We had a trace of rain yesterday morning with a high of 80°, the low was 64°. Sunrise today was 6:37 and sunset is at 9:03 pm. Today we will see mainly sunny skies with highs in the mid-80s, tomorrow will be another story.
One or more rounds of thunderstorms will be possible across Lower Michigan on Wednesday. As time goes on, the threat for severe thunderstorms will migrate from northwest to southeast. The later in the day that a thunderstorm develops in your area, the hotter and more humid the day will become. Any thunderstorms that develop could produce locally damaging wind gusts, large hail, perhaps a brief tornado, and potentially heavy rain with some flooding.
Below is the current outlook from the SPC for tomorrow, and I am sure there may be changes to it as time progresses.
A shortwave trough will affect the Upper Great Lakes region as a surface low moves northeastward out of Ontario. A cold front will trail southwestward across northern MI, southern WI, and into the lower MO Valley. Ample low-level moisture with dewpoints near 70 F will combine with heating to produce moderate levels of instability ahead of the front. Early day convection associated with the low-level jet may produce a few strong gusts or marginal hail over MI, as midlevel lapse rates will be seasonably steep. Air mass recovery is likely in the wake of any early storms, and potential outflow boundaries could locally enhance low-level shear. Winds around 850 mb will exceed 40 kt, though this, and deep-layer shear, will largely be parallel to the front. Models suggest afternoon redevelopment will be robust, with damaging gusts and a few reports of marginal hail most likely. Mesoscale factors may contribute to a brief tornado threat, or low-level rotation with the developing line.
Amid surface high pressure behind yesterday`s cold front, drier air advecting in from the northwest around 850 mb this morning will support lower dew points as boundary layer mixing depth increases today. Far southwest Michigan may not catch much break from the humidity, however. Well anticipated and fairly abrupt warm air advection commences tonight with a southwesterly low-level jet transporting a plume of air from the western CONUS heat dome. In the vicinity/north of an advancing warm front overnight, thunderstorms are likely to develop over WI/upper MI as midlevel lapse rates steepen above a 850-800 mb layer of moisture transport. Convection-allowing models in the 00Z HREF have been diverse in their handling of the convection overnight into Wednesday, though storms threatening the Ludington area by daybreak if not sooner seems to be where the clustering starts. Convection-allowing models typically underestimate the longevity and southward extent of well formed nocturnal MCSs in this pattern. Since over 2000 J/kg MUCAPE and little inhibition for MU parcels will be present over the area Wednesday morning, it would not be surprising for backbuilding to occur late into the morning on the southwest flank/outflow of whatever MCS evolves. This has big implications on the temperature/cloud/heat index forecast for Wednesday, which in the absence of storms, would be a sultry day with highs in the 90s, dew points in the 70s, and a heat index nearing 100. When an upper level anticyclone is not well established in the region and our upper levels are more influenced by a trough moving through the northern Great Lakes, this is a plausible "heat advisory bust" scenario. Not knowing how far south the morning thunderstorms will propagate into Lower Michigan, it seems we should just be prepared for anything. If much of the area remains storm-free through Wednesday morning, 2000-3000 J/kg MLCAPE and moderate deep-layer shear will be available for any convection that may break through an eroding cap during the afternoon. Hail, damaging winds, and perhaps a tornado could occur depending on convective mode and line orientation relative to the shear. Heavy rainfall rates are also likely, so any training convection (whether it be in the morning or afternoon) may produce locally substantial totals. Fortunately a break from the worst of the heat and humidity is still expected for Thursday and Friday. Another plume of warmer air from out west may wash over the area on Saturday, then another upper level trough moving through the northern Great Lakes on Sunday could support additional showers or thunderstorms.