249
FXUS63 KDTX 271000
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
600 AM EDT Mon May 27 2024

.KEY MESSAGES...

- Cooler for Memorial Day with scattered morning showers and a few
  thunderstorms transitioning to mainly dry and breezy conditions
  this afternoon.

- Continued unsettle tonight into midweek with periodic showers and
  average to below average temperatures in the 60s to lower 70s.

&&

.AVIATION...

A strong low pressure system sitting overhead with a pool of cold
air aloft will bring deteriorated conditions across the region
today. Pre-12Z area of convection should be pushing off to the NE by
12Z and most likely heavy showers. A cold front will then sweep
through early this afternoon ushering in a drier airmass and gusty
WSW winds to around 25 knots. Model guidance keep low MVFR CIGS
through the day and into the overnight which seems reasonable
looking at the current observations over southern WI which will be
pulled through the local area this afternoon. A secondary cold
front/trough rotating around the low will sweep southward through
lower MI tonight offering the next round of showers.

For DTW/D21 Convection...Thunderstorms should be over by 12Z as
lightning has already decreased significantly between 09-10Z.
Remaining showers will come to an end around 12Z with dry conditions
the remainder of the day. Next round of showers comes late tonight
into Tuesday morning on the next front.

DTW THRESHOLD PROBABILITIES...

* Low in thunderstorms after 12Z this morning.

* High in ceilings aob 5000 feet today and tonight.

* Low in crosswind thresholds being exceeded Monday afternoon.

&&

.PREV DISCUSSION...
Issued at 309 AM EDT Mon May 27 2024

DISCUSSION...

Scattered showers and a few thundestorms will pivot through the area
this morning as an upper level shortwave and associated low pressure
lifts into northern lower MI and a cold front wraps west to east
through the area. Mainly dry conditions are expected for much of the
afternoon with gusty westerly winds as the cooler air is ushered in
behind the front.

Showers will pivot back southeast into the area this evening into
tonight and persist into Tuesday as this upper level system opens
and shifts back through the area on its way to the eastern Great
Lakes. A fast moving Pacific shortwave will merge with this MI
system tonight and help re-invigorate the rain shower potential to
some degree and will increase pops just a bit overnight into early
Tuesday.

In the meantime, an upper low pressure system positioned east of
Lake Winnipeg will pivot southeast into the area in the wake of both
of these merging upper waves from Tuesday into Tuesday night. This
will result in a continuation of unsettled weather with periodic
scattered showers into early Wednesday. As the colder upper level
core of this northern stream system works over the area, instability
will increase enough to warrant a thunderstorm mention as well.
While this will be most prevalent during peak heating from Tuesday
afternoon into early evening, a small chance of a thunderstorm or
two will persist overnight Tuesday night into early Wednesday as the
upper low/trough crosses the area.

Thereafter, upper ridging will expand into the area late this week
once the upper trough that results from these various shortwaves
shifts off to the east. This will bring dry conditions from late
Wednesday on through at least Friday with temperatures gradually
moderating from the mid 60s to lower 70s in the Tuesday-Thursday
time frame back into the middle 70s by Friday.

By next weekend, the surface high pressure system that coincides
with the upper level ridge will shift off to the southeast with
south to southwest flow becoming established over the area. This
will lead to further warming with high temperatures into the upper
70s to lower 80s. By this point in the forecast, the next stream of
Pacific origin shortwaves begin to impact the Great Lakes and this
brings a return of at least scattered/widely scattered shower and
thunderstorm chances.

MARINE...

After a lull in winds early today, expect southwest to west winds to
increase again this afternoon into tonight as a cold front pivots
east through the area around low pressure to the north. Small Craft
Advisories are in effect in anticipation for this increase in wind
speed with wave heights responding as well. These gusty conditions
will be slow to subside over Saginaw Bay and the tip of the Thumb
where an advisory will continue into Tuesday. Cooler and unsettled
conditions will prevail into midweek with periodic showers and a
stray thunderstorm possible into Tuesday night as a secondary upper
level disturbance sweeps southeast across the central Great Lakes in
the wake of the current low pressure as it moves off to the east.

HYDROLOGY...

Periodic scattered showers and a few thunderstorms will impact the
region into Tuesday night and early Wednesday. Additional rainfall
will generally remain light to occasionally moderate. However, a few
localized downpours early this morning may bring one quarter of an
inch of rain to some locations. Otherwise, the highest precipitation
totals of one quarter to one half an inch from tonight into Tuesday
night and Wednesday morning will focus especially over the Saginaw
Valley and Thumb regions with perhaps one to two tenths of an inch
possible further south. Rises on local rivers associated with Sunday
evening rainfall will peak and subside today into tonight with this
additional early week rainfall having little to no additional
impact.

&&

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

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

     Small Craft Advisory from noon today to 4 PM EDT Tuesday for LHZ422.

Lake St Clair...Small Craft Advisory from noon today to 4 AM EDT Tuesday for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory from noon today to 4 AM EDT Tuesday for LEZ444.

     Low Water Advisory from 2 PM this afternoon to 11 PM EDT this
     evening for LEZ444.

&&

$$

AVIATION.....DRK
DISCUSSION...DG
MARINE.......DG
HYDROLOGY....DG


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