textproduct: Detroit/Pontiac

KEY MESSAGES

- Dry and warmer today.

- Summer like heat and humidity sets up this weekend and continues through early next week. The potential exists for temperatures in the middle 80s Monday and Tuesday.

- Multiple opportunities for thunderstorms over the weekend and early next week with low confidence on timing and coverage.

DISCUSSION

Shortwave ridge will pass to the east this morning while a zonal Pacific jet streak streches from the central Great Lakes to the PacNW with an associated low pressure system crossing through northern Ontario. At the lower levels, moist and warm advection will occur throughout today aided by the S-SW flow. Will see a bump in temperatures this afternoon to around 70 degrees. The better moisture will arrive in the mid and upper levels with weak PV advection. This will mainly bring an increase in cloud cover through the first half of the day with a brief period of lower cloud cover this evening.

Tonight into tomorrow will see a convective system develop across parts of the Midwest with its associated MCV tracking into southeast Michigan through tomorrow morning. Timing amongst the hi-res models has showers and thunderstorms associated with this MCV moving through mainly between 09Z and 14Z Saturday timed with the better thetae advection. As it stands now, the unfavorable timing at the diurnal minimum and the lack of strong instability will likely keep the potential for isolated severe weather pretty low. Given this limitation, we remain outlooked for General Thunder. A secondary window for showers and thunderstorms will be possible Saturday afternoon along a boundary that is laid out around the southern Michigan border. The afternoon will hold the best chance for instability to build, which will also supported by the greater warm air advection that will support highs in the upper 70s to low 80s. However, coverage of any convection looks sparse by Saturday afternoon with better coverage held to south of the state. Will continue to monitor trends, but outlook for Day 2 also remains General Thunder.

The main story for Sunday through the early part of next week will be the summer like conditions and the continued chance for thunderstorms. A strong Pacific Northwest trough will lead to downstream riding that builds across the Great Lakes sending 850mb temperatures to around 15C and 925mb temperatures to around 20C. This will draw temperatures up to around 80 degrees for most of the area outside of the Thumb on Sunday. A warm front will be drawn northward, which could kick off some scattered thunderstorm activity, but mid level capping may limit better convective potential. Monday and Tuesday will be warming into the mid/upper 80s range depending on cloud cover which may temper the higher values. Strong moisture transport will also send surface dewpoints into the 60s with near 70s possible. The associated thetae air will be more than supportive of continued thunderstorm chances through the early week, but uncertainty remains in timing and overall coverage.

MARINE

Flow reorients out of the south this morning as high pressure departs the Ohio Valley. Winds strengthen gradually through the day as the pressure gradient tightens in advance of low pressure that impacts the region this weekend. Gusts over Saginaw Bay will have the best opportunity to briefly touch 25 knots, although will be working against an increasingly stable environment so no Small Craft Advisories have been issued at this time. Surface troughing triggers an initial wave of showers and thunderstorms early Saturday morning, before washing out over the western Great Lakes through the daytime. This creates an unsettled pattern characterized by dry periods mixed with periods of showers and thunderstorms that lasts into early next week. Relief from this pattern then arrives mid-week with the passage of a cold front.

PREV DISCUSSION

Issued at 1142 PM EDT Thu May 14 2026

AVIATION...

High pressure in control tonight supporting light winds and cloud cover confined to cirrus. Mid-cloud increases Friday morning/afternoon tied the leftovers of decayed convection from the upper Midwest. Deep layer of drier low level air and light intensity to any remnant elevated shower should prevent precip from reaching the ground. Winds organize out of the southwest by Friday morning with peak gusts expected to hold at or below 20kts.

D21/DTW Convection... No thunderstorms are in the forecast through Friday. Slight chance for an isolated thunderstorm Saturday morning at the very end of the current forecast period.

DTW THRESHOLD PROBABILITIES...

* None.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None.