The buzz in the weather community is the developing storm this weekend across the Northern Plains. I want to start by saying this is NOT our storm for the Mid Atlantic, but a focus on Chicago. They are part of a region under a Winter Storm Warning. This storm will help drag down colder air over the weekend, but we won’t get snow from this. However, tracking the storm will give more insight to how storms closer to us this winter will behave. Remember when the Ravens made the playoffs? It’s like watching the other teams they would face next to see how they stack up. Winter is like our playoffs as forecasters.
The storm will be racing off of the Pacific and not an El Nino event, but rather the result of a warm phase of the Pacific Decadal Cycle (PDO). This PDO is a piling of arm water along the eastern central and northern Pacific Ocean and can send storms into the northern US like a sling shot. These fast moving storms often push farther east than computer models account for, and as we are seeing now, will travel farther east before making the eventual turn north. The result looks like Chicago will stay on the colder side, and in turn could get more snow. Compare the latest forecast model below and expected snowfall increasing over the National Weather Service outlook posted yesterday.
Why is this important to us?
I see tracking the trend of the storm to the east as a way to anticipate the track ahead of the models. Basically there will be a lot of late adjusting of storm tracks to the east due to faster upper level winds. Think about all of the adjustments to Hurricane Joaquin track that at one point was gong to hit the east coast. Coastal storms may have a tendency to skip off the coast. However western storms may have a better chance of hitting us, or shifting initial warm tracks to the east, that can bring us wintery mix or snow. So this doesn’t mean we get all overachieving snow storms, but that watching the tracks of those storms verifying farther east than first thought will be the trend.