-- Discussion containing changed information from previous version are highlighted. --
809
FXUS63 KGRR 102312
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
712 PM EDT Mon Jun 10 2024

.KEY MESSAGES...

- Cold Night; Pleasant Tuesday

- Low Rain Chances Tuesday Night, Wednesday Night

- Storms Possible Thursday, Could be Strong

- Weekend Warmup, Hot by Sunday/Monday

&&

.DISCUSSION...
Issued at 323 PM EDT Mon Jun 10 2024

- Cold Night; Pleasant Tuesday

A rather chilly night by June standards is in store as clear
skies, dry air and light winds promote min temps in the lower to
mid 40s. Even some lows in the 30s expected across the typically
colder spots near/north of M-20 and wouldn`t rule out some patchy
pre-dawn frost in a few spots. Chamber of Commerce weather
prevails on Tuesday with highs 70-75 and low humidity under an
amplified upper level ridge, although some increase in high level
clouds is expected in the afternoon.

- Low Rain Chances Tuesday Night, Wednesday Night

The next chance of rain arrives on Tuesday night as a shortwave
breaks down the upper ridge and a sfc frontal boundary tries to
lean in from the northwest. It`s only a low (20-30%) chance and
generally restricted to areas north and west of GRR as the air
mass is still quite dry. The elevated instability and main thunder
risk stays west of MI too. A slightly higher risk for a few
showers/storms arrives later Wednesday night as a low level jet
and better moisture return looks to be present along with steeper
mid level lapse rates.

- Storms Possible Thursday, Could be Strong

Will need to monitor the potential for some stronger storms on
Thursday as warm sector air mass sneaks in briefly and a mid
level wave and sfc cold front drops down from the north later in
the day. SB Capes of 1500-2000 J/KG are progged along with deep
layer shear increasing to greater than 40 kts. A faster frontal
passage would likely preclude a severe weather threat but there is
still much uncertainty/spread in that regard at this time.

- Weekend Warmup, Hot by Sunday/Monday

Currently the weekend looks predominately dry as the
aforementioned frontal boundary slips south of the state and a
sfc high builds in. The return flow on the back side of that high
and rising H5 heights ushers in a warming trend, with highs near
90 expected by Sunday and lower 90s by next Monday.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
-- Changed Discussion --
Issued at 712 PM EDT Mon Jun 10 2024

High confidence in VFR the next 24 hours as high pressure settles
over the region. Winds will relax with the setting sun after 01 Z,
staying mainly light through Tuesday but with some variability in
direction as lake/land breeze oscillations tug on air movement
locally.
-- End Changed Discussion --

&&

.MARINE...
Issued at 323 PM EDT Mon Jun 10 2024

Cool northerly flow of 15-25 kts continues to generate hazardous
conditions for beach goers and mariners at the lakeshore this
afternoon, particularly on the north side of piers and especially
south of Grand Haven. Conditions gradually falling to safer
levels by Midnight tonight, with areas south of Holland being the
last to see larger waves subside.

After relatively tranquil conditions on Tuesday, the next period
of potential concern comes late Tuesday night into Wednesday when
southerly winds increase. Most susceptible for large waves in
this regime will be places north of Holland.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until 8 PM EDT this evening for MIZ037-
     043-050.
     Beach Hazards Statement until 11 PM EDT this evening for MIZ056-
     064-071.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LMZ844>846.
     Small Craft Advisory until 8 PM EDT this evening for LMZ847>849.

&&

$$

DISCUSSION...Meade
AVIATION...CAS
MARINE...Meade