510
FXUS63 KGRR 111736
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
136 PM 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 /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 136 PM EDT Sat Apr 11 2026
VFR conditions continue with easterly winds becoming more
southeasterly tonight. The low level jet will also move into the
region creating low level wind shear of around 40 knots through
Sunday morning. Scattered showers will be possible late tonight
into Sunday morning as well with the best chances (60 percent or
greater) toward MKG and to the north. It is this area that
ceilings are expected to dip to MVFR with only a 20 percent chance
for IFR conditions at MKG Sunday morning into early Sunday
afternoon. There could be some embedded thunderstorms within the
showers but confidence was not high enough to include in the TAFs.
&&
.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...RAH
MARINE...Ostuno
NWS GRR Office Area Forecast Discussion
