March 6-8th Ocean Storm Discussion Part III

[Baroclinic Zone]

GGEM is doing sort of what the Ukie did as I was describing to Ray...that 2nd s/w dives in and helps lift the firehose northward...so it really helps out E MA.

Does the fujiwara dance too.

[eduggs]

45F on my thermometer with full clouds and -7C 850s just east of Albany, NY.  I hate March.

[bboughton]

not on Dec 29 or Feb 9th, you do realize it came back NE?

 

I mean just with this storm.  It seems to be leading the pack in terms of trends.  GFS is north, models cave north.  GFS goes south, models go back south. 

[FSUIZZY]

Honestly, I just want to the Euro to follow through to watch channel 7 fall flat on its face. "All Rain for Eastern Mass."

[Logan11]

If I could be anywhere for this event I think I would take the Catskills. Almost every model puts that inverted trough in a good position for them and upslope is likely there. P-type issues not a factor at 2k feet +.  Eastern NE obviously gets more qpf, but lots of uncertainty about the ability to accumulate snow.

 

I'm a little north of there so I have to worry more about southward shifts. Hopefully things work out.

 

 

bottom line is when ur told rates rates rates, and .2 qpf over 6 hrs wont get it done.....and you are not confident where hvy rates will set up, how can u be confident in hvy snow totals anywhere? u can't . This looks like nowcast IF euro doesn't go to the crapper SE. i mean i guess either way it will be nowcast and i'm thinking that second SW may turn out to gather more interest as the day goes on. Deep layer easterly flow and that second sw diving in on back side would probably mean good thinks for catskills...high elevations just SW of albany and E slope of berks

 

and WRT to gfs i think euro may tick sE but will in no may look like it wrt to precip field so far offshore....i'm just not confident in the conveyer belt till i see it set up on radar....i think E NY and W MA may get a more high confidence snowfall from deep easterly flow and that 2'nd sw (if it continues to be model'd well) as this system wears on later thursday

 

MQE is gonna be a fun place for this storm if they can get firehose. winds howling for about 48 hrs there

[ORH_wxman]

Does the fujiwara dance too.

 

 

The Euro was really the first model to pick up on that a couple runs ago...its one of the reasons the Euro was a bit of a late bloomer as well but it gets the job done. There's going to be a sick easterly LLJ off the atlantic and where its lining up with the best frontogenesis is where the firehose will be...we lift that north a little and it will mean some good things...even as the ML fronto and associated firehose weakens some...its a big moisture train. One of the reasons I haven't gotten too bearish.

[N. OF PIKE]

There is an epic firehose already going on, snj into the Delmarva

your not kidding.

 

to bad it wasn't 6 weeks ago and a fresh cold air mass for those folks.  they will prob verifty those crazy qpf totals

 

it's mostly 38 F rain  cept western burbs of DC getting destroyed and just outside BMI. This is an elevation storm in that area underthat firehose. 500 feet will be difference between scary totals and glop out there

 

lets see how this low pressure moves now that it's feeling the weight of that block and sorta looks to be crawling.

[HoarfrostHubb]

The Euro was really the first model to pick up on that a couple runs ago...its one of the reasons the Euro was a bit of a late bloomer as well but it gets the job done. There's going to be a sick easterly LLJ off the atlantic and where its lining up with the best frontogenesis is where the firehose will be...we lift that north a little and it will mean some good things...even as the ML fronto and associated firehose weakens some...its a big moisture train. One of the reasons I haven't gotten too bearish.

I thought Ryan mentioned the NAM doing it first?  My memory sucks though

 

I am bearish

[Logan11]

That seems awfully mild.  I'm at 36 and it may be a little collder because I don't have good sheltering around my thermo this time of the day.

 

45F on my thermometer with full clouds and -7C 850s just east of Albany, NY.  I hate March.

[jaf]

GGEM is doing sort of what the Ukie did as I was describing to Ray...that 2nd s/w dives in and helps lift the firehose northward...so it really helps out E MA.

 

How much QPF does it have for E MA?

[SouthCoastMA]

These temperatures were well modeled. Not sure what the panic over temps is all about. Once the heavy precip starts it will flip to snow. Rain in NJ or DC has no bearing on SNE

[N. OF PIKE]

how are the height rises doing to the right of our coastal LP . i know this was a question mark several days ago.

 

http://www.ssd.noaa.gov/goes/east/nwatl/flash-wv.html

 

is ULL gonna turn that corner .....i guess it goes E off coast then gradually gets pull'd N

 

it's center is right over NE NC/Se VA coast  3 contours closed at 5h

 

it looks almost vertically stack'd and ready to stall

 

http://www.spc.noaa.gov/exper/mesoanalysis/new/viewsector.php?sector=17&parm=500mb&underlay=1#

 

feet upon feet in some areas 700' plus just W of DC to just W of BMI? lol

[moneypitmike]

For some of us, it's a very easy forecast.  Will I get 1" or will I get 4".

 

Congrats on the 4' out east! lol

 

33.9/29

[FSUIZZY]

These temperatures were well modeled. Not sure what the panic over temps is all about. Once the heavy precip starts it will flip to snow. Rain in NJ or DC has no bearing on SNE

 

Tell that to the TV meteorologists.

[eduggs]

Eduggs the only reason I'm in agreement is the other models seem too good to be true. Given gfs long term performance in this range there is no reason to be weighing it at all, jmho. But there is always the chance it's right and the stakes are high.

Normally I wouldn't even consider it vs the GGEM Euro combo with nam and meso rgem support. Group think has gotten me

I can remember numerous times this winter where the Euro and GGEM busted too high with QPF in the short range.  I feel like it's easier to remember cases where a model busted too low in the short term, which is a GFS trait, and probably leads to a greater than deserved level of criticism.  QPF is by far and away the most inaccurate model parameter.  I find the UK QPF completely unusable, and the NAM generally too high.  Maybe the GFS is too light in some cases.  I think that just reinforces the idea that we should not be overreliant on model QPF.  Look at the synoptic features and blend and hedge QPF from there.

 

But your point is reasonable.  If the GFS is unreliable for QPF forecasting, it should not be blended at all.  If conservatism is warranted (which might be reasonable since lower QPF is more likely than high by atmospheric default), some kind of modifier should be used (say, x .75) instead of considering the GFS at all.  But I'm not convinced the GFS is unusable.  I prefer to blend it in most cases to avoid any IMBY personal bias that I might have.  I also think a 12 hour advantage in the short term (12z Wed vs. 0z Wed) is important here.

[Semper911]

Snowing in Franklin at the moment.

 

Sorry I don't have a more detailed obs report, but I am at work.

[N. OF PIKE]

i would also think the fire hose / deform will be more impressive over the delmarva because ML lows are just cranking right now and in close proximity

[40/70 Benchmark]

of course you would

You're right....where was my head; lets take the snowy outlier.

[Ginx snewx]

You're right....where was my head; lets take the snowy outlier.

yea I would take the Euro too

[Clinch Leatherwood]

how are the height rises doing to the right of our coastal LP . i know this was a question mark several days ago.

http://www.ssd.noaa.gov/goes/east/nwatl/flash-wv.html

is ULL gonna turn that corner .....i guess it goes E off coast then gradually gets pull'd N

it's center is right over NE NC/Se VA coast 3 contours closed at 5h

it looks almost vertically stack'd and ready to stall

This is what makes this so unpredictable...and aside of my frustration with the gfs the reason I still know it has to be factored. You have to factor the worst case models when we have three vortices dancing around one another. It's an impossible task to expect true accuracy.

This is really just a nightmare forecast overall. From blue hill to Ne Ri etc its either a few sloppy slushy inches or a damaging snowstorm.

Looking just at the verification I think the euro was a little NW with the low vs reality. So pretty sure it will correct to the consensus.

[Ginx snewx]

For some of us, it's a very easy forecast.  Will I get 1" or will I get 4".

 

Congrats on the 4' out east! lol

 

33.9/29

Huh?

[eduggs]

There is an epic firehose already going on, snj into the Delmarva

But that's the ccb of a deepening SLP tucking towards the upper level support.  Moving forward, the mechanism moves offshore and weakens somewhat during the mature stage.

[40/70 Benchmark]

yea I would take the Euro too

GEM is.

Happy shoveling...talk to me post verification.

[N. OF PIKE]

This is what makes this so unpredictable...and aside of my frustration with the gfs the reason I still know it has to be factored. You have to factor the worst case models when we have three vortices dancing around one another. It's an impossible task to expect true accuracy.

This is really just a nightmare forecast overall. From blue hill to Ne Ri etc its either a few sloppy slushy inches or a damaging snowstorm.

Looking just at the verification I think the euro was a little NW with the low vs reality. So pretty sure it will correct to the consensus.

is that thing not just gonna sit there for rest of day ....almost vertically stack'd now...block in place and just demolish areas above 1.5K in the highlands W of DC and BMI...granted not many people live above 1200' where the fire hose will be but some areas are gonna see well over 2 feet in mid atlantic elevated areas looking at nowcast IMO.

[RobertSul]

Picked a good week to be in Southborough, MA! The Detroit area just doesn't see big snowstorms.. So I'm hoping I get lucky this week!

Logan seemed a lot colder than 40 degrees.. But then again the wind was blowing at a pretty good clip.

[eduggs]

That seems awfully mild.  I'm at 36 and it may be a little collder because I don't have good sheltering around my thermo this time of the day.

I might be about 1F too high based on poor siting, but verifying with portible thermometers, I am always a degree or two warmer than the airport north of the City (which reported 42F at 12pm).  I think it's legitimately mild out there today.

[Clinch Leatherwood]

I can remember numerous times this winter where the Euro and GGEM busted too high with QPF in the short range. I feel like it's easier to remember cases where a model busted too low in the short term, which is a GFS trait, and probably leads to a greater than deserved level of criticism. QPF is by far and away the most inaccurate model parameter. I find the UK QPF completely unusable, and the NAM generally too high. Maybe the GFS is too light in some cases. I think that just reinforces the idea that we should not be overreliant on model QPF. Look at the synoptic features and blend and hedge QPF from there.

But your point is reasonable. If the GFS is unreliable for QPF forecasting, it should not be blended at all. If conservatism is warranted (which might be reasonable since lower QPF is more likely than high by atmospheric default), some kind of modifier should be used (say, x .75) instead of considering the GFS at all. But I'm not convinced the GFS is unusable. I prefer to blend it in most cases to avoid any IMBY personal bias that I might have. I also think a 12 hour advantage in the short term (12z Wed vs. 0z Wed) is important here.

The gfs JMHO seems to do okay outlining where the axis of heavier stuff will fall... Ie the .5 contour often seems to be the back edge of the heavy stuff that quite often was factors heavier. It's 12z idea was similar to the euro if we adjusted for the euro being a smidge faster and more progressive which is absolutely reasonable. Now take the gfs multiplier and we have a pretty good consensus. Or in the case of this system a straight blend. This is way too complicated at this point to worry about finite details.

But to be clear if the euro comes out with 1.5" qpf where the gfs had .75 I will put serious cash on the euro being more right.

[Ginx snewx]

GEM is.

Happy shoveling...talk to me post verification.

Will already told you its similar to Ukmet and Euro????

[N. OF PIKE]

But that's the ccb of a deepening SLP tucking towards the upper level support.  Moving forward, the mechanism moves offshore and weakens somewhat during the mature stage.

yup .....look at the position of 5h 7h 850 lows almost stack'd. 850 inflow crazy....ya there better be a firehose...we won't see that type of deal.....not that wide of a blasting wow down there.  if this thing spins it's top for next 10 hrs ....moving very slowly. i think some crazy qpf totals may verify in delmarva

[Clinch Leatherwood]

Btw. When I complained about the euro stall point...that's part of its slower bias it seems in those huge bombs. Partially relevant here and we should see that play out with some shifts now towards the ggem. But it is only partially relevant because the digging sw which it has handled better than most is almost as big a factor.