Joe’s Weather Blog: The ice is here…the cold air won (TUE-2/20)

Good morning…I mentioned over the weekend when I forecast the unfolding events of today…that IF I had 10 minutes of weather time to explain everything on TV…I would still probably go 2 minutes over…this has been fascinating to watch and see how things are playing out. Yesterday I recognized the potential for convection…and sure enough thunder and lightning are prevalent in the area. The sleet is a bit of a Mother Nature curveball…but as I mentioned yesterday…I hate ice…it does nothing for me…and just makes things a mess.

Before I get into the forecast and discussion though this needs to be said/written because a couple of weeks ago…I had about a 7 day period of extreme weather “frustration” to put it lightly.



Forecast:

Today: Ice Storm Warning. Freezing rain continues with sleet. The sleet will be associated with the convection that’s moving through the region. The convection should move away before 10AM or so. Then we’ll be left with freeing rain/drizzle. Areas to the SE of KC will have just plain rain…where temperatures are above 32°. From the KC Metro north and west though…issues will continue on the roads etc. Temperatures hover around 30°.

Tonight: Lots of high clouds in the area…cold with temperatures near 15-20°

Wednesday: Variable clouds and cold with highs around 30-35°

Thursday: Some light freezing rain is possible…not like today. A glazing though is possible.



Discussion:

My goodness gracious…what a wild and strange weather path we’ve been on this winter. Today’s events were forecast since last Thursday on the blog…heavily hit on the air over the weekend…this was always going to be about a low level jet “overrunning” a shallow cold air mass at the surface. That “lifting” created the rain.freezing rain>thunder sleet that has been prevalent in the area this morning. As this low level jetstream of 50-60 MPH early this morning weakens and shifts to the east of KC as the morning moves along…the radar returns will gradually diminish.

I’m noticing a decrease in the radar intensities to the SW of KC as I type this (8:45 am)…so the heaviest sleet will be ending fast in KC…perhaps by the time you read this…it will be over with. Expect more freezing rain/drizzle for the rest of the morning through lunch and into early afternoon.

I want to show you a profile of the atmosphere this morning…because it’s fascinating to me…as it usually is during freezing rain events. Twice each day (sometimes more for severe weather scenarios) a balloon is sent up from about 100 different locations around the USA. These balloons are filled with helium and end up going up to about 100,000 feet expanding as they go up in the atmosphere and eventually popping jut like a normal balloon. On their way up they take temperature and moisture information and are location tracked to help determine the wind speed and direction. After popping the weather instruments fall back to earth. There is a small parachute that deploys and they end up typically crashing in a field far away from their launching spots. All this data and a lot more is fed into the models that we rely on to get an idea of what may happen to the weather.

Here is the “sounding” data…the RED line is the temperature trace..the GREEN line is the dew point trace as the balloon went upwards.

I denoted 3 areas…A, B and C to write about…

Let’s start with A. Note the 32° line that is sketched in in cyan. Everything to the RIGHT of this line indicates ABOVE 32° air and to the LEFT of this line is BELOW 32°. Notice how far to the RIGHT the red/green lines go. This is a warm air layer above the surface. Notice roughly the right most extent of those red/green lines…past the 10°C/50°F range…that means the air roughly at 6000 feet or so is close to 52° or so! 

Now look at the letter C. This is the cold shallow air that is BELOW 32°…it occupies about the the bottom 2300 feet of the atmosphere this morning down to the ground (near Topeka…it may be even “thinner” in KC proper).

Now look at B…this would be the where whatever convection is forming allows the raindrops to turn to ice pellets then those ice pellets come down to the ground…they don’t have time to melt in the “warm” layer that they’re passing through…hence the sleet reports this morning.

It’s also possible>likely that this “warm” layer “A” has been “thinned out” since the sounding was taken…because of colder air being brought down from above “B” because of convective turbulent processes.

There are so many things happening in the atmosphere today...it’s just fascinating to see and watch unfold.

The Ice Storm Warning will continue through the afternoon…but things should be winding down for the most part early this afternoon…

Areas towards the east and SE of KC are OK…temperatures in many areas are above freezing there…here is the 9AM temperature map…

Note the freezing line that is east of KC…also note central MO where NW parts of Columbia are in the mid 40s while the Jefferson City area is near 70°…sound familiar?

Things locally should improve this afternoon…as the road treatments really kick in and the precip rates diminish.

The next event…will be lighter I think but still potentially impactful may move in later Wednesday evening into early Thursday morning…it looks like some sort of freezing rain/sleet combo to me. Why not snow…again the air aloft will not support snowflakes reaching the ground…as another warm layer should prevent that from happening…again above the surface…but more road issues are possible on Thursday.

Do you know it’s been 122 days I think since the last time we had more than 1/2″ of moisture in one calendar day? As of 9AM we’re up to .43″ at KCI…we may get there in the next few hours…finally.

OK that’s it for now…we get to a afternoon update…

Our feature photo is of…what else…the ice. It comes from Michelle via Twitter.

Jo

 

 

 

 

 

 

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