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Wintry Potential Dec 13-14 Ice Threat

Webberweather53

Webberweather53

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Sleet City USA said:
God almighty CMC
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Despite showing absurd ZR totals, I think the area affected by ZR on this CMC is a realistic threat zone for this event, at least for now. The US 1 corridor is probably on the outside looking in, towards Charlotte, Greenville-Spartanburg, & Greensboro this might be a close call, oth for the blue ridge escarpment and extreme W piedmont (Hickory, Wilkesboro, Mt Airy, etc), I’d feel halfway decent about my chances for some glaze Friday morning
 
Webberweather53 said:
Isentropic upglide over the CAD dome is usually hard for the globals to capture (& typically underdone on the models), don’t be shocked to see greater coverage of freezing drizzle or light ZR and perhaps some IP vs what’s currently being shown near the onset of this event.
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Can definitely see that signal on the gfs, obviously some frontogenesis on the mountains with WAA around the western piedmont/foothills with winds coming out of the SE at 850mb, those ingredients should allow spotty precip before the main stuff moves in like you said 1575914310776.png
 
euro is gonna probably barely show anything, but it did take a step towards more wintry by strengthening wave number 2 which speeds up precip and showing a stronger vortex, which acts as better confluence, this run is gonna be close tho
 
Myfrotho704_ said:
Can definitely see that signal on the gfs, obviously some frontogenesis on the mountains with WAA around the western piedmont/foothills with winds coming out of the SE at 850mb, those ingredients should allow spotty precip before the main stuff moves in like you said View attachment 27588
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Exactly. The key here with the earlier onset of even light precip driven by isentropic upglide and WAA vs what’s being modeled is that it establishes and reinforces the CAD dome sooner and generates corresponding low-level NEly flow that increases cold air advection over CAD favored areas faster than forecast. Processes like these are often overlooked but can mean the difference between mid 30s and rain vs near 30-upper 20s & ZR
 
SimeonNC said:
One thing I am noticing is a somewhat of a southern trend of the CAD high, all three globals now have it getting down to around the Mason-Dixon line before starting to move out, I am not sure but I think this could lead to a deeper CAD.
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Most likely it would lead to a stronger CAD and personally I am looking for models to trend the CAD stronger as we get closer.
 
don't really know why the models are trending to a high further south ? GFS does show a stronger trough in NE Canada, which would help, but the euro shows the trough more north, altho it was stronger, maybe @Webberweather53 can chime in ? gfs_z500a_namer_fh78_trend.gif
 
Ethan80963! said:
Most likely it would lead to a stronger CAD and personally I am looking for models to trend the CAD stronger as we get closer.
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The idea of a ~1040 HP being so far south despite it moving out quickly is what makes me think that the CMC isn't completely out to lunch with its p-type distribution.
 
CMC is believable if it's right about getting the precip in as quick as it's showing. It's the quickest model by far with getting precip into GSP/NC.

Euro - GFS - CMC valid 1am Friday morning

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Mods feel free to delete this but since all major models are now calling for at least some ZR in Western NC around 4-5 days out, I thought it would be appropriate to start the thread.

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In my opinion, I think with a strong high being so far south before moving out that the frozen precip field could be a bit wider, and with more areas close to VA seeing more in the way of IP than ZR. I do not expect nothing more than a minor glaze at the moment.
 
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SimeonNC said:
Mods feel free to delete this but since all major models are now calling for at least some ZR in Western NC around 4-5 days out, I thought it would be appropriate to start the thread.
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We can roll with it. I've just moved the relevant posts from the last page of the December thread over here.
 
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