Which System?!?

I decided to get one more post in before I head away on a trip back to Iowa for the Iowa State High School Wrestling Tournament. The reason for the update is mainly as a initial thoughts on what could be an interesting weather weekend for the central Plains states. Two waves are likely to travel across portions of the Plains and may bring the chance of precipitation, in both liquid and solid form. The best part about the upcoming forecast is that there really has not been a forecast model to get a good grip on a solution to this point. With the NAM favoring the initial wave, the GFS favoring the second wave, the ECMWF favoring the second but also being even slower, and the SREF ensembles which range anywhere from 0.00" to 0.97" for Kansas City Intl into this weekend. These are just subtle changes either, the 12z & 18z NAM today put out nearly 1"/hour rates of snowfall for Friday and Friday night leading to what the NAM believes is a foot of snow by Saturday at dawn for the Kansas City area! The GFS on the other hand, does not send out as much energy with the first wave and hence gives the Kansas City area a solid 0.00" of precipitation through Saturday morning.

The reason for the discrepancies is due to a wave of energy that will drop down into the Rockies late Thursday, and another wave that will drop southward from our arctic low. These two waves of energy would likely incur some phasing as they entered the Plains states on Friday, but the question that the models are trying to answer is how much energy from the 'southern' wave will actually eject out onto the Plains. The NAM of course has a majority of the wave coming out onto the Plains and thus forecasting a large amount of precipitation with it. The GFS on the other hand will keep most of the energy in the Rockies, providing little to no precipitation for the late week.

What happens with the initial wave will likely have large impacts on our second wave for Sunday/Monday. Looking at the ensemble members, you can judge that those which have this stronger system on Friday do not have as much energy shown with Sun/Mon and thus do not expect much of an impact with this system. With the ensemble members that do not expect much on Friday, have a much larger and significant system for the Sunday/Monday time frame. Essentially if a majority of our first wave is held back in the Rockies, it will contribute to the second wave that will be pushed out onto the Plains with the storm system entering the West Coast late Friday.

Although a good amount of time was spent looking at things today, it is still very hard to tell which model may have a better handle of this that far out. It would appear that it may be best to hedge towards the second event being the largest of the two, leading to some significant precipitation for Sunday/Monday across the central Plains. However, as mentioned it is pretty hard to make much of a justification for this. For now I will keep an eye on it as it may disrupt my travel plans for a return from Des Moines, but I won't likely see time to post any updates on the blog. For now keep an eye on what the various forecasters have to say, as it will be interesting to see who throws their hat out into prediction of the big storm as either Friday or Sunday/Monday.

The next update will likely not come until early next week, perhaps even after both storm systems have exited and there is a little downtime to post a recap of what occurred, or what didn't! In the meantime, enjoy a few days of quiet weather before we at least have a chance at adding to some snow totals across the Plains.