Simply put, this has been a weird November. There is a quote for Midwest weather patterns which has been true for this month. "If you don't like the weather, wait 15 minutes, and it will be different." Okay, maybe not 15 minutes, but the weather changes over one week has been incredible. Last week, we were experiencing temperatures in the upper 60s and into the 70s in Alton. The weather was nice enough, that one could have worn shorts if they so desired. This week, the weather has people grabbing jackets before heading out the door. That being said, let's take a look at this weather!
Let's start by taking a look at the surface map. Remember, this link will provide the current surface map, so it may be different than the map at time of this discussion. There are 3 low pressure systems spread across the country right now. The first low is in Canada, just north of New York state and Vermont. The next low is the one impacting Illinois. This low is in northeastern Oklahoma/southwestern Missouri. This low will be discussed in greater depth for this discussion. The last low is sitting out in the Pacific Ocean, northwest of Oregon, and it may cause forecast issues this weekend into early next week.
The main forecast concern for Alton is the low in northeastern Oklahoma/southwestern Missouri. This low is occluding, which means the system is weakening. This low has a warm front extending into portions of southern Illinois. Being north of the warm front puts us in prime position to see some precipitation. The radar from the National Weather Service in St. Louis, MO shows a "precipitation shield" heading towards the greater St. Louis area. This is mostly light rain, and should impact the area during the early morning hours of the 18th. This is mostly light rain, although lowering temperatures overnight may cause the occasional snowflake, but no accumulation is expected.
Upper air analysis shows the area is under a trough, but forecast models project that the area will be out of the trough midday tomorrow. Then a ridge will dominate the weather pattern for the next few days, bringing warmer temperatures along with dry conditions.
Overall, not too many major weather shifts should be expected over the next few days. Basically there should be some rain overnight on the 17th into the early hours of the 18th, and then rain is out of the forecast until the weekend. In that time span, temperatures should warm up a bit, but nothing as warm as last week. It looks like fall is going to try to stick around the area for a little bit.
10/18/2010 Alton, IL Forecast:
High: 47
Overnight Low: 36
Rain Amount: Less than .10"
Conditions: Mostly cloudy, with clouds decreasing during the day
10/19/2010 Alton, IL Forecast:
High: 57
Overnight Low: 33
Rain Amount: 0"
Conditions: Clear skies
I would like to add a quick note. I have been encountering some technical issues recently, or else I would have posted sooner.
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Actual Weather For 10/18/2010, Alton, IL.
ReplyDeleteOvernight Low: 39
High: 43
Rain Amount: 0.01"
St. Louis had a low of 40, high of 45, and 0.03" inches of rain.
Unfortunately, the clouds didn't really break up enough, so the high was lower than forecasted, and the low was higher than forecasted. Across the region, rain amounts were between trace (Less than .01") and as high as .21" (in St. Charles, MO). Part of the trouble with rain forecasting is that it falls in different amounts in different locations. That is part of the reason why meteorologists use ranges for precipitation forecasts.
Now, I just have to hope that Friday's forecast turns out to be correct.
Alright, time for the 10/19/2010 Alton, IL Forecast Verification:
ReplyDeleteOvernight Low: 32
High: 57
Rain Amount: 0.00"
Conditions: Partly Cloudy
The day two forecast ended up being more accurate than day one. Forecasted temperatures were a total of 1 degree off, which makes me very happy as a forecaster. We still had residual clouds in Alton, and they really didn't break up until later in the day.