Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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FXUS63 KDTX 241103

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
703 AM EDT TUE MAY 24 2016


The influence of high pressure will linger over SE Michigan today as
the center drifts farther from the Great Lakes. The result will be
ideal aviation conditions to start the day with light southwest wind
and only a few streamers of cirrus to combine with a few cumulus
during the afternoon. The departure of high pressure today will make
room for a front to settle into central lower Michigan tonight.
There is a chance of VFR showers along this boundary in the MBS area
overnight into Wednesday morning.

FOR DTW...Light southwest wind will favor preferred southwest
traffic flow operations today. Few to scattered coverage of shallow
cumulus may have bases around 5 kft to start before rising higher by
mid afternoon.

//DTW Threshold Probabilities...

* None


Issued at 314 AM EDT Tue May 24 2016


Very dry air mass still locked in over southeast Michigan...per
latest water vapor imagery and 00z DTX sounding. Still looking at
highs in the low to mid 80s today (increased confidence based on
yesterdays results at FNT/MBS) with strengthening low level
southwest flow ahead of a cold 850 mb temps rise into the
the mid teens (00z apx and GRB both showed 15 c at 850 mb). Upper
wave/jet energy working through Minnesota this morning lifting
northeast into Lake Superior today and into Ontario this
evening...helping to flatten the upper level ridge in place
slightly...but still questionable whether we will see any
shower/thunderstorm activity tonight as the moisture axis/plume
folding over into the Central Great Lakes constricts and weakens.
Still...there is narrow ribbon of negative showalter values north of
M-59 with frontal boundary which supports low chance pops. low level
frontal boundary to hang up and wash out over the CWA on
Wednesday...with some semblance of upper level ridge re-establishing
itself during the day...tending to cap/suppress activity...and
probably will have to wait until Wednesday night when warm front and
better surge of moisture arrives from the Midwest to support
scattered-numerous shower and thunderstorm activity. With less
activity expected during the daytime...temperatures should have no
problem rising at least in the lower 850 mb temps hover
near 15 C.

Southern Lower Michigan then looks to be caught in between upper
level ridge along the Eastern Seaboard with trough out over the
Rockies...leading to warm/unstable/moist southwest flow Thursday,
Friday, and right into the weekend...with daytime instability
becoming MLCAPES advertised to reach between 1000-2000
j/kg per blend of GFS/Euro/Canadian models. To far out to access
possible caps/lake breezes and timing of upper level impulses as we
reside in the ring of fire around the outer fringe of the ridge
axis...but stand a good chance of seeing periodic showers and
thunderstorms during the Thursday-Sunday time frame with the ample
moisture in place. Not much change in air mass will support highs
in the low to mid 80s...but better coverage or early initiation
time of activity could lead to cooler highs.


Generally light southwest wind will develop today over marine areas
ahead of low pressure moving through northern Ontario and as high
pressure continues to exit the Great Lakes. This will bring milder
air into the region that will interact with a cold front and produce
scattered showers and thunderstorms as the front settles into
northern Lake Huron tonight. The front is expected to reach the
south end of Lake Huron by Wednesday evening and leave a light wind
shift to the north. The main concern with this boundary will be
expanding coverage of showers and thunderstorms Wednesday night as
low pressure develops in the plains and pulls the front back
northward while supplying increasingly warm and humid air. Light to
moderate southerly flow will then develop all areas during Thursday
as the front clears the north portion of Lake Huron. A persistent
light south wind will then maintain warm and humid air over the
region into the weekend.


Warm air with increasing humidity will produce a chance of rain over
SE Michigan beginning tonight and persisting through the Memorial
Day Weekend. The greatest coverage and intensity of showers and
thunderstorms is expected Wednesday night as a cold front settles
into the region, stalls, and then returns northward Thursday.
Rainfall amounts are expected to vary widely depending on
thunderstorm coverage but should average 0.25 to 0.5 inch for the
Wednesday night-Thursday period with locally higher totals near 1
inch possible in thunderstorms. Warm and humid air will then remain
in place to support shower and thunderstorm potential into the
weekend with lower probability until arrival of the next front
possibly by Saturday.


Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.



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