Tuesday, February 7, 2023

 

 


Tuesday:  Mostly Cloudy. High: 49

 

 


Tuesday Night
:
Mostly Cloudy. Low: 36
 

 
 


Wednesday:
Widespread Rain. High: 46
 
 

 

Wednesday Night:
Rain overnight, heavy at times. Gusty winds. Low: 38
 
 
 
 
 Thursday: Partly cloudy. High: 50
 
 



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Discussion: Rain is expected to begin late Wednesday afternoon and continue to the early hours of Thursday morning. The rain is expected to be heavy at times with a rainfall total of 1 inch. The winds will also be very gusty Wednesday night into Thursday morning. After the low-pressure system passes over us, the winds will calm and pleasant weather is expected.

-Meier
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Forecasters: Simmons, Meier

Date Issued: 2/7/23 9:30AM CST

Technical Discussion:
 A cut-off low pressure system will pass over central Missouri Wednesday afternoon into Thursday morning. This will bring widespread precipitation throughout those hours. While the models were mostly in agreement, we decided to use the GFS12 12Z run because the NAM was showing temperatures much lower than what the other models were saying.

In the upper-levels of the atmosphere, a positively tilted long-wave trough is digging into the Four Corners region. This low will become cut-off from the upper-level flow Tuesday and meander throughout the central plains into Wednesday. This will then merge with a short-wave trough from the Pacific Northwest. The combination of the two will cause this trough to become negatively tilted Wednesday evening. This will then bring upper-level divergence into the area Wednesday afternoon. The divergence will exit the region Thursday morning as a shortwave trough lingers off to our west. 

In the mid-levels of the atmosphere, vorticity advection begins Wednesday morning ahead of the cut-off low. As the low-pressure system passes directly over our area, it will bring a vorticity maximum to the region late Wednesday night into early Thursday morning. Along with the vorticity max, ample lift combined with plentiful amounts of moisture from the south will build in. This will be strongest between the Wednesday afternoon hours and early morning hours of Thursday. This is when the bulk of the precipitation is expected to fall. By Thursday mid-morning, the low will have passed bringing us clearing. 

In the lower-levels of the atmosphere, a very strong LLJ forms Wednesday afternoon from Louisiana to southern Missouri. This, along with southern flow, will help advect moisture into the area just before the low passes over Wednesday night. Full saturation happens Wednesday around 18Z, as upper-levels continue to saturate throughout the afternoon. The strong pressure gradient associated with the passing low will bring us strong sustained winds at 15-25KTS overnight Wednesday, then winds will lighten up during the day Thursday as the system passes. The atmosphere will remain saturated until the low leaves the region early Thursday morning. Snow is not expected to fall over central Missouri due to the warm layer above the surface. After the system exits, calm weather is expected Thursday.

The system is expected to bring us around 1 inch of rain. All of the models and plumes were consistent in bringing Mid-Missouri around 1 inch of QPF. It is important to note the lurking short-wave just to our west Thursday night into Friday. The next forecast group should monitor the evolution of the shortwave and any moisture associated with colder air.


-Simmons, Meier

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