All models are switching gears as the Pacific energy comes inland. A jump in the models is expected as we continue to get better data coming in from the Pacific. Tonight will be a new set of runs with much better data but coming down the home stretch there is good news for snow lovers showing up on all models.
First I am going to do my best John Madden impression on WV imagery:
Two lows in around Alaska, the first one is weakening and retrograding towards the Aleutians and will merge with the main low to its southwest. The convection nw of HI caused this weakening and will result in ridging to take the place of the strong PAC jet. This was modeled but some can make an argument it happened quicker as main energy appears more amped up and slightly slower.
But we cannot jump to conclusions because the trough will split leaving a big piece meandering in the SE PAC with the upper level low. This has a tremendous amount of ascent form the southern jet *models are now picking up on*.
Now to the trends:
New Canadian is much more impressive compared to previous runs. It was a noticeable shift aloft and the other models followed.
The biggest difference can be seen at the sfc with the precip shield. Notice the mount of blue that developed in the latest run in response to the more amplified northern stream. In this situation going from 0.1-0.2 qpf could be 2-4" as most of the areas will be below -10C just above the ground.
This big change allows the ridge to build back west in the southern stream opening the gate for the northern stream to come down. But the northern stream does not respond on the NAM. If the next model run is more favorable in the northern stream like a few other models we could see a very interesting solution.
The newer GFS ensembles came in with more qpf and support the trend.
We have the trend we want to have going into the final 54 hours and we are not far off from seeing a significant winter weather event. With temps very cold aloft the snow will be very powdery and favor a high ratio. We could be talking 20-30:1 ratios!
OAK - same here with fully stocked top shelf bar. Is there any other way? I love beer - just not a big beer drinker. I did have the good fortune of having a job at one point that took me around the world. Had some awesome beers from many other countries - loved the belgiums the best, though Germany had some local pubs that knocked you off your feet as well. Enjoy the pub tonight. It may help to at least have the Oaktrain engine on and running - may bring us some good luck this week....
KAT - you are spot on. Can't ignore the cold, low dew points, and speed of the Ls moving through to merger land over the fishies. I can see it now - everyone will be screaming at the radar showing something and nothing is falling. Mom-nature's oldest trick in the book.
Bear in mind that with the models having a known track record for under forecasting WAA/overrunning and the dendritic growth layer being well below zero, the ratios will be at least 20 to 1. This means that even a low qpf, southern, minor event could drop significant snow, and by significant, under these hypothetical circumstances I would say 2.5-5".