207
FXUS63 KDTX 111720
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
120 PM EDT Tue Jun 11 2024

.KEY MESSAGES...

- Warming trend through mid-week with high temperatures possibly
  reaching 90 degrees for Thursday.

- The next chance for rain and thunderstorms will be Thursday.
  Isolated strong to severe thunderstorms will be possible with a
  Marginal Risk in place across much of southeast Michigan.

- Higher than usual confidence in hot and humid conditions early
  next week. Temperatures into the 90s Monday and Tuesday with
  relatively high humidity will likely bring the highest heat indices
  we have seen so far this year.

&&

.AVIATION...

VFR conditions are expected through the rest of the forecast as both
high and low clouds currently approach the area. Low clouds come
from developing diurnal cumulus making its way northeast. Confidence
is low on the final areal extent of this cloud deck before it
dissipates later today. High cirrus from the west continue to make
their way southeast through this evening and tonight. Ceilings will
gradually lower overnight as a cold front moves closer to the area
through Wednesday. No rain is expected to impact the CWA with this
system, with ceilings reaching 5000 feet at their lowest tomorrow.

For DTW/D21 Convection...Thunderstorms are not expected through the
TAF period.

 DTW THRESHOLD PROBABILITIES...

* Moderate for ceilings aob 5000 feet Wednesday afternoon.

&&

.PREV DISCUSSION...
Issued at 400 AM EDT Tue Jun 11 2024

DISCUSSION...

Clear skies and calm winds overnight with the cooler airmass in
place will allow for a somewhat chilly start to this morning. Observed
morning temperatures at many locations are down into the 40s.
Expecting mostly clear skies through the majority of today as an
upper ridge axis passes over the Great Lakes today. A surface high
pressure will also slide east of the state allowing for a moderating
south-southwest wind. Expecting high temperatures to respond under
full insolation through much of peak heating and climb into the low
to mid 70s.

Mid level trough will arrive on the heels of the exiting ridge axis
tonight, which will likely be supporting upstream convection this
evening along an advancing frontal boundary. Here in southeast
Michigan, we will see increasing high clouds late today ahead of
this activity. Precipitation associated with this frontal boundary
is expected to weaken as enters western Michigan and encounters the
resident dry lower levels. Any remnant high based showers
continuing to drift east into southeast Michigan should struggle to
reach the surface with these dry low levels. Will maintain a dry
forecast for tonight given the underlying environment.

The passing of this trough will mark the beginning of notable
warming and increasing moisture trends Wednesday into the late week
period. Strong mid/upper level westerly flow will drive 850 mb
temperatures upwards of 16C into Michigan for Thursday. Dewpoints
are also forecast to climb above 60 degrees with PWATs to around
1.50 inches. This will make for a hot and muggy day as daytime highs
reach into the mid/upper 80s with 90 degrees achievable across the
urban heat island of Detroit. This will also lead to moderate
instability in place with MLCAPEs to around 1000 J/kg forecast
during the afternoon ahead of a southward moving cold front. Deep
layer shear will improve over southeast Michigan on the southern
edge of a strong 70+ knot mid-level jet. The progged environment
would be support a severe thunderstorm threat with any cluster of
thunderstorms that develop ahead of the advancing front in this
unstable environment. A Marginal Risk for severe weather is in place
for Day 3.

There is higher than usual confidence in hot and humid conditions
early next week as a broad ridge builds across the central and
eastern CONUS. This will also bring fairly high confidence in dry
conditions for the weekend as return flow on the back of the passing
ridge ushers in 850 mb temperatures reaching upwards of 20C during
the early week period. Several ensemble members pointing towards
temperatures into the 90s across all of southeast Michigan for Monday
and Tuesday. The accompanied increase in moisture will likely result
in the highest heat indices we have seen so far this year.

MARINE...

High pressure builds southeast into the Ohio Valley today promoting
weak flow across the central Great Lakes. The ridge of high pressure
will migrate eastward Wednesday offering a return-flow setup,
veering winds southerly as the gradient slowly becomes more
established into the second half of the week. A low pressure system
is projected to arrive late Thursday into Friday which could support
a period of Small Craft Advisory conditions with several
opportunities for showers and thunderstorms.

&&

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

$$

AVIATION.....BC
DISCUSSION...AA
MARINE.......KGK


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