Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 281740
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
140 PM EDT SAT MAY 28 2016

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 315 AM EDT Sat May 28 2016

Scattered showers and thunderstorms can be expected today and
Sunday. Some of the storms on Sunday could have small hail and
strong gusty winds. Memorial Day should be fair with lower
humidity.

&&

.SHORT TERM...(Today through Monday)
Issued at 315 AM EDT Sat May 28 2016

Moist southerly flow continues today as low center tracks well to
the west of Lower Michigan. Once again there is not much to focus
convection despite another day of modest instability. Low or
slight chance POPs will cover it through tonight.

The low moves north of the Lakes on Sunday with weak sfc cold
front coming through in the afternoon around the diurnal peak of
instability. Instability and shear profiles are not really that
impressive so the severe threat is limited. MUCAPES are generally
around 1000 j/kg and 0 to 6 km shear is only around 25 knots
during the expected time of the event.

Once the storms go through, drier and slightly cooler air moves in
Sunday night and Memorial Day looks to be a pretty nice day.

.LONG TERM...(Monday night through Friday)
Issued at 315 AM EDT Sat May 28 2016

Temperatures will continue to average around 5 to 10 degrees above
normal through at least the middle portion of next week. There is a
chance of showers and thunderstorms on Tuesday well out ahead of an
approaching upper level disturbance and cold front.

The best chance for showers and thunderstorms will come Wednesday
through Wednesday night along and out ahead of the cold front and as
an upper level trough moves east into the Great Lakes region. A
slightly cooler and drier airmass should move in behind that system
for late next week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 140 PM EDT Sat May 28 2016

The few showers and isolated storms that were floating through
earlier have moved out for the time being. The mid cloud deck that
has been over the area this morning is now breaking up and
allowing more sun to break through. This heating will provide for
a bkn cumulus deck this afternoon with a few pop up showers and
isolated storms developing inland. These should diminish toward
00z.

The moist air mass in place and front coming in will bring a good
chance of some fog/stratus across the area later tonight. The
winds aloft holding up would favor a stratus deck. We have gone
with a sct002 and some haze for now with somewhat limited
confidence in the coverage of it. Any fog/stratus should dissipate
by mid morning.

Finally, the front will move through tomorrow afternoon. This will
potentially pop some showers/storms ahead of it. The favored area
will be South and East where the front will be during peak
heating. We have VCTS in for all sites except KGRR and KMKG
tomorrow afternoon.

&&

.MARINE...
Issued at 1133 AM EDT Sat May 28 2016

Have upgraded to a Small Craft Advisory and Beach Hazards
Statement for nearshore waters and beaches north of Grand Haven.
Winds have already been gusting above 20 knots this morning at
Manistee Harbor, Big Sable Point, and Muskegon. Winds are expected
to increase a bit more and peak in the 16-20z timeframe with gusts
up to 30 knots. Waves of 3 feet were reported early this morning
at northern beaches, so the potential is certainly there for a
sustained period of 3-5 footers this afternoon and evening. Winds
and waves will subside a bit late tonight.


&&

.HYDROLOGY...
Issued at 109 PM EDT Sat May 28 2016

River levels across the area are near to just above their expected
values for this time of year. Precipitation of up to an inch is
possible over the next week. Convection through the weekend will
produce mainly localized heavy rainfall. Rises will mainly be
confined to smaller creeks and streams and should not reach flood
levels.

&&

.GRR Watches/Warnings/Advisories...
MI...Beach Hazards Statement until 10 PM EDT this evening for MIZ037-
     043-050.

LM...Small Craft Advisory until 10 PM EDT this evening for LMZ847>849.

&&

$$

SYNOPSIS...Ostuno
SHORT TERM...Ostuno
LONG TERM...Laurens
AVIATION...NJJ
HYDROLOGY...63
MARINE...EBW



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