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Wintry Feb 19-20 Possible Front-End Snow/Ice Thump

It's been my experience over the years that weak overrunning events like this are often poorly modeled in regards to qpf placement and strength. This looks like it may be a similar scenario where models aren't handling the precip all that well. This is key because if the initial band is stronger/heavier than modeled in places like NC there might be a quick burst of snow/sleet whereas the models that form the band to the north of NC delay the precip too long. Based on ground observations and radar I would lean right now to the idea of a quicker arrival of precip with a better chance for some brief snow/ice before WAA takes over and changes areas to rain or zr in the CAD areas.
 
snowlover91 said:
It's been my experience over the years that weak overrunning events like this are often poorly modeled in regards to qpf placement and strength. This looks like it may be a similar scenario where models aren't handling the precip all that well. This is key because if the initial band is stronger/heavier than modeled in places like NC there might be a quick burst of snow/sleet whereas the models that form the band to the north of NC delay the precip too long. Based on ground observations and radar I would lean right now to the idea of a quicker arrival of precip with a better chance for some brief snow/ice before WAA takes over and changes areas to rain or zr in the CAD areas.
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I truly believe there may be more frozen precip with this in NC than originally forecasted, including the Triangle area. I can see the frozen precip holding on longer because of CAD. It's been a while, but it has happened here before.
 
Models underperforming on the warm nose esp in CAD events and tending to miss out on the initial precipitation in overrunning events esp for areas further north likely aren't unrelated in terms of the sources of both of these errors. Model vertical resolution is partially to blame imo.

The HRRR for example over northern Alabama hints there's some weak warm air advection (WAA) near 600-700 hPa just below the dendritic growth zone (DGZ) (notice the winds veering slightly in this layer from W near 700 hPa to SW a little higher up in the forecast sounding). This weak WAA is probably a bit stronger than currently modeled (as usual) which would partially explain the larger expanse of precipitation here and into N GA, and the Carolinas.

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We can’t speak in absolutes but we can speak truth. This is a novelty event for the bulk of this board. Everyone enjoy your sleet. Nice little change up from the 80’s we had last week
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#Crushed
 
A useful resource for tracking this storm is the SPC mesoscale analysis page. For this storm the 850mb and 925mb layers will be useful in tracking things in NC. I find the 925mb layer usually shows up the CAD pretty well and you can already see the beginning stages of it forming in Western NC. The 700mb layer is a good one to look at as sometimes a warm nose can show up here and also to see what the RH is.
 
Pouring rain here now. Take lots of pictures when the sleet starts to fall. It doesn’t last long
 
snowlover91 said:
A useful resource for tracking this storm is the SPC mesoscale analysis page. For this storm the 850mb and 925mb layers will be useful in tracking things in NC. I find the 925mb layer usually shows up the CAD pretty well and you can already see the beginning stages of it forming in Western NC. The 700mb layer is a good one to look at as sometimes a warm nose can show up here and also to see what the RH is.
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Agree.... like the images posting earlier. ;)
 
Nam pretty much shows me with a snow sounding for 2 hours now, forget ZR, it’s struggling to pick up on the overrunning precip aswell
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Jimmy Hypocracy said:
Pouring rain here now. Take lots of pictures when the sleet starts to fall. It doesn’t last long
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Were you forecast to get rain today or was it supposed to hold off until tonight? We are supposed to be dry until after 8:00 pm. There's that little batch to the south, but I'm not sure it holds together long enough to move in here.
 
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