00z NAM

[KFDM Meteorologist]

The NAM is a much better model on Spring and Summer thunderstorms in the south. The resolution is much small and does well on small scale features like seabreeze, MCC's etc..where the GFS does not.

[Scorpion]

The WRF(the one the new NAM will be based on) did well with Wilma if I remember correctly.

[WxGuy1]

The WRF(the one the new NAM will be based on) did well with Wilma if I remember correctly.

The 8km WRF-ARW (I think...) absolutely nailed Katrina. I'm not entirely sure why the NAM-ETA does so poorly with tropical systems, though it may have something to with convective parameterization and its effects on the surrounding thermodynamic and kinematic fields (or maybe it's something else to do with the physics package...?).

[HURAKAN]

The same forecast continues.

[Air Force Met]

here it is

http://www.nco.ncep.noaa.gov/pmb/nwpara ... loop.shtml

OK...again...I would ask you guys to look at the run on the main site...and note the difference.

But...if you all want to latch on to hope to the experimental run...here is a question for you:

Have you looked at the upper levels "associated" with this surface feature?

http://www.nco.ncep.noaa.gov/pmb/nwpara/analysis/carib/nam/00/images/nam_300_072m.gif

When you look at that big trof sitting right on top of this tropical system...maybe we should be saying "Hmmm...this experimental thing seems to have a problem. It's developing this system in the middle of an upper level trof with 25-30 knots of shear around. That can't be."

OK...that should let you know there is a problem with this model. It has a bug in it that allows it to develop tropical systems in the middle of cold core, long wave trofs.

I hate to bust bubbles here...but if that upper level feature verifies...then there is no way a sfc feature like that verifies unless it is attached to a front. This model has problems.

Again. It is the NAM.

[wxman57]

Probably two of the worst models for tropical systems are the NAM and Canadian. They're pretty clueless, developing storms in the middle of high-shear environments. Lots of people here can't wait for that first named storm, so they're latching onto any model that provides the slightest "hope" of development. One could even say that "W" word...

[feederband]

here it is

http://www.nco.ncep.noaa.gov/pmb/nwpara ... loop.shtml

OK...again...I would ask you guys to look at the run on the main site...and note the difference.

But...if you all want to latch on to hope to the experimental run...here is a question for you:

Have you looked at the upper levels "associated" with this surface feature?

http://www.nco.ncep.noaa.gov/pmb/nwpara/analysis/carib/nam/00/images/nam_300_072m.gif

When you look at that big trof sitting right on top of this tropical system...maybe we should be saying "Hmmm...this experimental thing seems to have a problem. It's developing this system in the middle of an upper level trof with 25-30 knots of shear around. That can't be."

OK...that should let you know there is a problem with this model. It has a bug in it that allows it to develop tropical systems in the middle of cold core, long wave trofs.

I hate to bust bubbles here...but if that upper level feature verifies...then there is no way a sfc feature like that verifies unless it is attached to a front. This model has problems.

Again. It is the NAM.

[Air Force Met]

Probably two of the worst models for tropical systems are the NAM and Canadian. They're pretty clueless, developing storms in the middle of high-shear environments. Lots of people here can't wait for that first named storm, so they're latching onto any model that provides the slightest "hope" of development. One could even say that "W" word...

Totally true. As you know...and I say this for the benefit of the rest...

One of the first things you do when you see something like this is look at everything the model is producing...not just one level (like the sfc) to see if it makes sense. You can't just look at one level and say "well, this is what the model says so let's go with it."

You have to evaluate all the levels to see if there is something that debunks what that level is saying...as there is in this case. When the sfc is deepening a tropical low in a high shear...an upper level trof in fact...environment...you have to now admit that there is a problem somewhere in the model run that it is not seeing.

Remember...look at every level...not just one. See if the level you are looking at makes sense in the light of what the other levels are saying.

That's the Met tip of the day.

[CHRISTY]

actually i couldn't agree more with guys...i remember jeff masters mentioned in his blog a couple of days back this season will start of slow...unfavorable conditions are going to prevail for the time being.so iam really next expecting any tropical development for a while. chrisy

[Extremeweatherguy]

Though the experimental NAM will likely be wrong, it is still pretty amazing to see it show a 980mb low!

http://www.nco.ncep.noaa.gov/pmb/nwpara ... p_084l.gif

[skysummit]

I'm so thankful to have pro mets on this board to explain things thoroughly like they do. Thanks again AFM and wxman57!

[rockyman]

The 06z GFS is also showing a low pressure center jumping from the EPac to the border of Guatemala/Belize/Mexico...not quite into the Gulf of Honduras, but close (between 96 and 120 hours):

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... &hour=96hr

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... hour=120hr

This low pressure is to the EAST of the one that is currently developing in the EPac...and is steered north around the east side of that developing EPac cyclone (according to 06z GFS).

[boca]

As long as we have that trough along the east coast which is causing strong shear in the Gulf of Mexico. The NAM can do whatever it wants because I believe it won't materalize with the current pattern.

[rockyman]

UKMet shows the surface low moving from the EPac east into Central America then dissipating:

[SouthFloridawx]

here it is

http://www.nco.ncep.noaa.gov/pmb/nwpara ... loop.shtml

OK...again...I would ask you guys to look at the run on the main site...and note the difference.

But...if you all want to latch on to hope to the experimental run...here is a question for you:

Have you looked at the upper levels "associated" with this surface feature?

http://www.nco.ncep.noaa.gov/pmb/nwpara/analysis/carib/nam/00/images/nam_300_072m.gif

When you look at that big trof sitting right on top of this tropical system...maybe we should be saying "Hmmm...this experimental thing seems to have a problem. It's developing this system in the middle of an upper level trof with 25-30 knots of shear around. That can't be."

OK...that should let you know there is a problem with this model. It has a bug in it that allows it to develop tropical systems in the middle of cold core, long wave trofs.

I hate to bust bubbles here...but if that upper level feature verifies...then there is no way a sfc feature like that verifies unless it is attached to a front. This model has problems.

Again. It is the NAM.

I posted this on page 5 and I knew that it was the experimental. I first posted the regular NAM then the experimental.

00Z NAM

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

the experimental one is only at 48 hours right now. I'll post it when it's finished.

[SouthFloridawx]

This was posted in the long range model thread in case anyone didn't notice it there.

00Z CMC continues its run of a major storm moving northward into the GOM. Seem the NAM and this model are holding tough on possible development. Well, the 00Z NOGAPS now shows a weaker surface low in the central GOM at 144 hrs so we may be on the something here. Stay Tuned.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... loop.shtml

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... =Animation

https://www.fnmoc.navy.mil/CGI/PUBLIC/w ... sf&tau=144

[cheezyWXguy]

both the experimental page and the real page have the NAM developing a low, although the experimental one is much stronger

[SouthFloridawx]

The GFS showing some something moving into the BOC at 144 hours.

http://bricker.met.psu.edu/~arnottj/cgi ... =Animation

[SouthFloridawx]

Although the NAM is not great on tropical development, here is the "Regular" NAM not the experimental. This is the 12Z run 84 hours.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_084l.gif

Experimental is here:

this is also 12Z but, only 60 hours cause the run hasn't finished yet.

http://www.nco.ncep.noaa.gov/pmb/nwpara ... p_060l.gif

[CHRISTY]

Although the NAM is not great on tropical development, here is the "Regular" NAM not the experimental. This is the 12Z run 84 hours.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... p_084l.gif

Experimental is here:

this is also 12Z but, only 60 hours cause the run hasn't finished yet.

http://www.nco.ncep.noaa.gov/pmb/nwpara ... p_060l.gif

if the regular NAM were to verify that would be amazing....