textproduct: Detroit/Pontiac

KEY MESSAGES

- Areas of fog this afternoon with patchy dense fog at times.

- Scattered thunderstorms this afternoon and evening with a marginal (1/5) risk for severe weather mainly between 3pm and 10pm. Damaging winds and large hail are the primary threats. An isolated weak tornado cannot be ruled out.

- Warm and windy on Saturday with a marginal risk for severe storms along a cold front. Southwest gusts of 35 to 45 mph during the day.

- Above average temperatures are expected through early next week.

AVIATION

Aviation conditions are dominated by the IN/OH front and its connection to Midwest low pressure this afternoon through tonight. The primary surface low is slow to move northward which leaves the front subject to delayed northward progress through Lower Mi due to cool easterly flow off the eastern Great Lakes. This combination prolongs the duration of LIFR/IFR ceiling and visibility across Lower Mi while showers and a rumble of elevated thunder move west to east over the region. Midwest low pressure finally moves far enough north to pull the warm front into the northern Great Lakes late tonight leading to rapid warm sector improvement across SE Mi into Saturday morning. Observations this afternoon are clear to scattered VFR toward the Ohio River as evidence of warm sector improvement, although some form of LLWS/low level jet driven MVFR stratus is likely to fill in toward sunrise followed by surface wind gusts reaching into the 30 kt range. There is also a late night break in shower/storm activity until after 12Z when and band of convection is expected to move in ahead of the inbound Midwest cold front. Showers/storms reach MBS around 13Z and then fill in to the south and east during the morning.

For DTW... Persistent LIFR ceiling/visibility is the primary weather concern this afternoon and evening. Showers also increase across the area while thunderstorm coverage remains low overhead or directed father north through the evening.

DTW THRESHOLD PROBABILITIES...

* High for ceiling at or below 5000 ft this afternoon and tonight.

* High for ceiling and visibility below 200 ft and/or 1/2SM this afternoon and evening.

* Low for thunderstorms at DTW this afternoon and evening.

PREV DISCUSSION

Issued at 943 AM EST Fri Mar 6 2026

UPDATE...

Enhanced mid level theta e convergence along the nose of 50 knot inflow is driving the region of showers and scattered thunderstorms across Se WI/nrn IL. The strongest convergence will slide across northern Lower Mi this afternoon and evening. Ample moisture advection/theta e convergence across Se Mi will sustain relatively high pops from mid/late afternoon into tonight, highest across the north. The 12Z DTX sounding and area observations indicate a formidable sfc stable layer courtesy of the east-southeast flow off the lakes, maintaining a cool and moisture laden boundary layer. This will keep any afternoon/early evening convection elevated, limiting any thunderstorm hazards to hail. Strengthening low level flow during the course of the evening into the overnight will gradually drive the warm sector into Se Mi. This will increase the chances for the development of storms rooted in the boundary layer. The strong wind fields will pose a low risk of severe convection overnight, limited by weak sfc based instability. A forecast update will be issued simply for minor adjustments in temps and pops this afternoon into tonight.

PREV DISCUSSION... Issued at 331 AM EST Fri Mar 6 2026

DISCUSSION...

Pervasive fog and low stratus continue to shroud the area this morning as a warm front sits a few counties south of the state line. Grungy conditions persist through much of the day, with increasing SW flow and moisture advection atop the inversion working to generate some pockets of drizzle as well. A shortwave will track across the western and northern Great Lakes today into tonight, inducing deeper southerly flow to send the warm front northward. Model guidance continues to advertise a backed component to the surface wind through the day, which presents the typical early spring scenario where the cold marine layer maintains a stable profile locally while the warm front lifts northward across western Lower MI. Temps look to be locked in the 40s and lower 50s for most of SE MI during the day, but western areas - especially parts of Lenawee County - could reach the lower 60s dependent on how far north the front lifts. A more convincing push of SW flow allows the front to clear the area during the evening, and the daily max temp is likely to occur after sunset.

Several windows for showers and thunderstorms exist in the next 48 hours. The first arrives this afternoon along the nose of the LLJ/theta-e surge. Plan view shows the bulk of unbalanced flow targeting western and northern Lower MI, but enough for a 90% PoP in the Saginaw Valley tapering down to around 50 to 60% for the rest of the area. Additional convection along the surface frontal passage is expected this evening as moisture advection ramps up within the strengthening LLJ. Mid-level lapse rates increase with MUCAPE to around 750 J/kg and effective shear 35+ kt supporting a marginal severe hail threat, and isolated damaging gusts will be possible if storms become rooted in the surface layer. Highest potential for this to occur is around the Saginaw Valley where several models inch a tongue of SBCAPE in late. The latest Day 1 outlook from SPC also indicates a 2% probability for a brief, weak tornado which is warranted with the increasing low-level helicity occurring along the passing warm front. Potential for training storms also exists, with HREF showing a 30% chance for stripes of 1"+ rainfall in the Saginaw Valley and Thumb.

50+ kt LLJ passes overhead on Saturday as a deepening low zips across the straits, leading to a windy day. Boundary layer moisture and morning pre-frontal showers/storms look to limit mixing depths to a degree, but there remains support for gusts of 35 to 45 mph as we reside in the warm sector. Still some variance regarding when the cold front pushes through, which will affect high temps, peak gusts, and convective vigor along the front. The bulk of hi-res guidance advertises fropa late afternoon to evening suggesting at a marginal threat for damaging wind gusts given the kinematics overhead and time for sufficient SBCAPE to develop through the day. In this scenario highs have a chance to reach the mid to upper 60s.

Another breezy day on Sunday with only a slight step down in temperatures as cold advection is weak behind the Saturday front. A series of systems track across northern Ontario Sunday into Monday with deep layer southwest flow across the Great Lakes bringing another warming trend through early next week. A frontal wave passes through the southern Great Lakes and Ohio Valley late Tuesday into Wednesday, offering relatively high confidence in additional precip. What remains uncertain is the thermal setup, evidenced by NBM interquartile range of max temperatures ranging between 50 and 70 degrees. The strength of this low will govern how far north the warm front lifts and whether any surface based thunderstorms will be possible, or whether an area of mixed precip affects northern portions of the area. Much cooler air will settle in behind this system with drier conditions likely on Thursday.

MARINE...

Lighter southeasterly winds and drier conditions hold through the afternoon as the region resides between systems. Stronger low pressure, relative to Thursday, tracks out of the Plains and into the northern Great Lakes Saturday. In advance, the attendant warm front lifts through the central Great Lakes late this evening supporting another round of scattered showers and a few thunderstorms with southwesterly winds developing post-front tonight. While strengthening warm advection results in 50-55kt flow only a couple thousand feet off the surface, magnitude of the airmass maintains strong thermal stability over the lakes keeping winds at or below 30kts. System's cold front crosses the region second half of the day Saturday generating wider spread showers and scattered thunderstorms, particularly towards the southern Great Lakes. An isolated strong to severe storm is possible over these southern waters. There is a couple hour window along/immediately following the front where west/west-northwest gusts could near entry- level gales. That said, while the gradient is supportive of stronger gusts, trailing airmass is not particularly cold relative to the current lake temps resulting in only slightly unstable to neutral thermal profiles acting as an inhibiting factor in peak wind speed potential. Confidence remains too low to warrant a Gale Watch. Southwesterly flow redevelops Sunday as low pressure slides over northern Ontario, though renewed warm advection again limits winds at or below 30kts.

HYDROLOGY...

Showers and thunderstorms are expected this afternoon and evening as a warm front lifts across the state, then additional showers and storms are likely on Saturday ahead of and along a cold front. Storm total rainfall amounts are forecast to range between 0.25" and 0.75", although potential exists for areas that see multiple thunderstorms to receive over 1.00". Rises on area rivers are likely and some may reach action stage if these higher amounts occur. Ponding of water on roadways is also possible.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...None. Lake St Clair...Dense Fog Advisory until 10 PM EST this evening for LCZ460.

Michigan waters of Lake Erie...Dense Fog Advisory until 10 PM EST this evening for LEZ444.