124
FXUS63 KGRR 171625
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
1225 PM EDT Wed Jul 17 2024

.KEY MESSAGES...

- Isolated showers and storms today

- Fair weather and below normal temps Thursday

- Dry pattern continues into next week

&&

.UPDATE...
Issued at 1124 AM EDT Wed Jul 17 2024

Based on the instability over northern zones at this time, along
with some increased low level convergence, I expanded the thunder
risk for today. Otherwise I kept the Beach Hazards and Small Craft
advisory going. The winds have been increasing over Lake MI and
they are expected to increase some more as the pressure gradient
tightens up this afternoon and evening. The flow will be from the
north northwest and thus the north sides of piers will experience
the most impacts this afternoon and evening as the waves build.
Water temperatures were in the 70s, so we may see an increased
number swimmers in the water during the changing conditions.

&&

.DISCUSSION...
Issued at 300 AM EDT Wed Jul 17 2024

- Isolated showers and storms today

A mid to upper level disturbance moving in from the nnw will
combine with weak instability from daytime heating and pool of
cooler air aloft to bring potential for isolated storms. The
relatively best chc for an isolated shower or storm will be over
our ne fcst area this aftn where stronger mid to upper level pva
will develop. However even there coverage of any pcpn will be
rather limited given weak instability and an increasingly drier
airmass with nw winds.

- Fair weather and below normal temps Thursday

The high pressure ridge will build overhead Thursday and bring
mostly sunny skies with seasonably cool temps in the lower to
middle 70s and mins mainly in the 50s.

- Dry pattern continues into next week

Stretch of dry/pleasant weather continues through the weekend
with comfortable temperatures and humidities. While some weak
troughing will exist aloft, the sfc pattern has a large area of
high pressure overhead. Highs near 80 and lows in the 50s with
partly cloudy skies will be the rule and can`t rule out the
possibility of some late- night/early morning shallow fog patches
given the light wind regime under the sfc high.

While an isolated shower or storm is possible mainly inland from
Lk MI Sunday through Tuesday, our next decent chance of rain does
not really emerge until the middle or late part of next week when
the troughing aloft becomes a bit more pronounced and somewhat
higher PWATs return. Even this is far from a sure thing though
given general lack of deep layer shear and limited potential for
organized systems. Many locations may not see any appreciable
rainfall for over a week which is more typical for late July and
in contrast to the active/rainy pattern we`ve seen recently.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 1225 PM EDT Wed Jul 17 2024

VFR conditions will dominate the weather today. The main exception
is isolated showers and storms this afternoon, especially at LAN
and JXN. A weak line of showers has already moved through LAN
around noon. Have vicinity showers in TAF though the threat of a
storm impacting a terminal is still low and variable enough to
mention thunder in the TAFs. Northwest winds increasing to 10 to
20 kts this afternoon then diminishing to less than 10 kts after
sunset.

&&

.MARINE...
Issued at 300 AM EDT Wed Jul 17 2024

A SCA and beach hazards statement is in effect from noon through
early Thursday morning. Northwest winds will increase to around 10
to 20 kts with a few higher gusts as the pressure gradient
strengthens a bit in advance of high pressure building into the
upper midwest today. Minimal wind speeds and wave heights are
forecast Thursday and Friday as the ridge builds over our region.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through late tonight for MIZ037-043-050-
     056-064-071.
MARINE...Small Craft Advisory until 6 AM EDT Thursday for LMZ844>849.

&&

$$

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