18z models 12.9

[Ian]

nam looks a smidge interesting at the end..

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/18/images/nam_pcp_078m.gif

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/18/images/nam_pcp_084m.gif

[afvet89]

yep.just a smidge tho. stay tuned till tonite for another episode of what will the NAM come up with next.

[WeatherGQ]

What the heck is going on here? it looks like north FL is getting snow and a low is forming of the NC shore. Monday, is this right?

nam looks a smidge interesting at the end..

http://www.nco.ncep....am_pcp_078m.gif

http://www.nco.ncep....am_pcp_084m.gif

[mitchnick]

84hr 700mb map on NAM looks interesting for sure

[Ian]

What the heck is going on here? it looks like north FL is getting snow and a low is forming of the NC shore. Monday, is this right?

i doubt that's snow in fl.. looks like frontal precip before it cools aloft. looks like two areas of lower pressure in the mid atlantic and off the coast.. 700mb looks decent though at least around here (mid-atl).. if it ran further it that piece near nc should come north. of course it's probably crap.

[Ian]

18z gfs pretty similar to 12z so far but maybe slightly more amplified at 60 hr with the weight of the s/w further south.

[usedtobe]

Here's the 72 hr. It still looks like it has some anafront characteristics but much quicker than the NAM with the base of the trof.

[EasternUSWX]

This looks good. I think if we can get the S/W to be amplified more SE we can get a low to form along the front and give areas in Central PA to central MD and good thump.

[Ian]

ends up about the same as the 12z it seems thru 78.. 500 a bit more energetic but not terribly meaningful for many.

[mattinpa]

Remember that the 18z is often the most suppressed. Looks like more back-end snow for PA and MD, but we'll see if the 0z says the same.

[usedtobe]

ends up about the same as the 12z it seems thru 78.. 500 a bit more energetic but not terribly meaningful for many.

Basically, it's held serve.

[Ian]

Here's the 72 hr. It still looks like it has some anafront characteristics but much quicker than the NAM with the base of the trof.

doesnt most or all the precip come (around here at least) before it's cold enough for snow?

[tmagan]

Rather stark differences in the 72 hour MSLP fields of the 18Z UKMET and GFS.

[usedtobe]

doesnt most or all the precip come (around here at least) before it's cold enough for snow?

I think so, the 850 is OK but the boundary layer is warm so the best we can do I think is a little slushy dusting but that is all it has ever really looked like. It makes me feel good about my CWG piece. You had me getting worried by posting the 84hr NAM.

[Ian]

I think so, the 850 is OK but the boundary layer is warm so the best we can do I think is a little slushy dusting but that is all it has ever really looked like. It makes me feel good about my CWG piece. You had me getting worried by posting the 84hr NAM.

im hanging on to any hope i can find at this point. i love the trough one way or another.. 500 mb maps make me tingly sometimes. it's tough falling back into "normal" as far as winter goes in these parts.

[mattinpa]

doesnt most or all the precip come (around here at least) before it's cold enough for snow?

For DC is does look like some light snow around hr. 78 - slightly more east.

[mattinpa]

im hanging on to any hope i can find at this point. i love the trough one way or another.. 500 mb maps make me tingly sometimes. it's tough falling back into "normal" as far as winter goes in these parts.

All I'm hoping for is a little accumulating snow to start the winter - really just got a coating on Thanksgiving.

[Ian]

For DC is does look like some light snow around hr. 78 - slightly more east.

maybe.. would have to see soundings i guess. but the surface has just become cold enough at that time (well, maybe 2 or 3 hours earlier if it's sub 32 then) but im guessing the precip shuts off before that in large part at least.

700 at the same time doesnt look super for much

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/18/images/gfs_700_078m.gif

[ParanormalWx]

With the negative tilt, you'd except it to have little if any precip after the front.

[Wonderdog]

On the 18z NAM, 500 map, can someone explain what it indicates for VA/NC?

[clskinsfan]

On the 18z NAM, 500 map, can someone explain what it indicates for VA/NC?

Rain.

[Wonderdog]

Thanks for the well thought out explanation. I guess I didn't make myself clear. I was referring to the circular yellow/orange rings. I just wanted to know what they are.

Rain.

[Ian]

Thanks for the well thought out explanation. I guess I didn't make myself clear. I was referring to the circular yellow/orange rings. I just wanted to know what they are.

it's basically just the trough at 500mb, lower pressure areas at that level. the x's are vort (rotation) maxes. in this case the trough as a whole at 84 is tilted negative.. se to nw. you often see a surface low to the se of the best vorticity at 500mb.

there's some more here, google.. not sure it's the best explain in this case but it is one nonetheless.

http://www.theweatherprediction.com/charts/500/basics/

[SeanVA]

Thanks for the well thought out explanation. I guess I didn't make myself clear. I was referring to the circular yellow/orange rings. I just wanted to know what they are.

That's vorticity, it shows how much the air is swirling. Mainly is the winds that one looks at; the origin of the flow shows how warm the air aloft will be.

[Wonderdog]

Thanks guys.

it's basically just the trough at 500mb, lower pressure areas at that level. the x's are vort (rotation) maxes. in this case the trough as a whole at 84 is tilted negative.. se to nw. you often see a surface low to the se of the best vorticity at 500mb.

there's some more here, google.. not sure it's the best explain in this case but it is one nonetheless.

http://www.theweathe...rts/500/basics/

That's vorticity, it shows how much the air is swirling. Mainly is the winds that one looks at; the origin of the flow shows how warm the air aloft will be.