Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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FXUS63 KDTX 161932
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
332 PM EDT Sun Jul 16 2017

.DISCUSSION...

Cold front now in process of slipping south of the border, with
surface riding and lower dew pts (note 50s in northern lower
Michigan) working in for the early evening hours, ending any
thunderstorm chances. Low clouds which have plagued area for much of
the day should also/are in the process of dissipating from west to
east, setting up favorable radiating night with mins in the mid 50s
to around 60 degrees.

Good start to the work week weatherwise, as large upper level ridge
centered over the Central Plains tracks East. The associated ridge
axis will fold over Lower Michigan Monday Night. Weak wind field
around on Monday, along with some diurnal flat cu, but should see
highs predominatly in the upper 70s to around 80 with 850 mb temps
around 12 C, slightly cooler northern Thumb region with onshore
northeast flow.

The ridge axis expected to hold through Tuesday Night, as dry and
warm mid levels around 11 C at 700 MB are in place. However, upper
level jet energy tracking through Lake Superior and flattening ridge
will allow for a good surge of moisture to arrive on Wednesday, as
PW values increase to values just short of 2 inches, but cold front
tending to wash out, as more potent shortwave tracks through
northern Plains/Minnesota. Highs in the 80s on Wednesday, lower vs
upper 80s dependent on cloud cover and coverage of potential
showers/thunderstorms.

The unsettle pattern continues through the extended period, starting
with another round of hot and muggy with a side of scattered showers
and thunderstorms for mid-week. It`s the scenario that keeps
repeating; a weak upper level trough drops through SE Michigan and
combines with a poorly defined surface short wave. At present, not
expecting much from this system outside of showers and garden
variety thunderstorms. Thursday morning shows the best potential for
rain, with pops getting a boost into the 40 percent range. Behind
this system, another broad surface high is expected to move across
from the North Central Plains providing dry weather and a sunnier
sky condition. The rewind button gets pushed for Saturday as chances
for rain return.


&&

.MARINE...

Onshore flow behind a passing cold front will bring a period of
elevated winds to the nearshore waters of Lake Huron. Significant
wave heights of 3 to 5 feet are anticipated in Saginaw Bay and along
the Thumb. Light to moderate winds expected for the remainder of the
week.

&&

.PREV DISCUSSION...
Issued at 105 PM EDT Sun Jul 16 2017

AVIATION...

Blanket of low VFR and MVFR stratus is filling into the area behind
a cold front that is currently approaching KPTK at 17z and is easily
identified by light radar returns. Fropa will be accompanied by a
wind shift from W to NW followed by gradual veering to NE as high
pressure builds into the west. Immediate Detroit area may see a
brief window of convective development prior to 20-21z fropa but
with instability lacking so far prospects are diminishing. Stratus
will gradually erode from north to south tonight into Monday morning.

//DTW THRESHOLD PROBABILITIES...

* High for cigs aob 5kft.

* Low for tstorms to impact KDTW. Medium for tstorms in southern
  portions of the airspace after 20z.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until midnight EDT tonight for MIZ049.

Lake Huron...Small Craft Advisory until midnight EDT tonight for LHZ421-422-441-
     442.

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

$$

DISCUSSION...SF/DE
MARINE.......JVC
AVIATION.....JVC


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.



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