779
FXUS63 KGRR 230737
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
337 AM EDT Tue Jun 23 2026
.KEY MESSAGES...
- Showers Wednesday into Thursday
- Zonal flow through rest of week
- Warmer Weather Ahead
&&
.DISCUSSION...
Issued at 328 AM EDT Tue Jun 23 2026
- Showers Wednesday into Thursday
Not a whole lot has changed in the forecast for the system
midweek. High pressure will continue to dominate the pattern
through Tuesday. A large upper level low will trek southward over
the Great Lakes region. This will correspond with a short wave
trough that will move across Lake Michigan with associated
moisture. Along with that as written in previous discussions
there will be a LLJ of 20-30kts advecting along with it. The main
question remains how warm we get during the daytime. The mid
level trough could allow for 6 to 7 C/km Lapse rates with MUCAPES
above 1000 J/kg and DCAPES upwards of 900 to 1000 J/kg. Given the
1.1 inches of PWATs this would give this system, instability,
moisture and forcing. However, if the temps are tempered, if the
clouds keep the mid levels moist, then the lapse rates will remain
subdued and any storm formation will be stunted. Currently, SPC
is keeping the region in the general thunder with a marginal risk
in Wisconsin. Given the latest RFFS this makes sense, as its CAPE
is lower than other CAMS. However, as stated, there is the
potential, between 22Z Wednesday until 06Z Thursday, when storms
could become strong. Showers and storms will linger into early
Thursday along with system passage before moving eastward
Thursday.
- Zonal flow through rest of week
Zonal flow with fair weather will continue through the latter
portion of the week and into the weekend. Temperatures will be
warming up, with highs in the upper 70s by Friday and into the
80s over the weekend.
- Warmer Weather Ahead
The 80s over the weekend will be a taste of things to come. As
the CPC has been showing in its outlooks, a warmer trend will be
upon us next week. The region is expected to jump to 5 to 10
degrees above normal by next week. While there could see chances
for rain, the most dominant feature next week will be the heat.
High pressure over the southern United States will be juxtaposed
to an upper level low over central Canada. This will leave
Michigan and central Plains in the track that will bring warm air
advection through the region with 850 mb temps potentially +21C
mid next week. That could bring Max temps into the 90s, with
dewpoints into the 70s.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 328 AM EDT Tue Jun 23 2026
Fair weather with VFR cigs and vsbys to dominate the weather
through the period. Expect gusty winds of 15 to 20 kts to mix
down mid to late morning.
&&
.MARINE...
Issued at 328 AM EDT Tue Jun 23 2026
Winds and waves will continue to subside overnight through the
first half of Tuesday. Gusty northwest flow could allow waves to
peak at 2 to 4 feet late in the day. Not expecting headlines at
this time.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Ceru
AVIATION...Ceru
MARINE...Ceru
NWS GRR Office Area Forecast Discussion
