Joe’s Weather Blog: The darn cap keeps storms at bay (but that may change) (SUN-5/13)

Good afternoon…a lot more sunshine in the region today and as a result it’s getting hotter. At 12PM we’re in the low to mid 80s already…and a run towards 90° is going to happen this afternoon for some of you. KCI’s record today is 90° set in 1940/56/62. It’s possible we can tie that…but odds favor we fall just short. (Update: Tied at least at 4PM). The front that has been incredibly stalled in NW MO and NE KS is still there…just lurking and wavering a bit south at night and north during the day. That front will get through the area later Monday night…and that is our best chance of storms locally. There should be some locally heavy rains with that front as well.



Forecast:

Tonight: Fair skies and balmy with lows in the upper 60s to near 70°

Monday: There may be a few scattered showers/storms around in the AM before lunch…otherwise variable clouds and steamy again with highs in the mid to upper 80s.

Monday night: Here is our main storm chance (possible upgrade to Weather Aware status by FOX 4…as the front finally moves towards the area the cap should be breaking too. This means storms will fire up and move through the region. Those storms may contain heavy rain/some hail and potentially some gusty winds. How strong they are by the time they get into the KC Metro area though remains to be seen.

Tuesday: Clouds break up in the morning then partly cloudy and not as warm with highs closer to 75-80°



Discussion:

A few blogs ago I wrote about how this surface pattern set-up should create a ton of rain around the region…and thus far…not so much as you can see.

That total along the I-70 corridor is from that storm that moved through yesterday.

Today we’re brighter than yesterday as the latest satellite picture shows

There are a few small cells bubbling up across far NW MO…

We’ve talked a lot these last few days about the cap…and this afternoon I wanted to take you up to about 10,000 feet or so to illustrate this a bit more and to show you the extent of the cap.

The map below represents the temperatures up there (called the 700 mb level). The temperatures are expressed in °C. For example the closest balloon launch to KC is Topeka. As the balloon goes up it records various weather parameters as it moves with the winds in the atmosphere.

Typically (but not all the time) this is roughly the level we look at for the presence of the “warm layer” aloft which tends to suppress a lot of the convection that can occur when there is instability present. It doesn’t ALWAYS mean there is NO storms at all however. Storms can also fire above the cap (we call those elevated storms).

Also we typically look for temperatures near or above 10°C (50°F) at around 10,000 feet for defining the extent of the cap (again not a hard and fast rule).

So notice in the Topeka data above the temperature at that level is +13° (sorry I put the arrow on top of it). That’s close to 55°F…which is pretty mild (even by summerish standards at 10,000 feet up. Notice as well the “warmth towards the SW of the KC region…for example towards Amarillo (+13) and Midland, TX (+10)…so the cap is maintained towards western TX and with the winds generally at that level from the SSW…that means the cap will be able to maintain itself locally.

Tomorrow I’m expecting to see some weakening of the. How much remains to be seen though. The surface front in question is still to the NW of the KC area…here is the noon surface map.

The temperatures are in RED…notice the cooler weather to the north of the front. I do wonder, assuming we get into that cooler air mass on Tuesday IF we could be cooler than I think right now.

So the front will waffle around on Monday before drifting southwards Monday night. The cap should be weakening as this occurs. The the suppression of storms will be removed. Temperatures Monday will heat up again…maybe not as hot as today though. So we’ll have many of the parameters in place to create storms and we’ll be removing/weakening the main obstacle in the storm development that’s been an issue for us these last few days.

That should mean thunderstorm development and perhaps even some stronger ones with some severe weather?

I’m going to think about upgrading Monday to “Weather aware” status. My conflict is that I’m not sure about the instability in KC proper by the times the storms organize and move towards KC in the evening. The data does show a lot of instability later in the afternoon…

The model data will struggle with this evolution in today’s runs. They do show convection in the region and with A LOT of moisture available in the atmosphere…the storms (while moving along) may produce locally heavy rains in the region if nothing else I think.

There are some other disturbances that may ripple through the flow during the week as well. So it’s worth noting that after Monday evening there may be other chances…but the better chances may wait till sometime next weekend after Monday.

I don’t like putting in rain chances every day IF I can avoid it.

Our feature photo comes from Blue Springs Lake and Tiffany Walters sent it in!

Joe

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