textproduct: Detroit/Pontiac

KEY MESSAGES

- Cold tonight. A gradual warming trend will then occur during the week.

- Chances for rain increase Tuesday into Thursday. There is a slight chance for a couple periods of freezing rain Tuesday morning and Tuesday night.

DISCUSSION

An arctic high with a surface pressure around 1038 to 1040 MB will slide from the northern Great Lakes this afternoon to the eastern Great Lakes/upstate New York by Monday morning. The ongoing northeasterly component to the low level wind fields will sustain some lingering strato cu and flurries across the thumb and Port Huron areas into the evening. Otherwise, mainly clear skies and light winds and very dry air low level air will drop nighttime mins into the teens, with single digit readings likely in areas which received fresh snow cover. Mid level confluence across the Great Lakes will sustain subsidence through a deep layer and surface ridging across Lower Michigan through Monday. This will ensure ample sunshine. Slight low level warm air advection and an early March sun angle will push daytime temps into the 30s Monday, with highs possibly touching 40 away from the lakes.

Short wave impulses and upper jet influence will invoke waves of frontogenetical forcing along the lower tropospheric baroclinic zone over the Ohio Valley Monday into Wednesday. There has been some model disagreement with respect to the extent of forcing within the mid level portions of the frontal zone over srn Lower Mi Tuesday into Wednesday. There also remains a wide variation in ensemble solutions with respect to precip chances over srn Mi. Overall model trends have suggested the better rainfall potential will fall closer to the low level front over the Ohio Valley. Residual dry air across the Great Lakes will also be a limiting factor for precip chances across Se Mi. This has led to some slight downward adjustment to pops Tuesday into Wednesday, especially north of the I-69 corridor. The influx of warm air will be efficient enough to support a liquid precip type. Dry easterly flow in the boundary layer may however keep sfc wet bulb temps at or below freezing over portions of the area, especially Tuesday morning and Tuesday night. This at least warrants a chance for some freezing rain.

A more amplified and compact mid level short wave is forecast to eject out of the central Rockies and track across the Great Lakes region Thursday. There has been considerable movement within the model solution space with respect this feature. While there is some better agreement among the 12Z deterministic solutions, there is likely to be additional model fluctuations over the next couple of days. This wave would likely draw a decent moist plume into Lower Mi and is suggestive of a mild and wet end of the work week.

MARINE

Expansive high pressure in place over the entire Great Lakes this afternoon, supporting light winds tonight, ~10 knots. As the large high pressure center moves off the East Coast late tomorrow, strengthening southwest flow will bring milder air into the Great Lakes region. With the increase in low level stability, it appears winds will top out just around 25 knots over Lake Huron. A weak low tracking through the northern Ohio Valley brings mostly rain over Lake St. Clair and Lake Erie, with dry weather and light winds returning Wednesday morning, as high pressure briefly returns. Another warm low producing rain looks to be arriving on Thursday. Easterly winds ahead of this low over the northern half of Lake Huron look to be at least moderate (potential gusts to 25 knots), but the increasing low stability should keep winds from getting much stronger.

Little if any cold advection behind the low Thursday night will result in light winds, with enough lingering low level moisture around to potentially support low clouds and drizzle.

PREV DISCUSSION

Issued at 1150 AM EST Sun Mar 1 2026

AVIATION...

Strong high pressure dominates the area through the forecast with subsidence and dry air maintaining widespread VFR conditions away from the Lake Huron shoreline. Weak marine moisture flux is producing a boundary layer cu field down to the Detroit terminals but this will wane with the loss of daytime heating. The high pressure tracks across southern Ontario this evening and into the eastern Great Lakes Monday morning, causing light wind to veer from northeast to east tonight and to southeast/south on Monday. Several models continue to hint at some additional moisture flux off Lake Erie spreading toward DTW during the early morning hours. This suggests a low probability for patchy fog in the vicinity, but the very dry air mass continues to favor prevailing VFR. SKC carries through much of Monday with dry ridging retaining influence over the area.

DTW THRESHOLD PROBABILITIES...

* Low for ceilings aob 5000 ft early Monday morning.

DTX WATCHES/WARNINGS/ADVISORIES

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