Current Conditions at Sanborn Field

Thursday: Partly cloudy. High: 54
 

Thursday Night: Mostly cloudy. Low: 38

 

 

Friday: Heavy rainfall for majority of the day. High: 42

Friday Night: Mostly clear. Low: 31

Saturday: Mostly sunny. High: 54

 

 

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Discussion:

Make sure to make the most of theses lovely above average temperatures for today as washout conditions are expected for tomorrow. All day rain on Friday can bring as much as 2 inches of precipitation for Columbia. As a result, flash flooding in flood plains may occur. Thankfully this rainy weather won't last too long as warm temperatures and sunny skies will return this weekend.

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Forecasters: Hefner, Macko, Samson

Date Issued: 03/01/2023 5:00 PM CST

Technical Discussion:

 

For this forecast period we decided to use the GFS20 due to it more accurately tracking the location of the low-pressure system currently centered in the southwestern United States. Additionally, GFS generated soundings and SREF ensembles were reviewed to examine both  the timing and amount of expected rainfall.

The focus of this forecasting period is the low-pressure system arriving over mid-Missouri on Friday morning which is expected to bring high amounts of precipitation over our area.  Currently at the 250mb-level rests a positively tilted trough centered over the Santa Ana region. This trough will progress west across the southwestern United States before transitioning to negatively tilted over the Texarkana region on Friday at 12Z. At this time period, intense circulation will be present over the same region with a vort. max located roughly over central Arkansas. Mid-Missouri will experience some circulation but less compared to the intense values expected in the south.

At the 700mb-level, upper level moisture begins to appear over our area on Friday at 00Z. High moisture values persist until Saturday 00Z until progressing west, leaving dry conditions over Columbia for the remainder of the forecast period. At the 850mb-level, high amount of moisture transport from the Gulf suggests an impact of a low level jet. Due to the combination of all of the factors associated with this low pressure system (negatively tilted trough, intense circulation, moisture transport, and wind shear) the Storm Prevention Center currently lists Texarkana region under moderate risk for severe weather. Thankfully, we are not expecting severe weather to occur over Columbia, in part due to a minimal temperature gradient leading to a lack of instability.

While severe weather is not expected with this low-pressure system, however, intense amounts of precipitation is. SREF ensembles resolve a high confidence in 1.5" to 2" inches of liquid precipitation. GFS generated soundings suggest saturation will be achieved Friday at 06Z. Furthermore the highest negative Omega values will occur from Friday 09Z-12Z which will result in the most intense rainfall during that time period. It is important to note these high amounts of precipitation may result in flash floods in flood plains. While most of this liquid precipitation will occur as rainfall, a chance of snowfall can not be ruled out. Temperatures are expected to decrease to 32 degrees Fahrenheit Friday 21Z. In the event snowfall occurs, ground temperatures will be above the freezing mark resulting in melting any would be accumulation. All liquid precipitation will stop by Saturday 00Z as the upper atmosphere begins to dry out as well as be cut off from negative Omega.

The low pressure system affecting our local area is expected to push out Saturday 06Z leaving zonal flow as less active weather to follow. Future forecasting shifts should pay attention to the low over the Pacific Northwest Coast and track future impacts it may hold over our local region.

 

-Hefner