11/12/2024

Tuesday: Partly Cloudy. High: 57°F

Tuesday Night: Mostly Cloudy. Low: 43°F

Wednesday: Mostly Cloudy with Rain. High: 57°F

Wednesday Night: Mostly Cloudy with Rain. Low: 43°F

Thursday: Partly Cloudy. High: 57°F

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General Discussion:

Slightly above average high temperatures (upper 50s) will continue throughout the week. Expect variable gusts up to 30mph starting Wednesday with potential for thunderstorms. With those thunderstorms there is a potential for a quarter to a half inch of rain.

– John

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Forecasters: John, Beach, Alcorn, Chirpich

Date Issued: 11/12/2024 09:00 AM CST

Technical Discussion:

Key Message

Around 18z Wednesday a cold front starts to move into the area bringing a good chance for rain. Expect totals to range from around .25”-.50”

This forecast was generated by using a blend of the NAM and GFS primarily, as they show a good amount of consensus. Starting off the week at 300mb, a high is sitting over the region keeping most unstable weather at bay. However, there is still some divergence aloft which could bring a few high-level clouds early on Tuesday. There is a strengthening trough in the Polar Jet that starts to combine with a more meridional Subtropical Jet late Tuesday over the western CONUS. This trough quickly moves into the Great Plains, starting to interact with Missouri’s atmosphere early Wednesday. Upper-level divergence from these initial interactions will bring increasing clouds from around 03z Wednesday before the primary trough moves in.

Progressing into 500mb, there is a vorticity max that moves in around 18z along with the trough. This vorticity will be a driving factor in bringing in warm air which will aid in storm development associated with the progressing trough. Moving down to 700mb there is heavy moisture advection around 18z (at the same time step as the vorticity max). Along with all these factors mentioned thus far, there is a cold front acting as the main forcing mechanism for this forecast. Convection with this front will be prefrontal with 700mb presenting strong lift values (≤–15).

There is an LLJ at 850mb that starts to set up around 15z on Wednesday as the front starts to move into the region. This jet will also aid in promoting convection during the day on Wednesday, funneling good amounts of shear and moisture into the area. At the surface, the humidity is mirrored similarly to the previous two layers. Soundings also support what is presented, showing humidity building into a majority of the column as the cold front moves in. PW values with these soundings are around 1” and when coupled with the previous factors could lead to rainfall values totaling around .25” to .5” for Wednesday. Future forecasters should watch as cold air starts to advect into Missouri after the cold front passes and a high-pressure system starts to move in.

• Beach, Chirpich