0z Models 12/22/10

[usedtobe]

maybe its me but the confluence in the northeast looks a good bit stronger so far.

It does and I think that outweighs the better southern stream but We probably won't know until the runs tonight or tmw are done.

[baroclinic_instability]

One thing worth mentioning about the 0Z NAM run...it is showing the typical NAM Phase Shift Westward where the entire 500 hpa height field is phase shifted too slow/Westward.

[Midlo Snow Maker]

hour 54 is S/W isneutral over new mex, more ridging and a little slower than theeuro. they both have the same s/w location just more pos tilted on the euro than the 0z nam

[Amped]

Troff in the same basic spot as 12z. It also extends further south.

[SteveB]

You beat me too it. To me, THIS is is the most noticeable change thus far from 18z. Nice to see it going to back to more like what it had at 12z.

Looks the same to me at 54 hrs vs 60 hrs from the 18Z.

[Clinch Leatherwood]

Very subtle but the s/w feature in the Dakotas is back this run. Overall I think 50+ it looks pretty good. Certainly there's nothing on those maps that says UTOH and at this range that's all that matters in this pattern.

[wxmeddler]

Can anyone comment on why this is slowing every run?

As I understand it.. all of the information that comes in from over the pacific is derived by satellite. So even if that is off by 25 kts then can be faster/slower. Once it gets over the CONUS then we have weather balloons which gives us actual observational numbers.

[ohleary]

yes but I liked the look of the 12z NAM, thought it was nearly identical to the euro through 72 hours. If the NAM shifts back to 12z after a less impressive 18z I would be happy.

Agreed.

[winter_warlock]

Looks the same to me at 54 hrs vs 60 hrs from the 18Z.

s/w looks a little stronger at 54 compared to 60 at 18z

[LVblizzard]

Comparing hour 60 to the 12z Euro at 72, the s/w is in the same spot but the Euro looks stronger.

[ohleary]

As I understand it.. all of the information that comes in from over the pacific is derived by satellite. So even if that is off by 25 kts then can be faster/slower. Once it gets over the CONUS then we have weather balloons which gives us actual observational numbers.

There are other obs over the ocean, ship, buoy, aircraft. A majority of it is satellite though.

[Amped]

The big deal will be if that southern piece of the 500mb troff that was supposed to cut off in Baja is able to stay attached with the slower northern half of the troff. That will suck up a lot more Gulf moisture it makes it across MX.

[psuhoffman]

at 54 the vortex over north atl is a little stronger and confluence a little worse over the northeast but the STJ shortwave is stronger and had more ridging in front...its a wash at this point to me

[Srain]

The southern stream is a little strong and slower but that may be tempered by the vortex from Hades extending farther to the southwest this run which is liable to again make it hard to get any warm advection going as the system moves east. I'll probably stay thru the nam and quit as I'm fighting a sinus infection and don;t have as much energy as normal.

Getting better soon Wes.

[jcwxguy]

hr 66 500 vort looks good, about closed off

[psuhoffman]

Comparing hour 60 to the 12z Euro at 72, the s/w is in the same spot but the Euro looks stronger.

that is good if looking for a sign that the euro is not making a mistake due to its bias of holding energy in the sw too long

[Eskimo Joe]

Lets put the 500 chart under the microscope for a moment. If you take a look at the 18z NAM at hour 54, you will notice the 582 contour is placed in the central Gulf of Mexico, with the center of the ridge situated between the western tip of Cuba and the Yucatan Peninsula. The s/w over the southwest United States appears to have a slight positive tilt as well. Fast forward to the 00z NAM at hour 42 and we see the ridge now centered over the northern tip of the Yucatan Peninsula, which helps to bolster the 582 contour to the Gulf Coast. This also slows down the s/w across the Four Corners region. A gif of the two timestamps is provided below

make an animated gif

[usedtobe]

Getting better soon Wes.

I'm on antibiotics and steroids so I should be OK in a couple of days.

[winter_warlock]

I'm on antibiotics and steroids so I should be OK in a couple of days.

hope ya feel better Wes

[Midlo Snow Maker]

euro and nam are real close at hr 66 with location of the shortwave and the nam is slower this run

[mitchnick]

I'm on antibiotics and steroids so I should be OK in a couple of days.

after 2 sinus surgeries, best of luck Wes, its a miserable feeling

[psuhoffman]

at 60 hrs the ridge out west is slightly west and much better. I like the overall h5 look across the CONUS, the vortex over the atl is slightly stronger but I think the setup of the STJ and the ridge out west outweighs that at this point. Those usually tend to get out of the way. I seem to remember last winter worrying about the PV squashing storms a few times and they always seemed to get out of the way in time.

[usedtobe]

Thanks, back to analysis. Looking at the 66hr Nam it's hard to see how the hieghts can build ahead of the developing trough because of the northwest flow over the northeast on this run of the nam.

[winter_warlock]

at 66 hrs short wave still stronger than 72 at 18z

[Dr No]

The energy in the northern plains is not quite as far out infront of the s/w as it was at 18Z.

Maybe a stronger cyclops actually helps out with the phasing aspects.

[mitchnick]

look at those UVV's developing in Texas at 66 hrs

[WhiteoutWX]

Theres an awful lot of confluence still over the east. I dont care how strong that s/w is, it cant amplify in the face of that. That atlantic low has gotta move outta the way quick to allow room for a storm on the east coast.

[winter_warlock]

look at those UVV's developing in Texas at 66 hrs

turnig out to be a good deal better run than 18z

[weathervswife]

Definitely 6 hours slower, but the NE storm is 6 hours behind too. It's the same distance between the two and the same strength.

[earthlight]

That confluence gets really far south into the Mid-Atlantic and really surpresses the H5 flow. Does anybody have a height comparison over the East coast between the ECM and NAM? I'd pull it up myself but I'm on a phone.