662
FXUS63 KGRR 111045
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
645 AM EDT Sat Apr 11 2026
.KEY MESSAGES...
- Excessive rainfall potential next week
&&
.DISCUSSION...
Issued at 156 AM EDT Sat Apr 11 2026
- Excessive rainfall potential next week
Sunday through Thursday holds the potential for more flooding
rains as Plains lows track into the Great Lakes. This is similar
to the synoptic pattern last week that brought flooding and could
also result in severe weather at times.
The first batch of rain moves in late tonight with an area of
warm advection/isentropic ascent. Expect some elevated convection
persisting into Sunday morning along and north of a warm front.
Surface-based instability is limited until the front pushes north
on Sunday afternoon.
Another round of rain and embedded thunderstorms then follows for
Sunday night along the front trailing the sfc low tracking into
southern Canada. Model soundings show deep moisture and this is
reflected in precipitable water of 1.5 inches. MBE vectors are
less than 5 knots during this time indicating any persistent
updrafts will result in flooding rains.
There is only a short lull before a series of surface lows move
along a baroclinic zone aligned from the Southern Plains to the
central Great Lakes from Tuesday into Thursday.
The pattern could continue even beyond that as both the GFS and
ECMWF depict a significant low arriving by next Saturday.
&&
.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 645 AM EDT Sat Apr 11 2026
VFR conditions through this evening with light winds early this
morning going southeast AOB 10 kts later today.
&&
.MARINE...
Issued at 156 AM EDT Sat Apr 11 2026
After a lull in the winds and waves today and tonight there will
be a chance for south gales late Sunday into Sunday night. Winds
and waves will remain hazardous to small craft through at least
Wednesday.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Ostuno
AVIATION...Ostuno
MARINE...Ostuno
NWS GRR Office Area Forecast Discussion