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Area forecast discussion 
National Weather Service Grand Rapids Michigan
149 PM EDT Thursday Oct 8 2015

Latest update...

issued at 329 am EDT Thursday Oct 8 2015

A cold front will sweep south through the area this evening and
tonight. A band of showers and possibly an isolated thunderstorm
will accompany the front. Rain will move into central lower Michigan
this afternoon and exit Southern Lower Michigan overnight. It will
be a warm day by October standards with many areas making it into
the lower 70s. Cooler weather is expected behind the front for
Friday and Saturday with highs in the lower 60s. Dry weather is
forecast for the weekend.


Short term...(today through saturday)
issued at 329 am EDT Thursday Oct 8 2015

Main item of concern is the frontal precipitation that will move
through the area this afternoon and evening. The system looks a
little less robust in terms of the amount and areal extent this
morning as compared to the last couple. Still expecting most areas
to see some rain...but amounts in many areas will likely be under a
quarter of an inch. Locations across central lower Michigan will
stand the best chance at seeing some totals above a quarter inch.

Threat for thunderstorms still looks fairly meager with cape values
on the order of a few hundred joules is all. An isolated storms
cannot be ruled out between 21z and 03z this afternoon and evening
along and ahead of the front.

Otherwise much of the day today in the south will be dry. Friday
into Saturday looks like a quiet period as well with the potential
again for some low clouds Friday morning. Saturday morning may
feature patchy frost across central lower Michigan.

Long term...(saturday night through wednesday)
issued at 329 am EDT Thursday Oct 8 2015

The long term doesn/T appear overly wet. In fact we have showers in
the forecast Monday and dry the rest of the period.

A couple of cold fronts are forecasted to to move through the Great Lakes
during the period. The first one arrives Monday. The European model (ecmwf) has more
precipitation with the front than the GFS and seems like the way to go. Even
the GFS show a strong short wave associated with the front that
would likely make up for somewhat limited moisture. The next front
moves through Wednesday. However the low associated with it is in
far northwest Ontario and moisture return ahead of it will be lacking due
to limited south flow behind the previous front.

Sunday and Monday look fairly mild with highs around 70...but then
fall to around 60 Tuesday behind the first cold front.


Aviation...(for the 18z tafs through 18z Friday afternoon)
issued at 148 PM EDT Thursday Oct 8 2015

Expect rain showers to move southeast across the terminals late
this afternoon into early tonight. There is good forecast certainty
with the timing. Isolated thunderstorms are possible but too
unlikely to include in the tafs.

What is less certain is ceilings and visibilities behind the showers.
Several sites over northern Wisconsin behind the showers are
currently reporting IFR and even LIFR ceilings. Have kept MVFR for
now at most terminals here after the rain...but this will be
something to watch overnight.

By late Friday morning...expect a rapid transition to VFR
conditions as northwest winds spread across the area.


issued at 329 am EDT Thursday Oct 8 2015

Will issue a Small Craft Advisory from tonight into Friday night as
the north flow is expected to kick waves up into the 4 to 6 foot
range. The southerly flow today does not look strong enough for long
enough to push waves into the Small Craft Advisory category. Expecting more of a 2-4
foot wave in the northern zones for a time this afternoon.


issued at 1124 am EDT Thursday Oct 8 2015

No flooding concerns to mention over the next several days.

A frontal boundary will bring rainfall (possibly a thunderstorm)
to the area later today and into tonight. Total rainfall amounts
through Friday morning will be enough to wet the soil. Rainfall
is expected to be nothing more than beneficial to what is generally
dry ground.

A dry period is expected over the weekend before another quick hit
of showers is possible early next week.


GRR watches/warnings/advisories...
Lm...Small Craft Advisory from 2 am Friday to 2 am EDT Saturday for



short term...Duke
long term...99

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