789
FXUS63 KGRR 101441
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1041 AM EDT Sat Aug 10 2024

.KEY MESSAGES...

- Below normal temps this weekend

- Dry with near normal temperatures most of next week

&&

.UPDATE...
Issued at 1033 AM EDT Sat Aug 10 2024

There`s been a few shallow showers up around KCAD. Radar indicates
that they may be extending into northern parts of our CWA. The
latest HRRR suggests there will be some showers developing this
afternoon and more so early tonight, even down into the I-96
corridor. There will be some low level convergence down this was
so perhaps enough low level lift and 0-3 km CAPE to warrant those
showers. The 12z KAPX sounding does show this 0-3 km CAPE. We did
shift the potential for showers south this afternoon to include
northern parts of the CWA and then further south into the I-96
corridor for tonight.

&&

.DISCUSSION...
Issued at 315 AM EDT Sat Aug 10 2024

- Below normal temps this weekend

Gusty wnw winds and fairly extensive stratocu today (particularly
over our northern/central fcst area as suggested by 00Z HREF cloud
progs) will result in unseasonably cool wx with high temps only
reaching the upper 60s to lower 70s. Isolated showers are expected
as well with the cyclonic flow and lake induced instability.
However moisture is lacking so only low pops are warranted.

High temps Sunday will be a few degrees milder reaching the middle
70s and dry wx is expected given a bit less in terms of lake
induced instability and rather dry airmass in place. West winds
will increase a bit again but will not be as quite gusty as
today as the pressure gradient eases up a bit begins to ease up a
bit as the low moves further from our region.

- Dry with near normal temperatures most of next week

Still no stronger signals in longer range guidance for rainfall
events of any consequence. PWAT values remain on the low side until
perhaps the end of next week into next weekend when it`s possible an
upper trough or closed upper low will set up nearby. At this time
only 20 pops are warranted for Thursday and beyond though.

Temperatures should be right around normal for mid August as surface
ridging dominates, with highs around 80 and lows 55-60. Dew points
look to remain the 50s most of next week so comfortable humidity
levels continuing. The passage of weak shortwaves aloft from time to
time may provide some occasional cloudier periods otherwise a good
deal of sunshine is expected next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 713 AM EDT Sat Aug 10 2024

VFR weather continuing today and tonight with scattered to broken
clouds located between 3500 and 6000 ft. Isolated showers are
possible tonight but confidence is too low to include any VCSH
remarks in the TAFs at this time. Westerly winds increasing by
mid-morning, with some gusts around 25 kts this afternoon. Sfc
wind speeds relaxing this evening with sunset.

&&

.MARINE...
Issued at 315 AM EDT Sat Aug 10 2024

Gusty west to northwest winds today along with cool air advection
will result in wave heights of up to around 4 to 7 feet. A
consensus of latest high res guidance suggests winds and waves
will stay up overnight into Sunday with wave heights still up in
the 3 to 5 foot range Sunday. Therefore we decided to extend the
sca and beach hazards statement through 21Z Sunday. Winds and
waves will finally subside late Sunday through Sunday night as the
low pulls away.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through Sunday afternoon for MIZ037-043-
     050-056-064-071.
MARINE...Small Craft Advisory until 5 PM EDT Sunday for LMZ844>849.

&&

$$

UPDATE...MJS
DISCUSSION...Meade/Laurens
AVIATION...Meade
MARINE...Laurens