886
FXUS63 KDTX 010413
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1213 AM EDT Sat Jun 1 2024

.KEY MESSAGES...

- Dry weather continues most of today. The next chance for rain
  arrives this evening through Sunday morning.

- The weekend finishes dry and warm Sunday with highs near 80.

- Potential for multiple rounds of showers next week.

&&

.AVIATION...

Expecting VFR conditions to prevail through this evening. High
clouds will be increasing throughout today in advance of a low
pressure system as winds hold out of the south to southeast at
around 10 knots or less. Rainfall expands across southeast Michigan
after 00Z this evening. It looks like VFR will largely prevail as
rain moves through, but any heavier showers may reduce
ceilings/vsbys toward borderline MVFR at times during the overnight
period. Increase in moisture will also bring possible MVFR ceilings
after 06Z early tomorrow morning.

For DTW/D21 Convection...Low chance for thunderstorms towards the
end of this TAF period. Instability upon the arrival of
precipitation should keep thunderstorm potential limited.

DTW THRESHOLD PROBABILITIES...

* Low for thunderstorms this evening and tonight

* Low or ceilings at or below 5,000 feet this evening.

&&

.PREV DISCUSSION...
Issued at 318 PM EDT Fri May 31 2024

DISCUSSION...

Clear skies have pushed temperatures into the upper 70s this
afternoon, slightly above normal for the end of May. Dry conditions
persist through the rest of the day into tonight. Overnight lows
will depend on timing and extent of clouds moving in, but with
enough time under clear skies, full radiative cooling could push
temperatures down to the low 50s.

Upper level ridge supporting the high pressure center moves out
beginning Saturday and a shortwave trough brings the next chance for
precipitation. Profiles remain very dry Saturday morning, with only
high clouds moving in at first. Southerly flow helps advect moisture
into the lower levels, slowly saturating the profile and lowering
ceilings as the day progresses. Temperatures Saturday will be a bit
inhibited by increasing cloud cover through the day, but the
aforementioned southerly flow also provides some warm air advection
to heat up to the mid-70s. The gradual saturation process keeps the
rain at bay until the late afternoon/evening, but pushes PWAT values
from below a half inch in the morning Saturday to 1.5 inches or
greater early Sunday morning. Little to no significant CAPE makes
its way into the area for this event, and the atmosphere remains
relatively stable. As such, thunderstorms look unlikely, although a
stray rumble of thunder may pop up.

Storm total QPF amounts will generally be greater in the southern
part of the CWA, with some areas seeing over a half inch of rain,
mainly in Lenawee and Monroe counties. Strong theta-e advection
along a 30 knot low-level jet provide some potential for excessive
rainfall with this setup. Hi-res models have yet to fully resolve
the end of the rainfall on Sunday, but since solutions have tended
to keep the system moving, concerns for excessive rainfall are not
strong at the moment.

Cloud cover keeps the temperature swing down on Sunday, with lows
Saturday night into Sunday morning staying up in the 60s and highs
cooling down slightly Sunday afternoon reaching the low to mid 70s.
Clearer conditions return on Monday as a brief ridge provides some
relief from the rain. Southerly flow continues to keep temperatures
high Monday with potential to touch 80 degrees across the CWA in
spite of advancing cloud cover from the next storm.

Upper level shortwave develops another low pressure center over the
northern Great Plains and brings it northeast into western Ontario
Monday evening. This system brings with it the possibility for
additional light rain for the CWA Tuesday morning as a warm
front moves across the region, but guidance suggests that the
strongest forcing, coming from the system`s cold front, will remain
to the north. Ensemble runs give a third of an inch of rain as a
reasonable upper limit for this event with this much lead time.

Behind Tuesday`s system a large negatively tilted longwave trough
begins to take shape, likely bringing multiple rounds of
showers for the end of the week. A very tight gradient in the
upper levels will bring strong flow aloft, over 100 knots at 500mb,
as well as a streak of high relative vorticity. Should this system
set up the right way, temperatures will drop significantly as the
center of the upper level low drops 540-550dam heights at 500mb into
the Great Lakes area in addition to the aforementioned
rain.

MARINE...

High pressure continues to influence the area through early Saturday
as it gradually drifts toward the mid-Atlantic. Low pressure
lifting into northern Ontario drags a cold front into the Great
Lakes Saturday as a secondary area of low pressure develops along
this boundary over the western Ohio Valley. Secondary low is set to
track northeast into southern Great Lakes late Saturday into the
first half of Sunday bringing widespread shower chances. A
thunderstorm or two remain possible from roughly Port Huron south.
Diffuse pressure gradient however results in generally lighter winds
(below 20kts) with this system. Weak high pressure then briefly
builds in late Sunday and Monday.

&&

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

$$

AVIATION.....AA
DISCUSSION...BC
MARINE.......KDK


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