To the left is the QPF (rain) total (guess) for this week.
The SPC has us in the marginal risk for storms over the next three days. Looking at the models I think most of the storms today will be north of Grand Rapids.
A weak cold front will slip down from the north today and stall out over the region tonight through Wednesday. A moist airmass will flow into the region and along this front. This should result in showers and thunderstorms at times. Some of those storms could be strong and contain locally heavy rainfall. Very warm conditions will persist south of this front while closer to seasonable temperatures will exist to the north.
We definitely need the rain – many areas of S.W. lower Michigan have received less than a quarter inch over the past four weeks.
HRRR and Futurecast models runs are for 18 hours beginning at 7am – a second model run begins at 3pm
Day and Week Planner
This feature has auto location.
(click images to enlarge)
A couple of concerns with the forecast include timing of any thunderstorms along with the temperature trends. Models support dropping the surface frontal zone located over northeast Wisconsin into the CWA today into tonight. This feature then meanders over the area Tuesday into Tuesday night before lifting north as a warm front on Wednesday.
This feature has been the focus for the thunderstorms over the past few days. With a tropical airmass pooling along this feature…some risk for locally very heavy rainfall exists. Overall the synoptic support for continued thunderstorm formation along this frontal zone exists through the period. As a result will feature increasing POPs today into tonight and then hold some risk for rain for the remainder of the period.
There is some suggestion of a weak low level jet moving in tonight along this frontal zone…which could focus the thunderstorm development. A marginal risk for severe weather exist into Tuesday. The combination of steeper mid level lapse rates and initially marginal deep layer shear supports this risk. The deep layer shear is advertised to drop off somewhat into Tuesday.
I am not as confident that we will see such warm temperatures as we have seen recently for today into Wednesday. With the front dropping down and stalling over the region…locations to the north will not warm up as much as previously thought. As a result I lowered temperatures for northern zones over the next couple of days. .
A fairly active wx pattern is anticipated for mid to late week as a warm front will result in development of showers and thunderstorms Wednesday night. An approaching cold front will also cause more showers and thunderstorms to develop Thursday.
Some of the convection in this time frame could be strong to potentially severe with potential for moderate to strong instability to develop with lift coming from the boundaries and high dew point air in place out ahead of the cold front. The upper level pattern will become zonal and active wx will continue Friday into Saturday with potential for more showers and thunderstorms with weak to moderate instability still present as there will not be much of an airmass change after fropa Thursday. A stronger cold front will focus development of convection Saturday with a cooler and drier airmass expected to finally move in beginning Sunday.