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Joe’s Weather Blog: Saturday night chances (SAT-4/15)

We’re halfway done with the month of April and temperatures are still running well above average. Today will feature another day with temperatures about 15° above average and that will send the monthly temperature more than 5° above average. We’ll see what the back side of the month looks like. There are strong signals for a least a couple of chilly days coming into play towards the end of next week.


Forecast:

Tonight: Storms developing and moving through the region. The timing appears to be somewhere between 9PM-1AM or so. Some locally heavy rain…perhaps some small hail and also some near severe wind gusts (60 MPH) are possible with the storms. Right now I’m NOT expecting a widespread severe weather outbreak. We may be placed under a Severe Thunderstorm Watch (or at least part of the area might) before the evening is over with. Lows by daybreak into the 50s

Easter Sunday: Clouds in the morning…there may still be some lingering showers around daybreak…mostly south of the Metro. Then mixed clouds and sun during the afternoon. Highs near 70°. Another chance of showers will develop later in the evening and overnight

Monday: Any morning showers end…then partly cloudy and pleasant with highs in the 70s


Discussion:

Well things are more or less going according to plan. Temperatures, as I type this blog, are in the 80° range. The dew points are above 60° and we have mixed clouds and sunshine. We’re getting more unstable…and a cold front is moving into SE NE.

At 2:45 here is a look at the surface weather map…the cold front is the key for what happens later this evening.

On the map above…the temperatures are in RED and the dew points are in GREEN. Ahead of the front the south winds are gusting to around 35 MPH. With the sunshine out there (in pockets) the atmosphere is getting more and more unstable. That shows up nicely when looking at the latest CAPE values. CAPE stands for Convective Available Potential Energy. Typically the higher the number the more unstable things are. Values as of this writing are near 2500. Pretty juicy energy waiting to be tapped and set into motion.

The cold front should be the trigger to get storms going tonight. As the front enters the region and taps that instability we should see at least a broken line of storms develop and drop towards the SE over about a 6 hour span. The individual cells will be moving towards the ENE.

The risk of severe weather is considered “slight” according to the mid afternoon update from the Storm Prediction Center.

The latest short range model…called the HRRR model shows convection blossoming this evening and dropping through the area. The model is shown below via IA State. It will auto-update through the night. As of this writing it mainly brings the worst of the storms through the area between 10PM-1AM.

The later into the evening we go though…the less instability there will be for the storms to work with. That’s because the atmosphere will be cooling down after sunset. So that’s a key reason why I wonder how widespread the potential severe weather will be. I won’t be surprised if there are a few severe storms out there between 8-11PM but something widespread may be tough to get. Overall at this point I’m expecting our typical squall line of storms to move through with brief heavy rains, thunder-lightning, and some gusty winds in places.

Tomorrow will mostly be OK it appears after whatever early AM rains move away. Sunday night may turn into nothing OR there could be more rain. It will depend on where the front coming through tonight bellies up and stalls. There may be some overrunning above the front. This is when a low level jet set’s up and blows over the front at the surface. This creates lift and is a common phenomena around these parts. The issue is where exactly does the front set up. Model data is sort of all over the place, perhaps favoring areas from KC southwards or more southwards of KC. Worth mentioning though so you’re not wondering what’s happening. It’s not the greatest looking set-up…but it’s something to at least monitor.

IF we miss out on that chance…then the rest of Monday and the vast majority of Tuesday looks good with mild temperatures. There may be another weak front try to sneak into the region Tuesday night and early Wednesday morning. It MAY not even get this far south…but with the same air mass that’s in place now…expected to be in place then..at least the chance of a few storms will be with us IF the front gets this far south.

More on the late week chances in future blogs.

I do want to briefly write about what happened last night in TX. There was an amazing long-lived (5 hours+) supercell thunderstorm that created some amazing tornadoes…from smaller ones to 1/4 mile+ wide ones. It was an amazing thing to look at on radar as it was constantly cycling (weakening then strengthening). I wouldn’t be surprised if there were different tornadoes in different parts of the storm since there were several different couplets within the supercell storm.

There are some amazing videos that you want to allow to play out…showing the different structures of the various tornadoes.

The NWS down there is surveying the damage today. It will be interesting to see how wide the tornado got because at one point the whole mesovortex was on the ground. That’s impressive.

It was fascinating to watch some of the videos that were online at the time.

Our feature photo comes from Samantha Brock of a pretty sunset towards St Joe about a week ago.

I’ll keep an eye on the storms tonight.

Joe

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