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Pattern January 2021 - Joyless January

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I mean overrunning is essentially just isentropic upglide due to differential advection and the air parcel conserving it potential temperature.. so in a way is it correct to say that CAD is a spatially controlled form of this by terrain resulting from less than 1 froude number
 
EastAtlwx said:
I mean overrunning is essentially just isentropic upglide due to differential advection and the air parcel conserving it potential temperature.. so in a way is it correct to say that CAD is a spatially controlled form of this by terrain resulting from less than 1 froude number
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CAD can be characterized as subset of overrunning sure I agree with that, but I want to clarify that they definitely aren't the same thing because CAD involves a geostrophic & hydrostatic adjustment process of cold air building up against the lee side of terrain (causing local sfc pressure rises) w/ the low-level flow that's blocked by the terrain, and acquiring a northerly component as a result. That doesn't always happen in overrunning in general, you can actually get overrunning w/ southerly sfc winds, which isn't possible in CAD. You see southerly wind overrunning more frequently in the northern US in the heart of winter where it's cold enough to support wintry precip almost regardless of wind direction
 
At least we continue to be pretty active. We have had a lot of minor events, sure. But Winter has stayed active. This looks to be yet another storm to talk about the remainder of the week.
 
This far out you probably be reciting the mantra, "it is the GFS". Even the EURO at this range is highly inconsistent. The pattern does look good for the final 11-12 days of the month but we don't always score even when it is.
 
deltadog03 said:
I know we need some low level help....but it could have some legs...

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I see no way this can improve for those outside of the favored climo regions (***of the southeast***). Without some cold high pressure, we will continue to track marginal events that will end up being slop storms that yield illusions of grandeur and end in great disappointment. I can't wait to be proven wrong, but I highly doubt I will be.
 
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sdm47 said:
I see no way this can improve for those outside of the favored climo regions. Without some cold high pressure, we will continue to track marginal events that will end up being slop storms that yield illusions of grandeur and end in great disappointment. I can't wait to be proven wrong, but I highly doubt I will be.
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Waco texas got the most snow its had since 1982 the other day.
 
Webberweather53 said:
CAD can be characterized subset of overrunning, but I want to clarify that they definitely aren't the same thing because CAD involves a geostrophic & hydrostatic adjustment process of cold air building up against the lee side of terrain (causing local sfc pressure rises) w/ the low-level flow that's blocked by the terrain, and acquiring a northerly component as a result. That doesn't always happen in overrunning in general, you can actually get overrunning w/ southerly sfc winds, which isn't possible in CAD. You see southerly wind overrunning more frequently in the northern US in the heart of winter where it's cold enough to support wintry precip almost regardless of wind direction
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Oh yeah I totally forgot about the geostrophic & hydrostatic components of CAD.. yet I’m sitting here using froude numbers which are ground in the hydraulic principles ??‍♂️
 
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