12z Model Thread 12/8

[Alpha5]

NAM running now, GFS and Euro coming up later.

Threat for some backend snow for the area is there, big snows possible for the interior

[Diego]

It's nice when Upton recognizes it.

BUT THE ECMWF AND GEFS MEAN NOW SUGGEST DEVELOPMENT OF A

SECONDARY LOW NEAR THE CAROLINA COAST THAT QUICKLY BECOMES THE

DOMINANT LOW BY MON MORNING. THE TRACK OF THE FIRST LOW WILL ALLOW

FOR PLENTY OF WARM AIR TO WORK IN OFF THE ATLANTIC...AND ANY FROZEN

OR FREEZING PRECIPITATION SHOULD BE BRIEF...AND ONLY AT THE VERY

ONSET LATE SAT NIGHT INTO EARLY SUNDAY MORNING. POTENTIAL DOES EXIST

FOR A MODERATE TO HEAVY RAINFALL EVENT...WHICH COULD CHANGE BACK TO

SNOW LATE SUNDAY NIGHT INTO MON MORNING MAINLY NORTH/WEST OF NYC.

From their MFD.

[blazess556]

One thing for sure, the 12z nam is much less wrapped up than the gfs. much less interaction with the pv and less ridging out in front.

[Wonderdog]

Heavier precip. showing up somewhat further south on 12z NAM at 78 in southern MO/northern Ark. compared to 06z run.

[Radders]

Our clipper really has diminished to basically nothing over the last few days.. I would hesitate to even call it a "clipper" lol

[Alpha5]

One thing for sure, the 12z nam is much less wrapped up than the gfs. much less interaction with the pv and less ridging out in front.

NAM at 84 is still positive with the trough while the GFS is neutral at the same timeframe....

[benfica356]

for anyone who can't see the image:

Nam is much further south with the storm and weaker

[Sundog]

Is this the first time we are seeing a 1028 high in Canada? That was where the "clipper" was previously wasn't it? I am also interested in the big low off the coast of Newfoundland. I wonder if that will have any staying power.

[Guest Patrick]

it is a new feature...may not be strong enough, but the fact that it is there speaks volumes. In my humble opinion, assuming that high is there, and the storm builds further south as it appears the models are doing, we could be in for quite a decent shot of frozen Monday.

Is this the first time we are seeing a 1028 high in Canada? That was where the "clipper was previously wasn't it? I am also interested in the big low off the coast of Newfoundland. I wonder if that will have any staying power.

[earthlight]

Didn't see this posted, but since we have no 06z model thread this is a good spot for it. The 06z DGEX is wrapped up and further east from it's previous runs, and the result is actually a dynamically driven snowstorm in the immediate suburbs. Not worth much, but cool to see.

http://www.meteo.psu.edu/~gadomski/DGEXEAST_6z/f138.gif

[NaoPos]

just to show some differences between the 12z nam and 0z gfs ( same time frame 12/12 0utc)

notice the 50-50 a lot stronger, but displaced east a bit more..

secondly, the GOA low being progged as stronger, hence, flattening out the ridge out west... and yes, i know, it's the 84hr NAM..

gfs 0z:

12z NAM:

[jm1220]

Didn't see this posted, but since we have no 06z model thread this is a good spot for it. The 06z DGEX is wrapped up and further east from it's previous runs, and the result is actually a dynamically driven snowstorm in the immediate suburbs. Not worth much, but cool to see.

http://www.meteo.psu...AST_6z/f138.gif

That run shows 50 degrees over NYC and Long Island, and 20 degrees over the Delaware River. It also shows a couple of feet of snow accumulating over my old Penn State stomping grounds. Yep-it's crazy!!

[A-L-E-X]

That run shows 50 degrees over NYC and Long Island, and 20 degrees over the Delaware River. It also shows a couple of feet of snow accumulating over my old Penn State stomping grounds. Yep-it's crazy!!

The Delaware River down by Philly?  Is it showing accumulating snow for them?  I wonder how much my sis will see in the Poconos NW of Allentown.

[whiteout]

Didn't see this posted, but since we have no 06z model thread this is a good spot for it. The 06z DGEX is wrapped up and further east from it's previous runs, and the result is actually a dynamically driven snowstorm in the immediate suburbs. Not worth much, but cool to see.

http://www.meteo.psu...AST_6z/f138.gif

Sure would be a nice solution for us in the Lower Susquehanna Valley!! For a novice, what factors lead to the DGEX showing such solution versus what the GFS/ECMWF are showing?

[Guest Patrick]

FWIW, GFS Hr 36 hangs the low back just a hair and recedes the high over us north just a bit faster than 6z.... probably negligible differences at this point.

[tombo82685]

so far through hr 42, hgts compared to 6z are lower, esp in the northeast...the low that turns into the 50/50 is stronger this run so far

[tombo82685]

through hr 54, hgts continue to be lower compared to 6z, with the biggest hgt decrease being over the northeast. This looks like its in response to the clipper, the 50/50 is a little stronger still, but isnt squashing the hgts that much

[isnice]

so far through hr 42, hgts compared to 6z are lower, esp in the northeast...the low that turns into the 50/50 is stronger this run so far

Probably not going to have any big impact in thé long run

[Guest Patrick]

probably not, but the cold air is slightly more stubborn at 54 as well. I am aware that the next frame could obliterate that though.. haha

Probably not going to have any big impact in thé long run

[tornadojay]

the track of that clipper has sure trended north in these past few days

[tombo82685]

Probably not going to have any big impact in thé long run

well the lower and flatter the ridge is off the east coast will help some what in the long run in prolonging a negative tilt.

[isnice]

the track of that clipper has sure trended north in these past few days

They Always do

[tombo82685]

looks less amplified in terms of the trof, do to the less ridging on the east coast through hr 72, broad area of 1012 pressure

[tombo82685]

a whole lot weaker through 75, still sub 1012 pressure, while 6z was sub 1008...ridge over the east still is flatter and the phasing processes on the 6z starting at 81 are slower compared to the 12z runs so far.

[Sampson]

look at how the 6z handled the low in the south today. It is much farther north than was projected.

[NaoPos]

They Always do

not really..

Tombo, hows that GOA low looking?

[tombo82685]

hr 90 has a sub 1004 in northern ten or lower ky, though the pv interaction is starting to get involved with the low

[tombo82685]

not really..

Tombo, hows that GOA low looking?

at hr 90 its further southwest, pushing down on the ridge somewhat

[tombo82685]

hr 102 has sub 992 low over norther nc, phasing in the process now, causing the low to prob lift nne or take on a more northerly component

[tombo82685]

hr 108 has a sub 988 low over delaware it looks, deff liking the trends with todays run so far. Bring out a weaker storm in the plains and further south, delay the pv interaction