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Wintry Winter Storm Dec 7-10

We honestly probably won't know what's going to happen until this is almost on top of us, for an event that's heavily dependent on melting aloft to get a precipitation type change over to snow, it's asking a lot out of the models to get the extent and intensity of the precipitation shield right this far out...
 
Again as I've said a few times already we really don't know who, where or exactly how much or what type of precipitation someone will experience in an event like this that's driven by latent heat absorption through melting of falling hydrometeors into an above freezing level near the surface. Precipitation and even more so, precipitation rate is the hardest variable for models to forecast so expect wild run-to-run swings, a plethora of forecast solutions, and few answers that actually end up being anywhere close to reality unless we're within 24-36 hours of the event
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Webberweather53 said:
Again as I've said a few times already we really don't know who, where or exactly how much or what type of precipitation someone will experience in an event like this that's driven by latent heat absorption through melting of falling hydrometeors into an above freezing level near the surface. Precipitation and even more so, precipitation rate is the hardest variable for models to forecast so expect wild run-to-run swings, a plethora of forecast solutions, and few answers that actually end up being anywhere close to reality unless we're within 24-36 hours of the event
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Webberweather53 said:
Again as I've said a few times already we really don't know who, where or exactly how much or what type of precipitation someone will experience in an event like this that's driven by latent heat absorption through melting of falling hydrometeors into an above freezing level near the surface. Precipitation and even more so, precipitation rate is the hardest variable for models to forecast so expect wild run-to-run swings, a plethora of forecast solutions, and few answers that actually end up being anywhere close to reality unless we're within 24-36 hours of the event
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Wow, better this round
 
Webberweather53 said:
Again as I've said a few times already we really don't know who, where or exactly how much or what type of precipitation someone will experience in an event like this that's driven by latent heat absorption through melting of falling hydrometeors into an above freezing level near the surface. Precipitation and even more so, precipitation rate is the hardest variable for models to forecast so expect wild run-to-run swings, a plethora of forecast solutions, and few answers that actually end up being anywhere close to reality unless we're within 24-36 hours of the event
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Still feel a NW trend is coming tomorrow
 
MSnowAtl said:
Still feel a NW trend is coming tomorrow
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accu35 said:
Wow, better this round
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RollTide18 said:
Better run for Alabama
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I'll say it once more, pecipitation rate is literally the hardest variable to forecast for and/or reanalyze w/ a reanalysis or NWP model. NCEP Reanalysis is a testament to this. If you're expecting to find or have solace in any legitimate, specific answers in spectral NWP this far out wrt precipitation type and especially snowfall amounts you're doing yourself a disservice.
 
SoutheastRidge said:
Webber, what is the timing of this ? Would this be coming in during the daytime in AL and GA ?
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The Euro moves the heaviest precipitation thru Thursday night but in situations like this as I just mentioned it is the hardest variable for the models to predict... If the precipitation is not heavy enough in your backyard it may not snow at all... Asking us to get that right is equivalent to telling us to pinpoint exactly where a large-scale mesoscale convective cluster will be, how intense it'll be, and how much latent heating will be removed by melting hail hydrometeors several days in advance... It's just not feasible whatsoever with spectral NWP and current forecasting capabilities
 
Webberweather53 said:
The Euro moves the heaviest precipitation thru Thursday night but in situations like this as I just mentioned it is the hardest variable for the models to predict... If the precipitation is not heavy enough in your backyard it may not snow at all... Asking us to get that right is equivalent to telling us to pinpoint exactly where a large-scale mesoscale convective cluster will be, how intense it'll be, and how much latent heating will be removed by melting hail hydrometeors several days in advance... It's just not feasible whatsoever with spectral NWP and current forecasting capabilities
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Heck, im just glad to be tracking something
 
SoutheastRidge said:
I'm debating on going on a snow chase so hopefully we will have a better idea by tomorrow night.
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The global models are not well suited for handling events like this that are heavily dependent on localized, intense areas of precipitation which ultimately determine precipitation type and amounts. We will need to get the high resolution guidance well into range to have a clue. The NAM may help a little once it's a good ways inside 36 hours
 
Webberweather53 said:
The global models are not well suited for handling events like this that are heavily dependent on localized, intense areas of precipitation which ultimately determine precipitation type and amounts. We will need to get the high resolution guidance well into range to have a clue. The NAM may help a little once it's a good ways inside 36 hours
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You've stated this a few times already, but a handful continue to ignore it. Pay attention, people.
 
ColaSnow said:
You've stated this a few times already, but a handful continue to ignore it. Pay attention, people.
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Yep, the forecast uncertainty here is nearly although not quite as bad as forecasting summertime thunderstorms and many can attest to how those forecasts often work out... Obviously wintertime convection is often more heavily sheared and diffuse but the premise remains the same. These second order cloud-radiative, aerosol interactions, momentum transfers, mass redistributions, as well as sensible and latent heating fluxes, and feedbacks amongst these are extremely hard to model and observe even with conventional NEXRAD radar, Lidar, and cloud radar, and other instruments. It's just an under-constrained problem meaning that we just don't have the necessary tools to properly observe with "sufficient" accuracy and confidence to know exactly what's going on much less exactly explain what's happening if we had the tools... Poor estimation and parameterization of these processes initially manifest as small-scale errors but exponentially grow upscale in time, often quickly projecting onto the synoptic scale in a matter of just a couple days or sometimes less...
 
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