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Area forecast discussion 
National Weather Service Grand Rapids Michigan
1130 am EST Friday Jan 30 2015

Latest update...

issued at 318 am EST Friday Jan 30 2015

A cold front moved through last night bringing with it gusty winds
and some light snow. Today will be colder with highs around 20 and
light snow showers along/west of US-131.

A developing storm will move across the Ohio Valley Sunday but may
be far enough north to give southwest lower Michigan accumulating
snow. Cold air with highs in the middle teens is expected Sunday and
Monday before warmer temperatures move in by Tuesday.


Short term...(today through sunday)
issued at 318 am EST Friday Jan 30 2015

Forecast concerns deal with a potential storm Sunday and to a lesser
degree light snow today.

As mentioned above a cold front moved through the County Warning Area a few hours
ago. Temperatures are in the lower 20s and will fall a few more degrees
before morning. Expect colder temperatures today than yesterday. Highs will
be around 20. Radar shows light lake effect snow showers moving south-southeast
across the County Warning Area. Instability is pretty good with 800 mb temperatures near -17c
flowing over the lake. This cold air is very transitory and will
move east today putting an end to the shsn by late in the day.
BUFKIT relative humidity profiles show very shallow moisture with not much lift so
any accums will be less than an inch.

High pressure will move across the County Warning Area this evening and skies may
briefly scatter before higher clouds arrive in the warm advection
pattern that will develop late tonight. It/S possible temperatures could
briefly dip to around 10 tonight before rising as clouds move in but
that isn't certain and I didn't go that low in the grids except in
the far northeast corner where clouds will be the last to move

Another cold front will drop south Saturday and we could see some
light snow from it. But moisture isn/T impressive and so little if
any accums expected.

The greater chance of snow will come Sunday when a southern stream
storm moves out of the Southern Plains toward the Ohio Valley. Model
trends have been a slight nudge to the north. We/ve increased probability of precipitation
considerably Sunday over the southern half of the County Warning Area. NAM brings in
snow late Saturday night and continues through Sunday. We may need
headlines for this system if the current track holds up. Several
inches of accumulation looks possible especially along/south of

Long term...(sunday night through thursday)
issued at 318 am EST Friday Jan 30 2015

Clearing followed by cold temperatures still expected Monday morning
over interior of central/northern lower Michigan with lows of 10 below or
colder possible in spots. Farther south towards I-94...snow will be
exiting the area.

After anemic prospects for lake effect snow Monday...potential for
lake enhanced snow steadily increases Monday night through Tuesday
night with the arrival of a compact upper pot vorticity anomaly. Tuesday
night especially could see a quick and intense convective burst of
snow with the upper system and ensuing Arctic cold front.

Wednesday evening also looks interesting with potential impacts to
travel as a reinforcing cold front and attendant deep moisture are
advertised by both the European model (ecmwf)/GFS to push through the area. We have
seen run to run consistency with the European model (ecmwf) and now agreement with
the GFS regarding this. Certainty is therefore bumped up a notch but
still low overall since we are dealing with a day 5/6 forecast.
We can say with better confidence that the latter half of the week
will be seasonably cold in the wake of the front.


Aviation...(for the 18z tafs through 18z saturday)
issued at 1130 am EST Friday Jan 30 2015

Mainly VFR conditions are expected through 18z Saturday. A few
flurries will linger at kmkg intermittently through the next 24 hours.
Northwest winds of 10 to 15 kts will back to the SW and subside to at or below 10
kts tonight into Saturday.


issued at 318 am EST Friday Jan 30 2015

Ice formation is the main concern during the next few days. Highs in
around 20 today and around 15 Sunday and Monday will be favorable
for ice development.


GRR watches/warnings/advisories...


short term...93
long term...tjt

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