After a long stretch of great weather, we’ve finally got some rain in the forecast. Currently, it looks as if we will be getting some decently heavy rain fall early in the morning on Friday. The storm chance in the morning is mild, and right now it only points to heavy rain. There is a possibility for storms to develop later in the afternoon on Friday as well but it is very speculative at this time. If you have a trip planned and you will be out on the river Friday I suggest you plan for some heavy rain and read up on weather and river safety under our “trip planning” tab at the top of this page. The rest of the weekend looks like it will be a lot better and I don’t anticipate the river levels to rise very much from Fridays rain.
Below is the forecast discussion for our area on Friday
the main shortwave is a little further back and expected to spawn a MCS over the Dakotas this evening that will likely ride the moisture axis towards central and southern WI Friday morning. Not expecting any strong storms during the morning hours as profiles become moist adiabatic and should just be very heavy rainfall producers. Looking through the various ensemble guidance and CAM solutions there is increasing confidence that the western half of the area will pick up at least 1 inch of rainfall through the mid-morning hours. Due to the PWATs being in the 95th percentile for climo and some modest potential for training rainfall amounts could be pushing 2-3 inches from tonight through mid-day Friday in the west. Luckily we`ve had a drier period recently and this will occur over a longer period of time that the concern for any more widespread flooding is low. But some minor flooding in urban areas or other low lying areas is possible. Then for Friday afternoon there has been a trend in latest CAMs and other guidance that a surface low will develop in response to the shortwave and departing MCS. A weak cold front over central/northern WI could strengthen as the low tracks across the area and drops south during Friday afternoon. If the morning round of showers and storms are able to clear in time we could see a window in the afternoon for a few stronger storms to develop as that cold front drops south. MUCAPE values in the afternoon would be upwards of 2,000 J/kg and deep layer shear does strengthen during the evening so a few damaging wind gusts are possible Friday afternoon/evening.