Current Conditions at Sanborn Field

 

 

Monday Night: Clear. Low: 44

 

Tuesday:  Mostly sunny becoming cloudy. High: 71

Tuesday Night: Partly cloudy. Light showers possible. Low: 58

Wednesday: Cloudy then clearing. Rain in morning. High: 59

Wednesday Night: Clear. Low: 32

Thanks to IconArchive.com for the icons! 

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

Discussion: 

 

This week we will see a roller coaster of temperatures as the highs climb into the lower 70s for Tuesday then drop to the upper 50s on Wednesday. This afternoon, as a weak warm front pushes through, the region will start feeling a warmer breeze as the winds continue out of the south. This makes for a warm and sunny day Tuesday after a clear and cool Monday night. These warmer temperatures are only sticking around for Tuesday though. Tuesday night, ahead and in line of a cold front, showers are possible. Going into Wednesday morning, this cold front pushes through bringing the possibility of precipitation and cooler temperatures. Highs will reach the upper 50s Wednesday before dropping near freezing Wednesday night.

- Gromada

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

Forecasters: Alexander, Gromada, Gotsch

Date Issued: 11/15/21 5:00PM CST

Technical discussion: 

A beautiful day has once again blessed us Mid-Missourians! Unfortunately, just like the last few weeks, the weather will be changing in the mid-week when yet another cold front will strike. The NAM and GFS were pretty similar in the upper levels, but the GFS struggled on the mid and lower levels, causing us to favor the NAM for this forecasting period. There does seem to be a consistent bias in the NAM’s surface temperatures, so a blanket offset of 4 degrees was also applied before we dove too deep into things.

Currently, a low pressure system sitting to the SE of the Hudson Bay has created a trough along the eastern seaboard. This trough is being kept in check by a weaker, yet still potent, high pressure system over the Gulf of Mexico. This high pressure system is supplying the Mid-Mississippi Valley with warm air and moisture, and will continue to do so for the next couple of days. The big player for this week’s active weather will be the low pressure system that is currently off the Alaskan coastline. This system will move east across Canada creating a positively tilted trough through the upper 1/3 of the CONUS. The fronts that are mentioned later are all primarily associated with this system.

Tonight, Columbia will see a clear sky that may become foggy around sunrise. There is a substantial inversion from the surface to 1 KM with light to no winds in the early morning hours. The inversion is strengthened by the warm front that will pass over us tonight. Fog may not form due to a lack of deep moisture near the surface. Once any fog that did form clears out in the morning, the sky is expected to remain clear until the afternoon hours when the LLJ begins piling moisture into the region causing clouds to form.

During the day Tuesday, surface winds are expected to be around 15-20 mph and LLJ winds over 55 mph, both from the south-southwest. The winds at the surface and aloft are due to the steep pressure gradient between the high pressure system over the Gulf of Mexico and the lows in Canada. These winds will be driving WAA and moisture advection into the Mid-Mississippi Valley until the cold front arrives.

Tuesday night will remain mostly cloudy keeping the temperature from falling too much. There is the possibility of scattered showers throughout the night as more moisture piles into the area. Precipitation totals are not expected to exceed .05inch Tuesday night. As dawn breaks Wednesday morning, a more organized line of showers will transit over Columbia causing showers throughout the morning hours. The precipitation event will be forcing driven as there is little CAPE, a lot of CIN and Omega values range from -15 to -20. As the day continues, the rain will cease with the passage of the cold front. After the FROPA, the clouds clear out, winds will shift to be northerly and temperatures will start dropping until Thursday morning, bottoming out around freezing. Precipitation totals for Wednesday are expected to be less than .25 inch. If the movement of this cold front slows, the line of rain may occur before sunrise on Wednesday.

The next forecasting shift should pay close attention to the timing of the cold FROPA and the temperatures after its passage.

 

-Alexander