Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 240225

Area Forecast Discussion
National Weather Service Grand Rapids MI
1025 PM EDT TUE AUG 23 2016


Issued at 330 PM EDT Tue Aug 23 2016

A low pressure system will bring showers and a few thunderstorms
Wednesday through Wednesday night into Thursday. Fair weather will
return Thursday night through Saturday. Another system will bring
another chance for showers and thunderstorms Sunday.


Issued at 1025 PM EDT Tue Aug 23 2016

Have added low chance pops for showers after 09z for wrn sections
of the cwfa to cover the arrival of the sharp PWAT gradient and
higher theta-e air from the southwest. Current PWATS are near
0.75 inches and are progged to rise to near 2 inches Wednesday
morning. This moisture advection may generate a band of scattered
rain showers moving in after 5 am.


.SHORT TERM...(This evening through Thursday night)
Issued at 330 PM EDT Tue Aug 23 2016

A low pressure system moving in tomorrow will bring showers and
a few thunderstorms. No severe weather is expected given weak
instability and lack of stronger forcing or wind fields with

Locally heavy rainfall is possible as low level moisture ramps up
with sfc dew points reaching the upper 60`s to lower 70`s and
precipitable water values up to around two inches. However
1000-850 mb moisture transport with this system does not look as
impressive as it did yesterday.

Some showers and perhaps isolated convection will linger into
Thursday. Most locations will only receive around a half an inch
to three quarters of an inch of rainfall tomorrow through
Thursday. Therefore hydro concerns are fairly minimal.

Dry wx will continue this evening with showers approaching from
the WSW by around daybreak tomorrow. A high pressure ridge will
build in from the west to bring fair weather beginning
Thursday evening.

.LONG TERM...(Friday through Tuesday)
Issued at 330 PM EDT Tue Aug 23 2016

Surface high pressure should provide dry weather from Friday through
Saturday. The upper flow is quasi zonal over the Great Lakes with an
upper ridge over the Southeast United States and shortwaves rippling
east along the U.S/Canadian border.

From Saturday night into early next week a shortwave trough is
forecast to slowly shift eastward through the northern Great Lakes.
At the surface, weak low pressure will traverse the area with an
influx of moisture from the south. Have low chance pops in the
forecast from Saturday Night through Tuesday. Certainly won`t be
raining all the time but the threat is there for a few
showers/storms each period. The best chances for precipitation look
to come from Saturday night through Sunday night.

Temperatures through the period look to be near seasonal normals.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 736 PM EDT Tue Aug 23 2016

We are looking at VFR conditions at all of the terminals for most
of the first half of the fcst period, before MVFR conditions will
move in from west to east Wednesday morning. Diurnal cumulus are
dissipating quickly this evening, leaving only high clouds. Winds
are coming down, but will remain up enough to keep fog potential
at bay.

After about 08-09z, a few rain showers will try to move in from
the west. The chances for rain will only go up toward and after
12z from west to east. We expect at least MVFR conditions with
some IFR possible. Thunder will be scattered about in the rain,
and remain through about mid afternoon. After that, we expect
showers and storms to end from west to east. MVFR conditions
should trend VFR by 00z Thu.


Issued at 330 PM EDT Tue Aug 23 2016

A small craft advisory remains in effect through late Wednesday
night from South Haven north to Manistee where wave heights of 3
to 5 feet are expected through then. South to southwest winds of
15 to 25 kts may diminish somewhat late this evening and overnight
before ramping back up to around 20 to 25 kts Wednesday.


Issued at 330 PM EDT Tue Aug 23 2016

Fair and dry weather will continue this evening. A flood warning
remains in effect for the Portage River at Vicksburg where minor
flooding remains possible. However the river level is forecast to
continue to slowly fall to below flood stage by early Wednesday

The next system will bring potential for around a half to three
quarters of an inch of rainfall Wednesday through Thursday. This
rainfall could cause a small rise on the Portage River Thursday into


.GRR Watches/Warnings/Advisories...
MI...Beach Hazards Statement through late Wednesday night for MIZ037-

LM...Small Craft Advisory until 2 AM EDT Thursday for LMZ845>849.



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