textproduct: Detroit/Pontiac

KEY MESSAGES

- Showers and a rumble of thunder this morning with rain chances continuing across the north into the day.

- Southwest wind gusting in the 30-40 mph range develops this afternoon helping to lift temperatures into the 70s.

- Warm and wet week ahead with highs reaching into the 70s each day and daily storm chances.

- There is a Marginal Risk of severe thunderstorms Monday night and Tuesday morning.

- Locally heavy rainfall potential also increases during the mid week period.

DTW THRESHOLD PROBABILITIES

* Low in ceilings aob 5000 feet this morning. High overnight tonight.

* Low in thunderstorms late tonight.

PREV DISCUSSION

Issued at 314 AM EDT Sun Apr 12 2026

DISCUSSION...

Active stretch of weather starting today which will persist through much of the coming week. A strong upper low over the West Coast will slowly drift eastward over the next few days, reaching the Plains on Wednesday. Meanwhile, a surface low develops over the Central Plains and moves very little while its attendant warm front wavers about through the Great Lakes and the cold front sags southward toward Texas. This setup will draw deep moisture from the Gulf up through the Midwest/Great Lakes with persistent 40+ knot low level jet, with shortwaves accelerating that to near 60 knots at times. The westward placement of the surface low will tend to keep the better surface based storms up through the Plains and into the Midwest, but the upper level low ejecting several shortwaves through the Great Lakes will act to draw better moisture and instability into the region at times leading to several rounds of showers and thunderstorms through Thursday. Besides storms this week, the other main story for the week will be the much warmer airmass offering daily high temps into the 70s, lows in the 50s, with dewpoints into the 50s and 60s much of the week.

Today will offer the first round of showers and storms as a shortwave tracking across the UP on the nose of a 50 knot jet sends a cluster of storms along the isentropic arm extending eastward from the low over the Plains. This will mostly pass north of SE MI but during the morning the forcing will reach farther south and east offering some showers and elevated storms locally before the warm sector starts pushing into southern MI capping off additional activity this afternoon. Winds in the warm sector later this afternoon will get gusty as the low level jet starts expanding into the area as peak heating still has max mixed layer depths. Model soundings suggest we could mix down 30 knots or more for a couple hours before sundown. Cold front sweeps through the area later tonight. The low will peal off to the north with the ribbon of vorticity shearing to the northeast as well, so a weaken band of showers will pass through tonight, possibly ending by 12Z Monday morning. Highest rainfall totals will be up through Mid MI where QPF could reach 1.2 to 1.4 inches. Amounts taper off drastically southward, with less than a tenth of an inch expected around the Detroit Metro.

Could see a lull in precip on Monday as low amplitude mid level ridge slides over with the main baroclinic zone well to the north but the next short wave is already targeting the U.P. again tonight. Best chances for precip will again occur to the north, but expanding area of elevated instability, a mid level vort max, and strong low level jet could lead showers and storms expanding farther south across much or all of the area. SPC has us in a Marginal Risk of severe weather for Monday.

Window for strong to severe surface based storms remains to be on Tuesday as a low ripples along the front laid across Mid MI and the main upper trough pushes into the Mid MS Valley. This will lead to a high shear, good instability environment, surface/mid/and upper level support, good moisture with PWATs over 1.25 inches and surface dewpoints into the 60s (some models advertising hitting 70). Plenty of time before this arrives to get more into the weeds with storm potential and timing but SPC already had most of SE MI in the Day4 15% area today. The mid/upper level troughs linger just to the west Wed and Thurs as well offering additional storm chances.

MARINE...

Winds organize from the south-southeast this morning as a return flow configuration arises from departing high pressure. Gradual gradient constriction causes winds to increase, exceeding 20 knots for the northern half of Lake Huron by sunrise. Expect a more active week of weather, beginning this morning, as showers move in ahead of a decaying line of thunderstorms. Locally higher winds and waves are possible as convection works across the Huron basin, but lower column stability should limit overall gustiness. Potential still exists for brief gusts to gales late Sunday into Monday as a 65+ knot low-level jet crosses the central Great Lakes. The main area of concern will be Saginaw Bay given funneling southwest flow and slightly higher potential for mixing. Winds respond accordingly, therefore an initial round of Small Craft Advisories are in effect, with more possible for the adjacent waterways on Monday. Several additional rounds of showers and thunderstorms are expected throughout the week due to a series of troughs, low pressure systems, and fronts.

DTX WATCHES/WARNINGS/ADVISORIES

MI...None. Lake Huron...Small Craft Advisory from 10 PM this evening to 10 AM EDT Monday for LHZ421-422.

Small Craft Advisory from 10 AM this morning to 10 AM EDT Monday for LHZ441.

Small Craft Advisory from 10 AM this morning to 10 PM EDT this evening for LHZ442.

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