359
FXUS63 KGRR 270520
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
120 AM EDT Thu Jun 27 2024

.KEY MESSAGES...

- Fair weather and cooler into Friday

- Showers and storms Late Friday into Saturday

- Warmer mid week next week with showers/storms

&&

.DISCUSSION...
Issued at 330 PM EDT Wed Jun 26 2024


- Fair weather and cooler into Friday

A large Surface to mid level level ridge is situated over the
mid west including the Ohio valley. That system will keep dry air
entrenched over the region tonight through tomorrow and into
Friday. Weak upper level flow will keep northerly winds through
this timeframe. Max temperatures will be around 5 to 10 degrees
below normal.


- Showers and storms Late Friday into Saturday

The ridging that will be bringing the nice weather to the area for
the first couple of days will give way to a couple of short waves
that will bring the next chance of rain to the area as early as
later Friday afternoon. The rain chances Friday afternoon and
evening will be on the lighter side, and not widespread. The first
short wave won`t have a lot of moisture with it coming off a couple
of dry days and a lack of strong Gulf moisture advecting in.

The best chance per model ensemble means and looking at individual
members will be late Friday night and Saturday morning. This will be
the result of another stronger short wave moving in, and a bit
better moisture to work with. Both of these systems look like they
will have little to no chance of severe weather. This is due to the
limited moisture with the first wave, and bad timing for instability
with the second.

Once the second short wave moves through Saturday, the sufficient
moisture will be swept out of the area. This will essentially end
rain chances. There does look to be another short wave come through
Sunday. A lack of moisture, and more broad scale subsidence building
in will likely keep it dry through Monday. The air will be a bit
cooler however with lower heights/troughing moving in for a couple
of days.

- Warmer mid week next week with showers/storms

We will see the upper ridge early next week shift east of the area
by Tuesday. A decent longer wave upper trough will emerge from the
Pacific NW into the Upper Midwest. What this will do is setup a
deeper SW flow aloft and at the sfc, to bring in warmer temperatures
and increasingly more humid air Tuesday/Wednesday.

Larger scale lift with the long wave trough, and some short waves
embedded in the trough will start increasing the rain chances over
the area beginning on Tuesday and lasting into Wednesday. The
instability will build sufficiently to provide for storms at times.
Timing of the individual short waves with respect to the time of day
will facilitate whether severe weather chances will be present. The
flow is such that it will try to help any storms that develop to try
and organize. We will continue to fine tune this portion of the
forecast.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 119 AM EDT Thu Jun 27 2024

VFR conditions will continue through Thursday with northwest
winds 5 to 10 knots.

&&

.MARINE...
Issued at 333 PM EDT Wed Jun 26 2024

Currently winds and waves are under performing however there are
some gusts getting into the 15 to 20kt range. Latest models show
winds and waves will build through the afternoon and evening so
will keep Will keep the beach hazards statement and the SCY in
place for now.

&&

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

&&

$$

DISCUSSION...NJJ/Ceru
AVIATION...Ostuno
MARINE...Ceru