Weather Blog - Changes Showing Up, The AO, & The NAO

Posted at 8:35 AM, Nov 25, 2020
and last updated 2020-11-25 09:47:58-05

Good morning bloggers,

We just experienced a series of storm systems that produced rain, sleet, snow, and thunderstorms. It wasn't that dramatic, but it was beneficial. We really needed some moisture as it has been dry to start out this developing weather pattern.

Rainfall Totals At KCI Airport:

  • November 10: 0.64"
  • November 21: 0.16"
  • November 23: 0.29"
  • November 24-25: 0.58"
  • TOTAL IN NOVEMBER: 1.67" (Average is 2.15", so 0.48" below average)

So, we almost caught up with average for the month after a very slow start. The weather pattern is still coming into focus for the winter and our winter special with our winter forecast will be on 41 Action News next Thursday evening at 6:30 PM, a week from Thanksgiving night. We will have our snowfall predictions from our weather team and some great information to get your ready for winter.

A cold front moved through earlier this morning:

As of 8 AM, the surface map above shows the temperature ranging from 10° in western Nebraska to 64° in northeastern Arkansas. The next storm appears that it will miss us to the south and east. It comes together into a potential major storm over the Tennessee Valley as you can see below by just after the holiday weekend:

This model shows snow over eastern Missouri, so we will be monitoring the new data closely. Once we know the LRC better, we will know where a storm like this is likely going to form, but right now we are at the mercy of these flawed computer models. There is a chance that this forms farther west, and suddenly snow could be in our early week forecast, but more likely it will form a bit farther east and it will be a dry cold front in KC. Again, confidence is low right now.

The Arctic Oscillation and the North Atlantic Oscillation (AO $ NAO):

Look closely at the end of these charts: see how they dip? The AO and NAO have been in positive territory for around the last month. When these two indexes are positive it is more likely to be warmer than average on temperatures. And, this storm that just passed through last night and early this morning was influenced by this positive index in the AO and NAO. If they were more negative, this storm would likely have been even stronger and had colder air to work with. Northwest Missouri would have had a snowstorm this morning instead of a cold rain, which is ending now. It would have really been a tough forecast for our area when you think 6 inches of snow would likely have fallen in Maryville, MO. Now, it didn't as it was just too warm. That negative dip at the end is indicative of major changes to the weather pattern. But to what? We will know more in the next week.

For now, it is looking nice for most of this holiday weekend with temperatures going up and down. Today, it will be in the 40s most of the day and breezy. And, for Thanksgiving expect that warm up into the 50s with light winds. And, then we will monitor that developing late weekend storm.

Thank you for spending a few minutes of your day reading the Action Weather Blog featuring the LRC. Have a great day and Happy Thanksgiving!