Winter Storm Threat *Technical* Discussion. No Op Run PBP or Snow maps

[psuhoffman]

18z AIFS was our win scenario. 

all ens guidance now shows this at day 5.  This general idea seems locked in now  

The decaying nao block X has retrograded to Hudson Bay.  There is a strong 50/50 feature Y from a strong wave that was forced under the retrograding block.  The pacific wave Z is entering the southwest.  The flow in front of it will prevent it from gaining too much latitude so long as it ejects quickly. 
 

Yes the pacific has gone to absolute shit.  But because the antecedent pattern was good we have a window of opportunity here.  
 

We want a healthy wave to eject and as quickly as possible imo. The 18z AIFS did this. The 18z EPS looked like it was also but doesn’t go out far enough. But I’ll take this…

the gfs products are washing more of the wave out and absorbing most of it into the approaching north pacific trough.  This means a weaker delayed wave.  that’s a loss  

BTW a “Hudson High” regime actually used to be a cheat code to a snowstorm here absent other features we typically look for  PNA, NAO… historically I found numerous Baltimore snowstorms where a high there seemed to be the main feature and it snowed despite flaws elsewhere.  But I’ve noted those have gone extinct recently and that some recent examples ended up slightly too warm and “perfect track rainstorms”  A recent example was a storm around the Super Bowl in 2023 I think.  This will be a good test to see if this can still work!  Assuming a wave ejects.