169
FXUS63 KGRR 020546
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
146 AM EDT Tue Jul 2 2024

.KEY MESSAGES...

- Showers/storms possible Tuesday/Tuesday evening

- Isolated Showers/Storms Wednesday

- Chance of Thunderstorms Friday

&&

.DISCUSSION...
Issued at 330 PM EDT Mon Jul 1 2024


- Showers/storms possible Tuesday

 Sunny and and cooler weather will continue today with some clouds
increasing overnight as a high continues to weaken as it moves
eastward. A large upper level low will be moving through southern
Canada tonight into tomorrow. this will bring a warm air out
ahead of it so temperatures will be closer to normal tomorrow. It
will also mean a frontal pattern will move through tomorrow
afternoon/evening. Scattered showers with some isolated storms
will be possible beginning in the northwest then spreading to the
southeast tomorrow night. Latest QPF is upwards of an inch to an
inch and a half in NW Mason county through most elsewhere it will
be a half an inch or less.

- Isolated Showers/Storms Wednesday

A weakening cold front will wash out over our area Wednesday. A
consensus of latest guidance suggests that an isolated shower or
storm may just clip our se fcst area but that dry wx will prevail
for the vast majority of the area. Convective development is more
likely se of our fcst area Thursday afternoon. No airmass change
will occur as this front washes out and warm and humid wx will
continue late in the week.

- Chance of Thunderstorms Friday

A sfc low pressure system and mid to upper level wave will combine
with increasing instability and deep layer shear to bring potential
for organized convection Friday. A risk for severe wx may exist but
this will be largely contingent on timing and how much instability
develops. Seasonably warm and fairly humid wx is expected to
continue through the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 140 AM EDT Tue Jul 2 2024

An area of showers and thunderstorms in southwest WI and southeast
MN will continue to track towards the TAF sites through the
remainder of the night and into Tuesday morning. As they approach
MI, they are forecast to weaken. However it appears they will not
completely dissipate before arriving so I featured VCSH at times
in the TAF`s. Elevated instability is show to arrive later Tuesday
and into Tuesday evening but confidence on thunderstorms at any
particular TAF site was too low to include in the forecast at this
time.

&&

.MARINE...
Issued at 330 PM EDT Mon Jul 1 2024

Winds will increase tomorrow afternoon and evening with the
south-southeasterly flow. These winds will slowly shift to a more
southerly wind flow. There will be periods, especially north of
Holland, where parts of the shore and near shore could be
hazardous for small craft and swimming due to waves and currents.
However, there will be large lull periods and winds will be
shifting. So due to this variability and the winds being marginal,
have held off on headlines for now.

&&

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

&&

$$

DISCUSSION...Laurens/Ceru
AVIATION...MJS
MARINE...Ceru