After 2 Straight Weeks with No Rain, It's Back in the Forecast
October 05, 2011 8:32 PM
After several straight days with temperatures well above average, it’s still hard to believe that it’s October. But to tell you the truth, it’s pretty common. From year to year, October is often the most inconsistent month of them all. For example, if you remember last year, we had a fairly mild and dry October finishing out the month with less then half our average precipitation and temperatures a good 3-5 degrees above average. But the year before that in 2009 was wild. Extremely wet and extremely cool across the board made it a harsh start to the winter season with temperatures 7-10 degrees below average and nearly tripling our average precipitation for the month. Not to mention, some of us even saw a couple inches of wet snow. So when you look back, nothing should really surprise any of us when it comes to weather in October. But it does look like things are going to begin to change as we head toward and into the weekend. Temperatures will begin to fall and rain will hopefully greet many of us as it has been a record dry 2 month period for many locations in the Upper Midwest.
Here is one look at why things do need to change. Now I realize that not everyone wants rain, but to keep things growing and to prevent a large drought from setting in before we go into winter (which would at the very least indirectly effect everyone) then we do need some rain. Check out some of these statistics… in many cases its been over 2 weeks since we have seen even so much as a drop of rain. Nothing like this has happened since March of last year, which is why this has become such a big deal. Not to mention, look at the amount of consecutive days since some locations have seen significant rainfall (>.25”). We have not had a streak last this long since February and March of 2009….almost 3 years ago!!!
Before we really get to the meat and potatoes of the rainfall though, we are going to have to go through more wind. In fact, winds will just continue to get stronger going through Friday. Gusts nearly hit 50 mph Wednesday and could easily top 50 in some locations both Thursday and Friday. Check out the images on the right. These show the probability of sustained winds above 15 mph for Thursday afternoon and Friday afternoon. It does look like the winds will be stronger Thursday then on Friday, but both days will be plenty windy. Notice that just about every location both days has a 100 percent chance of sustained winds at least 15 mph.
After the wind finally goes by, the bulk of the rain is expected to arrive, and until today it didn’t look all that impressive. However, it’s looking better and better for rainfall, especially for those in the southeast. This is all stemming from a giant trough that’s diving into the west coast today that’s bringing unseasonably cold air, heavy rain, and even heavy mountain snow to parts of the west. This is the earliest start to snow season in parts of the Sierra Nevada’s and Wasatch mountains in over 30 years. Now, I am by no means suggesting we will get snow! In fact, temperatures will likely stay at or above average right through much of next week. But rain is looking more promising. The images on the right show just how large this particular system really is. These images show the jet stream winds, or the river of air at the top of the atmosphere that is basically the steering current, pushing storms from west to east. Notice that it takes a HUGE dive into the west in the top image, which is what happened today. But watch as it moves into our area this weekend. Not quite as impressive but certainly putting us in pretty good condition to get at least some rainfall.
So how much rain are we talking?? Well, to be honest that question even stumps me a little bit. However, forecasting models are showing signs that more significant rain is possible for some of us as we go into the weekend. Just look at the forecast on your right. Below is a forecast by the Hydrological Prediction Center that shows the amount of rainfall they are expecting to fall in the U.S. over the next 5 days. There are two things that I want you to really pay attention to. The first is that linear feature in the middle of the country. Rainfall looks like it will begin to pile up from west central Texas all the way to central Nebraska. Thats great news for many of those areas because much of the western plains have been experiencing the worst drought since the Dust Bowl. But the other thing I want you to take notice of is that the far northern end of that heavy band actually extends into southeastern South Dakota and northwest Iowa. This shows that there could be some heavier rain in the southeast, by this forecasters' account, as much as 2 inches. So we will have to watch this very closely to see if this will end up being a major weather maker for some areas.