403
FXUS63 KGRR 071040
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
540 AM EST Thu Nov 7 2024

.KEY MESSAGES...

- Tranquil Weather Late This Week

- Unsettled Pattern Ahead

&&

.DISCUSSION...
Issued at 139 AM EST Thu Nov 7 2024

- Tranquil Weather Late This Week

A sfc high pressure ridge to our west will bring tranquil wx today
through Friday. IR sat trends and sfc obs early this morning show
extensive low cloud cover continues to linger across our area.

It is anticipated that low clouds today will not dissipate as
quickly as most short range guidance suggests. This is due to
ample lingering low level moisture near to below around 3 kft agl.
Forecast soundings show this will linger which in conjunction
with a substantial temperature inversion will result in extensive
lingering low cloud cover this morning particularly over our
western fcst area. IR sat trends due show some clearing may work
into our eastern fcst area this morning.

More in the way of clearing will gradually develop across the rest
of our fcst area this afternoon as drier air advects in and partly
cloudy to mostly clear skies are expected tonight through Friday.
High temps will reach the mid to upper 50s today and tomorrow with
low temps mainly in the mid 30`s to mid 40`s (mildest near the
Lake MI shoreline).

- Unsettled Pattern Ahead

We`ll be dry until Saturday night as a cutoff low over AZ, UT, NM,
CO becomes absorbed into an open wave and moves into the region.
Upper level jet dynamics, positive vorticity advection, warm air
advection, and low level jet convergence will all be in play. A
few rumbles of thunder overnight into Sunday morning are not out of
the question either. There are some timing differences and a signal
for a later start time Saturday night. There also continues to be a
signal for a brief lull sometime during the morning/early afternoon
as drier air briefly works into the area before the vorticity
maximum with the upper level low moves over the area bringing
another round of showers and maybe a few rumbles of thunder. Within
the northwest flow and cold air advection lingering lake effect rain
showers are possible overnight Sunday into Monday with 850mb and
lake temperature differences around 13 C.

Ensembles highlight a break in precipitation Tuesday as high
pressure briefly takes residence. Otherwise attention turns to the
middle of next week as a strong, negatively tilted trough swings
through the region sometime during the Wednesday/Thursday timeframe.
Models highlight a strong low level jet with the low centered north
of the area. The overall timing will impact how unstable we are with
this system, at this point ensembles highlight the overnight
timeframe which could limit our CAPE values. Either way, we`ll have
to watch the potential for severe storms with this system.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 540 AM EST Thu Nov 7 2024

A mix of VFR/MVFR conditions will continue this morning with MVFR
as a result of lingering low clouds. Conditions will slowly improve
to mostly VFR this afternoon as low clouds gradually dissipate.
Northwest winds aob 10 kts will veer to the west today.

&&

.MARINE...
Issued at 301 AM EST Thu Nov 7 2024

Fairly minimal winds and wave heights are forecast today. However
we will hoist a sca from Holland northward from late tonight
through mid afternoon Friday as west winds will increase as a low
pressure system moves across Hudson Bay.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory from midnight tonight to 3 PM EST Friday
     for LMZ846>849.

&&

$$

DISCUSSION...Laurens/RAH
AVIATION...Laurens
MARINE...Laurens