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Wintry 3/12 White Rain Potential

Question: why does the NAM 3km always looks really icy in almost every setup? Does it overdo warm noses a tad?
The rule used to be, the worm nose is always under modeled. But if you have a disagreement between the NAM and RGEM or HRRR, then not sure what to bank on. NAM is normally good with thermals but there have been some resent storms the past few years where it seemed like the HRRR did better here. The NC crew also has examples of where all the models have broken their hearts.

Hoping tomorrow works out!
 
The rule used to be, the worm nose is always under modeled. But if you have a disagreement between the NAM and RGEM or HRRR, then not sure what to bank on. NAM is normally good with thermals but there have been some resent storms the past few years where it seemed like the HRRR did better here. The NC crew also has examples of where all the models have broken their hearts.

Hoping tomorrow works out!
I mentioned this in the March thread before I realized that this was open, but it’s important to note that this potential is from strong FGEN forcing collapses the column to at least temporarily overcome the warm nose. The NAM does not pick up this up well until literally inside just a few hours. The HRRR, RGEM, and RAP do pick up this cooling of the column very well which could be why they are showing less of a warm nose.
 
38

Wow the RAP really shows who could some white grass tomorrow, unfortunately it’s kind’ve a ------ model
 
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12z vs 18z HRRR. Big time downtrend
 
In marginal setups, the HrrrrrRR almost always shows much more snow at its longer leads and then reduces as we work in.

It's likely that there will be some snow mixed with the rain north of 40, especially the closer you get to the border...maybe even all snow for a short period right along and north of the border. I don't see it being a bigger deal than that.
 
One thing I noted is the NAM drops the areas with heaviest snow down to freezing.
I feel like realistically in these situations areas that so get heavy snow should drop into that 32-33 range, regardless of what the modeling shows.

Also, as usual, I’d much rather be where you are than where I live for this one. ? This definitely has the feeling of one where N Durham County gets a ground whitener while all I get is mangled flakes and wet ground.
 
I feel like realistically in these situations areas that so get heavy snow should drop into that 32-33 range, regardless of what the modeling shows.

Also, as usual, I’d much rather be where you are than where I live for this one. This definitely has the feeling of one where N Durham County gets a ground whitener while all I get is mangled flakes and wet ground.

Yeap being north of 85 makes a huge difference.


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Pretty sweaty forecast in the morning if I'm being honest. Just a couple of degrees in a deep layer makes the difference between a few hours of snow and nothing. If I had to guess right now I think the main change to all snow line even briefly is HKY to RDU to RWI with mixed rain/snow/Sleet possible 25-30 miles south of that, any accumulations are pinned into the better climo areas from say Elkin to Henderson N&W

Really interested to see how this initial shot if fgen and waa manifests on radar if this is accompanied by moderate banded constant precip it may aid in expanding the snow area and increase aerial coverage of light snow accumulations 3f2ee777-f789-48b6-a879-9537cb1f5668.gif
 
Pretty sweaty forecast in the morning if I'm being honest. Just a couple of degrees in a deep layer makes the difference between a few hours of snow and nothing. If I had to guess right now I think the main change to all snow line even briefly is HKY to RDU to RWI with mixed rain/snow/Sleet possible 25-30 miles south of that, any accumulations are pinned into the better climo areas from say Elkin to Henderson N&W

Really interested to see how this initial shot if fgen and waa manifests on radar if this is accompanied by moderate banded constant precip it may aid in expanding the snow area and increase aerial coverage of light snow accumulations View attachment 134203
Yeah I think that’s the ballgame. The earlier we can get going and the more forcing, that enhances the chance for the better model depictions.
 
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