Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 280730
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
330 AM EDT WED SEP 28 2016

LATEST UPDATE...
Synopsis/Short Term/Long Term/Marine

.SYNOPSIS...
Issued at 330 AM EDT Wed Sep 28 2016

An expansive area of low pressure moving south through the Great
Lakes Region this morning will stall south of Michigan Thursday and
Friday then lift back north through the state over the weekend.
While it won`t be raining all the time, clouds and scattered
showers associated with this low will impact the area for the next
several days.

&&

.SHORT TERM...(Today through Friday)
Issued at 330 AM EDT Wed Sep 28 2016

Shortwave currently over srn Lk MI, rotating through the base of the
upper trough, will bring a bring a brief increase in showers and
isolated tstms to areas west of Hwy 131 early this morning. However
as the upper low settles south into Indiana, that shortwave heads
back to the west toward WI, which should lead to a decrease/lull in
showers for a time during the mid to late morning. Also the low
level flow goes offshore so any lake component will shift away from
the coast and toward the Milwaukee/Chicago areas.

Primary feature of interest later today is another shortwave
pivoting around the south side of the upper low which takes aim on
southeast and south central lower Michigan this afternoon. Guidance
is similar in showing numerous showers/isolated tstms developing
south and east of GRR as a trowal-like feature curls in from the
southeast and wraps around the north side of the low.

Highest pops tonight and Thursday will continue to be south of I-96,
particularly along I-94, within persistent trowal/deformation zone
on the north side of the upper low. Meanwhile, as the upr low
reaches it`s southern-most position, the potential exists for some
sunshine on Thursday northwest of GRR per RH progs. Downsloping low
level northeast flow with sun could lead to high temps in the lower
70s for the Muskegon/Ludington areas.

Thursday night/Friday sees clouds/pops lift back north/northwest
through the area as the upr low bounces back northward again.

.LONG TERM...(Friday night through Tuesday)
Issued at 330 AM EDT Wed Sep 28 2016

The upper low is still progged to be somewhere near CVG into
Saturday before finally lifting NE toward Toronto by Sunday.
Scattered to numerous showers should continue through Saturday, then
gradually diminish into Saturday night/Sunday.

The pattern finally becomes more progressive with an upper ridge
sliding across the region on Monday bringing a period of fair
weather.  Despite the building ridge there is not much indication we
will see a warming trend, with H8 temps holding 8-10C.  So daytime
temps should largely stay in the mid 60s to lower 70s through much
of the long term, which is near normal for this time of year.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 148 AM EDT Wed Sep 28 2016

Forecast trends continue to indicate that much of the area will
remain VFR through much of Wednesday as the deepest moisture and
lower conditions remain to our west and south. I did put in a
period of MVFR ceilings at MKG early this morning as steadier
rains have occurred there and ceilings should lower prior to
daybreak. However even this should last only a few hours. The
rest of the area is expected to remain VFR until we approach
nightfall.

The trend into the evening should be that the lowering ceilings
and vsbys from the south drift back north toward the I-94 TAF
sites, along with some light rain. Expect some MVFR will develop
here, and even some patchy IFR will be possible toward midnight.


&&

.MARINE...
Issued at 330 AM EDT Wed Sep 28 2016

Will be cancelling the small craft advisory early as winds and waves
have subsided below criteria. However will keep a mention of
waterspouts over the lake through the day. Strengthening northeast
flow could necessitate new small craft advisories for the
southernmost zones later tonight into Thursday.

&&

.HYDROLOGY...
Issued at 140 PM EDT Tue Sep 27 2016

River levels are around normal for this time of year. Lake enhanced
rain showers are possible through Wednesday. Rain showers continue
to be possible into Sunday. Rainfall totals into the weekend will
range from a half inch up to an inch and a half. Rivers and streams
should remain below bankfull through the weekend.

&&

.GRR Watches/Warnings/Advisories...
MI...None.
LM...None.

&&

$$

SYNOPSIS...Meade
SHORT TERM...Meade
LONG TERM...JK
AVIATION...JK
HYDROLOGY...63
MARINE...Meade


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