After scattered showers and temperatures cooled off earlier today, conditions are starting to dry up now that the low pressure system is moving northeast out of Mid-Missouri. Tonight's clouds will continue to to push out of the Mid-Missouri region and become clear overnight with temperatures dropping into the low 50s. Tuesday temperatures will reach into the mid 70s with skies becoming partly cloudy with an increasing chance for scattered showers overnight. Temperatures overnight Tuesday will drop into the low 60s and remain partly cloudy Wednesday morning. The chance for showers returns with the possibility of thunderstorms Wednesday afternoon. Wednesday evening lingering showers will stay in the Mid-Missouri then becoming partly cloudy with lows in the mid 60s.
Forecasters: Gromada, Alexander, Gotsch
Date Issued: 10/11/21 5:00 PM CST
For this current forecast period, analyzing the GFS and NAM, the GFS seems to be handle the atmosphere better than the NAM overall. The NAM does seem to have a better grip on the moisture in the mid levels, but is placing the current low pressure system farther northwest than it currently is. With this in mind, we chose the 12z GFS for 11 October, but we are keeping in mind that a mid-level moisture offset needs to be applied.
The negatively tilted upper-level low pressure system that caused severe weather Sunday evening is leaving the area Monday night, taking the clouds with it. The jet stream will begin weakening as it moves farther northeast tonight and into Tuesday. During the day Tuesday, upper level clouds are expected to enter the area.
More moisture is expected to move into the Mid-Mississippi Valley on Tuesday night with the passage of a warm front. This frontal passage is expected to keep temperatures from falling too much and to cause showers overnight. Precipitation values are expected to be around .4 of an inch. As the sun rises, the jet stream will position itself over Western-Mid-Missouri and place the right exit region over Columbia as another negatively tilted new low pressure system pushes into the Mid-Mississippi Valley. As the low pressure system enters the area, the low level jet also picks up and will help advect more moisture into the system. This will be enough moisture to cause up to .5 inch of precipitation by Wednesday evening when a cold front moves through Missouri. Lingering showers are expected to persist through the overnight hours into Thursday morning. CAPE values are not expected to exceed 500J/kg, and that will be on Wednesday afternoon.
The low on Wednesday night could drop to the mid 50s if the cold front moves quicker than the GFS is currently predicting.
The next forecasters should be monitoring another incoming low pressure system set to bring increased probabilities of showers and storms Thursday night into Friday.