Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 290405
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1205 AM EDT THU SEP 29 2016

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 220 PM EDT Wed Sep 28 2016

A large area of low pressure will remain anchored over the Great
Lakes through much of the weekend. That will result in numerous
showers and high temperatures in the mid 60s.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 220 PM EDT Wed Sep 28 2016

There was little change to the going forecast. Short range models
continue to have a good handle on the progression...or lack
thereof...of the upper low as it tracks across Michigan and south to
Indiana.

Latest radar imagery shows an area of showers moving northwestward
from southeast Lower. This is in response to a short wave pivoting
around the upper low that`s anchored over indiana. We`re going to
see a few more waves rotate around the low as it moves slowly back
north toward the cwa by Saturday. Pops will remain high across the
southeast cwa through the period and decrease as you go toward the
northwest away from the upper low.

Not much change in temperature is expected either under this cloudy
environment. Highs in the mid 60s and lows in the mid 50s are
expected.

.LONG TERM...(Saturday through Wednesday)
Issued at 150 PM EDT Wed Sep 28 2016

The main issue today is when does the upper low move away far enough
to end the periods of rainfall. There is a decent amount of model
agreement on Sunday night being that time period when the rain
should finally end. There is an issue of heavy rainfall into at
least Saturday from the wrap around on the north side of the system,
feeding moisture from the Atlantic back into Michigan.
That will have to be watched but where the heaviest rain will be is
hard to say this far out in time.

Once that system gets out of the way we should see upper ridging
bring a dry period Monday into Wednesday. Then the next Pacific
system will bring the threat of rain back to the area later Wed into
at least Friday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1202 AM EDT Thu Sep 29 2016

A mix of mvfr and vfr conditions will continue overnight with mvfr
conditions at times due to low clouds and showers. Conditions will
gradually deteriorate to primarily mvfr Thursday due to low clouds
and showers through the day. Northeast winds will increase to
10-15 kts with gusts to around 20 kts from mid morning through the
afternoon. Conditions may deteriorate further to ifr Thursday
evening due to low clouds/lowering cigs and showers.

&&

.MARINE...
Issued at 220 PM EDT Wed Sep 28 2016

Issued a small craft advisory through Friday. The combination of
northeast winds 15 to 25 knots coupled with waves aoa 3 feet will
make the lake hazardous for small craft.


&&

.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...Small Craft Advisory until 6 PM EDT Friday for LMZ844>849.

&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...WDM
AVIATION...Laurens
HYDROLOGY...63
MARINE...04



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