The Miller snowstorm question

[earthlight]

The past several days, and even dating back to last winter, we have had several discussions regarding the differences between a Miller A and Miller B. There definition is definitely somewhat vague in the discussions on the forums--but we can use this thread to clear things up a bit. The best way, I think, to clear up the question would be to post the "official" definition as well as some classic examples from recent years.

A Miller A, by definition, has a primary storm with no secondary development, that rides up along the east coast or spine of the Appalachians typically. Some classic examples of Miller As producing snowfall in our area include:

February 12, 2006

http://www.meteo.psu.edu/~gadomski/NARR/2006/us0212.php

December 19, 2009

http://www.meteo.psu.edu/~gadomski/NARR/2009/us1219.php

A Miller B, by definition, has a primary storm track that comes out of Alberta, Canada that develops a secondary storm along the east coast from the Carolina's all the way up the coast. Some classic examples of Miller Bs producing snowfall in our area include:

January 22-23, 2005

http://www.meteo.psu.edu/~gadomski/NARR/2005/us0122.php

http://www.meteo.psu.edu/~gadomski/NARR/2005/us0123.php

December 9, 2005

http://www.meteo.psu.edu/~gadomski/NARR/2005/us1209.php

This should certainly help clear up some questions as we move forward, but the real debate remains in which setup is better for our area. For the sake of argument, I would say that Miller A's definitely have a history of producing more prolific snowfalls for our area, but we have also seen some rather robust Miller B snowfall events. There are also the newly coined "Miller B/Miller A Hybrids" which, for example, could be a storm system coming out of Canada that phases aloft or redevelops on the coast and strengthens before turning northeast towards the benchmark. These hybrid terms can get confusing, but they technically should go back to the initial definition which bases the categorization on the origin of the storm system itself.

I'm sure we will have plenty of opportunities this winter to reference this thread, hopefully not in vein.

[SnoSki14]

What about overrunning systems or SWF events. They remind me a pre miller A or B type of system where we see a lot of precipitation well ahead of the storm due to the warm, humid air from the gulf colliding with a very strong and cold area of high pressure. The lows in that case are generally very weak but the amount of moisture is very plentiful such as in the Feb 03 storm.

[SnowGoose69]

What about overrunning systems or SWF events. They remind me a pre miller A or B type of system where we see a lot of precipitation well ahead of the storm due to the warm, humid air from the gulf colliding with a very strong and cold area of high pressure. The lows in that case are generally very weak but the amount of moisture is very plentiful such as in the Feb 03 storm.

The PDII storm had some of the most unbelievable overrunning generated precip amounts I've ever seen from a coastal system with such a strong high in SE Canada....some may have called it a semi- SW flow event, it was similar to the 2/11/94 event, a weak low aided by a strong high but I envision SW flow events to be more like 12/28/90, 2/8/94, 12/14/03, or 12/20/08 where the system or disturbance originates more across the north-central U.S. and not so much the Gulf region or Mid-Atlantic.

[CoastalWx]

The PDII storm had some of the most unbelievable overrunning generated precip amounts I've ever seen from a coastal system with such a strong high in SE Canada....some may have called it a semi- SW flow event, it was similar to the 2/11/94 event, a weak low aided by a strong high but I envision SW flow events to be more like 12/28/90, 2/8/94, 12/14/03, or 12/20/08 where the system or disturbance originates more across the north-central U.S. and not so much the Gulf region or Mid-Atlantic.

That storm had a stationary or even slightly back-building entrance region of the H3 jet. When that occurs the LLJ will get enhanced and move toward the region of divergence. This LLJ dumped on the MId Atlantic for hours thanks to that entrance region of the jet. You could argue, the entrance region of jet streaks are where the most fun happens.

[earthlight]

The PDII storm had some of the most unbelievable overrunning generated precip amounts I've ever seen from a coastal system with such a strong high in SE Canada....some may have called it a semi- SW flow event, it was similar to the 2/11/94 event, a weak low aided by a strong high but I envision SW flow events to be more like 12/28/90, 2/8/94, 12/14/03, or 12/20/08 where the system or disturbance originates more across the north-central U.S. and not so much the Gulf region or Mid-Atlantic.

PDII is the textbook overrunning event, and as CoastalWx mentioned above the low level jet was really enhanced in that system as well. The synoptic setup of that system was really terrific as well. The high pressure that was built to the north was literally "of epic proportions", the isobaric cold air damming signature is textbook as well as a result. Just an awesome, awesome storm system.

http://www.meteo.psu.edu/~gadomski/NARR/2003/021703.png

As far as the question from the poster above, yes we can definitely characterize "overrunning events" in there as well--but I don't think they can be strictly defined as either Miller A's or B's unless you track back to the point of origin. Even then, the system is redeveloping, especially in the case of PDII where we saw a surface low develop off the Mid-Atlantic coast, move north and then northeast. This became the dominant feature of the storm system. I think you can probably define PDII as a redeveloping Miller A/overrunning system, if you track back the shortwave it came out of the southern stream--it was a closed low southwest of Baja a few days earlier.

http://www.meteo.psu.edu/~gadomski/NARR/2003/021300.png

[Chris L]

Miller A's are tougher to stall due to the sheer size.

Miller B, as we saw in n 1978 and 2005, can stall pretty easily.

But, if you were to tell me which is better for this area?

Miller A (Feb 2010 and Jan 1996) simply because we don't have to worry about getting screwed if the sfc low develops too far north and bombs SNE (2005).

[earthlight]

Miller A's are tougher to stall due to the sheer size.

Miller B, as we saw in n 1978 and 2005, can stall pretty easily.

This has more to do with the pattern surrounding the systems. In order to get a prolific Miller B to redevelop in our area, we need either a very strong shortwave, or a blocked pattern to the north. This is why it seems like the systems are slower or have more of a tendency to stall out. In a Miller A, we can get a few hours of prolific deformation banding underneath the cold conveyor belt, and that could be it. February 2006 is a prime example of this. We can also have much slower moving Miller A's when the pattern is blocked up/etc. It has more to do with the area of PVA and the orientation of the trough and upstream troughs/blocking than it has to do with the size of the system itself.

[Chris L]

This has more to do with the pattern surrounding the systems. In order to get a prolific Miller B to redevelop in our area, we need either a very strong shortwave, or a blocked pattern to the north. This is why it seems like the systems are slower or have more of a tendency to stall out. In a Miller A, we can get a few hours of prolific deformation banding underneath the cold conveyor belt, and that could be it. February 2006 is a prime example of this. We can also have much slower moving Miller A's when the pattern is blocked up/etc. It has more to do with the area of PVA and the orientation of the trough and upstream troughs/blocking than it has to do with the size of the system itself.

Yeah, I should have explained my post better; but you did a great job explaining better than I could.

It also depends on the state of the STJ, PJ and AJ....

Last year was ripe with Gulf Lows due to the high STJ....

[tornadojay]

This has more to do with the pattern surrounding the systems. In order to get a prolific Miller B to redevelop in our area, we need either a very strong shortwave, or a blocked pattern to the north. This is why it seems like the systems are slower or have more of a tendency to stall out. In a Miller A, we can get a few hours of prolific deformation banding underneath the cold conveyor belt, and that could be it. February 2006 is a prime example of this. We can also have much slower moving Miller A's when the pattern is blocked up/etc. It has more to do with the area of PVA and the orientation of the trough and upstream troughs/blocking than it has to do with the size of the system itself.

yea.. Jan 1996 was a nice long lasting Miller A that took its sweet old time coming up the coast.

[Chris L]

yea.. Jan 1996 was a nice long lasting Miller A that took its sweet old time coming up the coast.

Feb 5, 2010 was very much like that, only to hit a brick wall of dry air....

[tornadojay]

Feb 5, 2010 was very much like that, only to hit a brick wall of dry air....

I still have nightmares about that one... boy, I hope that doesn't happen again this year, although it was very interesting Meteorologically.

[earthlight]

I still have nightmares about that one... boy, I hope that doesn't happen again this year, although it was very interesting Meteorologically.

Yeah, that was a pretty sweet event. Talk about a crawler. That storm was a great demonstration of the power of blocking. Slightly off topic, but the guidance (especially high resolution) really performed exceptionally well with the gradient in that event.

[Stormlover74]

Isn't there an agreement that we never speak of that storm again?

I still have nightmares about that one... boy, I hope that doesn't happen again this year, although it was very interesting Meteorologically.

[Riptide]

Isn't there an agreement that we never speak of that storm again?

It was the real deal down here and it would of undoubtly became a hideous rainstorm without the historic blocking. You rarely see a system that impacts both the mid-atlantic and northeast with a historical snowfall.

You'll probably take revenge this winter, though.

[rgwp96]

wasnt the millenium storm a miller B?

[earthlight]

wasnt the millenium storm a miller B?

I believe so, most of the energy came out of the northern stream through Alberta. There was some southern stream component to the system, but I believe it definitely should be considered a Miller B redeveloper. A very extreme example, too.

[Chris L]

I believe so, most of the energy came out of the northern stream through Alberta. There was some southern stream component to the system, but I believe it definitely should be considered a Miller B redeveloper. A very extreme example, too.

Yes it was a Miller B, it just phased in time to give NJ-North a good dumping.

[Chris L]

Here's some excellent (some complex) information on cyclogenesis....

http://www.comet.uca...tframesTWO.html

This really breaks everyting down from 200 mb level (jet streaks) to sfc.

[forkyfork]

96 had coastal redevelopment...

http://www.meteo.psu.edu/~gadomski/NARR/1996/us0107.php

[forkyfork]

96 had coastal redevelopment...

http://www.meteo.psu...1996/us0107.php

so did PD2

[forkyfork]

most of you are getting type A storms wrong:

"Type A appears as a cyclone wave along the front of a cold outbreak. This type of cyclogenesis is not peculiar to the Atlantic coastal region or even to east coasts in general"

[rgwp96]

I believe so, most of the energy came out of the northern stream through Alberta. There was some southern stream component to the system, but I believe it definitely should be considered a Miller B redeveloper. A very extreme example, too.

i still remember thats storm. Radar went from nothing to an explosion within hrs, off the nj coast right into north jersey. 

[SnoSki14]

So Feb 5, 2010 was a miller A but the one a few days after it was a miller B correct or was it the last big storm in February that was a Miller B. Oh and I bet if the blocking was a bit weaker for the Feb 5 storm, it would have been a top 3 storm on the NESIS scale, probably tying Jan 96.

[earthlight]

bump. we've had plenty of discussion regarding this today, so let's carry that discussion into this thread.

[jm1220]

The blizzard of 1978 was a miller B that started as a clipper as well.

[Fozz]

Was 2/10/10 a Miller B or a hybrid?

[A-L-E-X]

This has more to do with the pattern surrounding the systems. In order to get a prolific Miller B to redevelop in our area, we need either a very strong shortwave, or a blocked pattern to the north. This is why it seems like the systems are slower or have more of a tendency to stall out. In a Miller A, we can get a few hours of prolific deformation banding underneath the cold conveyor belt, and that could be it. February 2006 is a prime example of this. We can also have much slower moving Miller A's when the pattern is blocked up/etc. It has more to do with the area of PVA and the orientation of the trough and upstream troughs/blocking than it has to do with the size of the system itself.

PD2 and Feb 1983 were two great examples of overrunning events.

Miller A-- Feb 1961, Jan 1996, Feb 2006

Miller B-- Feb 1969, Feb 1978, Jan 2005

There's also Miller C, but I forget what the specs are on those.

It would be nice if someone did a breakdown of all our 16" plus snowstorms and gave out percentages on what type of "Miller" they were.

Also-- what is the most snow we have ever gotten from a noncoastal? My vote goes to Jan 2004-- about a foot of snow from that at 40:1 ratios!

[A-L-E-X]

So Feb 5, 2010 was a miller A but the one a few days after it was a miller B correct or was it the last big storm in February that was a Miller B. Oh and I bet if the blocking was a bit weaker for the Feb 5 storm, it would have been a top 3 storm on the NESIS scale, probably tying Jan 96.

I think all of the storms last winter were Miller A's

[Fozz]

Also-- what is the most snow we have ever gotten from a noncoastal? My vote goes to Jan 2004-- about a foot of snow from that at 40:1 ratios!

Are you talking about that frigid clipper that was followed by temps near 0?

Was it really a foot???

[A-L-E-X]

Are you talking about that frigid clipper that was followed by temps near 0?

Was it really a foot???

Yes, or close to it lol-- I remember it was like 11.7 inches here. Parts of central long island had a bit more-- up to 15 inches or so I think.