Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 301509
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1109 AM EDT FRI SEP 30 2016

LATEST UPDATE...
Hydro

.SYNOPSIS...
Issued at 315 AM EDT Fri Sep 30 2016

Low pressure will slowly spin across Lower Michigan bringing wet
weather through the weekend. Fair weather will finally arrive
early next week as the low finally moves away.

&&

.UPDATE...
Issued at 1102 AM EDT Fri Sep 30 2016

We have cancelled the flood watch this morning. Rain amounts last
night we not all that impressive, and did not really cause any
additional issues, especially for the areas hit hardest the night
before. Additional rain showers are likely, with the next wave
moving through later this afternoon. Areas of rain showers should
be fairly progressive in nature with the short waves moving around
the center of the upper low.

We believe that the worst case scenario at this time is that an
areal flood advisory may be needed if rain showers become too much
of a problem. We do not believe that it would rise to the level
where an areal flood warning would be needed.

&&

.SHORT TERM...(Today through Sunday)
Issued at 315 AM EDT Fri Sep 30 2016

No changes to the Flood Watch. Current radar loop shows steadier
rain moving into the SE forecast area with long fetch of moisture
streaming in as the upper cutoff low spins across the Ohio Valley.
It is forecast to move north back into Lower Michigan by the end
of the period then finally get kicked east as longwave trough
moves into the western CONUS.

Expect rains to continue this afternoon and into tonight and
persist into Friday before beginning to taper off as the occluded
low moves into the forecast area. Marginally steep lapse rates
this afternoon makes diurnal enhancement of thunderstorms
possible. The persistent nature of the flow regime and the
presence of tropical moisture feeding in will mean that excessive
rains are possible and the Flood Watch will remain in effect.

.LONG TERM...(Sunday night through Thursday)
Issued at 315 AM EDT Fri Sep 30 2016

A few showers may linger into Sunday evening before fair weather
returns Monday as the upper level low will finally move east of our
region as upper ridging builds in from the west.

Temperatures will be seasonable Monday before moderating to reach the
lower to perhaps middle 70`s by next Tue/Wed. The next chance for
showers will come Wednesday night and Thursday as a strong low
pressure system moves slowly northeast into the upper midwest.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 747 AM EDT Fri Sep 30 2016

Rain and low stratus will bring widespread IFR conditions to Lower
Michigan through tonight. East to northeast winds will gust to 20
knots at times through the afternoon.


&&

.MARINE...
Issued at 315 AM EDT Fri Sep 30 2016

Winds and waves will continue to be hazardous to small craft
into this evening. Conditions will slowly improve tonight but the
small craft advisory may be needed to continue through tonight as
the pressure gradient continues to generate wind gusts to 25
knots. Waves will be highest further away from shore because of
the offshore component of the wind.


&&

.HYDROLOGY...
Issued at 1109 AM EDT Fri Sep 30 2016

The Sycamore Creek is nearing its crest over a foot above
bankfull, and will begin its slow recession which may modulated
by any additional rainfall Friday into Saturday. Other rivers
approaching bankfull the next few days include the Red Cedar above
Williamston, the Looking Glass near Eagle, and the Grand at Ionia.
The current forecasts are dependent on roughly another 0.75 inches
falling in those basins through Saturday morning. Will hold off
on flood advisories for those rivers until confidence is higher.

&&

.GRR Watches/Warnings/Advisories...
MI...None.
LM...Small Craft Advisory until 6 PM EDT this evening for LMZ844>849.

&&

$$

UPDATE...NJJ
SYNOPSIS...Ostuno
SHORT TERM...Ostuno
LONG TERM...Laurens
AVIATION...Ostuno
HYDROLOGY...CAS
MARINE...Ostuno



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