Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 160829

Area Forecast Discussion
National Weather Service Grand Rapids MI
329 AM EST Mon Jan 16 2017

Synopsis/Short Term/Long Term/Marine

Issued at 306 AM EST Mon Jan 16 2017

A low pressure system will track from Texas today through Michigan
on Tuesday. This system will result in a wintry mix of
precipitation for the region that changes to rain as some warmer
air tries to move in. An area of high pressure then moves in for


.SHORT TERM...(Today through Wednesday)
Issued at 306 AM EST Mon Jan 16 2017

Challenging forecast today and tonight as far as timing and type
of precipitation. The main culprits is the dry airmass that is in
place and surface temperatures that will hover around freezing
for a period this afternoon and tonight as steadier and heavier
precipitation moves in.

We will issue winter weather advisories for much of the region.
The band of precipitation upstream across IL and NRN IN is mostly
aloft at this time. This is forecasted to move into southwest
lower MI this morning and early afternoon. Tough call as to how
soon and what type the onset will be. However the main type across
southern parts looks to be ZR or R depending on the surface
temperature...while further north a mix looks likely. Icing seems
to be the main risk given the warm layer that moves in today.
The window for ZR looks shorter for the southernmost counties so
we did not include them in the headline. This is is from South
Haven to Jackson. It is possible that if they do not warm up above
freezing as quickly as forecasted...the may need to be
incorporated into the headline. Up to a quarter inch of ice looks
possible further north. Fortunately the wind does not look that
strong at this time...mostly under 15 knots. A small risk exists
for even heavier amounts of ice if surface temps end up rising
above freezing slower than expected. So close monitoring is
needed for today and tonight.

.LONG TERM...(Wednesday night through Sunday)
Issued at 306 AM EST Mon Jan 16 2017

A mild period is expected for the end of the week and into early
next week.  H8 temps hold from +4C to +7C throughout the long term.
This should keep temps well above normal for this time of year,
with daytime highs mainly 45 to 50.

The overall pattern that should bring this persistent warm air into
the Great Lakes is a rather stagnate one.  Upper troughing remains
fairly stationary over the center of the nation, leading to deep
southerly flow over the Eastern U.S.  A couple of weakening waves
spin off of this trough and head toward us, but they run into an
upper ridge and weaken further.  A few rain showers may occur
Friday, then another higher chance into Sunday.  Otherwise the
January warmth will come with relatively dry conditions.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1159 PM EST Sun Jan 15 2017

Some patchy light fog may produce MVFR conditions briefly early
this morning, otherwise it will remain VFR.

A mixed bag of wintry weather will move into the region toward
mid day Monday. The I-94 TAFs should largely be rain, but a brief
period of freezing rain will likely also occur. The I-96 sites
will see a longer period of mixed pcpn. All areas will switch to
plain rain by late afternoon/early evening.

As the pcpn moves in, conditions will gradually lower to IFR and
even some LIFR. This will settle in between 20Z and 23Z and
continue through the remainder of the evening.


Issued at 306 AM EST Mon Jan 16 2017

Despite a low pressure system moving in...the wind values are
forecasted to remain relatively low with an offshore component. As
a result...not headlines are planned with this issuance.


Issued at 122 PM EST Sat Jan 14 2017

Rivers are running above normal across the area due to rain, melted
snow and ice jams. The Grand River at Robinson Township has an
active warning for minor flooding. Multiple sites also have active
advisories. A period of colder than normal temperatures through the
weekend may allow river ice to thicken. Next week looks warmer than
normal with highs possibly reaching the 50s. This could melt the
river ice and allow the rivers to flush out.


MI...Freezing Rain Advisory from 11 AM this morning to 2 AM EST
     Tuesday for MIZ050-056>059-064>067.

     Winter Weather Advisory from 4 PM this afternoon to 9 AM EST
     Tuesday for MIZ037>040-043>046-051-052.



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