144
FXUS63 KGRR 262307
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
707 PM EDT Fri Jul 26 2024

.KEY MESSAGES...

- Dry and increasingly warmer into Sunday

- Shower/storm chances late Sunday through Tuesday

&&

.DISCUSSION...
Issued at 240 PM EDT Fri Jul 26 2024

- Dry and increasingly warmer into Sunday

More of the same weather that we have seen over the last couple of
days will continue through Saturday and into early Sunday. High
pressure at the sfc and aloft will remain in control of the weather
over the area through that time frame. This means just some cumulus
clouds, and a little bit of high level smoke that will filter the
sunshine at times. A relatively dry air mass will allow temps to
drop into the 50s again tonight, and warm up into the 80s on
Saturday. A return flow from the south/southwest will bring a bit
warmer temperatures over the area, and eventually additional low
level moisture.

- Shower/storm chances late Sunday through Tuesday

There will be a noticeable increase in the humidity levels by Sunday
afternoon, along with warm temperatures well into the 80s once
again. This will be brought over the area by the upper low toward
the Gulf that will be drawn to the NE by the long wave trough coming
in from Western Canada and the Pacific NW. The low level flow will
bring warmer and more humid air ahead of it.

We continue to expect that this will not be a widespread rain event,
but more of a scattered to numerous shower/storm event that will
peak in coverage during the afternoon/evening hours with peak
heating away from cooler Lake Michigan. As has been mentioned
previously, instability is not that impressive late Sunday with the
moisture just arriving. The limited moisture/instability combined
with weaker flow over the area aloft means a very low threat of
strong to severe storms late Sunday. This will be repeated on Monday
with the trough moving slow. There will be plenty of dry hours, but
rain chances will be there each day.

The shower and storm chances will continue on Tuesday, but
associated with another feature. This will be a short wave that will
approach the area late in the day. There are features there to help
trigger shower/storm development in the warm and humid air mass.
These features are not strong, and the winds aloft do not look
conducive to stronger storms at this time.

There could be a break in the action potentially around the
Wednesday time frame. This is because the Tuesday short wave could
clear out some of the moisture and some upper ridging builds in
behind it. The confidence in this timing is not high as we are 5
days out and talking about shorter wavelength features that are
tough to time. Chances are there will be a little bit bigger of a
break, before another short wave in a somewhat zonal upper flow
moves in toward the end of the period and brings back rain chances.
Temperatures will remain seasonable well into the 80s without any
significant cooling in the region, and the better ridging staying
south that would bring hot weather.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 707 PM EDT Fri Jul 26 2024

High pressure brings little to no chance of impactful weather at
all terminals for the next 24 hours. High confidence in VFR
conditions as a few lingering Cu around 5kft dissipate over the
next hour or two. Mainly clear skies then follow through the end
of the TAF period. The lake breeze at MKG ends shortly after
sunset with the wind shifting to the prevailing southeasterly flow
with winds under 10 knots. This wind pattern continues for all
sites except MKG through the end of the TAF period, while a lake
breeze develops again at MKG after 15z.

&&

.MARINE...
Issued at 240 PM EDT Fri Jul 26 2024

We do not anticipate the need for headlines through the upcoming
weekend into Monday at the very least. Weak pressure gradient in
place with the area of high pressure will stick around through
Saturday. We will see an increase in wind beginning on Sunday and
lingering into Monday, but it does not seem that it will be strong
enough to necessitate a need for headlines at this time.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

DISCUSSION...NJJ
AVIATION...Thomas
MARINE...NJJ