Friday Night: Partly cloudy building up throughout the night. Low: 63
The low pressure system to our south east will continue to bring moisture into our region. Precaution is needed Thursday morning as there is a chance of fog. Throughout tonight and into tomorrow, there will be a chance of showers which will culminate into thunderstorms Thursday around 1pm with an anticipated 0.1" of rain. As the low moves out of our area Thursday night, it will leave us with partly cloudy skies until Friday night. Throughout the rest of the week, we will see temperatures slowly increase as our winds change to the west, just in time for Homecoming weekend.
- McMullen, Noblitt
Forecasters: - McMullen, Noblitt, Cochran
Date Issued: 10/6/21 5:00 PM CST
The 12Z run of the NAM40 was used in today's forecast. We compared the GFS and NAM to the surface map provided by the NWS for 15Z, which had the NAM following much closer to the observed pressure contours from this map. The SREF and GEFS plumes were referenced for temperature and precipitation values as well as NAM soundings for the Columbia area for sky conditions and timings.
The 250-mb plots of heights, winds, and divergence displays a low pressure system to the SE that will gradually move north along the Mississippi River until 9Z Friday. This LPS dominates the weather for the region as it resides over Missouri. As this system leaves, a ridge over the Four Corners forms and begins to push eastward. The high pressure system will bring the jet streak into our upper levels as the forecast period comes to a close.
The 500-mb plots of heights and vorticity show the LPS following a similar path as in the 250-mb plot. This system will bring in increasing vorticity values with the peak occurring at 18Z Thursday. As the LPS departs, so to does the circulation for our region.
The 700-mb plots of heights, relative humidity, and omega indicate notable moisture from the south carried in from the low. This moisture will begin to dissipate over Mid-Missouri beginning 4Z Thursday as the system leaves the area. Afterwards, Columbia will continue to see sporadic bursts of saturation for the duration of the forecasting period.
The 850-mb plots of heights, winds, and temperatures shows southerly winds over the Lower Mississippi Valley until 12Z Thursday. This will aid the moisture advection seen in the 700-mb plot. Winds will shift to the west starting 18Z Thursday, which will draw in the warmer temperatures from the Southwestern United States. This will result in warming temperatures at the end of the week which is supported by the weak WAA seen on the MSLP and the 1000-500-mb thickness plots.
NAM soundings indicated increasing saturation levels until a peak at 18Z Thursday with strong implications for thunderstorms as shown by the 1405 J/kg of CAPE and a LI of -5. A slight temperature inversion could indicate the formation of fog at 12Z Thursday. Following this, we see a slight decrease in saturation keeping our skies partly cloudy for the remainder of the week. Total QPF values are predicted to be about 0.1" as shown by the SREF plume for the forecasting period.
Future forecasters should pay attention to the incoming upper-level ridge toward our west and its accompanying jet streak.
- McMullen, Noblitt, Cochran