056
FXUS63 KGRR 301730
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
130 PM EDT Thu Apr 30 2026
.KEY MESSAGES...
- Cool with chances of rain and likely frost/freeze through Saturday
- Warming up with chances of rain early next week
- Stronger system mid next week with better chances of rain
&&
.DISCUSSION...
Issued at 256 AM EDT Thu Apr 30 2026
- Cool with chances of rain and likely frost/freeze through Saturday
We are seeing the last vestiges of the system exiting the eastern
portion of the area that moved in yesterday and overperformed for
most of the area. We will see a bit more dry weather for today along
with some sunshine as we will be under the influence of some short
wave ridging following the short wave trough exiting.
The next wave embedded in the flow around the upper low centered
over the Lake Superior/Ontario area is poised to move toward the
area this evening. The difference with this one is that it is taking
aim at far Southern Lower and Northern Indiana. This is where the
majority of shower activity will take place this evening and early
overnight tonight.
For the rest of the area, we really expect little to no rain for
tonight. There is a thought that we may need some frost/freeze
headlines if skies clear out enough with light winds. The issue is
that we are likely to see a good deal of mid cloud cover which will
prevent temps from really tanking enough. We will hold off on any
headline decisions given the current headlines out, and the
uncertainty for the affects of the clouds.
Friday should be mainly dry also, with just a small chance once
again for southern and eastern areas with the wave moving out early,
then better instability to the east. Friday night looks to be the
best chance of a frost/freeze with highs on Friday only in the 40s,
and then dropping quickly at night with dew points in the 20s and
lighter winds holding on. No real strong short wave is expected on
Saturday either, so mostly dry conditions expected.
- Warming up with chances of rain early next week
Sunday is now looking mainly dry also in this unsettled weather
pattern. We will start the day out with short wave ridging building
over the area. A short wave and associated cold front will approach
likely toward or after dark. We will see a flow from the SW, helping
to bring warmer air over the area after a couple of colder days.
This will help with instability some, but will wane as the front and
short wave arrives after peak heating.
Monday will start out milder and dry, but the potential for rain is
increasing through the day. There is a fairly strong jet streak and
short wave digging SE toward the area at that time. Model solutions
are now showing a trend toward more moisture from the south being
absorbed into the stronger northern stream wave to bring more
widespread rain than previously expected. The increase in moisture
and warmer air, combined with cooler air with the wave looks to
produce some potential instability for thunder. This moves out by
Tuesday.
- Stronger system mid next week with better chances of rain
Yet another stronger northern stream wave dives SE and digs a
stronger long wave trough over the Northern Plains late Tuesday and
early Wednesday. That will induce a stronger low out ahead of it.
That in turn will assist Gulf moisture making it further north all
along the front. The track and strength of this system is a bit more
uncertain as one would expect 7-8 days out. It is definitely
something to watch as it could produce some good convection, or
bring down some colder air.
&&
.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 128 PM EDT Thu Apr 30 2026
Scattered to broken vfr cu was noted on latest visible imagery.
Upstream cloudiness will move across the terminals tonight as low
pressure moves across northern IN. Light rain is possible at the
I-94 terminals and a prob30 group was added for this.
&&
.MARINE...
Issued at 256 AM EDT Thu Apr 30 2026
No headlines expected at least through Thursday night expected at
this time. There have been a couple of isolated gusts to SCA
criteria, and some waves of 3+ ft, just a little under criteria. We
expect that today better winds aloft will not mix down over the
colder Lakes, and should stay below 15 knots.
Our next headline event could be on Friday. This is one of the more
subtle scenarios where high pressure building in can squeeze the
gradient a bit with the land mass warming. There is decent potential
that we see 20+ knots Friday afternoon and evening.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Frost Advisory from 2 AM to 8 AM EDT Friday for MIZ037-043>046-
051-052.
Freeze Watch from late Friday night through Saturday morning for
MIZ037>040-043>046-050>052-056>059-064>067-071>074.
Freeze Warning from 2 AM to 8 AM EDT Friday for MIZ038>040.
MARINE...None.
&&
$$
DISCUSSION...NJJ
AVIATION...04
MARINE...NJJ
NWS GRR Office Area Forecast Discussion
