507
FXUS63 KDTX 060712
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
312 AM EDT Mon Apr 6 2026

.KEY MESSAGES...

- Stretch of colder conditions will exist through Tuesday with
  temperatures remaining below normal during this time.

- Potential for a mix of rain and snow exists this afternoon into
  tonight. Brief higher intensity bursts of snow showers will be
  possible, with a dusting of accumulation on grassy surfaces in some
  areas.

- The next good chance for rain will be Thursday into Friday.

&&

.DISCUSSION...

General mid level troughing to remain a fixture throughout the early
week period. Latest water vapor analysis highlights two distinct,
minor perturbations propagating east-southeast into the broader
lower height anomaly. The first feature on pace to translate across
the local area this morning. Latest observational and radar trends
solidify current expectation for a focused, weak area of ascent to
provide a supportive environment for some pockets of very light
precipitation production thru mid morning. Subtle window here for
brief, modest warm air advection before another meaningful period of
cold air advection emerges this afternoon and evening as a
secondary, more potent shortwave shears through. Daytime heating
beneath a cold mid-level core at 500-700 mb will yield very steep
lapse rates across a deep layer. This environment will support a
scattered to numerous coverage of showers. Given lower wet-bulb zero
heights and weak low level instability, some heavier convective
bursts are plausible leading to brief instances of graupel or higher
intensity snow showers, even as temps peak in the 40s. Late day
gustiness to northwest wind into the 30 mph range.

Strongest period of cold air advection occurs tonight. This process
likely fuels additional light snow shower production, with
enhancement offered by some degree of convergence with the cold
frontal passage and a trailing surface trough migrating off lake
Huron. Highest probability will exist across the thumb. Minor
localized grassy accumulation at less than half an inch expected
given limitation in duration. Higher magnitude thermal advection will
lead to 850 mb temps below -12c by Tuesday morning. Lows in the low
to mid 20s. Coldest conditions of the week then noted throughout
Tuesday with the low level thermal trough in residence. Some
lingering stratus and possible flurries early in the day, before
increasing influence of encroaching high pressure offers greater deep
layer drying and stability. Highs Tuesday mainly in the 30s.

Notable shift in the larger scale pattern for the latter half of the
week, as the mean flow reverts back to Pacific origin. Modest height
rises will initiate a respectable warming trend starting Wednesday,
moderating temperatures back to near normal. Warm frontal boundary
will lift through sometime late Wednesday with little fanfare given
limited moisture quality, effectively establishing a meaningful
window for deeper warm air advection Wednesday night into Thursday.
This occurs as a dynamic mid level wave ejecting across the
US/Canadian border drags a slow-moving cold front into lower
Michigan. Backed by a greater influx of moisture under deeper pre-
frontal southwest flow, this will lead to a good chance of rain.
Eastward pace of the frontal boundary remains in question at this
stage as the boundary becomes increasingly parallel to the mean
flow. Outgoing forecast maintains a broader, more prolonged
opportunity for rain lasting into Friday. Further forecast revision
likely this period.

&&

.MARINE...

A weakening of the pressure gradient occurs this morning as a
clipper system tracks across the region. This system will excite
another period of cold advection late today through tonight and into
early Tuesday, with north to northwest wind increasing to the 15 to
25 kt range with brief gusts to 30 kt over Lake Huron. Small Craft
Advisories are in effect for the Lake Huron nearshore waters where
waves will build over 4 feet across the southern basin. High
pressure builds in briefly on Tuesday causing wind and waves to
subside. Flow then strengthens out of the south on Wednesday as the
next low pressure system tracks into the upper Midwest. This system
will send a slow-moving cold front across the Great Lakes Thursday
and Friday.

&&

.PREV DISCUSSION...
Issued at 1158 PM EDT Sun Apr 5 2026

AVIATION...

A pair of cold fronts will drop through the region overnight and
Monday afternoon providing two windows of light rain/snow and MVFR
conditions. The obs upstream with the front currently over southern
WI are not dropping much with many reporting VFR still. This will
affect the local region mainly before 12Z. A second stronger wave
will pass over the area Monday afternoon which will again present a
window to produce a rain/snow mix. There is better frontal forcing
which should result in a better organized band of precip sliding
through for a couple hours. More scattered activity will be possible
before and after the frontal band. MVFR CIGs and possibly VSBYs will
be possible with this activity.

DTW THRESHOLD PROBABILITIES...

*  Moderate for ceiling at or below 5000 ft initially but high again
   after 08Z through Monday.

*  Moderate for ptype to be rain/snow mix Monday morning and Monday
   afternoon.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 4 PM this afternoon to 10 AM EDT Tuesday
     for LHZ421.

     Small Craft Advisory from 4 PM this afternoon to 4 AM EDT Tuesday
     for LHZ422.

     Small Craft Advisory from 8 PM this evening to 4 PM EDT Tuesday for
     LHZ441>443.

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

$$

DISCUSSION...MR
MARINE.......TF
AVIATION.....DRK


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at www.weather.gov/detroit.