National Weather Service Raw Text Product

Displaying AFOS PIL: AFDGRR Received: 2019-02-10 23:26 UTC


069 
FXUS63 KGRR 102326
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
626 PM EST Sun Feb 10 2019

LATEST UPDATE...
Aviation

.SYNOPSIS...
Issued at 310 PM EST Sun Feb 10 2019

- Light snow tonight...up to an inch.

- More snow Monday night/Tuesday.
    -- 2-4 inches south of I-96. Freezing rain also possible.
    -- 3-5 inches north of I-96.

- Stronger system Thursday night/Friday. Significant snow
  accumulations possible. 

&&

.DISCUSSION...(This evening through next Sunday)
Issued at 310 PM EST Sun Feb 10 2019

We have a weak system moving through tonight. Light snow has 
developed over Indiana and southern Lower Michigan. Accumulation-
wise, it won't amount to much. Up to an inch is expected, but most 
locations will be a half inch or less. Snow should be over shortly 
after midnight. 

The next system comes in Monday night and continues through Tuesday. 
This system will begin as snow during the early evening Monday. 
Light snow will continue overnight and accumulate 2-4 inches south 
of I-96 before it mixes with and changes over to a brief period of 
freezing rain. The good news is that temperatures should be above 30 
and climb above freezing by 10 am or so. Impacts should be limited 
from the ice, especially since we'll have some snow to absorb the 
rain. Farther north...north of I-96...precipitation should be all 
snow. Snow totals will be in the 3 to 5 inch range. The good news in 
all of this is that model trends have pushed the freezing rain 
farther south with each of the past few model runs. Hopefully this 
trend continues. 

We have issued a Winter Weather Advisory for Monday night and 
Tuesday.

The strongest system of the week arrives Thursday night. Latest 
Canadian and GFS models show much of this system being rain south of 
a Holland to Alma line and snow north of this line. ECMWF points 
toward 6-8 inches north of I-96. We'll see how the track of the low 
evolves over time. At this point, freezing rain doesn't look to be 
much of a player in this system. 

Highs will be mostly in the 30s through Friday before colder air is 
brought down on the back side of the late week low. 

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 623 PM EST Sun Feb 10 2019

The initial burst of snow was pushing eastward through the TAF
sites at this time and noticeable improvement has occurred at
KMKG. This could happen at the TAF sites further inland but the
risk for IFR or lower will exists through much of the night. The
risk for freezing drizzle is not zero but was not high enough to
include it in the forecast which we will need to monitor closely. 

Ceilings and visibilities should increase for Monday afternoon
ahead of the next storm moving in. Conditions are expected to
deteriorate considerably Monday night...beyond the current
forecast period as snow moves in.



&&

.HYDROLOGY...
Issued at 310 PM EST Sun Feb 10 2019

he hydro situation remains largely unchanged, with 3 flood warnings 
in place on the Grand River; at Portland, Comstock Park, and 
Robinson Township. The Portland flooding is due to a combination of 
multiple ice jams as well as higher flow from snowmelt and recent 
rains. Downstream at Comstock Park and Robinson Township, the higher 
flows were due to snowmelt and recent rains. All 3 flood warnings 
look like they will need to continue for the next few days. The 
situation is not likely to change much as we head into the work 
week, given high flows down the length of the Grand River. 

The one thing that could change the situation is the variable that 
is the least predictable: ice. There is ice in the river, at least 
in spots from upstream of Portland down to Robinson Township. Ice 
may break up in spots and jam in locations such as shallow areas, 
bends in the river and at locations where the river channel narrows. 
So, persons with interests along not only the Grand, but other 
rivers as well in the Southwest quarter of the state will need to be 
mindful that levels could change rapidly.  

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 7 PM Monday to 1 AM EST Wednesday 
for MIZ037>040-043>046-050>052-056>059-064>067-071>074.

&&

$$

SYNOPSIS...04
DISCUSSION...04
AVIATION...MJS
HYDROLOGY...63