textproduct: Detroit/Pontiac

KEY MESSAGES

- A warming trend through the early week with 60s on Monday and into the lower 70s Tuesday.

- Monday night and Tuesday afternoon/evening hold the next chance for rain and thunderstorms. An isolated storm could approach severe intensity Monday night. Continued severe weather potential exists on Tuesday afternoon and evening. Marginal Risk of severe weather is in place covering both periods with hail and wind as the main threats.

- Temperatures drop back to normal or slightly below normal for Wednesday through late week.

- Pattern remains active mid-late week and into the weekend.

AVIATION

VFR conditions tonight as some intervals of thicker mid and high level cloud lift through at times. Greater potential for cloud featured across the 5 to 6 kft level to arrive during the early and mid morning hours, particularly across the Detroit airspace. Some strengthening of wind will occur off the surface as the low level jet arrives, but sufficiently mixed surface flow precludes a mention of low level wind shear at this time. Prevailing wind direction remains from the southwest. Higher based VFR cloud likely to persist throughout Monday under sustained warm/moist air advection. Some lowering below 5000 ft will be possible during the afternoon and evening hours. The advective process may allow for widely scattered showers to develop by evening.

DTW THRESHOLD PROBABILITIES...

* Low for cigs aob 5000 ft Monday afternoon and evening.

PREV DISCUSSION

Issued at 344 PM EDT Sun Mar 29 2026

DISCUSSION...

Surface high pressure translates off the mid-Atlantic coast today while southwest return flow ushers in warmer air and eventually greater moisture to the region. Thermal moderation is evident this afternoon with temperatures into the 50s. Stable conditions will keep the weather free of precipitation through the remainder of the day into tomorrow. Clearing tonight favors radiational cooling potential, but should be somewhat limited by the overnight gradient flow. Lows tonight should hold mostly in the 40s with localized upper 30s possible.

Another appreciable jump in temperatures tomorrow with low variability in the surface temperature spread that points towards temperatures in the 60s for most of southeast Michigan. A sagging frontal boundary near north/central Michigan may lead to a period of onshore flow across the Tri-Cities/northern Thumb. That would keep temperatures a little cooler along the lakeshore areas if it sags far enough south. Noticeable moisture will also arrive with surface dewpoints climbing into the mid 40s to low 50s and good low-mid level moisture transport sending 850mb dewpoints to 5-10C. This comes with increasing cloud cover and sets the stage for increasing precipitation chances.

Overall convective potential Monday evening through Tuesday will be the primary forecast concern. Increasing ascent will arrive with the strengthening low level jet winds into Michigan as a central plains low begins to migrate towards the Midwest. Some weak showers may be possible across during the afternoon/early evening Monday across the southern half of southeast Michigan, but the greater probability with widespread coverage will be Monday night from midnight through mid Tuesday morning. Monday night will begin with elevated convection supported by strong theta-e advection aided by the 50+ knot lower level jet. Steep mid-level lapse rates, MUCAPE above 1000 J/kg, and bulk shear to around 40 knots will be enough to support elevated thunderstorms with hail as the main threat. Some potential for stronger winds also exists given the strong low level flow just above the surface. A Day 2 Marginal Risk of severe weather remains in place for this potential.

Progression of the low pressure into the Midwest will lift the frontal zone northward expanding the warm sector across southeast Michigan. Still some question as to exact placement of the frontal features by Tuesday afternoon and the morning rain and clouds may also limit potential for a stronger instability response. Will continue to monitor these trends, but models still advertising surface based CAPE increasing to 500-1000 j/kg ahead of the cold front supported by surface temperatures climbing to upper 60s and low 70s. Sufficient 0-6km bulk shear of 40+ knots and steep mid- level lapse rates remains in place through the afternoon. If convection can become surface based, there will at least be a low tornado threat. However, shear vectors are not all that favorable given the mostly unidirectional profiles. Organized convective potential along with PWATs to around 1.25 inches will also bring a localized heavy rain potential. SPC has updated the Day 3 Outlook to include a Slight Risk for Tuesday afternoon/evening activity. This update appears tied to the CSU-ML and NCAR AI NWS Convective Hazard Forecast pages that continue to highlight the severe potential for Tuesday afternoon and evening with hail and wind being the main threats. This event still carries some uncertainty and greater confidence in overall hazard potential will come with more runs within the hi-res window. Cold front is forecast to clear Michigan by Wednesday morning and settling across central IN/OH. This will drop temperatures back down to normal or a few degrees below. Precipitation may be sustained along the southern Michigan border during the early part of the day as the boundary stalls out. Another potentially impactful system may set up Thursday as a trough advances across the plains and triggers development of a low pressure system along the frontal zone. Cold air will be hanging on across the northern half of the CWA early Thursday presenting a chance for rain/snow mix or some periods of wintry mix before warmer air is driving northward. Will have to keep an eye on lower level thermal profile trends and progression of the warmer air northward. If colder surface air wants to hold on longer across parts of southeast Michigan throughout the day, an increasing chance for a longer duration of freezing rain will be possible. LREF- NH currently paints a ~20-30% chance of 0.1" of freezing rain roughly along and northwest of a Flint to Bad Axe line Thursday by late Thursday afternoon. Pattern remains active with models sending another low pressure system through the region over the weekend.

MARINE...

Southwest return flow has set up over the Great Lakes today as high pressure settles into the mid-Atlantic. Influx of warmer air aloft has established stable over-lake profiles to keep wind gusts capped at 20 knots amidst modest gradient flow around 15 knots. Offshore flow directs elevated waves into the open waters through most of Monday. Surface convergence along the warm front intensifies Monday night into Tuesday morning, triggering showers and elevated thunderstorms overnight which will be capable of hail and lightning. The front also causes winds to veer to the east for portions of Lake Huron, resulting in an uptick in wave heights Tuesday. A strong cold front then sweeps through Tuesday afternoon-evening, drawing a line of thunderstorms across the area. A few of these storms may be strong to severe, with the main concern being wind gusts over 35 knots. Post-frontal winds shift sharply to the northwest with high pressure filling back in by mid-week and introducing snow chances back into the forecast.

DTX WATCHES/WARNINGS/ADVISORIES

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