Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 181904

Area Forecast Discussion
National Weather Service Grand Rapids MI
304 PM EDT Tue Oct 18 2016

Synopsis/Short Term/Long Term/Marine

Issued at 304 PM EDT Tue Oct 18 2016

Breezy conditions will subside this afternoon as cooler, drier
air replaces the unseasonably warm, humid airmass. Quiet
conditions are expected through much of Wednesday, before rain
chances increase through Southern Lower Michigan late Wednesday
into Thursday. A reinforcing shot of cold air will have the week
ending slightly below normal with high temperatures struggling to
make it into the in the lower 50s Friday and Saturday.


.SHORT TERM...(This evening through Thursday night)
Issued at 304 PM EDT Tue Oct 18 2016

We will be returning to reality as conditions more indicative of
fall settle in over the course of the next 24-36 hours.

Much cooler and drier air is pressing into the Great Lakes Region
today. Dry weather is likely to extend into Wednesday afternoon
behind this front and while temperatures are cooler, they`ll be
comfortable Wednesday with lower humidity and highs in the 60s.

Not much has changed in regards to the storm system passing
through the Ohio Valley late Wednesday into Thursday. The northern
extent of measurable rainfall lands through the middle of the
forecast area (Muskegon, Grand Rapid and maybe Mt. Pleasant),
where less than a tenth of an inch could fall through Thursday
afternoon. It is likely that a steep gradient exists in overall
amounts, as well as duration, with Jackson pushing a half inch by
the time all ends late Thursday. Given recent rainfall,
southeastern sections may need to be monitored for potential river
rises. Heavier rainfall, however, seems as though it will remain
south of Lower Michigan.

.LONG TERM...(Friday through Tuesday)
Issued at 304 PM EDT Tue Oct 18 2016

The mid level closed low will be pulling away from the Great Lakes
region Friday into Saturday.  At this time the low level thermal
trough will be pushing through.  The atmosphere will be plenty cold
enough for some lake effect rain showers. The low level flow will be
mostly  northerly...which favors the locations closest to the
lakeshore for possible rain.  The forecast soundings show the depth
of the moisture to be relatively low...only to the -12 deg c level
or so.  If that ends up being the cloud top temperatures...the
coverage will be rather limited. Below normal temperature are
expected for Friday into Saturday.

The GFS shows the mid level heights rising steadily Sunday into
Monday as the flow backs.  This would support a warming trend. The
new High Res Euro is trying to bring down a reinforcing shot of
cooler air Sunday Afternoon into Monday. This would support some
showers Sunday followed by a cool down.  For now will keep it
dry...and show only a slow warmup.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 137 PM EDT Tue Oct 18 2016

A cold front was tracking eastward through the TAF sites this
afternoon. A narrow line of showers may develop along it as it
pushes through KLAN...KJXN...KAZO and KBTL in the next 3 hrs. A
brief period of MVFR cloud cover may occur behind the front...but
overall a diminishing trend to the cloud cover is forecasted from
about mid afternoon...on. The gusty winds will also decrease and
veer slightly behind the front this afternoon. Gusts over 25 knots
are still possible for the next 1 to 3 hrs as the front pushes


Issued at 304 PM EDT Tue Oct 18 2016

We will be dropping the small craft advisory in this update.
A few gusts around 15-20 kts are possible through early evening,
but overall conditions will continue to improve. Winds out of the
west and southwest will turn out of northwest and decrease to 5-15
kts tonight. Rather tranquil conditions are anticipated through
Wednesday with wave heights around 1 foot or less in most


Issued at 1149 AM EDT Tue Oct 18 2016

Although rivers continue to run well above normal, most sites have
leveled off and have begun a downward trend. No flooding is

Today`s frontal boundary will come through mostly dry. The main
question then shifts to the potential for rainfall with the
midweek system passing through the Ohio Valley. The latest update
of the GFS continues to plot the northern most edge of the
rainfall across southern sections of the CWA, mainly I-96 and
south. Heavier precipitation is likely to stay south of Lower
Michigan, but minor river rises cannot be ruled out along and
south of I-94.


LM...Small Craft Advisory until 4 PM EDT this afternoon for



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