Joe’s Weather Blog: Can You Wait A Week? (SAT-12/6)

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The 1st week of December is just about done with in the KC area…no snow is expected at this point for at least the next 7 days, and we may end up getting rather mild…but we just need some patience.

Forecast:

Tonight: The fog/mist will likely reform overnight with lows in the 30s

Tomorrow: Not too optimistic at this point. Highs again near 40°. Clouds/mist to the start the day with some potential of breaks in the clouds later in the PM. Should we get those breaks, we could pop into the mid 40s. There may be a few showers in the later PM hours as a weak disturbance slips through.

Monday: This looks to be a better day with mostly sunny skies and highs near 50°

Discussion:

Every so often I like to show you the atmospheric profile above us resulting in the balloon launch from Topeka, KS. Each day about 100 launches take place in the USA. The closest ones to the KC area are Topeka, KS, Omaha, NE and Springfield, MO.

 

 

 

(image via: NOAA)

As the balloon ascends to around 100,000 feet the reduction of air pressure around the balloon causes the gases inside the balloon to expand and eventually the balloon bursts. Once it does so, small sensors which are attached in a box then fall to earth but luckily, and normally, a parachute opens up and the instruments fall to the ground where they are recovered, often by farmers, and mailed back in to a reconditioning center (right here in KC!) where they are then sent back out into service.

These sensors measure three things and indirectly the balloons location measure the 4th. That would be pressure, temperatures and dewpoints as the balloon ascends, then as the balloon moves through the air in whichever way the winds carry the balloon, it’s tracked with radio waves/GPS and the position is then calibrated from which wind direction and speed are computed.

The end result to us is plotted up on a SKEW-T chart…for example the one this morning from the launch looked like this.

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The RED trace is the temperature line as the balloon ascends through the atmosphere. The GREEN trace is the dewpoint line.

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What we look for this morning, are where the lines are nearly together. That tells me that the temperature and the dewpoints are nearly the same or the same indicating that the air where the measurement was taken is virtually or totally saturated.

In the case of this morning the air was practically saturated from the surface to about 900 mbs or clse to 3100 feet up. That tells me that the clouds above us are roughly 3000′ thick or so. Notice how the lines above that saturation level start spreading out. This tells me that the air dries out above the cloud tops rather dramatically.

So now we know the thickness of the moisture layer…let’s see the extent using the satellite image to detect the clouds…

 

Let’s broaden things out a bit…

 

The thick clouds this afternoon are essentially covering all of MO and most of the eastern 1/3 of KS.

Tomorrow I anticipate a bit more of a SE wind blowing…however that same wind will just recirculate the moisture…plus if you look out towards the Rockies and even western KS…notice the milky look to the clouds…those are lots of cirrus clouds and they-re pretty thick. Those clouds will help to filter the sunshine tomorrow above the lower clouds trapped near the ground. This will NOT help the sunshine burn the clouds off tomorrow so that is working against us as well. There will be a bit more of a churning to the airmass tomorrow which could help to punch a few holes in the cloud deck.

So we have that going for us.

The models are correct in forecasting a nice warm-up for later in the week…and come next weekend, especially Saturday, we should be a lot warmer. There is potential for record warmth later this week in the Plains, but a lot of that will be determined by clouds whether they be of the high variety of the lower gulf moisture type clouds which could affect us next weekend. Temperatures may well be above 60° from FRI-SUN of next week should things work out.

Have a great weekend and enjoy all the football on TV!

Joe

 

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