The Next Storm Too Close to Call
by Cody Matz
November 06, 2011 7:58 PM
Now that we are finally done with the winds, at least for a little while, we look ahead to our next storm down the line. Monday should be pretty tranquil with light winds and some sunshine, but by Monday night, things could go downhill pretty rapidly….. or will they? Here is what we know. A large trough is diving into the west coast and is forecasted to pop out into the Plains sometime Monday night or early Tuesday. Ahead of this trough, warm air will be moving north and cold air will be funneling in from Canada setting up a classic battle of the airmasses. This is what we know for sure… unfortunately there is a lot more that we don’t know, that could mean the difference between dry conditions, a cold rain, or a very heavy wet snow.
Looking at all of the forecasting models allows us (meteorologists) to get different perspectives on upcoming weather. In a lot of cases, they will agree with one another (to a point). However in this case, they are not so friendly and are showing a pretty good discrepancy between all of them. Let me show you…
The following 2 images are 2 forecasting models showing expected precipitation (in the form of liquid equivalent, meaning that precipitation type is not depicted on there) for the same time period on Tuesday. See if you can spot the BIG differences.
If you cant find it, let me help you out. The first image shows precipitation making it into most of southern South Dakota with heavier amounts in the southeast. The second image shows all of the precipitation staying just to our south into portions of northern and eastern NE. These are the types of differences that we have been dealing with forecasting this particular storm from day 1. Now there are several other models, but they all show pretty much the same thing; the southeast will likely be on the edge of the precipitation line, but how much if any will we get?? That is the million-dollar question.
Of course it is November so then we have to determine whether it will be rain or snow and once again, we unfortunately cannot come up with a conclusive answer. Temperatures will be very close to the freeze mark not only at the surface, but the lower few thousand feet of the atmosphere as well, meaning that just a couple degrees up or down could make a huge difference. Here is the current forecast from the Hydrological Prediction Center. These images show the probability of receiving at least 4 inches of snow Monday and then again on Tuesday.
Now, if you want me to make a conclusion about our upcoming storm here ya go. As of right now I would say some light rain and even some light snow looks likely in the southeast, however I would not count on either rain or snow to amount to a whole lot with a good deal of dry air in place and the best dynamics to make precipitation staying off to our south and east, however, this is really something we are going to have to watch. One side step sideways and this storm could become a pretty big deal for our area. We will keep you updated through the day Monday with the latest.