In-Depth: Beyond the 10-Day Forecast
The day is Sunday, which means another update for "Beyond the 10 Day." Currently across the Unites States, the jet stream enters to the north of Seattle and moves east until it dips slightly through the northern Great Lakes then moves northeast through the Northeast. After a mild stretch of weather the past couple of weeks, things have come back down to average locally and will generally be there as we progress through the next two weeks. Also, our wintry mess we saw yesterday seems to be a precursor of what is to come as there will be chances for storms, but staying all snow or seeing snow in general will be tough to come by.
As we push through this work week and towards Christmas, not much can be said that sticks out. We will see another miss of a snowstorm well off the East Coast Tuesday/Wednesday and temperatures are not expected to take big leaps or drastic drops through the next few days. Atmospheric blocking over Greenland and Alaska will persist, which is great, but troughing over the Western US is putting a large wrinkle in the whole outlook as this continues to keep the jet stream from dipping across the Eastern US. Our next storm chance will come on Christmas. An area of low pressure will develop to the lee of the Northern Rockies during the middle of this week and move east. As of now, models are signaling this area of low pressure lifting a warm front through our region and quickly changing any snow over to rain for Christmas Day. The door for snow is open, but we need to see some changes for that to occur. We need high pressure to the north to be stronger and wedge between our Christmas storm and an area of low pressure over the Atlantic. This wedging will cause low pressure to travel south of what models are showing right now and push more cold air into the region locally. Until those changes occur, if they even do, we will be looking at a milder system with some light snow early before quickly changing over to rain with no snow accumulation for Christmas. Regardless of what we see locally, just be aware of unsettled weather ahead for the holiday weekend with either rain or snow.
Moving forward form there and into New Years week, there seem to be no sudden switch in the pattern that will increase our snow chances. The troughing over the Western US likely persists along with our blocking. Until that troughing breaks down out west, there will be no time period in which screams snow for us locally. Also the weak, but stubborn, Southeast ridge will try to stick its nose northward from time to time and break any type of interaction between the polar jet and sub-tropical jet until it is too late. However even with this ugly setup for snow we still have storm chances ahead, whether it will be snow or rain is a different story and will have to be judged storm by storm.
Our first storm chance for New Years week will come around December 29th. The jet stream looks to be active across the eastern US and potentially spur up an area of low pressure. Based off of the current pattern, and with the lack of change ahead, it will be tough to say all snow but the door will be open for snow locally. Regardless, it looks like an area of low pressure will again develop over the Central US before trying to move northeast and through the Great Lakes. Depending on strength, we will watch out for strong gusty winds but no significant gusts expected at this time. After that, it does not seem too long before another active period we are watching. The next time period comes on New Years Eve. Once again the jet stream will be active across the Eastern US. As said before, based on the lack of change in the upper levels of the atmosphere into next week this will be another situation where we will be looking at a possible Great Lakes Cutter. After that system, the same situation pops up again for January 3rd. The bottom line is, until the troughing over the Western US weakens, there will be little support for snow across the region even with the fantastic blocking in place near Alaska and Greenland. Hopefully things change ahead, but overall it is a bleak snow pattern locally the next two weeks. The next update will come on Wednesday, December 22nd.
Temperatures: Generally near normal with highs in the mid and upper 30s over the next two weeks.
Precipitation: Near normal.
December 25th: Alberta Clipper slides across the Great Lakes. Does it slide north or south of us? track determines precipitation type locally
December 29th-30th: No changes in overall upper level pattern. Great Lakes cutter likely at this time, track determines precipitation type. Likely breezy.
December 31st-January 1st: Low pressure develops over Central US and moves East. track determines precipitation type. No real signs at this point that signal all snow.
January 3rd: Another area of low pressure moving eats with track determining it all.