Current Conditions at Sanborn Field

 

    Friday: Cloudy with breezy conditions. High: 80

 

     Friday Night: Rain with a chance of Thunderstorms. Low: 47
 

 

 

     Saturday: Decreasing clouds throughout the day. Breezy. High: 55

 

 

 Saturday Night: Mostly Clear. Low: 45

  

   Sunday: Mostly Sunny. High: 67

 

 

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Discussion: 

A strengthening low pressure system will bring beneficial rain to our region tonight along with a strong cold front. The rain should exit by sunrise Saturday morning leaving colder temperatures and windy conditions in its wake. Expect a dry, but chilly and breezy Mizzou football game tomorrow.

 - Peine

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Forecasters: Peine, McCormack, Aldrich

Date Issued: 11/4/2022 9:00 AM CDT

Technical Discussion:

 

 

A mixture of both the 06Z GFS and 06Z NAM were utilized for temperatures due to the consensus between the two models. For precipitation, the 06Z run of the GFS was utilized due to the accuracy with synoptic feature placement. The problem of the day is in regards to the speed of the strengthening low pressure system, which will determine the arrival time of the rain and rainfall amounts forecasted for tonight. 

 

The rainfall setup for tonight involves several factors. First and foremost, a strong low level jet will provide plenty of moisture transport and the approaching cold front will provide ample lift allowing for sufficient rainfall tonight over Central Missouri. The potential for embedded thunderstorms exists tonight with CAPE values around 500J/kg, but will be limited due to the weak environmental lapse rates that are forecasted. Another limiting factor for convection tonight includes the low equilibrium levels (400-500mb) that will inhibit any deepened convection from developing. Therefore, a few thunderstorms may be embedded within the heavier precipitation tonight. However, any thunderstorms that develop are expected to remain non-severe. Given the track of the low pressure system, sufficient moisture transport, and a lifting mechanism, we are forecasting rainfall amounts from 1"-1.25" tonight.

 

At 250mb, there is currently a deepening trough located over the Central Plains with a jet streak core positioned from Kansas to Iowa. At 500mb, a positively tilted area of low pressure is positioned over eastern New Mexico along with an abundance of vorticity centered around the low pressure system. Plenty of moisture is in place from 700mb down to 850mb, which is resulting in the stratus clouds that are currently over the region. At 850mb, the low level jet stream is currently positioned from the Gulf of Mexico up through Missouri with wind speeds approaching 45kts within the strongest jet core. The low level jet will continue to strengthen tonight leading to winds approaching 80kts within the center of the jet core. This setup will provide sufficient moisture transport from the Gulf of Mexico which will further enhance our sufficient rain potential for tonight.

 

At the surface, strong southerly winds are present due to the deepening low pressure system to our southwest which is leading to a tightening pressure gradient over the area. The strong southerly winds currently in place are leading strong warm air advection, which is to blame for a low last night of 67F(new record low high), and will be the reason we approach our record high for today(record: 83). The cold front associated with the aforementioned low pressure system is currently positioned over northwest Missouri. As the low pressure system rapidly moves across the region to the northeast and becomes negatively tilted by tomorrow morning, the cold front will be wrapping around the system which will result in a switch to southwesterly winds in the wake of the frontal passage. Even with continued southerly winds after the frontal passage, cold air advection will occur behind the cold front due to the cold air wrapping around the strengthening low pressure system. This will lead to slightly below normal average(avg high: 60) high temperatures on Saturday and decreasing cloud cover into Saturday evening. Sunday's temperatures are expected to rebound back to above average due to the sunny conditions forecasted.

A ridge will form over the eastern two thirds of the CONUS by the beginning of next week, potentially leading to above average temperatures next week.

- Peine, McCormack