HECS Checklist.....What to Look for to Avoid

[Ginx snewx]

The ORH water equiv def looks wrong. No way we had 1.45" of liquid in this snow. I'm guessing we had close to 1" of liquid, maybe just a bit shy. I don't have the tools to do a core sample, but just going of past knowledge, no way its over 1".

That's what the official f6 says, no way but that's what it says that's why I asked the question.

[ORH_wxman]

That's what the official f6 says, no way but that's what it says that's why I asked the question.

The f6 often gets augmented in snow events since the ASOS can't accurately catch the water equiv in snow events...particularly when its windy. I think the ASOS water equiv was 0.34" which is obviously too low, but the 1.45" seems way high to me. But I didn't do a core sample. So I can't be 100% sure. The airport came in with 12.7" of snow so maybe they augmented slightly less than 10 to 1 ratios.

However, in my experience, even with this big wind, the ratios usually come out at about 12 to 14 to 1.

[Ginx snewx]

The f6 often gets augmented in snow events since the ASOS can't accurately catch the water equiv in snow events...particularly when its windy. I think the ASOS water equiv was 0.34" which is obviously too low, but the 1.45" seems way high to me. But I didn't do a core sample. So I can't be 100% sure. The airport came in with 12.7" of snow so maybe they augmented slightly less than 10 to 1 ratios.

However, in my experience, even with this big wind, the ratios usually come out at about 12 to 14 to 1.

Cocorahs in ORH county tops were .87

[ORH_wxman]

Cocorahs in ORH county tops were .87

That sounds more reasonable to me. I would have expected 20" with an inch and a half of qpf.

[radarman]

Does the CT Valley ever see a funneling low-level convergence enhancement like the Champlain Valley and Hudson Valley can on a more northerly wind flow? I feel like the CT Valley gets screwed more often than both the Champlain and Hudson valleys though it has about the same orientation. Also, the CT River Valley has smaller terrain on either side of it relative to both the Hudson and Champlain valleys, so why would it seem to get downsloped and screwed more often than the other two? I mean, the Hudson has the Catskills with peaks above 3,500ft on the west and the Berkshires with 2-3K foot terrain on the east... and the Champlain has 4-5,000ft Adirondacks on one side and 4,000ft Greens on the other.

Actually I think I just answered my first question... it must be the higher terrain on either side that causes enhanced convergence on a north wind in the Hudson and Champlain valleys. But why does it seem like the CT Valley gets screwed straight out almost every storm unlike the other two valleys which can jackpot more often than people think...especially the Champlain Valley where directional and speed convergence can cause them to clean up in certain situations.

The storm that crushed Burlington Jan 3, 2010 is a perfect example of what you are talking about. Moisture funnels directly out of the St. Lawrence.

[Baroclinic Zone]

[H2Otown_WX]

Its even worse they went with 13.9". There was no good banding that persisted over them which is the only way they would almost double most others.

As for their qpf, it must have been adjusted to better match that total cause the ASOS certainly didn't come up with that number. It was 8.4 to 1 here with .87" to 7.3" snow. I did actual snow core samples not made up.

Yeah, they're up to their old tricks I guess. I have heard they are notorious for inflating their snowfall totals. How much did you get in Collinsville?

[powderfreak]

However, in my experience, even with this big wind, the ratios usually come out at about 12 to 14 to 1.

Really? That seems a bit higher than I would've anticipated in big wind. I always have a hard time believing anything more than 12:1 in high wind snow events... and usually expect only like 10:1 during high wind.

I guess it makes sense though... this storm probably would've been a nice 20:1 or greater ratio snowfall without the wind.

[powderfreak]

Man what a band... I was so close just south of Albany... so close. Ended up with 11" or so instead of the two feet that fell a few miles (next county over) to the east.

[Collinsville]

Yeah, they're up to their old tricks I guess. I have heard they are notorious for inflating their snowfall totals. How much did you get in Collinsville?

It was in my last post. 7.3" with an asterisk that with wind could be a touch high or low. The only other time I recall wind this strong with snow was the short lived nuclear storm in early March 2005.

[H2Otown_WX]

It was in my last post. 7.3" with an asterisk that with wind could be a touch high or low. The only other time I recall wind this strong with snow was the short lived nuclear storm in early March 2005.

Sorry totally missed that. So you got about the same as I did. March 2005 was the famous "flash freeze" that I missed while in FL.

[CoastalWx]

I think overall models had the "ideas" right. That is, a jackpot where the best mid level frontogenesis and deformation was (NYC-MA/NY border) another potential jackpot over eastern areas from low level frontogenesis and convergence, and the in between area of less qpf. I do think that models sometimes are too generous in these "in between" areas. I remember thinking, "wow that's still a ton of qpf for these areas." The one thing we can't stress enough is the placement and orientation of mid level lows and RH. Dryslots always seem to sneak a little further north or northwest than we think. I feel this one was well modeled, but the question was how fast it would fill in. I feel like we just didn't have a forcing mechanism to wring out the moisture, and also, despite cyclonic east flow at H7, we were circulating the crap dry air around, overhead. The same air over us, was being forced west and lifted due to huge frontogenesis over the NYC area and eastern NY state. We all mentioned the possible dryslot numerous times, but it may have got lost in the post countering that, saying HECS etc. I did think the dryslot would be more confined to se mass, but it was modeled to creep into all of sne above 700mb. Big red flag.

If you recall, the radar was trying to fill in south of sne, but that convective..showery look to the radar is a sign of dry air and more in the way of CI (convective instability). I thought perhaps it may be trying to fill in, but I was wrong.

http://www.rap.ucar....me=1&duration=2

Here is the 850-500 RH/VV prog for 27/03z. Notice how it has a dry area of centrl mass, with high RH and VV over the west and down through NYC, due to mid level frontogenesis. Also, notice the area of BOS and se. This is due to strongly forced low level convergence and almost slantwise convection in this area.

Check out H7 at this time. Notice the sucker hole in central mass.

Now here is 850 and 950 millibars. Notice the big time convergence down by the Canal. This gave rise to the continuous redevelopment of precip in this area, as it pivoted nw. The CF definitely enhanced the snow near BOS, but I think this was the big culprit. It sort of reminds me of Dec '03.

Here is the surface prog.

[40/70 Benchmark]

I mentioned Dec 2003 about 100 times.

[Ginx snewx]

I mentioned Dec 2003 about 100 times.

I got obliterated in 03 , not

[CT Rain]

Does the CT Valley ever see a funneling low-level convergence enhancement like the Champlain Valley and Hudson Valley can on a more northerly wind flow? I feel like the CT Valley gets screwed more often than both the Champlain and Hudson valleys though it has about the same orientation. Also, the CT River Valley has smaller terrain on either side of it relative to both the Hudson and Champlain valleys, so why would it seem to get downsloped and screwed more often than the other two? I mean, the Hudson has the Catskills with peaks above 3,500ft on the west and the Berkshires with 2-3K foot terrain on the east... and the Champlain has 4-5,000ft Adirondacks on one side and 4,000ft Greens on the other.

Actually I think I just answered my first question... it must be the higher terrain on either side that causes enhanced convergence on a north wind in the Hudson and Champlain valleys. But why does it seem like the CT Valley gets screwed straight out almost every storm unlike the other two valleys which can jackpot more often than people think...especially the Champlain Valley where directional and speed convergence can cause them to clean up in certain situations.

Well I think a lot of it is we've just been unlucky. There really wasn't a downslope issue in this storm we just got hosed with some mesoscale banding east and west and just in a screw zone. This was the perfect type of storm for the CT Valley to cash in with a due northerly wind for most of the storm and some subtle convergence zones. We were battling mid level issues virtually the entire storm.

The last few winters we've had storms east and west and just plain unlucky.

I think many people think the valley is a lot more of a snow pit than it really is... especially down here west of HFD. Even the areas in the hills just west of here that normally cash in have gotten screwed royally the last few winters.

[OKpowdah]

I mentioned Dec 2003 about 100 times.

Yeah, very similar in a number of ways. IIRC it was also one of only a few set ups with the upstream ridge axis so far east.

Scott, really nice reanalysis there!

[ice1972]

Well I think a lot of it is we've just been unlucky. There really wasn't a downslope issue in this storm we just got hosed with some mesoscale banding east and west and just in a screw zone. This was the perfect type of storm for the CT Valley to cash in with a due northerly wind for most of the storm and some subtle convergence zones. We were battling mid level issues virtually the entire storm.

The last few winters we've had storms east and west and just plain unlucky.

I think many people think the valley is a lot more of a snow pit than it really is... especially down here west of HFD. Even the areas in the hills just west of here that normally cash in have gotten screwed royally the last few winters.

This......

I have been on Eastern and now American for 5 years now and only recently have people been discussing the CT Valley Screw Zone.......coincidental to the very unlucky couple of years we have been having here.......while certain setups certainly are more or less favorable I think the same could be probably be said about every other are in SNE....please correct me if I'm wrong......I guess we're paying for Feb 2006 still......

It has been good to be able to catch up on the more important things in life now that last weekends storm passed.....the week leading up to that was a total fail at work and at home......

[40/70 Benchmark]

Well, I'm sorry, but I'd rather be anywhere in MA over the CT river valley.....maybe there over the cape, but that's it.

Here on the cp, at least I don't have to worry about downsloping off of the ORH hills during nor easters.

I think a better way to state it would be that it's not as bad as it has seemed over the course of the past few years, but make no mistake about it....it is a snowhole.

[ice1972]

Yeah.....I get what you are saying.....I've seen the snowfall maps and for sure - we don't get as much on average.....but the way folks have been talking about it recently you would think the valley gets next to nothing when in reality we get a decent amount.....anyway....would be nice to see a series of storms that don't teeter on the verge of fail every time....would love a foot plus storm with less than 48 hours notice.....that would be glorious.......

[CT Rain]

This......

I have been on Eastern and now American for 5 years now and only recently have people been discussing the CT Valley Screw Zone.......coincidental to the very unlucky couple of years we have been having here.......while certain setups certainly are more or less favorable I think the same could be probably be said about every other are in SNE....please correct me if I'm wrong......I guess we're paying for Feb 2006 still......

It has been good to be able to catch up on the more important things in life now that last weekends storm passed.....the week leading up to that was a total fail at work and at home......

Yeah totally correct. I average in the mid 40s... people just northwest of me are over 50 and still "in the valley".

That's better than a lot of places in SNE. We've just had an unlucky stretch.

[Damage In Tolland]

Yeah totally correct. I average in the mid 40s... people just northwest of me are over 50 and still "in the valley".

That's better than a lot of places in SNE. We've just had an unlucky stretch.

I honestly don't think it's bad luck. The valley is a relative snowhole second only to SE CT. I don't buy the argument it's bad luck..Many met. factors come together to screw the valley relatively speaking when you compare to areas west and east

[CT Rain]

I honestly don't think it's bad luck. The valley is a relative snowhole second only to SE CT. I don't buy the argument it's bad luck..Many met. factors come together to screw the valley relatively speaking when you compare to areas west and east

Relative to normal the last 3 years have been horrific in the valley. Totally horrible.

Of course we get less snow than you... but BDL only gets about 12" less. It's not that significant.

[free_man]

Relative to normal the last 3 years have been horrific in the valley. Totally horrible.

Of course we get less snow than you... but BDL only gets about 12" less. It's not that significant.

I think it depends on the year. When using an avg maybe BDL gets 12" less than the higher hills, some years it might be 3 or 6" and others 15-20" which is very signficant.

[CT Rain]

I think it depends on the year. When using an avg maybe BDL gets 12" less than the higher hills, some years it might be 3 or 6" and others 15-20" which is very signficant.

Of course. My point is that relative to normal the Hartford area has seen substantially less snow than other areas in SNE. For example last year we saw 50% of our seasonal normal while most other areas were like 80% of normal. That's a significant difference that typically gets written off as "the CT Valley snow hole".

[Damage In Tolland]

Relative to normal the last 3 years have been horrific in the valley. Totally horrible.

Of course we get less snow than you... but BDL only gets about 12" less. It's not that significant.

But more often than not the valley is going to get screwed..They'll get screwed in heavy, wet snowstorms, and they;ll get downsloped to hell in a big coastal..Not that my area doesn't to a lesser degree off the ORH hills..but when you add it all up...it's not really bad luck in the valley..It's more related to actual meteorlogical reasons why .

[CT Rain]

But more often than not the valley is going to get screwed..They'll get screwed in heavy, wet snowstorms, and they;ll get downsloped to hell in a big coastal..Not that my area doesn't to a lesser degree off the ORH hills..but when you add it all up...it's not really bad luck in the valley..It's more related to actual meteorlogical reasons why .

You're not getting what I'm saying. I'm saying the past couple winters we've just been screwed relative to normal. It's been bad luck.

Obviously we don't average as much as ORH but we average more than Boston!

[Damage In Tolland]

You're not getting what I'm saying. I'm saying the past couple winters we've just been screwed relative to normal. It's been bad luck.

Obviously we don't average as much as ORH but we average more than Boston!

That is surprising..since it seems like Boston is in a better snow spot than BDL mostly due to latitude.

[CT Rain]

That is surprising..since it seems like Boston is in a better snow spot than BDL mostly due to latitude.

BOS averages 42" I think... BDL is close to 50" lol.

[free_man]

You're not getting what I'm saying. I'm saying the past couple winters we've just been screwed relative to normal. It's been bad luck.

Obviously we don't average as much as ORH but we average more than Boston!

That is true, valley % rel to their norm has been below that of other areas.

[CT Rain]

That is true, valley % rel to their norm has been below that of other areas.

Yup... it's been unpleasant.

The horrible valley that is so terrible in all winters still managed 6" more snow than BOS on average. So it's not that bad.

Hell, it's better than all of RI practically.