769
FXUS63 KDTX 280009
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
809 PM EDT Mon May 27 2024

.KEY MESSAGES...

- Additional showers and a few thunderstorms return to the area
  tonight and Tuesday as unsettled conditions persist.

_ There remains a chance of showers Tuesday night into Wednesday,
  before drier conditions return to finish the work week.

- Temperatures will remain near to below average throughout the
  midweek period.

&&

.AVIATION...

large upper level low pressure system and cold air aloft will bring
periodic rain showers to Southeast Michigan throughout the taf
period. Two time periods of specific interest for more organized
precipitation potential. The first one is this evening for the
northern taf sites as deformation forcing will dig through the
region. The second time period of interest will be after 19Z Tuesday
as diurnal heating will lead to instability showers and possible
thunderstorms over Southeast Michigan. Prevailing MVFR ceilings
heights with stratus is expected.

For DTW/D21 Convection...There is a chance of thunderstorms Tuesday
afternoon. Confidence is low on coverage and timing.

DTW THRESHOLD PROBABILITIES...

* High in ceilings aob 5000 feet tonight and Tuesday.

&&

.PREV DISCUSSION...
Issued at 323 PM EDT Mon May 27 2024

DISCUSSION...

Larger scale pattern will lend to unsettled conditions over the next
48 hours, as episodic bouts of meaningful height falls occur within
broader upper level troughing. Holiday weekend ending on a cool/damp
note as expansive region of low level moisture translates into some
areas of light rain/drizzle late this afternoon. Plume of deeper
moisture looming just to the northwest will pivot back into
southeast Michigan through the course of the night, lead by veering
low to mid level flow toward the northwest in the wake of a trough
passage. Supportive upward vertical motion as the advective process
engages ongoing dcva will bring an increase in shower coverage
through the evening hours, mainly north of I-69. Some degree of
southward expansion possible with time overnight as forced ascent
improves upon arrival of the mid level wave noted on water vapor
ejecting across MN/IA.

Daytime heating offers a diurnal boost to convective shower/t-storm
potential Tuesday, as lapse rates steepen modestly within the
background of a perturbed mid level environment and sufficient
moisture depth. Overall convective vigor muted by lack of greater
instability, but a few instances of small hail plausible with the
healthiest late day convective cores given the suppressed freezing
levels. A more seasonable late May thermal profile now entrenched -
highs 70-75F. Stronger mid level wave of central Canadian origin
arrives Tuesday night. Greater corridor of dcva may remain just
south and west given a southeast trajectory, but at least a glancing
shot of meaningful forced ascent maintains a higher probability for
shower production lasting into early Wednesday morning.

A notably cooler airmass funnels into the region Wednesday as
northerly flow attains greater depth with time. Daylight readings
holding in the 60s, with some upper 50s in the thumb region given
the trajectory off lake Huron. Pace of accompanying dry air
advection dictates whether one final round of convective showers
ultimately emerge with daytime heating, greater potential would
exist with southward extent. High pressure governed conditions then
take control for the late week period, offering a stretch of
tranquil wx and seasonable temperatures.

MARINE...

Upper low and weakening surface reflection migrate over northern
lower Michigan this afternoon, maintaining shower chances for the
northern half of Lake Huron through tonight. Further south, passage
of a cold front earlier today has led to lighter and more scattered
showers in comparison to this morning. Overnight a second upper
wave, currently over Minnesota, dives toward the Ohio Valley which
effectively draws another round of showers into the Great Lakes by
early Tuesday morning. Western flank of the departing pressure
gradient also maintains gusty northwest flow of 20-25 knots. Small
Craft Advisories continue as a result. Unsettled and cooler weather
continues through mid-week until high pressure builds in from Canada
late week.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until 4 AM EDT Tuesday for LHZ442-443.

     Small Craft Advisory until 4 PM EDT Tuesday for LHZ421-422-441.

Lake St Clair...Small Craft Advisory until 4 AM EDT Tuesday for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory until 4 AM EDT Tuesday for LEZ444.

     Low Water Advisory until 11 PM EDT this evening for LEZ444.

&&

$$

AVIATION.....CB
DISCUSSION...MR
MARINE.......MV


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