000
FXUS63 KGRR 290009
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
809 PM EDT WED SEP 28 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 00Z TAFS through 00Z Thursday evening)
Issued at 809 PM EDT Wed Sep 28 2016

Ceilings vary across the TAF sites at 800pm from MVFR at KAZO and
KBTL to VFR at the other sites. The MVFR ceilings may be short
lived this evening, but lower ceilings are forecast to push back
in from the southeast overnight. Between 200am and 800am expecting
MVFR ceilings to push back into most of the TAF sites.

During the day on Thursday, expecting IFR conditions to show up
for at least KJXN with MVFR ceilings at all of the other TAF
sites. Some models depict more widespread IFR showing up on
Thursday, but was not confident enough to include that in this set
of TAFs. Rain will be prevalent the next 24 hours with off and on
rain occurring at all TAF sites. Winds will be steady out of the
northeast through Thursday evening.

&&

.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...Duke
HYDROLOGY...63
MARINE...04