Quick forecast discussion - Friday night

Well, it's been some time since I've put together a forecast discussion, but I feel compelled to do so with a significant wind event on our doorstep. Haven't spent a great deal of time looking at things, so there won’t be much of a model analysis… but I’ve looked at enough to take a quick look at a forecast…

An unusually strong Alberta clipper continues to zip through the homeland (Wisconsin) tonight. On the back side, another strong polar front is rapidly diving south, and will be ripping though here probably by the time I finish this discussion. Winds behind the front are already sustained at 20-30kts in NE, and we can expect winds to only increase as the storm continues to strengthen. Models continue to show a pressure gradient on the realm of 1mb per 25-50 miles. Even tighter across IA. This could easily bring winds on the order of 45-50 mph around here before sunrise. The weather service believes that the fog and clouds may limit the mixing of momentum down to the surface (up to 65kts at 1000mb progged), but I believe that this won't be too much of a limiting factor until morning once the boundary layer recouples. Plus, the cloud line is just west of here, and we may clear out some overnight. With peak winds coming sometime between 3 and 9, we could easily see gusts up to 55-60mph. Either way, the windows will be a-rattlin' tonight. It should be interesting to compare readings from OJC and IXD to the ol’ Davis on the roof.

The winds will slowly subside through the afternoon, and tomorrow night should be cold, with readings in the single digits after temps in the teens (and wind chills -5 to -15) during the afternoon. Certainly nothing quite like thye -20 with -55 wind chills I got to experience last week in MSP. We should continue in the current weather pattern for some time (trough to the east, ridge to the west... we are caught in-between). Sunday afternoon, we should start to benefit from the storm pushing east enough to modify the longwave pattern a little further east. Temperatures should continue to moderate as we head into the first part of the week, as once again get the benefit of the advection of downslope air from the west. The models are typically too aggressive with modifying cold-dense air during the winter, but I believe the timing of the warmup is such as though they should do too bad this time around. A weak wave moves through Sunday night, which the models respond by bringing slightly warmer 850 temps in. With limited overnight mixing, and the difficulty of maintaining downslope heat overnight, I don’t think it’s going to make much difference. Otherwise the warmup it pretty realistic. We may be talking temperatures once again well into the 50s by Tuesday.