Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 241900

Area Forecast Discussion
National Weather Service Grand Rapids MI
300 PM EDT Thu May 24 2018

Synopsis/Short Term/Long Term/Marine/Hydro

Issued at 300 PM EDT Thu May 24 2018

Warm weather will remain in place over the area through the next
week. High temperatures will generally be in the 80s everyday.
Humidity levels will increase this weekend, and then drop a bit
early next week.

Rain chances will be rather low much of the weekend, however they
will not be zero. Friday will remain dry, with shower/storm chances
increasing a little on Saturday. A majority of the time will remain
dry, especially toward the lakeshore. The chance will be best also
in the afternoon and evening hours. Rain chances will drop by next
Tuesday as a slightly cooler air mass moves in. They will return by
Thursday of next week.


.SHORT TERM...(This evening through Saturday night)
Issued at 300 PM EDT Thu May 24 2018

No impacts expected through Friday across the area. Shower/storm
chances will increase beginning Friday night and linger into
Saturday evening.

Upper ridging situated just west of the area today, will slowly
traverse the state through Friday afternoon. Limited moisture return
through Friday and sufficient subsidence with the ridge will keep
the area dry. A bit more humidity will sneak in on Friday, but will
not be enough to cause rain.

A short wave will approach the area Friday night and Saturday as the
upper ridge shifts east of the area. The better forcing with the
short wave will remain just north of the area. The associated sfc
front will try and drop down into the area, but likely gets hung up
just north with the short wave staying mostly north. This will keep
the better chances for showers/storms north Fri night.

Then on Saturday as the sfc wave moves by, wrly winds will likely
stabilize much of the area with flow off of the lake. Inland areas
could see ML CAPEs increase to 1500 j/kg before the west winds kick
in. Deep layer shear is fairly weak, so we do not expect anything

.LONG TERM...(Sunday through Thursday)
Issued at 300 PM EDT Thu May 24 2018

We could see an afternoon or evening shower/storm Sunday with temps
well into the 80s once again and dew points around 60. The coverage
will once again be limited as there will not really be a good focus,
other than maybe something along the lake breeze or any other
boundary that could form on the small scale.

The chance for afternoon showers/storms on Mon has gone down
compared to previous forecasts. The models indicate that a back door
cold front will drop south through the area Mon morning. This will
shunt instability south of the area. High pressure will build in for
Tue, along with a NE wind around the high to our North.

The ridge will slip east of the area mid-week next week, and allow
warm and humid conditions to return to the area. Eventually enough
instability will return to bring a chance of an afternoon/evening
storm to the area. A short wave looks to come through around the
Thursday time frame, bringing a little better chance of rain.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 119 PM EDT Thu May 24 2018

The aviation weather pattern looks rather quiet through the
period. VFR weather is forecasted with lighter than normal winds.
With the atmosphere continuing to dry out...the fog risk is
diminished. I did add wind gusts to KMKG by noon Friday....but
those should remain under 20 knots.


Issued at 300 PM EDT Thu May 24 2018

No headlines expected through the holiday weekend, and likely
through much of next week. Winds will come up some beginning
tonight, and lingering into early Saturday ahead of a weak system.
The strongest winds will stay further North and offshore. Winds and
waves will try to approach advisory criteria, but are expected to
remain short of it at this time.

Winds coming up should keep the fog chances limited over the lake,
even as dew points come up a bit. Can not rule some fog out, but it
should not be significant enough at this time to need another


Issued at 300 PM EDT Thu May 24 2018

No hydrology issues expected over the next week, and likely beyond.
Any rainfall expected over the next week will be spotty at best, and
thus not cause impacts on the rivers and streams. The higher levels
currently on the rivers and streams will only fall through next




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