Expect a warm and pleasant beginning to the weekend as a high pressure system moves into the Central Missouri area. Clear and sunny skies are expected for the majority of the weekend allowing temperatures to rise into the mid-70's. Hold onto your hats on Saturday though! Winds from the southwest are expected to reach up to 16mph in the afternoon. However, anticipate a gloomy Sunday as a low-pressure system approaches from the southwest bringing rain showers and a possibility of some isolated thunderstorms. Overall, Central Missouri will experience an enjoyable weekend.
The NAM40 was chosen today because of its superior tracking of the LPS centered on the southern border of New Mexico. GEFS and SREF plumes were referenced for temperature and soundings were used to aid in forecasting sky conditions. The main focus of this forecast will be the LPS over New Mexico and the associated trough.
The 250-mb plots of heights and winds show a low pressure system sitting stationary on the border of New Mexico and Mexico until it starts to progress eastward Saturday morning. However, the associated trough reaches mid-Missouri on Thursday at 23Z. The trough facilitates divergence aloft that encompasses the majority of our state. As the trough advances, the NM low starts moving NE on Saturday night. It quickly approaches our area Sunday evening only to be absorbed into a long wave trough.
A similar image can be seen on the 500-mb plots of height and vorticity. The trough at the 250-mb level passes earlier at this level. Associated circulations start to penetrate a majority Missouri until Thursday night. Rotations at this level aren't seen again until the LPS passes south of our area Sunday night.
The plots of height, omega, and relative humidity on the 700mb level show the atmosphere continuing to dry out on Thursday night into Friday morning. We stay dry at this level until Saturday, when an influx of moisture from the north enters the forecast area. Peak saturation occurs on Sunday night as the LPS advances, allowing moisture advection to take place.
The 850-mb plot of height, temperature, and wind show northerly winds dominating the area until a high-pressure system passes through. After its passage, winds will shift SW for the remainder of the weekend. Looking at the surface 1000-500mb thickness and MSLP plot, the high-pressure system is present for most of the forecast period promoting clear skies. On Sunday, a surface low pressure system is seen approaching Missouri.
Lastly, soundings show sunny conditions until Saturday night when clouds quickly move into Columbia. By Sunday at 18Z, deep saturation paired with wind shear and upward motions allow rain showers and a possibility of scattered thunderstorms to occur.
The next forecast period should continue to watch the LPS approaching our area on Sunday and the ensuing weather it brings.