Thursday: P. Cloudy. Windy High: 81°F 

Thursday Night: Decreasing Clouds. Low: 66°F 

Friday: Increasing Clouds, chance of showers and storms. High: 82°F 

Friday Night: Cloudy and Rainy. Low: 50°F 

Saturday: Mostly Cloudy with showers. High: 58°F 

General Discussion:   

The work week may be coming to a close, but our rain chances are just beginning. Although Thursday has started on the unsettled side, decreasing clouds and a warm afternoon are expected. However, the weather pattern will once again become active starting Friday morning, and into the weekend, as clouds and training waves of rain hinder Easter plans. 

Bean

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Forecasters: Bean, Bivens

Date Issued: 17 April 2025 // 10:00 AM

Key Messages:   

• Slight risk of severe weather Friday afternoon and evening, with large hail, and damaging winds being the primary threats 
• Heavy rainfall and localized flooding possible this weekend with a ½” of rain expected, with 3-5″ of rain more likely further south and east. 

Technical Discussion:  

At the 250 mb level, the overall weather pattern is looking to be quite active, with the polar jet stream exhibiting a meridional flow aligned with persistent bands of upper-level wind divergence throughout the forecast period. Analysis at this level also revealed signs of enhanced jet coupling and indicated the potential for widespread rainfall, based on the positioning of the jet core. Using the four-quadrant model, Columbia appears to be situated in a transitional zone between regions of convergence and divergence with the jet core. An upper-level ridge is currently providing southerly WAA in the form of return flow which will boost afternoon temperatures into the upper 70s to low 80s both today and Friday. At the same time, there is a swirling upper-level trough building out to the west which will be the main weather maker for this weekend. This upper-level low will make landfall on the U.S. west coast by 00Z Friday and will quickly eject out into the northern Rockies, setting the stage for an active weekend. The resulting trough will shove the upper-level ridge down to the SE over Florida, taking the dry, calm weather with it. It is also important to note that the trough will be positively tilted Friday and Saturday, which will aid in keeping the severe weather risk low for Friday.  

At the 500 mb level, positive vorticity advection remains prominent beyond Thursday, with multiple vorticity lobes evident throughout the remainder of the forecast period. This suggests increased cloud cover and the potential for continued unsettled weather. Additionally, a significant area of circulation is present over the Four Corners region. I strongly recommend that the next forecast team closely monitor total rainfall amounts on Sunday and keep watch on the progression of this circulation feature as it moves into our area by Monday. Moving down to 700 mb, moisture values remain notably low, accompanied by modest omega values. However, the presence of positive WAA and PVA suggests the potential for lower cloud development starting Friday and lasting through the weekend. Additionally, a well-defined mid-low-level ridge over the Gulf of Mexico previously mentioned, is helping to transport Gulf moisture northward and enhance warm air advection ahead of the approaching storm system. 

At the 850 mb level, low-level moisture, although exiting the forecast region today, is expected to return after sunrise on Friday and persist through the remainder of the forecast period. The low-level jet (LLJ), which was responsible for this morning’s shower and thunderstorm activity, continues to weaken, along with the associated convection. However, the LLJ is forecast to reamplify around 18Z this afternoon and evening. Additionally, the mid-latitude cyclone appears to mature by Monday, with a distinct comma-shaped structure and a well-defined dry air intrusion becoming evident. This evolution should be closely monitored by the next forecast shift as well as future teams, as it may significantly influence local weather conditions early next week. 

Down near the surface, current satellite imagery has low-level moisture in the form of rain and storms moving out of central Missouri and continuing to move SE. As a result, skies have begun to clear in central Missouri, this is expected throughout the afternoon with intervals of clouds and sun. Looking at the HRRR soundings for Thursday, it was observed that the storm activity seen this morning will cool down the atmosphere, which will act as a precursor to the creation of a cap, of which will have a role in Friday’s weather. Starting Friday morning, clouds are expected to thicken as temperatures begin to rise due to southerly winds and prefrontal warming, which aligns with temperatures expected to reach the low 80s. Moisture and instability are expected to build throughout the day on Friday as dew points rise, aided by the strengthening low-level jet, CIN values should drop to more favorable levels by early Friday afternoon around 19Z, allowing storms to initiate shortly after, as parcels will have an easier time lifting with the LCL and LFC close in proximity. Lack of Mid-level dry air combined with weak vertical motion continues to support the potential for elevated severe storms Friday afternoon and evening. Rainfall totals are expected to range around 1½”.  

However, some model soundings (specifically the GFS) are hinting at a marginal tornado risk, but the lack of wind shear and SRH, along with weak CAPE, and lapse rates under 5 degrees Celsius all point towards a more stable surface environment that would be more suitable for elevated storms capable of damaging winds and more significantly, large hail. 

Bean