Current Conditions at Sanborn Field
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Discussion:
The low pressure system that has been dominating the Central Missouri area finally moves east on Thursday night, taking the precipitation and colder temperatures with it. Expect a lovely weekend as high pressure system from the northeast will take it's place early Friday morning. Winds shift from northeast to south Friday afternoon, bringing warmer air from the Gulf of Mexico, increasing temperatures throughout the weekend. Sunday will experience some clouds moving into the area as a low pressure system developing in the western United States starts to push east. Overall, the weekend will be pleasant and comfortable.
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Forecaster: Lamb, Cochran
Issued: 5:00 PM CST 18 March 2021
Technical Discussion (The nerdy stuff we are discussing in class):
The GFS was chosen for today’s forecast because it was more accurate in tracking the significant LPS moving eastward. GEFS and SREF plumes were also referenced for temperature, and as always, GFS model soundings helped in forecasting sky conditions. The main focus for today’s forecast will be the departure of the LPS and an area of high pressure that follows.
The LPS that has been the cause of the severe weather in the midwest and southeast can be seen leaving Missouri on the 250-mb plots of height, wind, and divergence starting Thursday at 15Z. With its easterly retreat, it carries the significant values of divergence aloft and jet streak away, leaving us with NW winds as an upper-level ridge approaches.
A similar story can be said for the 500-mb plot of heights and vorticity. The vort max is carried out of our region on Thursday at 12Z indicating that the several days of severe thunderstorms Columbia has seen are finished. Mid-Missouri will, however, continue to experience lower values of circulation associated with the exiting of the LPS, leaving us with continued cloud cover Thursday night. Skies will clear as this vorticity continues to decrease as the weekend advances and on Saturday at 21Z, Columbia starts to see an absence of circulation as the area of high pressure begins to enter Missouri.
Moving down to the 700-mb level to look at heights and RH, Missouri is fully saturated Thursday afternoon. As most of the moisture has been clinging to the LPS, it will move east with the low and we will continue to become drier and drier throughout the weekend, not becoming fully saturated again during this forecasting period. The area of high pressure will present itself to the midwest earlier on this level, around Friday at 12Z. It is also more significant at 700 mb, even closing off over SE Iowa at 18Z. It leaves Sunday at 3Z as another LPS starts to approach next week.
Temperatures on the 850-mb plot show cold air leaving the region throughout the weekend. While Columbia is currently dominated by NE winds as the cyclone departs, these winds begin to rotate southerly with the high pressure system moving through, accounting for warming temperatures. Thickness plotted with MSLP supports this warming trend with WAA occurring over Missouri on Sunday.
The next forecast period should focus on the exit of the high pressure on Sunday and the trough that will follow.
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