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Area forecast discussion 
National Weather Service Grand Rapids Michigan
317 PM EST sun Dec 28 2014

Latest update...
synopsis/short term/long term

Synopsis...
issued at 317 PM EST sun Dec 28 2014

An Arctic front will move through tonight and light snow showers
are expected near Lake Michigan the next few days. A storm could
bring snow or mixed precipitation by the end of the week.

&&

Short term...(this evening through Tuesday night)
issued at 317 PM EST sun Dec 28 2014

Only forecast issue in the near term is for extent of lake effect
snow showers in the wake of Arctic frontal passage tonight. Lower level flow
GOES northerly overnight as the cold air moves in and inversion
heights are prognosticated to be below 5 kft...so snow showers will be
light and confined to near Lake Michigan.

The flow begins to go northwest Monday night and snow showers will
move further inland...although inversion heights remain low. Still
there could be a couple inches of fluff along the coastal counties
and perhaps 1 to 2 inches total by Wednesday morning from
Kalamazoo to Big Rapids.

Long term...(wednesday through sunday)
issued at 317 PM EST sun Dec 28 2014

It will be cold Wednesday when maximum temperatures will only reach around
twenty degrees along with a few light lake effect snow showers and
flurries with 800 mb temperatures down around -18 c. Temperatures will average fairly
close to normal for this time of year Thursday and Friday. A weak
system moving in from the northwest may bring a few more light snow showers
Thursday night into Friday.

There is potential for a significant low pressure system to move
NE from the Southern Plains states or Gulf Coast region very late in
the week. This system could potentially bring significant precipitation to
lower Michigan late Friday night and Saturday. Precipitation type would be
dependent on the exact track of the system.

It is noted though that 12z European model (ecmwf) guidance has trended much further
southeast and keeps all precipitation with that system southeast of lower Michigan next weekend. So
there is still a considerable amount of uncertainty regarding
track/strength/timing and evolution of that potential system.

&&

Aviation...(for the 18z tafs through 18z monday)
issued at 1130 am EST sun Dec 28 2014

A mix of MVFR/VFR conditions will gradually transition to VFR this
afternoon and evening as lower clouds dissipate. A cold front
approaching from the north tonight may bring MVFR ceilings back into
kmkg overnight through midday Monday. VFR conditions should prevail
overnight further south at all the rest of the terminals. Wind
speeds through the next 24 hours will be at or below 10 kts from the northwest then
north.



&&

Marine...
issued at 329 am EST sun Dec 28 2014

Continued the Small Craft Advisory through 11 am today. Waves are
expected to subside to 2 to 4 feet later today as winds are
diminishing. West winds 10 to 15 knots expected today.



&&

Hydrology...
issued at 329 am EST sun Dec 28 2014

No significant precipitation is expected today or tonight.
However...more significant snowfall accumulations are possible
Monday night right along the Lakeshore. A more significant Hydro
impact this week will be colder temperatures. With temperatures
below 20 degrees at times this week...ice will begin forming on
rivers.

&&

GRR watches/warnings/advisories...
Michigan...none.
Lm...none.
&&

$$

Synopsis...ostuno
short term...ostuno
long term...Laurens
aviation...Laurens
hydrology...ebw
marine...ebw

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