Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 192030

Area Forecast Discussion
National Weather Service Grand Rapids MI
330 PM EST Thu Jan 19 2017

Synopsis/Short Term/Long Term/Marine

Issued at 330 PM EST Thu Jan 19 2017

Well above normal temperatures will extend through the weekend
with variable precipitation chances through the period. A cold
front will bring temperatures back to near normal territory
through the middle of next week, possibly including some wintry
precipitation as early as Monday night.


.SHORT TERM...(This evening through Saturday night)
Issued at 330 PM EST Thu Jan 19 2017

The main story in the short term will continue to be the warmth
and additional chances for rain.

Not much has changed with regards to the upper level wave that
will be progressing from south to north through the Central U.S.
late tonight into Friday. Precipitation is expected to develop
along and ahead of a warm front that extends to the east. Rainfall
develops and moves in from the southwest around/just after
midnight. I continue to believe that a couple of areas near Clare,
Harrison and Mount Pleasant could mix with freezing rain or sleet
in the onset. While the profiles do not suggest anything
impressive, it is worth mentioning with the shallow cooler air
hanging near 30 degrees into early Friday morning.

The main wave of rainfall should come to an end through Friday
afternoon with lull between any additional precip. Even warmer
air surges north into the region for the weekend with highs that
could surge well into the 50s Saturday. Another upper level wave
rotates northward through the upper Midwest, along with a decent
surface low tracking through Minnesota. This will keep
precipitation chances in the forecast and weaker bits of energy
rotate out ahead of the main circulation and through Michigan. The
upside to this is that if remains mild and showers are expected
to remain light.

.LONG TERM...(Sunday through Thursday)
Issued at 330 PM EST Thu Jan 19 2017

An active weather pattern looks to be in place through the long term
period. Troughing will be in place aloft to start the period on
Sunday, which will persist into Monday. A brief respite in the
weather is possible on Tuesday as ridging moves through aloft. An
upper low will pivot through the Great Lakes region from Tuesday
night through Thursday.

Temperatures will be well above normal on Sunday with a gradually
cooling trend through the rest of the period. After highs on Sunday
in the 50s in spots, we will cool to the 30s by Thursday.

Light rain showers will be possible from Sunday into Monday, but the
precipitation looks fairly light. A better chance for precipitation
is expected Tuesday night through Thursday associated with the upper
low. With the temperatures cooling, mixed rain and snow showers
Tuesday night and Wednesday will be transitioning to all snow for
Wednesday night into Thursday.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 157 PM EST Thu Jan 19 2017

An area of clearing has developed across Southern and Central
Lower Michigan as of 18z. This trend will continue through the
afternoon with most sites expected to scatter out. There will be
some mid and high clouds streaming in, but bases on these clouds
will be above 6000ft.

This evening, the low clouds will likely start to redevelop with
ceilings below 1000ft forecast by midnight. Rain will develop as
well, spreading in from south to north after 03z. By 12z on
Friday, we will likely have widespread IFR and LIFR in place with
low ceilings, rain and fog. The poor aviation conditions should
persist through the morning hours of Friday.


Issued at 330 PM EST Thu Jan 19 2017

Southerly winds look to be around 15 knots (or less) during the
daylight hours over the weekend. Wave heights will be greatest
over open water, but even that is fairly tame at 1-2 feet. Rain
showers move in overnight tonight into Friday morning with areas
of fog possible.


Issued at 330 PM EST Thu Jan 19 2017

The Grand River at Robinson Twp has risen several inches in the past
couple days as runoff from rain earlier this week is being routed
downriver and ice continues to restrict the flow. Most other rivers
are rising due to the rain but seem to have less notable ice impacts
now. Temperatures (and dew points) will be above 32 degrees through
about the middle of next week, with highs at or above 50 possible
Sat/Sun. Melting river ice should eventually break up, at which time
flooding at Robinson Twp would likely alleviate. Nonetheless, rivers
across the area, especially in the greater Grand basin and lower
Kalamazoo basin, continue to run high due to above-normal liquid
precipitation this month. A quarter to half inch of rain on Friday
won`t help either. Runoff efficiency is high due to saturated ground
and a lingering frozen soil layer. Low-land flooding near riverbanks
is occurring at multiple forecast points, but impacts to property
are not too out of the ordinary. The Maple River near Maple Rapids
has some risk of reaching Minor Flood Stage this weekend.




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