Monday, March 4th – Afternoon Forecast
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Monday Night: Rain and Thunderstorms. Low: 48°F
Tuesday: Mostly Cloudy. High: 55°F
Tuesday Night: Mostly Cloudy. Low: 41°F
Wednesday: Partly Cloudy. High: 63°F
Wednesday Night: Mostly Cloudy. Low: 44°F
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General Discussion:
A cold front is currently extending from northeast Missouri into southeastern Iowa. Although it will not be bringing strong cold air like the previous cold front, it will be bringing a line of thunderstorms into the area this evening. These thunderstorms could be strong to severe, with the highest chance of this happening in the evening hours. The cold front will bring slightly cooler air into Missouri by Tuesday morning and clouds will be sticking around throughout the majority of the forecast period.
-Jackson
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Forecasters: Jackson, Beam, Sallot
Date Issued: 3/04/2024 6:00 PM CST
Technical Discussion:
Key Messages:
- A line of storms have formed ahead of a cold front in northeastern Missouri and southeastern Iowa, with some storms in very northeastern parts of Missouri already displaying severe characteristics.
- This cold front is moving through a favorable environment for storms to develop rapidly, but the timing of when this reaches Columbia will hinder how much energy the storms are able to latch on to. Storms are currently expected to develop in the area by 00-03Z this evening.
- After this cold front exits Tuesday morning, upper-level moisture will stick around and slightly cooler temperatures will follow.
The NAM was leaned on more in this forecast to get a clearer picture of the storm development this evening since this is a higher resolution model and allows for convection.
Surface analysis is showing a line of storms extending from southern Wisconsin down into northeastern Missouri ahead of a cold front that is draped through northwestern Missouri into central Wisconsin. The origination of this can be seen at 850 mb, as a large low over Canada has produced a secondary trough that extends into central Missouri, lining up with the cold front. Using SPC Mesoscale analysis, it is clear that central Missouri has a favorable environment for storm development. There is most unstable CAPE values of 1500-2000 J/kg and very little CIN. This cap would be broken if the cold front shifts far enough southeast in the time that we have these ingredients, which would allow the growth of storms. Timing of when this cold front passes through mid-Missouri will play a big factor in if there are any strong to severe thunderstorms.
At 300 mb, a line of divergence is observed over northeastern Missouri and southeastern Iowa, which lines up with the current line of storms. This divergence pushes into central Missouri by 00Z-03Z this evening. 500 mb shows the same picture as vorticity aligns with the current storm systems. The vorticity around the current storm systems match up with the upper-level divergence and is set pass over mid-Missouri at 00Z-03Z this evening. 700 mb further solidifies the picture with relative humidity at 90-100% in the current storm cells. Along with this, omega surrounding these cells in northeastern Missouri are at –15 to –20 µbar/s. The strong relative humidity along with these omega values stick with everything mentioned above and pass over the area at 00-03Z. All of this concludes that all the ingredients are present for thunderstorm activity this evening with the favorable setup stronger storms that could become severe. The limiting factor of the intensity of storms is dependent on timing. By the expected arrival time, the sun will have set and temperatures will begin to drop. This means the CAPE present will diminish and CIN will return. Despite this limiting factor, the lifting mechanism of the cold front will still have the ability to break through the returning cap and latch onto remaining energy, allowing for storm development. NAM soundings during the expected arrival time still display CAPE values of 1000-1500 kg. This is why strong to severe storms are not out of the question this evening.
The storm potential falls apart through the overnight hours because of the diminishing CAPE, but rain is still an expected impact until 09Z-12Z tomorrow morning as the cold front shifts further southeast. Tuesday afternoon, a mostly cloudy sky is expected because of upper-level moisture. This upper-level moisture exits into Wednesday, leading to a more sun-filled setup. This will not last long though as a low over Colorado/Kansas and a high over Wisconsin working together to usher in moisture from the south by Wednesday night.
Future forecasting shifts should be aware of the wet pattern that is setting up Thursday and lasting into the weekend due to several troughs developing to the west.
-Jackson