848
FXUS63 KGRR 031151
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
751 AM EDT Fri May 3 2024

.KEY MESSAGES...

- Showers and thunderstorms taper off today

- Next Chance Showers Saturday Night; Dry Sunday into Monday

- Continued Mild Next Week with Occasional Showers and Storms

&&

.DISCUSSION...
Issued at 343 AM EDT Fri May 3 2024

- Showers and thunderstorms taper off today

Numerous showers and scattered thunderstorms cover the area first
thing this morning. These storms have been just some good old
fashioned garden variety storms with some isolated small hail and
wind gusts of 30 to 40 mph winds. We will see more of the same over
the next few hours, with the thunder threat diminishing a bit as the
better instability shifts east.

The area is under a nice moist axis, out ahead of a front that is
over Eastern Wisconsin as of 07z. Instability is weak with only a
few hundred J/kg of CAPE and slightly negative LI`s. These
parameters are just enough to produce some lightning and thunder.

It looks like we should see the front gradually start clearing the
area from West to East after 13-14z. With the front clearing the
area, the showers and storms will be coming to and end also. We
should see some sunshine break out this afternoon in the wake of the
front, bring a nice half day to the area.

The only thing of note tonight is the potential of low stratus
advecting over the southern half of the area from the SE overnight.
All of the low clouds/moisture getting swept out with the front will
make a partial return overnight. The low level flow becomes from the
SE, and taps the low level moisture with the front. Tough to say how
far it will make it. The far SE portion of the area toward Jackson
has the best chance, while the Muskegon area and areas north will
see the lowest chance being further removed from the moisture source.

Most of the day on Saturday will remain dry and warm. There are a
couple of small chances for a little bit of spotty rain. The first
is over the SE portion of the area during the afternoon. The
lingering low level moisture, combined with a weakening front moving
over the area may touch off a few showers/weak storms.

The second area that may see a few showers late in the afternoon
will be the lakeshore, with northern areas seeing the best chance.
The front that meanders over the area on Saturday will be mainly dry.
We do see some almost pure convergence develop along/behind the
front, and a weakening short wave aloft. These factors will combine
to produce a line of showers and isolated storms, possibly as early
as late Saturday afternoon at the lakeshore.

- Next Chance Showers Saturday Night; Dry Sunday into Monday

A weak cold front will cross the state on Saturday night into early
Sunday with a few showers and storms along it. High pressure builds
in behind the front providing a period of dry weather Sunday into
Monday before a warm front returns north on Monday night and
Tuesday.

- Continued Mild Next Week with Occasional Showers and Storms

Guidance pops still 70-80 percent Tuesday/Tuesday evening as Plains
trough sends out a shortwave in our direction, although some timing
differences on this feature are still present.

The middle to late part of next week appears to remain rather active
as broad/positively tilted longwave trough edges slowly in our
direction. Series of fronts/troughs pivoting around a slowly
approaching upper level low along with lingering warmth/instability
will maintain a daily convective threat.

Temperatures remaining above normal most of next week before cooling
off next weekend with the eventual arrival of the upper low/trough.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 751 AM EDT Fri May 3 2024

Areas of IFR will be present this morning as showers continue to
pull through, but the threat of thunder appears to be over now.
Improving conditions expected this afternoon as showers end from
west to east, with VFR following. However stratus makes a
reappearance late tonight, starting first at JXN around 06Z or
so, then spreading westward from there through 12Z Sat.


&&

.MARINE...
Issued at 343 AM EDT Fri May 3 2024

It appears that we should not need any marine headlines through at
least Saturday. We could be looking at a possible Small Craft
Advisory event for Saturday night and Sunday.

Even with the system overhead this morning, there is not much of a
pressure gradient on either side of it, so no big wind events for
the time being. We do see a weak front slide over the area on
Saturday, and then move out by Sunday. The way the systems come
together, there ends up being a decent gradient on the back side of
the system that could push winds up above thresholds Saturday night
into Sunday.

The next potential headline event after Saturday Night/Sunday will
be Monday night into Tuesday with the next system.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Meade/NJJ
AVIATION...Meade
MARINE...NJJ