March 6-8th Ocean Storm Discussion Part III

[Brian5671]

Will is there any historical precedent for such a thing?  1000-850mb thicknesses are frigid even here, yet the 8h 0c is out by Logan11.   Euro is cold, and a brutal, brutal snowstorm.

 

It's curious to me that the NAM has been right 1 time out of about 300.  The Euro been wrong maybe 2 times all winter at this range, and we're waiting on...presumably the NAM to come around?

 

Just looking at the Euro it's a devastating snowstorm.  I'm really puzzled by the group mind f8ck that is going on (not here, everywhere else)

 

 

I had thought the Euro was still a bit south?

[Ginx snewx]

Will is there any historical precedent for such a thing?  1000-850mb thicknesses are frigid even here, yet the 8h 0c is out by Logan11.   Euro is cold, and a brutal, brutal snowstorm.

 

It's curious to me that the NAM has been right 1 time out of about 300.  The Euro been wrong maybe 2 times all winter at this range, and we're waiting on...presumably the NAM to come around?

 

Just looking at the Euro it's a devastating snowstorm.  I'm really puzzled by the group mind f8ck that is going on (not here, everywhere else)

 

 

This is not a dying primary cutting to Detroit , save a horse ride the Euro.

[HIPPYVALLEY]

wrt?

With regards to

[Clinch Leatherwood]

I had thought the Euro was still a bit south?

 

Not for Boston PVD south, Will put up the QPF numbers it's over 2".  Again this is kind of the mythology about this storm that the Euro isn't onboard.  It's really bizarre.

 

 

This is not a dying primary cutting to Detroit , save a horse ride the Euro.

 

 

Ginxy, Will, Scooter, Quincy, Mekster, Ocean, Ryan et al:

 

Is the NAM problem simply that it never phases in the northern s/w?  IS that why we see no cold infusion?  Systemically it's not able to generate/advect cold because the cold air aloft never gets drawn down like all the other models? 

 

Check the 500mb panels 48-80, NAM just slip slides away, never allows that vortmax down it heads towards Quebec.  Everything else is phasing it in and helping to lower heights.

[ORH_wxman]

I do like the comparisons to the Feb 10th 2010 storm...I mentioned that a few days ago...quite similar.  The NAM did come NW from 06z.whatever that's worth.  Perhaps the SE NCEP guidance trend has stopped.

 

 

That would be a massive QPF bust here if we had the same result. Probably an order of magnitude worse than that storm. The ULL track is pretty similar though...the biggest difference I see is the ageostrophic component...in that one we got devastated by dry air from the north in the lower levels. The ageo component in this one is much more northeasterly rather than like due north or almost NNW. The circulation in this one looks a tad more robust on the northern side in addition to the more easterly LLJ fetch.

 

 

But I would definitely feel a bit safer with one more bump NW from the scraper models.

[Clinch Leatherwood]

I'm answering my own question because looking at the 3 NAM runs since 0z that is the problem, we toss.

 

It's gotten closer to phasing in each run and is pretty close to the 0z Euro by todays run.  It's a horrible model..it's a shame so many mets are holding back on forecasting this storm because they're afraid it's going to be right this time.

[ROOSTA]

After the game, the king and the pawn go into the same box.

 

Speaking of proverbs. Like a puzzle take all the pieces, mesh em together and there is the solution.

 

BIG INCOMING!

[Allenson]

Just watching for fun but the NAM is a real nice hit for the Daks & VT.

 

Entertaining. 

[Damage In Tolland]

That would be a massive QPF bust here if we had the same result. Probably an order of magnitude worse than that storm. The ULL track is pretty similar though...the biggest difference I see is the ageostrophic component...in that one we got devastated by dry air from the north in the lower levels. The ageo component in this one is much more northeasterly rather than like due north or almost NNW. The circulation in this one looks a tad more robust on the northern side in addition to the more easterly LLJ fetch.

But I would definitely feel a bit safer with one more bump NW from the scraper models.

Yeah that storm gave you under 2 inches. Not a good analog at all

[SlantStickers Anonymous]

So euro came in a bit better, gfs gave a little ground to euro, has this somehow trended us to a meh solution?

[OSUmetstud]

That would be a massive QPF bust here if we had the same result. Probably an order of magnitude worse than that storm. The ULL track is pretty similar though...the biggest difference I see is the ageostrophic component...in that one we got devastated by dry air from the north in the lower levels. The ageo component in this one is much more northeasterly rather than like due north or almost NNW. The circulation in this one looks a tad more robust on the northern side in addition to the more easterly LLJ fetch.

 

 

But I would definitely feel a bit safer with one more bump NW from the scraper models.

 

 

There's a much more favorable high and a strongest easterly LLJ for this one, so hopefully the helps you guys out a great deal.  I think I ended up with like 3" overnight on that one.  I think some news stations were forecasting 12-18".

[ORH_wxman]

Yeah that storm gave you under 2 inches. Not a good analog at all

 

 

It could be a good analog, if we get fringed again, lol...right now I doubt we see a repeat of that disaster, but you cannot completely discount it. Some of the guidance has a few red flags.

[ORH_wxman]

There's a much more favorable high and a strongest easterly LLJ for this one, so hopefully the helps you guys out a great deal.  I think I ended up with like 3" overnight on that one.  I think some news stations were forecasting 12-18".

 

 

Yeah the bolded part is I think it the biggest plus in this compared to that one...everything really drained out of the NNE fairly quickly...even at 850mb in the 2/10/10 event. There was a really efficient dry air drain. That doesn't look like it will happen in this one.  

[Bostonseminole]

It could be a good analog, if we get fringed again, lol...right now I doubt we see a repeat of that disaster, but you cannot completely discount it. Some of the guidance has a few red flags.

 

Will, I'm still surprised by some of he local mets with the EURO coming in bullish, is it a temp deal? most are saying <3" all the way to 495.. not sure what I'm missing.

[jaf]

Do you guys agree?

 

Todd Gutner‏@ToddWBZ

With a NE wind off H2O, surface will be too warm for first half of storm for much if any snow accum outside of hills...IMO...

[Patrick-02540]

I do like the comparisons to the Feb 10th 2010 storm...I mentioned that a few days ago...quite similar.  The NAM did come NW from 06z.whatever that's worth.  Perhaps the SE NCEP guidance trend has stopped.

Not that it follows, but FYI...

 

http://www.erh.noaa.gov/aly/Past/2010/Feb_10_2010/Feb_10_2010.htm

[Baroclinic Zone]

http://www.spc.noaa.gov/exper/sref/fplumes/index.php?YMD=20130305&RT=09&PRM=Total-SNO&SID=IJD&INC=ALL&NNC=&max=&min=&mZOOM=8&mLAT=41.8120143976451&mLON=-71.63127578125&mTYP=roadmap

 

Link is above

 

SFZ

H/L 37.09"/2.40"

Mean 19.55"

 

OWD

40.37"/1.84"

19.75"

 

EWB

29.32"/2.92"

11.52"

 

PYM

29.12"/0.02"

11.09"

[CoastalWx]

Gutner should look at the euro more.

[SR Airglow]

Not that it follows, but FYI...

 

http://www.erh.noaa.gov/aly/Past/2010/Feb_10_2010/Feb_10_2010.htm

I would be one of the few on the forum that would have no problem with that, 5-7" sounds nice

-skisheep

[mattb65]

Do you guys agree?

 

Todd Gutner‏@ToddWBZ

With a NE wind off H2O, surface will be too warm for first half of storm for much if any snow accum outside of hills...IMO...

Well the globals (GFS, Euro) are showing advection of very cold air at 850 mb and cold air at 900 mb from the northeast with surface temps of 31-34 so no I don't agree with the caveat being there needs to be decent snowfall rates if it's during the day time. If it's light snowfall rates then it probably won't accumulate too fast, and it appears the heavy stuff doesn't move in until later in the day anyways. So while it's true we may lose some accumulation it won't be the QPF that matters, IMO.

[Clinch Leatherwood]

This would look just like that event in 2010 if the s/w to the NW didn't exist.  Really not all that close of an analog, JMHO.

 

Weak comparison.

[ORH_wxman]

Do you guys agree?

 

Todd Gutner‏@ToddWBZ

With a NE wind off H2O, surface will be too warm for first half of storm for much if any snow accum outside of hills...IMO...

 

 

It really depends on how heavy the precip is. I think awfully close to the coast can do well if its coming down heavily.

[OceanStWx]

Ginxy, Will, Scooter, Quincy, Mekster, Ocean, Ryan et al:

 

Is the NAM problem simply that it never phases in the northern s/w?  IS that why we see no cold infusion?  Systemically it's not able to generate/advect cold because the cold air aloft never gets drawn down like all the other models? 

 

Check the 500mb panels 48-80, NAM just slip slides away, never allows that vortmax down it heads towards Quebec.  Everything else is phasing it in and helping to lower heights.

 

 

I think it helps to view it in a potential vorticity model. The phasing makes a little more sense than looking at individual vorticity maxima at H5. The NAM advects the potential vorticity on the tropopause eastward, resulting in a missed phases. It tries at 12z, but just misses the connection. The GFS on the other hand (06z) advects this PV anomaly in the northern stream south and east, which interacts with the southern stream PV anomaly by tugging it northward. The two stream phase completely later on, which is when we get the stall and loop S of the benchmark.

 

I think the warmth aloft comes from the missed phase. The NAM isn't dynamically as intense as the GFS, so heights remain high to the north rather than tighten towards the center as the GFS depicts. The GFS does draw down that northern stream cold pool, while the NAM lingers it over the Lakes.

[Ginx snewx]

Plumes are pedestrian only 10 to 25 from PYM to ORH to IJD to ORD to PVD, crushed

[Baroclinic Zone]

I think it helps to view it in a potential vorticity model. The phasing makes a little more sense than looking at individual vorticity maxima at H5. The NAM advects the potential vorticity on the tropopause eastward, resulting in a missed phases. It tries at 12z, but just misses the connection. The GFS on the other hand (06z) advects this PV anomaly in the northern stream south and east, which interacts with the southern stream PV anomaly by tugging it northward. The two stream phase completely later on, which is when we get the stall and loop S of the benchmark.

 

I think the warmth aloft comes from the missed phase. The NAM is dynamically as intense as the GFS, so heights remain high to the north rather than tighten towards the center as the GFS depicts. The GFS does draw down that northern stream cold pool, while the NAM lingers it over the Lakes.

I agree with this bolded statement and why I think the 850s are too warm verbatim on the NAM.

[Baroclinic Zone]

Plumes are pedestrian only 10 to 25 from PYM to ORH to IJD to ORD to PVD, crushed

meh.

[Logan11]

Looks to me like we have some model convergence taking place with the US models and the ECM. You know who is in the screw zone (as expected), unless the inverted trough can do it's dirty work as the NAM shows. The ECM also had .5" here strictly from the inverted trough type feature. Any true banding with the offshore low seems to maybe skirt NYC and then get SNE a bit...then its essentially a norlun-esque situation.

[mattb65]

I think it helps to view it in a potential vorticity model. The phasing makes a little more sense than looking at individual vorticity maxima at H5. The NAM advects the potential vorticity on the tropopause eastward, resulting in a missed phases. It tries at 12z, but just misses the connection. The GFS on the other hand (06z) advects this PV anomaly in the northern stream south and east, which interacts with the southern stream PV anomaly by tugging it northward. The two stream phase completely later on, which is when we get the stall and loop S of the benchmark.

 

I think the warmth aloft comes from the missed phase. The NAM is dynamically as intense as the GFS, so heights remain high to the north rather than tighten towards the center as the GFS depicts. The GFS does draw down that northern stream cold pool, while the NAM lingers it over the Lakes.

Thanks for the excellent explanation. 

 

In a nutshell, if the NAM has the synoptics right it'll score a coup, but if we look at synoptic verification scores for GFS vs NAM past 48 hrs or better Euro vs NAM, this is a no brainer on which model camp will probably be more right come verification time.

[Brian5671]

Not that it follows, but FYI...

 

http://www.erh.noaa.gov/aly/Past/2010/Feb_10_2010/Feb_10_2010.htm

what an epic bust that one was-most outlets going for 1-2 feet and then very little fell.   SW CT got lucky due to a weenie band that set up in the early stages of the snow.  I remember seeing the radar all the sudden shift south and knew we were cooked.

[MJHUB]

meh.

 

How are you feeling for our area?  lots of QPF potentially, temps are a worry for me.