Good afternoon everyone! The rains that we have been tracking through the course of the day continue to slowly lift eastward with time with most precipitation now clearing the state of SD. Areas of light rain are impacting a large portion of MN as of 4:35pm CDT while some additional redevelopment in far eastern ND into northwestern MN has occurred (area of greatest energy). ND will work out this convection through the evening hours while MN continues to see rain showers into the night.
Simulated radar through 7am CDT Friday: Light rains continue to work east with a slight build-up in northern MN where the low pressure system is tracking into. The areas affected by the low pressure system will have the greatest lift, resulting in better rain chances. Rains will persist into the overnight hours, but with a gradual decrease in intensity heading into Friday morning. By this point, most rain activity will be substantially light with widespread drizzle occurring in central/northern MN. Another weak pulse of energy will begin to infiltrate from the north into northeastern ND by 5am CDT.
Areas of patchy fog are likely to develop in portions of the eastern Dakotas in western MN where rain activity will be gradually clearing late tonight and Friday morning. This is not expected to be widespread, but a threat none-the-less. Any fog that develops in the circled region below will gradually dissipate after sunrise with surface temperatures warming in the boundary layer (layer of the atmosphere below an inversion).
Here’s a brief synopsis of what to expect going through the day Friday into Friday night: We’ll watch some additional energy infiltrate from the north into the far eastern Dakotas and western MN Friday that will bring light shower risks to these areas. Off to the east in eastern MN, low-level moisture will continue to hang around from the storm system currently impacting the area. This will result in low-level clouds lingering and areas of drizzle through the course of the day. A vorticity max (area of increased energy associated with an upper-level trough) will clip northern MN and bring shower chances to the area. Some energy to the south will cause light rain/drizzle risks in MN Friday night while a new disturbance entering western ND will increase rain coverage as it spreads eastward Saturday.
Relative Humidity levels at the surface can be a good indication of where areas of drizzle will be found during the day Friday. The higher the relative humidity, the more saturated the layer is. This saturation extends vertically into the atmosphere, hence the drizzle and mist risks tonight and Friday behind the main wave of this system. The greatest threat for drizzle will be in MN.
Simulated radar from 7am CDT Friday through 7am CDT Saturday: We’ll see another weak wave of energy move into Friday and lead to additional light rain risks in eastern ND and into MN. This wave will gradually exit west to east Friday evening into the overnight hours, with most activity off to the east by 7am CDT Saturday. A few lingering patches of drizzle are possible in far eastern MN Saturday morning.
Here’s a look at total rainfall through 7am CDT Saturday: The bulk of the rains during this timeframe will remain in far eastern NE into MN where a general 0.1-0.5″ of rain is expected. The heaviest rains will be located in north-central/northeastern MN where upwards of 1″ of rain is possible. The central/western Dakotas will remain virtually dry, but rain chances increase through the day Saturday.
If you have any questions do not hesitate to reach out! Have a great evening!