057
FXUS63 KGRR 031913
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
313 PM EDT Fri May 3 2024

.KEY MESSAGES...

- Increasing Chance for Showers/Storms Later Saturday into
  Saturday night

- Dry end of the weekend

- Many chances for rain next week


&&

.DISCUSSION...
Issued at 231 PM EDT Fri May 3 2024

- Increasing Chance for Showers/Storms Later Saturday into
  Saturday night

Southerly winds ahead of an approaching cold front will draw up
moisture from the south Saturday into Saturday night. Instability
increases as well later Saturday afternoon into Saturday night,
but overall remains weak. Aloft some upper level divergence is
seen Saturday night over the CWA so that may enhance the lift.
Thus the combination of moisture, lift and instability will likely
lead to showers and a few storms. Ensemble QPF values, while low,
have been trending up with the precipitation for this period.


- Dry end of the weekend

High pressure over the upper Mississippi Valley will produce plenty
of sunshine Sunday. Highs will climb to a couple of degree either
side of 70.

- Many chances for rain next week

The persistent upper trough over the western US is progd to cut off
over the northern High Plains during the middle of the week. The
result will be several short waves that move in our direction and
bring chances for showers and storms.

Tuesday night through Wednesday night will be a time frame that will
see increased chances for precipitation. An occluded front will lift
north toward Lower MI Tuesday afternoon and this will produce some
showers/storms. Present indications are that the strongest
instability will remain south of the state. However, that could
changed this far out. SPC has already highlighted areas to the
southwest of the state for the potential of severe storms.

Another chance of showers/storms will come Thursday and Thursday
night, when the surface low over the northern Plains moves east.
Accompanying short waves and a feed of moisture rich air from the
south will spur convective development during this time.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 136 PM EDT Fri May 3 2024

A cold front is moving slowly across Lower MI this afternoon. A
line of showers has developed along it between GRR and LAN. This
line should clear LAN/JXN by 21z. Cigs are generally MVFR but a
few pockets of IFR exist. Look for improvement by the end of the
afternoon when VFR conditions will develop.

Models show a fairly strong signal for stratus to develop over
Canada tonight and move east in easterly flow. We`ll see IFR
develop overnight at LAN/JXN and then spread west and lift a bit
as it approaches GRR/MKG.

&&

.MARINE...
Issued at 231 PM EDT Fri May 3 2024

Southerly flow will be on the increase Saturday into Saturday
night as a front moves in from the west. This will be warm air
advection and overall the values are expected to remain under 20
knots. Thus we don`t plan on needing headlines a this time.



&&

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

&&

$$

DISCUSSION...MJS/04
AVIATION...04
MARINE...MJS