March 6-8th Ocean Storm Discussion Part III

[Clinch Leatherwood]

I want to give you props for sticking with this early on.

Same with Tip (John)

 

18z GFS just threw a monkey wrench in the parade.  It could be one of those times it finds a nugget but it looks suspicious to me.  Everything else at 18z came in more amped even the lowly NavGEM....motley crew I know in the NAM/RGEM/NavGEM but it makes the GFS kind of stick out as an anomaly.

 

Let's see what the GEFS show.

 

I'd be disappointed if interior areas only got 8-10", going to be honest.  This has so much more potential but even if the GFS is wrong it shows how an unstable top wobbling around can really mess up forecasts.  Andy is a huge fan of the UKMET, and it swears in a faster ULL progression and more SE.  We'll see.

[powderfreak]

Where? About that for BOS...top 3 at BOS are 27.5, 27.2, and 26.4...not happening or even close this storm. Well unless this goes April '97 on us.

Thanks, yeah I was just curious as messenger said he had moderate confidence in a top 3 snowstorm for BOS-PVD....I wanted to see what numbers needed to be hit.

[HoarfrostHubb]

You're focusing too much on the fact that the ranges are different. This could be as small as 8.3" and 8.4". The latter will round up to 8-10".

Just wanted to mention that I really appreciate your input this winter.

[Damage In Tolland]

Just wanted to mention that I really appreciate your input this winter.

You are very welcome Hunchie

[nutmegfriar]

it just keeps the low and mid-level warmth pretty much offshore of SNE entirely. doesn't have the westward flood that it has shown recently. euro is similar in that regard.

Ok.  Thanks.

[powderfreak]

I'd be disappointed if interior areas only got 8-10", going to be honest.

To put it in perspective though, remember that 36 hours ago this was cirrus. So even 5" is a win, as its better than the original theme of partly cloudy.

[HoarfrostHubb]

You are very welcome Hunchie

I was really hoping to catch your totals late in the game...but that does not look like it will happen. But at least 1 member of the Scooter family likes your forecasts!

 

Rain on the tail end of the GFS

[Damage In Tolland]

I was really hoping to catch your totals late in the game...but that does not look like it will happen. But at least 1 member of the Scooter family likes your forecasts!

Rain on the tail end of the GFS

I wonder if this is our last one?

[Clinch Leatherwood]

Thanks, yeah I was just curious as messenger said he had moderate confidence in a top 3 snowstorm for BOS-PVD....I wanted to see what numbers needed to be hit.

Top 10 probably better as things were, I thought the bar was a little lower than it is.

 

That said when we speak of probabilities, that isn't far outside of the HPC progs...they had a 40% probability for 18" or greater just west of the Bos to Pvd corridor, and somewhere between 20-30% for 2' plus along and just west of I95.  Again, moderate confidence is how i'd describe 40% at 2-3 days.

 

The 18z GFS is a reminder if even totally wrong how fickle the setup is.

[capecod04]

Top 10 probably better as things were, I thought the bar was a little lower than it is.

That said when we speak of probabilities, that isn't far outside of the HPC progs...they had a 40% probability for 18" or greater just west of the Bos to Pvd corridor, and somewhere between 20-30% for 2' plus along and just west of I95. Again, moderate confidence is how i'd describe 40% at 2-3 days.

The 18z GFS is a reminder if even totally wrong how fickle the setup is.

havent seen you this bullish sine 2005

[HoarfrostHubb]

I wonder if this is our last one?

Maybe the last biggie...who knows? Of course, this could fall on its face, too, a la 2/10/10...but not expecting it.

[weatherMA]

Just wanted to mention that I really appreciate your input this winter.

This.

Great to have another met from GYX in here.

[CoastalWx]

If models are right, the interior and possibly coast are not done. Blocking FTW. Warministas FTL.

[free_man]

Apparently the OT chat only applies to a certain few,  not surprisingly.

[DFRI]

 

 

 

 

 

 

 

 

[Mr Torchey]

GEFS?

[SouthCoastMA]

GEFS?

Drier like the OP

[eduggs]

looking at the 18z RGEM, 18z/12z GFS and 12z Euro:

 

I think the GFS is probably OTL at 18z.  It's suddenly weaker with the feature coming into the Lakes.  As a result/in combination with, the ULL being a little faster and probably also a little weaker.  I suppose it could be right, but it looks more like the GFS off hour BS.  Looks different all across the northern hemisphere like something happened.   With the offshore ULL it was well NW last night, jumped hundreds of miles SE at 12z, and then stayed there but got weaker this run.  The Euro meanwhile has moved a decent amount NW.   Impossible to pick a winner but my odds would be on a more Euro esque solution.

RGEM kind of broke towards the Euro, is stronger in the Lakes and more like the 12z GFS offshore.  So in between.  If you look at the 48 hr 18z RGEM it looks to be somewhere in between the GFS/Euro.

 

Hey it's that time, but if I had to do a forecast I'd pretty much give the 18z GFS zero credence until proven otherwise, actually zero credence.  If I'm wrong on that, so be it.

I'm a little confused.  When I overlay the GFS and Euro, they look very similar in all features.  The differences are pretty minor in my opinion for a highly anomalous setup.  I see no reason to toss the GFS.  The Euro has a small area of higher QPF in eastern MA that sums to a noticable difference over 24 hours, but the GFS has enhanced QPF (albeit lighter) in a similar area at the same time intervals.  QPF is the most dubius parameter.  I appreciate your efforts to analyze the finer points of this, but I feel like you might be overanalyzing it.  It is not like the Euro has been showing the same solution for several runs... it will change somewhat tonight.  I feel like both the Euro and GFS are comfortably within the spread of consensus.

[Clinch Leatherwood]

havent seen you this bullish sine 2005

 

Maybe overly so, we'll see.  There's no way of knowing if what the GEFS/GFS just did is a trend in being faster like the UK (I've read innumerable NOAA and NCEP discussions saying there's no way this ULL will move faster due to the block but that doesn't mean it has to not go fast) or if this was just a bad run.

 

Remember Andy's UKMET.  It missed being much of a storm for the same reasons the GFS is tickling towards at 18z.  I wouldn't put the UKMET up there as a top performer and this would pretty much be unprecedented for the Euro to build inside of 48-60 only to fail, but we'll see.

 

Everything else at 18z looked great.

 

The NWS forecast map is a great starting point for now.

[eduggs]

Maybe overly so, we'll see.  There's no way of knowing if what the GEFS/GFS just did is a trend in being faster like the UK (I've read innumerable NOAA and NCEP discussions saying there's no way this ULL will move faster due to the block but that doesn't mean it has to not go fast) or if this was just a bad run.

 

Remember Andy's UKMET.  It missed being much of a storm for the same reasons the GFS is tickling towards at 18z.  I wouldn't put the UKMET up there as a top performer and this would pretty much be unprecedented for the Euro to build inside of 48-60 only to fail, but we'll see.

 

Everything else at 18z looked great.

 

The NWS forecast map is a great starting point for now.

I'm not seeing it.  I'm overlaying panels right now, and the 18z GFS is nearly a carbon copy of 12z.  I don't see any tickling on the model and I don't see huge differences between the GFS and the other globals.  Are you putting too much emphasis on QPF?

[weathafella]

GEFS 1 inch line is Tolland eastward.

1.5 BOS E/SE

2 for the Canal east

Not alot of change in the east from 12Z but contracted in the west some.

[Clinch Leatherwood]

I'm a little confused.  When I overlay the GFS and Euro, they look very similar in all features.  The differences are pretty minor in my opinion for a highly anomalous setup.  I see no reason to toss the GFS.  The Euro has a small area of higher QPF in eastern MA that sums to a noticable difference over 24 hours, but the GFS has enhanced QPF (albeit lighter) in a similar area at the same time intervals.  QPF is the most dubius parameter.  I appreciate your efforts to analyze the finer points of this, but I feel like you might be overanalyzing it.  It is not like the Euro has been showing the same solution for several runs... it will change somewhat tonight.  I feel like both the Euro and GFS are comfortably within the spread of consensus.

 

18z GFS looks nothing like the 12z Euro at 500mb at 48 hours in terms of what matters.

 

The 18z GFS is probably 250 KM further NE with the main energy/ULL off the coast.  The 18z GFS is also weaker coming into the lakes compared to earlier runs and flatter.  By that I mean it's coming down in more of a belly flop elongated out on a 1030 to 430 orientation end to end versus the earlier run and the more aggressive models which are digging at a sharper rate, 1130 to say 530..LOL...I suppose degrees would have been easier to use.

Nothing else supports that.  Look up into the Lakes at the orientation of the energy on the 12z Euro at 54 hours, the 18z RGEM/NAM at 48 vs what the GFS just did.   I may be wrong on this but my OPINION is that the GFS whacks at 18z.  It's the little perturbations that make all the difference.

 

http://www.weatheroffice.gc.ca/data/model_forecast/colour_images/18_054_R1_north@america_I_4PAN_CLASSIC@012_048.jpg

[N. OF PIKE]

the GEFS 18z give messenger about 2.10 qpf Bos near 1.50 . basically it slid qpf 25 miles se but it was so pack'd of a gradient most people lost .5 qpf   damn ULL better not be a trend following ukie wrt other camps going forward

[eduggs]

18z GFS looks nothing like the 12z Euro at 500mb at 48 hours in terms of what matters.

 

The 18z GFS is probably 250 KM further NE with the main energy/ULL off the coast.  The 18z GFS is also weaker coming into the lakes compared to earlier runs and flatter.  By that I mean it's coming down in more of a belly flop elongated out on a 1030 to 430 orientation end to end versus the earlier run and the more aggressive models which are digging at a sharper rate, 1130 to say 530..LOL...I suppose degrees would have been easier to use.

Nothing else supports that.  Look up into the Lakes at the orientation of the energy on the 12z Euro at 54 hours, the 18z RGEM/NAM at 48 vs what the GFS just did.   I may be wrong on this but my OPINION is that the GFS whacks at 18z.  It's the little perturbations that make all the difference.

 

http://www.weatheroffice.gc.ca/data/model_forecast/colour_images/18_054_R1_north@america_I_4PAN_CLASSIC@012_048.jpg

I'm overlaying the panels right now.  The distance between the modeled ULL over the Atlantic is less than 100km at 48hours... and less as you move back in time.  And the differences over the lakes are minor.  I'm just not seeing what you are seeing.

[N. OF PIKE]

http://www.erh.noaa.gov/btv/html/4kmwrf/

 

loves the 95 corridor .  no sliding SE please

 

pretty similar but more enhancement on E slope or orh hills

 

http://www.erh.noaa.gov/btv/html/12kmwrf/index.php  touch colder with surface temps as well.

[eduggs]

There are differences between the model depictions to be sure.  And those relatively small differences will make a large impact on the outcome.  But I don't see any clear outliers.  All the global solutions appear to lie within the ensemble spread.  I don't see how we can reliably rule out any of them at this point.

[Clinch Leatherwood]

I'm not seeing it.  I'm overlaying panels right now, and the 18z GFS is nearly a carbon copy of 12z.  I don't see any tickling on the model and I don't see huge differences between the GFS and the other globals.  Are you putting too much emphasis on QPF?

 

You don't see the differences in both the angle and location of the critical s/w feature and the subsequent effects both offshore and later in the run between these two panels?  The GFS is dropping in flatter than the other models...in conjunction with the faster offshore...I just don't buy it.   Once offshore the GFS has a series of QPF bombs and takes a faster track with the 500mb feature that could be partially due to feedback. It wouldn't be the first time this system, read the earlier HPC Heavy Snow Discussion.   In short I'll take the Euro every single time.

 

I can't be sure it's wrong it hasn't happened yet, but I think it is.

 

These are displayed top to bottom, 12z Euro, 12z GFS, 18z GFS. 

[Mr Torchey]

Really liked the 18z rgem.

[HoarfrostHubb]

Definitely subtle changes on those.

[Clinch Leatherwood]

There are differences between the model depictions to be sure.  And those relatively small differences will make a large impact on the outcome.  But I don't see any clear outliers.  All the global solutions appear to lie within the ensemble spread.  I don't see how we can reliably rule out any of them at this point.

 

Of course they're minor.  The net net is the GFS at 18z is like 1.5" of QPF and the Euro is 2".  But those minor differences have a huge impact later.  The GFS runs a stripe of enormous QPF along the eventual track of the dog eared 500mb structure.  It's alone in doing that, it's a typical GFS thing.  I think it's wrong.

 

Is there a single event where the GFS has been right inside of 48 hours this winter?  It wasn't with the blizzard.  It stunk with all the scrapers in that range.  The NAM had 1 or 2 coups.  The Euro was right most of the time inside of 48 hours.

 

That said the Euro has had a tendency to park things too far west and southwest.  So, a compromise is in order for now.

 

You can do whatever you'd like with the GFS and I appreciate your opinion, I'm tossing it.   I've been pretty clear for at least 2 days on what I felt and when, riding some models when I felt they had a reasonable solution, others at a later time.  I'll take an 18z RGEM, 18z NAM, 12z Euro/ENS, CMC compromise over anything the GFS has unless it's a retrospective look at what has fallen.