899
FXUS63 KGRR 291139
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
739 AM EDT Wed May 29 2024

.KEY MESSAGES...

- Lingering rain this morning, clear and cold night into Thurs

- Low Chance of Weekend Showers, Mainly on Saturday

- Periodic Shower/Storm Chances Early Next Week

&&

.DISCUSSION...
Issued at 330 AM EDT Wed May 29 2024

- Lingering rain this morning, clear and cold night into Thurs


 The slow moving upper level trough continues to fuel a quasi
stationary boundary allowing for continued rain showers through
far southwest Michigan. Rain showers continue along and south of
the I 94 corridor and west of Battle Creek. While the showers
continue to decrease in intensity they have spread out in area.
Building ridge over the the central Plains into central Canada
will slowly push the upper level low and the moist boundary
fueling these showers eastward this afternoon. Dry northerly flow
downsloping off the building ridge will advect into the area,
ending showers this afternoon as the boundary is finally pushed
into the Ohio river valley and the Mid Atlantic.

Lower Michigan will remain in a juxtaposition between the positively
tilted upper level trough extending from the upper level low to the
northeast and the building ridge to the west. This will keep dry air
over the area into Thursday with persistent northerly winds. The
northerly flow advecting dry air into the area will bring clear
skies tonight into Thursday morning. Lows will drop tonight into the
mid 30s along and north of the US 10 corridor. So patchy frost is
likely, however the winds should remain strong enough for it to not
become widespread.  Maximum temperatures will creep back into the
upper 60s to low 70s today and tomorrow though highs remain slightly
below normal.

- Low Chance of Weekend Showers, Mainly Saturday

After a sunny/pleasant Friday with highs in the mid 70s, models are
still sending a shortwave from the Central Plains through the region
on Saturday. However incoming precip could struggle due to a pre-
existing dry/stable air mass over MI. Generally only a 20-30 percent
shower chance anticipated at this time and any thunder threat should
be restricted to far srn sections. Still fairly good potential for a
dry Sunday in the wake of that shortwave but a small (20) pop was
maintained mainly south and east of GRR.

- Periodic Shower/Storm Chances Early Next Week

Flat/zonal upper flow for early next week will probably send a
shortwave or two through Lwr MI but timing of such waves remains
low. Currently it looks like the best wave comes through later
Monday into Monday night with shortwave ridging following on
Tuesday, but will have to see if that holds. Otherwise rising dew
points and sfc instability in warm pattern will support a daily
shower/tstm chance each day early next week, enhanced by any
shortwave troughs and/or areas of sfc convergence.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 739 AM EDT Wed May 29 2024

VFR weather can be expected today and tonight. Lingering light
showers near and south of a BTL-LAN line will end soon, but a few
isolated showers could redevelop this afternoon. A tstm is not
completely out of the question either but the chance is too low to
have in any of the TAFs at this time. Cloud bases today generally
between 6000 and 9000 ft then skies clearing out this evening
after 00Z from north to south.

&&

.MARINE...
Issued at 330 AM EDT Wed May 29 2024

Bottom line up front, have expanded the small craft advisory this
afternoon to include all zones due to the northerly flow. The
downsloping northerly gradient will peak this afternoon into the
early evening. This will lead to an increase of the flow of
hazardous conditions. The northerly winds could allow brief
periods of hazardous conditions along the lakeshore and while
northerly beaches could be affected briefly, wave severity is
marginal and short lived.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from noon EDT today through this evening
     for MIZ064-071.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LMZ844>848.
     Small Craft Advisory from 2 PM this afternoon to 8 PM EDT this
     evening for LMZ849.

&&

$$

DISCUSSION...Meade/Ceru
AVIATION...Meade
MARINE...Ceru