Good morning bloggers,

Kansas City Weather Time-Line:

  • Today: The clouds move out with sunshine returning: Light winds. High:  62°
  • Thursday:  Some morning fog, then sunny and nearly perfect with a light north wind from 5-10 mph. High:  74°
  • Friday: Mostly sunny and becoming humid. South winds increasing at 10-25 mph. High:  84°
  • Saturday:  Partly cloudy with a 50% chance of showers and thunderstorms during the day and a nearly 100% chance of thunderstorms Saturday night. Flooding and some severe weather is possible. High:  80°
  • Sunday:  Rain ending early and drying out for tailgating and the Chiefs game. It will be dry for the Sporting KC game as well.  Cooler with a high of 63° dropping into the 50s by 6 PM in the fourth quarter of the Steelers/Chiefs game.

Screen Shot 2017-10-11 at 7.14.20 AMThere is a risk of severe weather on Saturday as the next storm system moves across the plains. One of the big differences to these severe weather risks in October and November from how they look in the spring is the amount of daylight we have.  We are now three full weeks into fall and we have about the same amount of daylight as there is three weeks before the beginning of spring. There are severe weather risks and outbreaks at any time of the year depending on the strength of these storm systems and other parameters such as low level moisture available and heating ahead of these systems. If the conditions all come together you can have big severe weather set ups.  Some of the conditions appear to be coming together for strong to severe thunderstorms on Saturday or more likely Saturday night across parts of Kansas, Missouri, and Iowa.  The risk from the Storm Prediction Center for day 4 is shown on the left.

A storm system is approaching aloft by early this weekend as you can see on this 500 mb chart:

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This is a rather energetic series of waves that are carving out this trough aloft that is approaching.  High levels of humidity will be pulled in from the Gulf of Mexico, and there is a stalling front that will be approaching Kansas City on Friday.

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This map above shows a forecast for the cold front with some strong surface ridging over Nebraska behind this front.  The trough aloft that is approaching is also strong enough to cause the pressure to begin falling and the front will stall as a result. Look at the front 24 hours later in this 7 PM Saturday surface forecast:

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Now back to the timing of this and the “time” of the year. 7 PM is now 30 minutes past sunset, so it will be dark.  This will begin limiting the instability, but before sunset there should be enough heat and humidity to create initial strong to severe thunderstorms with hail and damaging winds the main risk, but a few tornadoes can not be ruled out near and ahead of where that surface low over Iowa is located.  For KC it looks like a slow moving line of thunderstorms Saturday night that could produce very heavy rainfall amounts from 1″ to 3″.

Yesterday we showed you the Arctic Oscillation and the North Atlantic Oscillation going into the positive. Today we show you how fast these indexes can change as they are just tied to the error ridden computer models. Once we know this years LRC (Cycling Pattern Hypothesis) better we will know so much more. The cycling pattern is evolving and KC just had two early storm systems with this third one on the move and about to affect the plains.

Screen Shot 2017-10-11 at 7.26.16 AM

The Arctic Oscillation is positive right now. Let’s see where it goes in these next two very critical weeks.

Thank you for participating in this weather experience featuring Weather2020 and the cycling pattern. Let us know if you have any questions. We continue to have some great discussions on the Weather2020 blog. Go over there and join in and share with the rest of us.  Have a great Wednesday.

Gary