Even if the Mid-week Nor'easter misses you >>

[Erica]

I have some great news. The GGEM Is looking increasingly impressive for the weekend across the Northern Mid-Atlantic and Much of the Northeast.

Here, we are going to assume that the Nor'easter in the mid week period moves northeast toward Newfoundland as it bombs out, and therefore, becomes the new 50/50 low on Saturday.



If this does happen, the wavelengths in the northern stream should sharpen considerably and the NAO possibly turn negative.

The the s/w across the midwest would be forced to take a track further south and east of what the Operational GFS has been showing for the past several runs, and as you can see the 0z GGEM has a 999mb low sitting across southeastern Ohio on 0z Saturday.



On sunday, the 50/50 low continues to progress northward toward the southern tip of greenland, which would qualify it as displaced, though sill evident. This, as the trough across the eastern part of the country tilts negative.



At this point, the Surface low will have already jumped to the coast, and is down to 992mb.



There is still plenty of time to watch this, and remember, alot of the questions will not be answered until we see exactly what happens with the mid week event. The only way to correctly predict this potential event would be to pin down what happens with the midweek Nor'easter.

The new 0z GFS does support the GGEM somewhat too.





Both have the 50/50 low, and the Polar Vortex is in a climatological position. The only problem is the GFS surface evolution is slightly different, and in my opinion, suspect.





The GFS is much further north and west with the surface low, although both the GFS and CMC seem to be within a few Millibars of one another when it comes to the strength of the surface low pressure centers. The CMC idea seems much better given the synoptic set-up.

[Chris the Weather Man]

March.... looks good for a Major Nor'easter

[Lindaloo]

When is the last time they have seen a Nor'Easter?

[Stephanie]

I think that the last storm we had back at the end of January was considered a Nor'easter - it could contain anything from rain to sleet, freezing rain to snow.

Good analysis Erica!

[Erica]

I think that the last storm we had back at the end of January was considered a Nor'easter - it could contain anything from rain to sleet, freezing rain to snow.

Good analysis Erica!

100% Right, however, Nor'easters are really a dime a dozen, some track right along or just inland from the coast, and others go out to sea. Some are weak, others very strong. Two basic classifications are Miller type A, and Miller type B.

The most severe Nor'easters are usually Miller type A, in which low pressure emerges out of the Gulf of Mexico, and then deepens rapidly as it moves up the east coast. The textbook example would be the March 1993 Superstorm.

It was a sub 970mb low.

A Nor'easter can become a Significant or Major East coast snowstorm when the cold air remains in place along the coast. But in most cases in order to have snow all the way to the coast, you need to have high pressure over Quebec. But it's still not as simple as that.

I'll put together a little something on Nor'easters later tonight for everyone, to clear up the confusion.

[WXBUFFJIM]

Hey Erica, correct if I'm wrong, but did the '93 superstorm peak at 953 mb???

That was some storm, and I truly believe the superstorm of 1993 was the storm of the 20th century because of how it affected 26 states severly crippling travel both on the ground and in the air. I think there was up to 5 feet of snow in the western part of North Carolina with this storm.

Jim

[Chris the Weather Man]

Hey Erica, correct if I'm wrong, but did the '93 superstorm peak at 953 mb???

That was some storm, and I truly believe the superstorm of 1993 was the storm of the 20th century because of how it affected 26 states severly crippling travel both on the ground and in the air. I think there was up to 5 feet of snow in the western part of North Carolina with this storm.

Jim

960mb..... Superstorm of 1993 ( I think)

[Erica]

Yea, your right, Chris.

[WXBUFFJIM]

I was just checking on the '93 superstorm and it peaked at 960 mb. Thanks.

Still for this to severely affect 26 states and to have heavy snow deep down to the south and major tornadoes and storm surge in Florida, amazing stuff and this was even before the entire eastern seaboard got crushed!! 5 feet of snow in western North Carolina if I'm not mistaken. We had nearly one foot here in Baltimore, MD with very strong winds.

Jim

[Anonymous]

It was a sub 970mb low.

Yeah, I was just looking at the data from that storm a week or so ago and it was damn impressive! Check out this surface map from MAR 13 22z:



A 968mb bomb just west of SBY with IAD at 28 degrees... if only I wasn't 5 years old and living in LA at the time ! And good lord, look at MCO... 45F at 5PM in mid-March... that just doesn't happen!

BTW, nice post about the nor'easter classifications. I believe since I moved here in 1997 the only good Miller A snowstorm we've seen was JAN 25 2000, so hopefully there'll be another soon.

[WXBUFFJIM]

I was only 11 years old back in 1993. I remember that storm well. Very intense!! Probably a once in a century type storm for the eastern seaboard.

Jim

[ColdFront77]

A 968mb bomb just west of SBY with IAD at 28 degrees... if only I wasn't 5 years old and living in LA at the time ! And good lord, look at MCO... 45F at 5PM in mid-March... that just doesn't happen!

...and the mid 40's in middle January with a gusty northwesternly wind at MCO, (I am 1 1/2 hours northwest of Orlando), a couple years ago was something, too.

There have been a few other days with afternoon highs in the mid to upper 40's across central Florida in the winter, not very late winter.

[Guest]

It was a sub 970mb low.

Yeah, I was just looking at the data from that storm a week or so ago and it was damn impressive! Check out this surface map from MAR 13 22z:



A 968mb bomb just west of SBY with IAD at 28 degrees... if only I wasn't 5 years old and living in LA at the time ! And good lord, look at MCO... 45F at 5PM in mid-March... that just doesn't happen!

BTW, nice post about the nor'easter classifications. I believe since I moved here in 1997 the only good Miller A snowstorm we've seen was JAN 25 2000, so hopefully there'll be another soon.

PD2003 was a Miller A

[Anonymous]

PD2003 was a Miller A

Hmm... I guess that's been debated before... I was under the impression that if there was secondary redevelopment on the coast it was Miller B. I know that PDS2003 was a STJ-induced system that originated in the southern Plains, but it did move up into the Tennessee Valley and then jump to the NC coast.

[Stephanie]

I think that both redevelop off of the coast but the Miller B comes from the Midwest where the Miller A comes from the Gulf Coast, if I'm not mistaken.

[Erica]

The best example of a Miller Type B Major east Coast snowstorm would be the christams 2002 Nor'easter, shown below.

The event was characterized by an area of low pressure which re-developed along the North Carolina coast, and then moved northeastward as the low underwent bomb cyclogenesis.



Here's also some 500mb height forecasts from the ETA prior to the event.





Very heavy snow fell over a wide area of Pennsylvania and New York as the result of fast snowfall rates underneath strong CSI bands which set-up across the region.



The cross section above from La Guardia to Syracuse New York of frontogenesis and EPV (negative only).

The areas of negative EPV indicate areas of Symmetric instability as the absolute vorticity of the flow is either neutral or slightly negative. Once the environement reached saturation, CSI was released and mesoscale snow bands developed. This was aided by the areas of intense frontogenesis below it, and the area of intense UVM at 700mb located across the Lower Hudson Valley.

[Stephanie]

Thanks for that example. I figured someone would correct me or provide better info!