Thanks to IconArchive.com for the icons!
Above average temperatures has shown once again with highs topping out in the low 80s. The next storm system sits out to our west on the Colorado/Kansas border. Overnight Tuesday clouds will increase, overnight temperatures will only drop to the mid 60s due to the increasing cloud cover and southwesterly winds. Muggy conditions and partly cloudy skies are on the horizon for Wednesday as the storm system to our west approaches. With southwesterly winds, a few peaks of sun and partly cloudy skies highs will reach into the lower 80s once again for Wednesday. Wednesday night rain chances increase as well as the chance of seeing a few thunderstorms, a few becoming strong to severe is not out of the question. A cold front also will pass through the area around 2am Thursday morning. Thursday thunderstorms are expected to end early morning with a few lingering showers until the early afternoon, skies will begin to start clearing by 1pm, temperatures struggle only reaching the upper 50s. Sunny skies return for Friday to round out the work week with highs reaching the mid 60s and looking good for the weekend.
Forecasters: Azzara, Munley, and Brown
Issued: 5:00 p.m., 15 April 2019
Technical Discussion (The nerdy stuff we are discussing in class!)
We had a almost summer like day today here in Columbia, Missouri with temperatures reaching into the 80’s and most of the Midwest is feeling the heat as well. The reason for these warmer temperatures is because the tropical jet is to our north at the moment, aiding in our above average temperatures for the middle of April. A low is currently developing and pushing inland off the pacific coast and will travel across the Rockies overnight and into tomorrow which will continue to funnel in the warmer air from the south and southwest and keep mid-Missouri well into the warm sector of the CONUS for the rest of tonight and into Wednesday. But our main concern for this forecast period is the system that will push through Wednesday night and into Thursday morning as that low that is to our west, pushes towards the Midwest.
Overnight tonight we will see increasing clouds which will not allow radiational cooling to take too much affect since the days heat will be trapped between the surface and the cloud layer. Wednesday during the day should be much like today was, being stuck in zonal flow and winds coming from the south/southwest and staying dry, with the exception of seeing more clouds, but we will be just as warm. Wednesday evening is when the next system will start to approach. The jet will start to situate its core right over Missouri by 12Z on 4/18 and be running north/south and behind that jet core will be an abundance of divergence at 250mb.
Around this same time we can expect to see what seems to be a few different bands of circulation at 500mb, the first two bands being ahead of the incoming trough at 15Z 4/18 and 06Z on 4/19 and the last trailing the trough. But, the strongest circulation is going to stay well to our south in central Texas.
Moisture seems to be an issue and a disagreement between models. Using the GFS and looking at 700mb RH, the moisture that is available is pretty low to that compared to the NAM. Looking at Skew-t’s for this system, the column stays fairly dry especially when we have the highest likelihood of seeing potentially severe weather, the rain will most likely be on the backside of any thunderstorms. However, the GFS Skew-T has a loaded gun sounding for Columbia, MO from 18Z 4/18 to 00Z 4/19 and has indices that bring attention to the potential severity of this storm.
Like the loaded gun skew-t, specifically looking at 00Z 4/19, suggests the atmosphere is going to be moderately to very unstable and the Lifted-index which has a value of -7 C and a CAPE value of ~2000 J/kg. The totals-totals index does give good confidence of likely severe thunderstorms and the SWEAT index alludes to the possible threat of a potential tornado however, confidence of that is low but the possibility can’t be ruled out. The biggest threat with this storm system seems to be small sized hail around 06Z on Thursday, since there is a large amount of lift associated with this system and the wet bulb zero height is slightly higher up in the atmosphere.
The rain and storms associated with this system will move out of the area after the noon hour on Thursday. The GEFS ensemble mean for QPF’s are around an inch of total rain after the system is all said and done but there is a large spread amongst the members, however with the trend that the GFS is taking, it looks like Columbia will get the lesser end of the rain. Once the system pushes off to our east, the trough will deepen significantly but leave us in the cool sector of the system. This will leave us a bit cooler that we had been the last few days with high temperatures sticking around the 60 degree mark for the rest of the work week