Big Snow threat, what will it do, part II

[TalcottWx]

DT thinks most of us are getting crushed, apparently

You know, time and time again, DT and Bastardi prove to be that the farmers almanac can be more accurate than a lot of their forecasts.

 

Call me crazy but I'd much prefer a degreed met to produce a map telling us what they think the region will get rather than 6 probabilities. And I'm sure the general non weenie public would prefer that method, but maybe I'm crazy

I would prefer snowfall totals than probabilities as an amateur weather hobbyist. 

 

You know people north of the Pike will get some good overrunning for a time. In fact, there are signs they may be snowing for a while while southern areas dryslot a bit. The DS will not last as they play catchup Thursday night, but that is how I see it. 

Eeek. Sounds kinda messy, snowgrowth probs then too at some point, might have to rely on being in the banding. Overrunning hints disorganized to me.

 

You are going to be severely disappointed with the future of forecasting then.

 

As things currently stand (NWS forecasts at least) you have very little idea of forecast uncertainty. There are days where 90 degrees for a high at BDL is high confidence and days where it is low confidence, but you wouldn't know that from the point and click. WFOs are already moving towards probabilistic products for QPF (and thus ice and snowfall). I know you've seen those from BOX.

 

Ensembles are probabilistic forecast tools. WPC uses probabilities for QPF, snowfall, and ice. SPC uses them for severe weather. Hurricane track forecasting is probabilistic. 

 

The more deterministic you become the more you run the risk of leaving people unprepared for the eventual outcome. You will overwarn the people who bust "negative" but underwarn those who bust "positive." You can be black and white when you are nowcasting the near term, you have to be gray beyond that because there are no atmospheric certainties.

I think for the general public this is the way to go. I just prefer snowfall maps.

 

FYI I am also suspicious of all the WAA snows because to me 700mb looks like crap and notice how the GFS/Euro really are not quite as gung ho on the overrunning snows as the NAM is....if it were 24-36 hours out I'd feel more confident the NAM's idea at least north of 42N was right but I even worry about that idea being hogwash rightt now.

I think the NAM has proved time and time again it really should not even be put into consideration. A shrug of the shoulders to that model in general.

[CoastalWx]

Well there too.  I just did not like the whole look of the NAM.  Garbage SLP, garbage 850mb, garbage 700mb.  I'm just point out what I see.  Would I take the run seriously, no, just discussing it.  Some get all bent out of shape though when you do.

 

This is why disco does not equal forecast and why the NAM deserves like 3 posts..lol. Like I said..I could care less what it shows to be honest. I still remember when it took the Feb blizzard over Phil like 36 hrs out. Ever since then I wipe you know what with it. However it's a model disco and people need to be aware of that. I know you know this.

[TauntonBlizzard2013]

LOL this is the bullsh*t spewed by horrible OCMs.

"The NAM and GFS have lower totals over SE MA because they show mixing, but the european model has the most snow because the storm is further offshore.."

This is them ripping snow algorithms that make zero sense. Shoot me.

Lol saw that this morning as well. I can't wait too see how the 5 inches in southeast ma works out because of mixing

[CoastalWx]

Lol saw that this morning as well. I can't wait too see how the 5 inches in southeast ma works out because of mixing

 

The problem is...the models they show are giving snow amounts less there due to different reasons. It's flawed logic.

[OceanStWx]

FYI I am also suspicious of all the WAA snows because to me 700mb looks like crap and notice how the GFS/Euro really are not quite as gung ho on the overrunning snows as the NAM is....if it were 24-36 hours out I'd feel more confident the NAM's idea at least north of 42N was right but I even worry about that idea being hogwash rightt now.

 

Even the Euro versus the GFS are pretty stark differences. The GFS begins WAA snows much earlier and continues to have a WAA component well into Friday morning. The Euro is a shorter duration overall (which does have some credence given the flow).

 

For those that are unfamiliar, I have the isentropic charts for the GFS and Euro here, for 280 K (which includes the major lifting levels of 850 mb and 700 mb). Shading is indicative of saturation (cool colors saturated enough for precip), wind barbs show winds on the 280 K surface as do streamlines. At 00z both models show isentropic upglide (lift from WAA). Euro first, then GFS.

 

 

 

By 06z, check out the changes between the two models. The Euro has neutral to maybe even downglide across most of the area. We would need to rely on deformation only for snowfall. The GFS continues strong upglide, and this lasts through 12z. Euro first, then GFS.

 

 

[powderfreak]

But there is the exact problem. It's fine to discuss it..but because it's discussed there are now posters who think that it's going to happen..when the chance is very very slim..Discuss it..but also add that it's not likely

Well that's no ones fault except there own.

I mean when a bomb model run comes out it's the same...shame if you believe that. But you should expect that every model run from here on out will be mentioned and discussed. Who cares what others think will happen or chose to believe. If you are confident in an outcome, let it ride and let others believe what they want.

[OceanStWx]

To me, my post probably explains the QPF difference between the two models on the northern edge of the storm.

[Logan11]

Sounds like we are heading away from these forecasts with a specific high temp for a specific location maybe. Back to the past then...all the old NWS forecasts when I was a kid would give temp ranges...  Sunny with high temperatures of 35-40, etc. Then somewhere along the line everyone (maybe led by tv met forecast graphics) started putting out specific temps for specific locales. It always strikes me as ridiculous because we cant be so precise.

 

You are going to be severely disappointed with the future of forecasting then.

 

As things currently stand (NWS forecasts at least) you have very little idea of forecast uncertainty. There are days where 90 degrees for a high at BDL is high confidence and days where it is low confidence, but you wouldn't know that from the point and click. WFOs are already moving towards probabilistic products for QPF (and thus ice and snowfall). I know you've seen those from BOX.

 

Ensembles are probabilistic forecast tools. WPC uses probabilities for QPF, snowfall, and ice. SPC uses them for severe weather. Hurricane track forecasting is probabilistic. 

 

The more deterministic you become the more you run the risk of leaving people unprepared for the eventual outcome. You will overwarn the people who bust "negative" but underwarn those who bust "positive." You can be black and white when you are nowcasting the near term, you have to be gray beyond that because there are no atmospheric certainties.

[ORH_wxman]

Sometimes I wonder if its worth having model threads again like years ago. I noticed the NYC forum just started doing it for this storm. You want to have storm discussion...but wading through 80 posts per model run can get more than a bit tedious at times.

[40/70 Benchmark]

FYI I am also suspicious of all the WAA snows because to me 700mb looks like crap and notice how the GFS/Euro really are not quite as gung ho on the overrunning snows as the NAM is....if it were 24-36 hours out I'd feel more confident the NAM's idea at least north of 42N was right but I even worry about that idea being hogwash rightt now.

Yea, I'd just feel a lot better if we actually had a well organized low....I hate these "smoke and mirror" systems...

[dendrite]

Well that's no ones fault except there own.

I mean when a bomb model run comes out it's the same...shame if you believe that. But you should expect that every model run from here on out will be mentioned and discussed. Who cares what others think will happen or chose to believe. If you are confident in an outcome, let it ride and let others believe what they want.

After all these years I can't believe we have to keep bringing up the same points to the same posters for every system. It makes you want to pull your hair out.

[Damage In Tolland]

After all these years I can't believe we have to keep bringing up the same points to the same posters for every system. It makes you want to pull your hair out.

Agreed..It's partially why some posters are hairless

[Baroclinic Zone]

Sometimes I wonder if its worth having model threads again like years ago. I noticed the NYC forum just started doing it for this storm. You want to have storm discussion...but wading through 80 posts per model run can get more than a bit tedious at times.

We need to have a serious discussion about how we should run these.  The whole thread was derailed with the probabilistic forecasting method.  Not needed in a storm discussion thread.  There is still far too much banter.  We really need a model only discussion thread.  Than maybe a general storm discussion thread.

[N. OF PIKE]

I'd like to see the more reliable models amp up the over running for ne mass at 12z

Thanks oceanst wx great post

[40/70 Benchmark]

Sometimes I wonder if its worth having model threads again like years ago. I noticed the NYC forum just started doing it for this storm. You want to have storm discussion...but wading through 80 posts per model run can get more than a bit tedious at times.

 

You've been beating Kev and I down on this topic for years.

[Stash]

It's how I remembered it too. The first instance I can remember of forecasting specific high temps, was watching CT's NBC station. Brad Field (who I remember as a great met) would forecast a specific high temperature for BDL, and if he was more than +\- 5 degrees, someone would win an umbrella or something. No idea if they still do that, it's been years.

Sounds like we are heading away from these forecasts with a specific high temp for a specific location maybe. Back to the past then...all the old NWS forecasts when I was a kid would give temp ranges...  Sunny with high temperatures of 35-40, etc. Then somewhere along the line everyone (maybe led by tv met forecast graphics) started putting out specific temps for specific locales. It always strikes me as ridiculous because we cant be so precise.

[Boston-winter08]

lol, SNE special

[ORH_wxman]

 

You've been beating Kev and I down on this topic for years.

 

 

Really? I don't recall that at all. I have been in favor of more specialized threads ever since we went to subforums, but the masses have all gotten so used to the "superthread" mentality where everything gets chucked into one bloated thread.

[CoastalWx]

Love those maps, Chris.

[HoarfrostHubb]

Really? I don't recall that at all. I have been in favor of more specialized threads ever since we went to subforums, but the masses have all gotten so used to the "superthread" mentality where everything gets chucked into one bloated thread.

Set up a poll. See what the masses want

[N. OF PIKE]

lol, SNE special

Whats the issue w the map

[40/70 Benchmark]

Really? I don't recall that at all. I have been in favor of more specialized threads ever since we went to subforums, but the masses have all gotten so used to the "superthread" mentality where everything gets chucked into one bloated thread.

Ok, I misunderstood.

 

I have no qualms with model threads....

[HoarfrostHubb]

Love those maps, Chris.

What is the sig of the 280 K surface?

[NorEastermass128]

Sometimes I wonder if its worth having model threads again like years ago. I noticed the NYC forum just started doing it for this storm. You want to have storm discussion...but wading through 80 posts per model run can get more than a bit tedious at times.

 

Maybe start a thread for ALL the 12z model runs.  Close that.  Start a new thread for 18z model runs...etc.  I would do this when there is a defined imminent threat (like now).  Otherwise, when we're in a boring pattern, the long threads like this one would suffice.

[TalcottWx]

Wow, accuwx is a brutal

[HoarfrostHubb]

Whats the issue w the map

Widespread 12"+??? Ummmmmm

[Logan11]

And when the tv met's waste like a full minute of their limited time reciting specific high temps for all the towns inn their DMA, then you know its all for ratings basically. It serves no useful meteorological purpose.

It's how I remembered it too. The first instance I can remember of forecasting specific high temps, was watching CT's NBC station. Brad Field (who I remember as a great met) would forecast a specific high temperature for BDL, and if he was more than +\- 5 degrees, someone would win an umbrella or something. No idea if they still do that, it's been years.
 

[Boston-winter08]

Whats the issue w the map

I don't think there's much consensus for 12+ at this point for that widespread an area, i'd probably go general 5-10 from CON to Rutland, VT southward

[dendrite]

We need to have a serious discussion about how we should run these.  The whole thread was derailed with the probabilistic forecasting method.  Not needed in a storm discussion thread.  There is still far too much banter.  We really need a model only discussion thread.  Than maybe a general storm discussion thread.

Sometimes a side topic comes up and people want to finish a debate/point on something. As long as it doesn't go on past a page I don't see the big deal.

Do we really want model threads again? It may work if we keep it to just 0z, 6z, 12z, and 18z all inclusive model threads, but we don't need 18z DGEX and 6z NMM WRF threads clogging the forum.

[OceanStWx]

What is the sig of the 280 K surface?

 

The idea is to pick a surface that includes the levels where you would expect snow growth, saturation, and lift. If you picked a surface that include only pressure greater than 500 mb, that wouldn't be too helpful to the precipitation generation process most of the time.

 

With this air mass 280 K slopes up from near 900 mb through 700 mb. So it covers most of our low to mid level significant layers.