Yesterday we had a high temp of 86°! Though not uncommon this was a sign summer has not been willing to give up its grasp on us this September. Now it is abundantly clear we have seen the last of our warm and dry month come to an end with the remnants of tropical depression Nicholas heading our way and a cold front pulling in behind it on Tuesday. Below is the QPF depiction through Wednesday which hasn’t chanced much since yesterdays run.
Sunrise today is 7:28, sunset is 7:43 pm.
- Periods of showers and storms Today through Tuesday Showers will lift into the forecast area from the south this morning. These showers are associated with the left over moisture from the former tropical system Nicholas. So, there will be efficient rain processes occurring leading to moderate to heavy rain at times. We expect a diurnal boost to the activity which is depicted in the 4hr max reflectivity prog in the HREF. After 300pm or so we should see some embedded thunderstorms form which will lead to a locally heavy rain threat. Most Unstable CAPE values today will reach near 1,500 J/KG with PWATs approaching 2.00 inches. Expecting rain totals in spots to reach the 0.50 to 1.00 inch range. Not expecting severe weather given extensive cloud cover and overall low instability. The precipitation will taper some tonight as the main surge of moisture heads off to the north. A cold front will approach from the west however with likely an even better swath of precipitation. The front will be moving into an air mass that will still have PWAT values on the order of 1.9 inches so locally heavy rain will remain a threat. Heaviest rain tonight will be over northwest portions of the forecast area for places north and west of Grand Rapids. The front will continue marching to the east on Tuesday with a swath of showers and embedded thunderstorms transitioning across the area. Heaviest rain on Tuesday will be from Grand Rapids to the south and east in a post frontal setup. Locally heavy rain will remain a threat, with fairly widespread totals around an inch across the southeast and eastern CWA. Lansing and Jackson stand the best chance to see the heaviest rain where totals through Tuesday evening could push towards or exceed 2 inches. We still feel that we should be able to handle this level of rainfall as the rivers are all quite low. That said if training does occur and it will likely do that in the northwest CWA tonight and over the eastern CWA on Tuesday, we could see some local, short term drainage issues. If we become concerned with any areas they would be handled by short term Flood Advisories. At this point, not expecting that to take place. Instability dwindles even further on Tuesday, so not expecting severe weather with the cold frontal passage. - Showery weather expected mid to late week Will opt to follow the ECMWF in terms of the overall pattern in the mid to late week time frame as the GFS seems to be playing catch up to it with regard to a low retrograding into our area. The low is overhead in the Wednesday and Thursday time frame which will lead to additional showers. Some areas of the CWA will get a good soaking out of this pattern by Thursday and Friday. Soil moisture levels will certainly be on the rise by the end of the week. When the flow turns off of Lake Michigan (and much of the time it will be northerly) we will stand the chance at lake effect rain showers. The lake is around +21C right now, so lake effect rain begins with 850mb temps around +8C. We are cooler than +8C much of the forecast period. - Cool down still on track behind Tuesday`s cold front The cool down remains on track with 850mb temperatures mainly in the single digits C after Tuesday. Coldest air is on Wednesday and again on Saturday. It will certainly feel like fall with highs in the 60s much of the time. We do even have some 50s highs across Central Lower and I see this expanding in area as we get head towards Wednesday.