Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 170730

Area Forecast Discussion
National Weather Service Grand Rapids MI
330 AM EDT Mon Oct 17 2016

Synopsis/Short Term/Long Term/Marine

Issued at 330 AM EDT Mon Oct 17 2016

A warm front was located across Southern Lower Michigan this
morning. The front will lift north this morning and be responsible
for shower and thunderstorm development into early afternoon. It
will remain mild today by October standards with highs ranging from
70 to 80 degrees across the area. Tonight strong southerly winds
will keep in mild and breezy. On Tuesday as cold front will move
southeast through the region with a few isolated showers possible.
It will turn cooler behind this cold front with highs cooling back
into the 50s for the end of the work week.


.SHORT TERM...(Today through Wednesday)
Issued at 330 AM EDT Mon Oct 17 2016

Main weather in the short term appears to be confined to the today
portion of the forecast. At 06z, a warm front was located across
southern portions of the CWA near I-94 with low clouds and fog to
the north of it. Showers and thunderstorms are expected to develop
early this morning either in the vicinity of Lake Michigan or
overhead in a zone of strong moisture transport. The activity will
trend northward into Central Lower Michigan during the midday and
early afternoon hours. The precipitation should become more
scattered and isolated as we head through the afternoon and evening
hours, if not completely lifting north of the area.

Another concern today is the low clouds that are in place at present
and how this may affect the high temperature forecast. Feel that
Central Lower Michigan may hang on to the clouds for the bulk of the
day which will lead to highs holding around 70 degrees. If we do
clear the low clouds out of the south which appears likely we
should make a run at 80 degrees.

Tonight any precipitation should be near or north of Central Lower
Michigan in vicinity of the warm front and the low that will be
moving through the northern lakes. It will turn windy tonight at the
gradient tightens. Feel we are looking at 15-30 mph winds tonight
from the southwest, with the strongest winds in the lakeshore
counties down wind of Lake Michigan.

Tuesday we may see some isolated showers traversing the area as the
cold front pushes southeast through the region. The precipitation
will not be widespread but decided to include a small 20 pct chance
given convection allowing models are showing a few showers.

Tuesday night and Wednesday will be quieter periods as high pressure
builds into the region.

.LONG TERM...(Wednesday night through Sunday)
Issued at 330 AM EDT Mon Oct 17 2016

A low pressure system moving northeast across the Ohio Valley region
will bring some rain showers Wednesday night and Thursday. The best
chance for rain in that time frame will be over our southeast
forecast area. A consensus of latest medium range guidance continues
to suggest that the axis of relatively heavier rainfall will stay
southeast of our area.

Northwest flow cool air advection will occur on the back side of the
system Friday. A few synoptic light rain showers will linger Friday
with potential for some lake effect rain showers as well as h8 temps
fall to around 0 to -2 C by Friday evening. High temps Friday and
Saturday will only reach the 50`s.

Fair weather will return later next weekend as high pressure takes
hold of the wx pattern. Temperatures will undergo a slow moderating
trend late in the weekend into early next week.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1106 PM EDT Sun Oct 16 2016

A mix of ifr/lifr conditions will continue due to areas of fog
and low cigs. However conditions will gradually improve somewhat
overnight to predominantly mvfr later this morning as fog
gradually dissipates as southerly winds increase. Scattered rain
showers will likely develop during the early morning hours Monday
and linger through mid morning before dissipating.

Conditions will gradually improve further to mainly vfr with some
lingering mvfr toward midday when southerly winds will also ramp
up to around 15 kts with gusts to 20-25 kts through the afternoon
and evening. Some showers may redevelop later Monday but there is
not enough potential for that to occur to warrant inclusion in the
terminal forecasts at this time as the vast majority of showers
later today should stay north of all the terminals.


Issued at 330 AM EDT Mon Oct 17 2016

Small Craft Advisory remains in effect and made no changes to the
headline. Still looks like southerly winds of 15-25 knots today out
on Lake Michigan, increasing to 20-30 knots tonight. Waves will
build into the 3 to 6 foot range this afternoon and to 5 to 9 feet
tonight. It will take most of Tuesday for the waves to subside below
advisory levels. A lighter wind regime looks to be in place from
Tuesday evening into Thursday.

Will let the Marine Dense Fog advisory expire at 400am this morning
given visibilities in both observations and webcams look to be above


Issued at 317 PM EDT Sun Oct 16 2016

A widespread half inch of rain fell this morning. Over an inch was
common in the lower Muskegon basin and the lower Grand basin. Over
two inches was reported in northern Kent County and northern
Muskegon County. Fortunately, the smaller river basins that received
the most rain have enough room to handle the runoff. Many rivers
will continue running much higher than seasonal normals this week.
The flood threat is limited by a rather low chance of widespread
heavy rain events this week, though Thursday bears watching for the
upper Grand basin if the expected axis of heavy rain shifts


LM...Small Craft Advisory until 4 PM EDT Tuesday for LMZ844>849.



LONG TERM...Laurens
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