wrong around here is having to count on cold air coming in during a storm unless it comes in with CAD. Depending on cold air having to cross the mountains almost never works out here. The cold air needs to already be in place ahead of the precip for us to get major snow or ice 90% of the time.

[Bevo]

By the way ONCE AGAIN a large segment of folks on AmericanWx just decided to ignore the obvious BL issues that existed with this storm and now are wondering what happened. I wish I understood the "it's too early to worry about BL" line that I read over and over on these boards? WHY is it too early? Why do we just assume that because there is a big bowling ball low that -- like magic -- models will be wrong and temps will be not be 34-37 as soundings show, but closer to or at freezing? When a model shows 850s too cold, it's perfectly acceptable in this community to talk about how the models doesn't sustain snow, but the minute someone gets on the north side of the 850 0c line, all the sudden it's aumotically a snowy model run, even if the 10m 0c line is somewhere in the Northwest Territory.

 

That's twice this year I got shouted down for EVEN BRINGING UP boundary layer as just a CONCERN. And that's twice that those who did so were just wrong.

 

HOW MANY TIMES do we get burned on this before BL becomes a legitimate topic of discussion 3, 4, 5 days before a storm?

 

Well Skip, in this case it resulted in being irrelevant to me.  I've only ever said that I will consider BL temps if within 3 days I still have a legitimate threat.  Otherwise it makes no difference.  I never said anything close to being in the same vicinity of " Don't talk about BL issues".  Just in case you were referring to me.  

[LovingGulfLows]

Well, people were acting like this storm as taking place in them middle of January as opposed to March. Of course, you have to take in account BL issues...this wasn't a full blown blizzard like '93 where rates were extreme and could overcome sun angle. It's funny because days before the storm, people were harping on the guy who was saying it was going to be a rain storm and saying, 'watch what happens. I bet you it's going to snow'. Look what happened. Hilarious.

 

The northern trend always wins and climatology 90% of the time wins out. Sorry to say.

[MidlothianWX]

I think it's relevant to look at boundary layer temps, but by the same token, I don't think you can just look at a 10m temp that's above freezing (not saying that's what you are doing) and assume there still can't be a good snowstorm. Dynamics matter/precip rates. Dew points matter. Depth of the above freezing layer matters. Magnitude of the positive above freezing differential matters. Any warm nose present matters. Maybe you mean all of that when you say "boundary layer".

One thing I noticed is that this system sort of acted as a Miller B. That always makes me suspicious of snow. I don't know if any warm air aloft worked in as a result of that process with this system, but that's always a concern of mine with a Miller B. I don't know if this was a true Miller B or not, but it seemed to have some of those characteristics.

 

Just to sort of back up your point, the BL stuff is obviously important but it's certainly not the end-all-be-all. I thought we were dead in the water (RIC area) after looking at the Tuesday night runs. Not only was the depicted low track terrible for snow here but the 10m temps were torching.

 

What ended up happening was the 5h max tracked 25-50 miles SE of what the models had shown. As a result, I was getting +TSSN while DCA and BWI were raining. Incredible dynamics/lift can overcome some pretty crazy temp issues. Case in point, I accumulated approximately 4" in 5-6 hours at ~34 degrees.

 

I'm sure you guys have your own microclimo issues further south so obviously I don't speak for everyone - just trying to make a larger point really.

[beanskip]

Oh no, not referring to you -- or anybody else, really -- in particular. I just don't understand why BL issues are "off the table" but other specific factors are not. Are BL temps any less important, ultimately, to snowfall than 850 temps? Why get hyped up about a storm JUST because the 850 temps look good? I don't know, I think there is way too much confidence in dynamic cooling on these boards.  

Well Skip, in this case it resulted in being irrelevant to me.  I've only ever said that I will consider BL temps if within 3 days I still have a legitimate threat.  Otherwise it makes no difference.  I never said anything close to being in the same vicinity of " Don't talk about BL issues".  Just in case you were referring to me.  

[Bevo]

Oh no, not referring to you -- or anybody else, really -- in particular. I just don't understand why BL issues are "off the table" but other specific factors are not. Are BL temps any less important, ultimately, to snowfall than 850 temps? Why get hyped up about a storm JUST because the 850 temps look good? I don't know, I think there is way too much confidence in dynamic cooling on these boards.  

 

I can only speak of my own confidence in dynamic cooling - but it has been pretty good to me with several systems over the years.  But then, I have received the "prison end" on some as well - this past January is still a fresh enough memory.  Those damn 925's were the Legos that your kids left on the floor before bedtime.  All you wanted was a quick drink of water.  You didn't need to turn on the lights.  No reason to wear slippers. 

[SnowNiner]

Oh no, not referring to you -- or anybody else, really -- in particular. I just don't understand why BL issues are "off the table" but other specific factors are not. Are BL temps any less important, ultimately, to snowfall than 850 temps? Why get hyped up about a storm JUST because the 850 temps look good? I don't know, I think there is way too much confidence in dynamic cooling on these boards.  

 

I agree.  I think there was a general "it's an ULL, it's going to be ok" vibe to it.  It was less about the validity of the BL issues but more about how unquestionable the ULL is in producing snow.  It makes me think, if DC had issues up north even though they were on the good side of the storm (AND colder), we would certainly have had the same issue here.  

 

I just don't believe in ULLs.  I've gotten snow with them, but it's always been slushy (and usually in March).  Yeah you may win a little bit every once in a while, but usually you just lose. 

[franklin NCwx]

The problem with dc was the lack of upward motion. Just look at midlo. He was farther south and was able to under some good vv. If you are relying on dynamic cooling then you need dynamics. Without dynamics you get what dc and surrounding areas got.

[QC_Halo]

So considering the amount of time you spend on here, how does that make you feel?

Just goes to show you the models can give you a general idea of the potential that's there, but the weather is just going to do what it's going to do.

[superjames1992]

As Franklin notes, it was a huge QPF bust for DC.  Most areas around the city got half (or less) of what they were forecasted.  That played a role as temperatures gradually climbed during the day with only light precip being reported.

[isohume]

After a cursory look at the DC area data...the 12Z WAL sounding showed a pronounced e/ly sfc-h85 marine layer. This saturated the llvls and by the time the sfc winds backed in caa...the saturated layer was too much to overcome as far as cooling to support -snsh. The sfc layer tw/s were already reached above freezing...so the p/type remained as ra with some mixing of sn/ip as colder air aloft descended. The precip intensity had little, if any, effect.     

[ColdRainsStr8cashhomey]

After a cursory look at the DC area data...the 12Z WAL sounding showed a pronounced e/ly sfc-h85 marine layer. This saturated the llvls and by the time the sfc winds backed in caa...the saturated layer was too much to overcome as far as cooling to support -snsh. The sfc layer tw/s were already reached above freezing...so the p/type remained as ra with some mixing of sn/ip as colder air aloft descended. The precip intensity had little, if any, effect.     

 

now that is a quality post... thanks for your input

 

the few, the proud, the marine layer... dun dun dun