Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 231857
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
257 PM EDT Fri Jun 23 2017

LATEST UPDATE...
Hydro

.SYNOPSIS...
Issued at 330 AM EDT Fri Jun 23 2017

A cold front will push south through the area this morning bringing
rounds of showers and thunderstorms. Cooler and less humid air will
filter in behind the front this evening and tonight. Lows tonight
will dip into the upper 50s with highs on Saturday only making it to
around 70 degrees. The cooler conditions will persist into Sunday as
well with highs around 70 once again. After a dry night tonight,
small chances for showers and a scattered thunderstorm return to the
forecast for the weekend.

&&

.UPDATE...
Issued at 1105 AM EDT Fri Jun 23 2017

Have updated the forecast to reflect the latest trends. Showers
are winding down/exiting with decreasing cloud expected this
afternoon. Forecast wording has been freshened up accordingly.

&&

.SHORT TERM...(Today through Sunday)
Issued at 330 AM EDT Fri Jun 23 2017

We will be dropping the areal flood watch with this forecast
issuance as the heavier rain is winding down across Central Lower
Michigan. This area is covered by Flood Advisories and Flood
Warnings at this time. South of that area, we are expecting more
transient showers and storms as the cold front is finally on the
move south. The front stalled across Central Lower Michigan earlier
in the night resulting in rainfall totals in excess of 5 inches
across portions of Isabella County. Showers and storms will work
south into the I-96 corridor before day break and move south of I-94
around noon. Skies will turn partly cloudy this afternoon as deep
layer RH values below 50 percent late this afternoon and evening.

A quiet night tonight will be followed by a return to more unsettled
weather this weekend. Not expecting a washout, but diurnal
instability will build each afternoon with a chance for showers and
a few storms both Saturday and Sunday. The upper pattern will
feature northwest flow with embedded shortwaves working through the
area.

.LONG TERM...(Sunday night through Thursday)
Issued at 330 AM EDT Fri Jun 23 2017

The long term period starts off with a mid to upper level trough
over the Great Lakes Region.  Models are in decent agreement in
tracking it slowly east Sunday night into Tuesday.  The latest GFS
is quicker with this features departure.  So it looks unsettled with
the cold core system overhead and relatively warmer lakes around.

Mid level heights rise steadily into Wednesday as warm air advection
strengthens.  Will need to monitor the risk for showers and
thunderstorms as the warm front lifts north.

Another mid level low/trough drops out of the Canadian Prairies for
Thursday resulting in height falls for MI. We could see
thunderstorms developing by the end of the period.

I did warm up temperatures slightly during the warm air advection
period as we commonly see values that end up higher than forecasted
in those regimes this far out.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 143 PM EDT Fri Jun 23 2017

MVFR conditions with ceilings 1500 to 2500 feet will continue
early this afternoon then VFR conditions are expected this evening
through Saturday morning. Some showers and isolated thunderstorms
will develop by 18Z Saturday.

Winds will be west to northwest through Saturday and gust over 20
knots at times this afternoon and again Saturday afternoon.


&&

.MARINE...
Issued at 1105 AM EDT Fri Jun 23 2017

Waves have settled down since the early morning reports near 4
feet, with buoys now showing 1-2 feet.

Winds and waves should remain below criteria tonight, with
borderline SCA conditions expected Saturday into Sunday.

&&

.HYDROLOGY...
Issued at 257 PM EDT Fri Jun 23 2017

Major flooding is expected along the Pine River in Isabella County
and sharp rises are also occurring along the Muskegon basin and
will continue the next couple days as the crest moves down the
river. From 3 to 5 inches of rain fell last night combined with
earlier heavy rains.

The good news is that no heavy rain is expected through the
middle of next week which will allow those areas that are flooding
to recover. The next chance for significant rain will be Thursday
of next week.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...None.
&&

$$

UPDATE...Meade
SYNOPSIS...Duke
SHORT TERM...Duke
LONG TERM...MJS
AVIATION...Ostuno
HYDROLOGY...Ostuno
MARINE...Duke



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