743
FXUS63 KDTX 010925
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
525 AM EDT Mon Jul 1 2024

.KEY MESSAGES...

- Pleasant conditions today with mostly sunny skies and lower humidity,
  with temperatures slightly below average.

- Seasonable conditions Tuesday as clouds thicken through the day.

- Potential for showers to develop Tuesday night, with isolated
  thunderstorms. Chance of showers and thunderstorms will continue
  into Wednesday as conditions turn more humid.

&&

.AVIATION...

High pressure remains firmly in place today maintaining clear or
mostly clear skies. Winds hold under 10 knots and gradually veer
from northerly this morning to easterly by evening.

For DTW/D21 Convection...Thunderstorms are not expected during the
upcoming forecast.

DTW THRESHOLD PROBABILITIES...

* None.

&&

.PREV DISCUSSION...
Issued at 308 AM EDT Mon Jul 1 2024

DISCUSSION...

Deep layer stability held within existing low-mid level ridging
offers benign weather conditions today. Limited moisture quality
throughout the column lends to a high degree of insolation
potential. Veering low level flow from northeast to east maintains a
neutral pattern for thermal advection, so any airmass modification
generally reliant on the underlying increase in mean thickness
readings as upper heights build combined with the mostly sunny
skies. Ideal conditions overall for the first day of July, as peak
afternoon temperatures of mid 70s combine with continued lower
humidity.

Pervasive ridging slow to relinquish control Tuesday, as the local
area holds position well downstream from ongoing deeper moisture
transport and corresponding convective activity over the upper
midwest. Thickening high cloud deck with time as mid level moisture
funnels downstream, but with minimal potential for shower
development through at least the daylight hours given magnitude of
dryness remaining below 700 mb. A few high based showers/sprinkles
plausible toward over central lower mi as emerging mid level
southwest flow directs higher moisture quality into northern lower.
Elevated upper height field atop prevailing low level south-
southeast flow further moderates the existing airmass, despite some
reduction in diabatic heating given thickening cloud. Highs arriving
right at average.

Shortwave energy lifting through broadening mid level southwest flow
will lead in a period of modest height falls Tuesday night and
Wednesday. This process will ease a weak frontal boundary through
the region, offering some degree of upward vertical motion within
this window. Southeast Michigan still largely outside the axis of
greater forced ascent and moisture transport overnight, as upscale
growth of late day midwest activity tends to propagate toward the
northeast with a greater focus over western/northern lower Mi. There
does remain some potential for areas particularly north of I-69 to
witness a more widespread, elevated convective episode late Tuesday
night/early Wednesday depending on exact trajectory.  Further
refinement of precipitation chances within the 06-12z early Tuesday
morning window likely as confidence in positioning of inbound
activity improves. Forecast continues to highlight a chance of
showers and thunderstorms Wednesday as a weak frontal passage
lacking in meaningful convergence attempts to engage a moistening
and gradually destabilizing boundary layer. Those model projections
for an early day frontal passage certainly lessens the risk for a
more vigorous convective response. Highs tentatively projected for
the 85 to 90 degree range /highest southeast/ per latest NBM output.
Above average warmth with elevated humidity then expected for the 4th
of July holiday and into Friday. Convective potential generally ill-
defined yet at this stage, but the underlying airmass lends to some
chance depending on realizing meaningful forced ascent.

MARINE...

A high pressure center slides overhead today, gradually veering
winds from the northwest this morning to southeast by this evening.
Deep layer ridging ensures low magnitude winds through much of the
column, capping gusts at 15 knots. These conditions hold for most of
Tuesday with the next impactful weather system arriving Tuesday
night. Gusts to increase Tuesday afternoon-evening with shower and
thunderstorm chances overspreading the marine zones, especially the
northern half of Lake Huron, late Tuesday night. Unsettled
conditions continue Wednesday as a weakening cold front slowly drags
across SE Michigan before settling just south of the Michigan state
line.

&&

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

$$

AVIATION.....KDK
DISCUSSION...MR
MARINE.......MV


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at www.weather.gov/detroit.