Current Conditions at Sanborn Field

Monday Night: Mostly clear. Low: 34

Tuesday: Sunny. High: 53

Tuesday Night: Increasing clouds. Low: 46

Wednesday: Showers and thunderstorms. High: 67

Wednesday Night: Clearing, becoming breezy. Low: 42

 

Thanks to IconArchive.com for the icons!

====================================================================

Discussion: It might be February, but warm temperatures this week sure make it seem like spring is in the air! Enjoy the pleasant weather tomorrow, as widespread showers and even some thunderstorms will move into MO on Wednesday. And don't put away that winter coat just yet... you'll want it for the end of the week!

-Shaw

============================================================

Forecasters: Shaw, Russell

Date Issued: 2/20/2023 05:00 PM CST

Technical Discussion:

 

    Unseasonably, warm, spring-like temperatures will continue to infiltrate mid-MO Tuesday before a dramatic (but brief) pattern shift occurs during the second half of the work week. Several consecutive vortmaxes guided by a larger open shortwave will move across much of the Midwest and Deep South Wednesday, bringing with them showers and even some thunderstorms. At the same time, a low-pressure center will eject out of the Rockies and deepen considerably as it pushes east toward IA. The cold front associated with this low will sweep through early Thursday morning, prompting a rapid cool-down and gusty winds Thursday. 

    Presently, an impressive jet streak with winds approaching 200 kts is providing central MO with rigid zonal flow. This pattern sticks around through Tuesday before a closed low stuck over the Baja Peninsula becomes dislodged by developing low pressure over the Pacific NW. As the low weakens and morphs into an open wave with its progression over the Desert SW, several vorticity maxima form ahead of it, providing the catalyst for rain chances on Wednesday. 

    As is the case in the upper levels, an impressive zonal flow regime is present in the mid levels at the start of the forecast period. By Tuesday morning, however, winds rapidly take on a southerly component, with tight solenoids hinting at impressive WAA and moisture advection during the day Tuesday. Aforementioned moisture becomes quite plentiful by Wednesday morning ahead of the passage of the main shortwave, and will be more than enough for widespread showers and even some thunderstorms across the area. While this is ongoing, another area of low pressure will move off the Rockies and deepen as it moves across KS and IA. By the time its associated cold front makes its approach Thursday morning, however, almost all of the mid-level moisture will have cleared MO. Consequently, this will be a dry FROPA... though it will still bring with it very cold temperatures by Thursday night. 

    A moderate LLJ will rapidly advect low-level moisture and warm temperatures overnight Tuesday, setting the stage for Wednesday's rain. This LLJ will help push up a weak surface warm front that will stall out over the region Wednesday, with surface dewpoints near 60F along and south of this boundary. The axis of this front will coincide with a narrow band of higher PWATs, and thus the potential for higher rain totals. Currently, model guidance is suggesting that this band will fall right over central MO. If this does resolve, Columbia could see rainfall totals approaching 1.25". It should be cautioned, however, that a slight shift north or south in the location of the warm front would cause lower rainfall totals, in the .75"-1" range. Thunderstorms are also a possibility, given the presence of ML and SFC CAPE values in excess of 300 J/kg, which is impressive for February. Severe weather is not expected this far north, though, even with the presence of sufficient low-level veering and modest Omega values, as the environment looks to foster a more elevated storm mode. By Wednesday evening, moisture will have moved out of MO and clouds will begin to clear ahead of Thursday morning's cold FROPA. Gusty winds are certainly a possibility Thursday morning, as the pressure gradient associated with the low-pressure center tightens across MO.

-Shaw