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000 
FXUS63 KGRR 251749
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1249 PM EST Sat Feb 25 2017

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 328 AM EST Sat Feb 25 2017

Colder weather along with snow showers can be expected into this
evening. Snow and blowing snow will reduce visibility at times
near Lake Michigan through the afternoon. The snow will taper off
to flurries tonight.

&&

.UPDATE...
Issued at 1102 AM EST Sat Feb 25 2017

Radar estimates show over an inch of snow has already occurred
over parts of Muskegon, Ottawa, Allegan and Kent Counties. Other 
lakeshore counties are probably being under estimated by the 
radar. The back edge of the deformation was still just east of 
Madison WI. So along with the lake enhancement we will see snow 
showers throughout the day and into the evening. Still believe 1 
to 3 inches will suffice, but I have expanded the area of 2-3 inch
totals for most of the advisory counties.

&&

.SHORT TERM...(Today through Monday)
Issued at 328 AM EST Sat Feb 25 2017

Will leave the Winter Weather Advisory as is. Snow accums only 
expected to be 1 to 3 inches in the advisory area, but 
visibilities could be reduced by snow and blowing snow as winds 
gust to 30 mph at times through the afternoon.

Deformation axis shifts east and sfc ridging builds in tonight 
with snow ending. Quick hitting clipper follows for Sunday
afternoon and evening with an inch or two of snow possible across
the northern zones.

.LONG TERM...(Monday night through Friday)
Issued at 328 AM EST Sat Feb 25 2017

Temperatures will get steadily colder through the period, beginning 
with highs Tuesday in the lower 50s and ending with highs in the mid 
30s Friday.

South flow ahead of the next system will push temps into the lower 
50s Tuesday. We're likely to see some rain too as both the ecmwf and 
gfs show pcpn moving north. The low, which is in Kansas Tuesday 
morning, will move northeast to Lower Michigan Tuesday night. Looks 
like a rainy night, although some wet snow may mix in with the rain 
over the northern cwa. Both models show a second wave moving 
northeast along the frontal boundary. This will result in more rain 
Wednesday before colder air advect southeast across the cwa 
Wednesday night. Wednesday night h8 temps fall from -6c to -12c and 
we should see some lake effect snow showers develop. There may be a 
brief lull Thursday afternoon as slightly warmer air advects in from 
the southwest ahead of a clipper, but then another surge of colder 
air will move in and h8 temps fall to around -18c by Friday. The 
main change to the grids was to add more snow showers and less rain 
showers Thursday-Friday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1250 PM EST Sat Feb 25 2017

Expect IFR snow showers to continue till around 00z at MKG, GRR
and AZO while BTL, will have occasional MVFR snow showers. LAN and
JXN will have MVFR ceilings with flurries and the ocnl MVFR VIS 
snow shower. 

Tonight the moisture thins out so the snow showers should come to
an end by 03z or so. I would think VFR cigs will prevail.  

Sunday should mostly be VFR but we will have to watch for the
chance of a southwest flow snow shower event mid morning into mid
afternoon. That event would only impact MKG.

&&

.MARINE...
Issued at 328 AM EST Sat Feb 25 2017

Gale Warning was left in place until 2 pm. It may be replaced with
a Small Craft Advisory or the Gale Warning may have to be
extended as conditions will be marginal for gales through Sunday.


&&

.HYDROLOGY...
Issued at 1237 PM EST Fri Feb 24 2017

Widespread rainfall overnight will produce rises on area rivers 
over the next few days. Rainfall was generally one quarter to one 
half inch...with amounts in excess of one inch across northern 
portions of Lower Michigan. Current forecasts keep all rivers 
below flood stage...but additional rainfall today could produce 
stronger rises. Heaviest rain today should fall over southern 
sections of Lower Michigan...which received less rainfall 
overnight.

Colder temperatures return for the weekend...with a series of storm 
systems bringing additional precipitation to the region this week. 
While temperatures are not expected to be cold enough for ice 
formation on rivers...the additional precipitation could cause 
slower recession or additional rises on area rivers. 

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory until 8 PM EST this evening for MIZ037-
     038-043-050-056-064-071.

LM...Small Craft Advisory until 5 AM EST Monday for LMZ844>849.

&&

$$

UPDATE...JK
SYNOPSIS...Ostuno

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