Dearborn, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

248
FXUS63 KDTX 122338
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
738 PM EDT Wed Mar 12 2025

.KEY MESSAGES...

- Dry conditions will prevail tonight through Friday.

- Warming trend Thursday into Saturday with above normal
temperatures.

- Windy conditions are expected Saturday, with gusts over 40 MPH.

- There is a chance of thunderstorms late Friday night and then
again Saturday and Saturday night.

&&

.AVIATION...

Surface ridging will remain in place tonight allowing strong static
stability in the lowest 12.0 kft agl and a dry airmass to maintain
VFR conditions. The combination of the surface ridge breaking down
locally and passage of a mid-upper level anticyclone through the
OH/TN valleys will result in a very quick development of southerly
flow Thursday. Model data shows higher thetae content in the lower
atmosphere surging northward quickly after 15Z. Likely that some
areas will have a ceiling below 5.0 kft agl but low confidence
exists in location and coverage. Modest east wind is anticipated
throughout the period.

.DTW THRESHOLD PROBABILITIES...

* Low for ceilings aob 5kft late Thursday morning.

&&

.PREV DISCUSSION...
Issued at 304 PM EDT Wed Mar 12 2025

DISCUSSION...

Strong mid level confluence will linger over the eastern Great Lakes
into Thursday. Subtle mid level height rises will also persist
across Lower Mi. This will sustain the ridge of sfc high pressure
across the region into late Thursday. Satellite trends are
indicating diurnal mixing helping erode some of the daytime cloud
cover across Se Mi. Shallow isentropic ascent focused along the
290K surface will also lift north and east of the area during the
evening. The result will be mainly clear skies tonight. The easterly
flow will weaken during the night. This and the dry low levels will
support decent radiational cooling tonight, warranting lows into the
20s. Diurnal heating amidst ample sun, a slight rebound in the low
level thermal fields and a weaker easterly flow off the lakes will
drive temps into the 50s on Thursday, with cooler readings near the
lakes.

The main feature of interest will be a large dynamic system to
affect much of the central and eastern US Friday through the weekend
within a highly amplified flow. A deep compact mid level wave will
emerge from the southern Rockies into the central Plains on Friday
and will support rapid sfc cyclogenesis as it lifts north-northeast
to the Upper MS Valley/wrn Great Lakes by Saturday. In response, low
level southerly flow will increase across the Great Lakes Thurs
night into Friday. Shallow moisture advection will result in
periodic clouds. 925mb temps are forecast to rise toward +10C by
Friday afternoon. Model soundings suggest enough diurnal mixing to
boost afternoon highs well into the 60s. Southeast winds at the sfc
will maintain cooler readings near the lakes. A narrow axis of deep
layer moisture is forecast to track across Se Mi overnight Fri into
early Saturday morning associated with the occlusion of the
aforementioned sfc low. Steep mid level lapse rates within this theta e
plume will result in 0-3km MU CAPE values potentially up to 1k J/kg.
This will warrant a chance of thunderstorms with high probabilities
for showers.

By Saturday morning, the central pressure of the sfc low is forecast
to be around 978 MB in the Wisconsin/Minnesota border region. The
mid level dry slot associated with this occluded system is forecast
to move across Lower Mi by Saturday afternoon. Given the compact
nature of the occluded low, there will be a strong warm sector wind
field associated with this system (40-50 knots between 925 and
850mb). The strength of the wind gusts Saturday will hinge on the
mixing depths. If a stronger inversion develops in the wake of the
early morning rain, the strongest winds are likely to remain
elevated. However, if mixing depths are able to eclipse 5k feet,
southerly wind gusts over 45 MPH will be highly probable. The
majority of ensemble members are supportive of a better mixed
profile, warranting forecast highs near 70 with gusty winds. Both
the NAM and GFS drive a plume of weak instability (sfc based CAPE
just under 1k J/kg) into Se Mi Saturday afternoon. Despite the weak
instability, this could pose a severe wx risk in light of the strong
shear profiles. One caveat may be a potential capping inversion.
This potential will have to be monitored the next few forecast
cycles.

A secondary mid level wave lifting out of the base of the longer
wavelength trough over Texas and excellent upper jet coupling will
invoke upscale convective growth across the TN and OH Valleys
Sat/Saturday night. Embedded mid level short wave impulses
originating from this convection is forecast to lift nearly due
north into the eastern Great Lakes. There has been uncertainty
within the model solution space with respect to how far west some of
the more intense elevated convection reaches into Se Mi Sat night.
Probabilistic guidance suggest high probabilities of showers (70-80%)
but low chances (<20%) for heavier convective rain amounting to over
an inch QPF at this stage in the forecast.

The occluded low will lift north into Ontario Sat night and phase
with a northern stream wave, resulting in a closed over Manitoba/nrn
Ontario Sun night. Colder air (850mb temps down to -10C) will
overspread Se Mi Sunday in the wake of the associated occluded
front. With 30 knots in the mixed layer, it will be another windy
day. The cold air intrusion will be very progressive as rebounding
heights and southerly flow will drive warmer air back into Se Mi next
week.

MARINE...

Gradient over the region weakens this evening and remains diffuse
through Thursday maintaining lighter winds (less than 15kts) across
the central Great Lakes. Southeasterly winds strengthen over the
course Friday in response to strong low pressure lifting out of the
Plains to the northlands of MN. Strongest gusts develop late Friday
night-early Saturday morning persisting through Saturday afternoon
as the low crosses MN. As is typical this time of year with the cold
lake waters, stable thermal profiles over the lakes are expected to
hamper mixing and subsequent gale potential. Despite 45-55kt flow
expected down to 1.5kft agl, model profiles advertise very stable
conditions near the lake surface keeping forecast peak gusts ranging
from around 30kts to borderline gales. Local probabilistic guidance
current suggests only around a 20% chance to reach 34kts. System
also brings widespread showers as well as a few thunderstorms,
particularly towards Lakes Erie & St Clair, daytime Saturday.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....CB
DISCUSSION...SC
MARINE.......KDK


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