Joe’s Weather Blog: Creeping drought in the region (FRI-5/10)

Good morning…there is some more dryness developing in the region again. I noticed it especially on the golf course (where else) and also in the yard when I was mowing. We’re entering the wettest time of the year…we should get well over 1″ of rain per week…but as I was outside yesterday I realized that I was sweating wayyy to much for early May. Despite the fact that dew points were tolerable by KC standards (50s) with temperatures in the mid-upper 80s…it was toasty. You know I love perspective…our average highs for this time of the year is 73°. Yesterday KCI hit 87°. Downtown hit 90°. This should happen again today depending on the cloud situation.



Forecast:

Today: Scattered very brief morning storms/showers…then gradual clearing with more warmth and humidity. Highs well into the 80s

Tonight: Partly cloudy and similar to the last few evenings with lows in the 60s

Saturday: Partly cloudy and warm. Highs 85-90°

Sunday (Mother’s Day): Variable clouds and warm again with highs well into the 80s. IF the front can sneak southwards and through the area…it could be cooler though



Discussion:

Rain can be allusive here in the Plains. It seems many EXPECT us to have perfectly timed rains so that the yard never needs watering. Most of you know that that is sometimes a pipe dream around here. We are prone to floods and droughts. The last big drought (locally) was in 2012. That was pretty bad. Everything turned brown…the trees were terribly stressed…there was even an issue with the low water levels in the KS/MO River area…which affected drinkable/treatable water for some of the cities around the area.

So far we’re not there! I will tell you however that I’m bothered by this lurch from winter to summer. We’ve started this month with temperatures every single day that are above average…often by over 10°. That’s impressive in a sense…it’s happened before but it seems the lurch from such a cold April to a warm 1st half of May has been dramatic and people are asking me about it.

That’s a fair question because when we’re that warm…we really need the rain sooner rather than later. The latest drought report came out yesterday…and moderate drought conditions continue to creep through the area.

On the MO side…there’s been an increase in abnormally dry terrain

on  the KS side…not a lot of change.

As you know…I don’t really get myself too revved up about these reports through March (unless we’re in a prolonged drought already). Now though is the time to watch these more carefully. With the terrain now out of dormancy and with the needs of the vegetation increasing dramatically…it needs water.

It’s be one thing if it was gray and cool…but it’s been sunny and warm…add in wind and the top soil loses it’s moisture even quicker and that can create some stress, especially on younger more shallow rooted plants etc.

We had over 2″ of rain earlier this month @ KCI…so that was a good thing…but we need more spread out rain for the region…and that seems sort of tough right now to achieve.

The models have varied with how we get rain over the next 1-2 weeks…there is certainly some hope for sometime next week especially as some energy from the SW lingers…

This weekend should be a recipe for flooding rains in at least part of the region because of a front that will be languishing across N MO…and gradually drifting southwards. 80s+ ahead of the front…respectable dew points in the 50s/60s ahead of the front…temperatures that should create decent instability…so why the predominantly dry forecast?

Well we have “cap” issues. The cap is basically a layer of warm air…it will vary in altitude…sometimes it’s in the lower part of the atmosphere, about 5,000 feet up…sometimes it’s higher up. Basically the “cap” acts as a lid to air that rises. It keeps that air from rising strong enough to penetrate the cap…this means that that air can’t cool down enough…can’t have the moisture in it’s little “bubble” to condense and as a result can’t allow serious thunderstorms to form readily.

You can see the “cap” readily by looking at the forecast profile of the atmosphere, for example this one for this afternoon at around 4PM (based on last night’s model data). The RED line is the forecast temperature as you go higher into the sky…the GREEN line is the forecast dew point. This whole image is called a forecast sounding.

The numbers on the far left (white…1000…850…700…500) are atmospheric levels in millibars. For simplicity of this discussion…it’s roughly 1000 mbs (near surface)…850 mbs (around 5000′ up)…700 mbs (around 10,000′ up) and 500 mbs (around 18,000′ up).

The takeaway I want you to pay attention to is how the RED line which starts at about 87° here at the surface…drops as it goes up to about 825 mbs (or about 5500′ or so up. NOW look at how the rED line takes that hard right turn…indicating that the air, instead of cooling as you go up…now starts warming up again…that is the cap!

So air “bubbles” in the bottom few thousand feet of the ground are rising…hit that warm air layer aloft and get stuck.  That will usually cut down convection chances despite a front being in the region.

IF there was some sort of disturbance out there moving into the area that could “upset” and eradicate that cap…we’d be in business, perhaps even with severe weather risks because those winds as you go up in the atmosphere certainly would favor stronger storms. Alas though the cap will mostly live.

By Saturday afternoon the front is right on top of KC…in May…this should be WET with several exclamation points but yet the forecast continues to show this strong cap in place. Not a lot of change on Mothers Day either.

Could there be a surprise in this weekends mostly dry forecast. Yes…but we will need that cap to break OR we’ll need something to develop even higher in the air (above the cap). Another possibility is IF something can disturb the atmosphere enough…for example like a thunderstorm complex, like what happened in NE last night. The models won’t deal with those complexes well…so there is some hope for something.

Next week looks to bring more chances…so odds are we’ll be getting something over the next 7 days or so. During this time of the year as well…with the atmosphere loading up with spring moisture, heavy rains in parts of the area are always possible. The concern would be just how widespread this activity is going to be. We’ll see.

It does seem strange that as we enter the middle of May…and looking at the SPC forecast over the 4-8 day period, through the morning on the 19th there isn’t any strong indicator of severe weather risk showing up on their maps.

Our feature photo comes from ‎Renee Jobe of a gorgeous sunrise at Truman Lake in Warsaw, MO

Have a great day…and I’ll update the blog as weather dictates over the weekend.

Joe

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