Springport, Michigan Weather Forecast Discussion

745
FXUS63 KGRR 221758
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
158 PM EDT Mon Sep 22 2025
.KEY MESSAGES...
- Chances for showers and storms the next 3 days
- Drying out towards the end of the week and into the weekend
- Temperatures near to above normal
&&
.DISCUSSION...
Issued at 403 AM EDT Mon Sep 22 2025
- Chances for showers and storms the next 3 days
All of southwest Lower Michigan is in a general thunder outlook
from the SPC for today, Tuesday and Wednesday. This is due to the
fact that we do not change the airmass (surface dew points in the
60s) through Wednesday. Aloft, we are located in the southern
portion of an upper trough both today and Tuesday and move beneath
a developing upper low on Wednesday. What this means is unsettled
weather will continue with a diurnal boost to showers and storms
each day. The instability lessens a bit each day as the surface
boundary associated with the upper trough slides south into and
through the area. We cannot rule out a few storms each day
however. Not expecting severe weather with any of the activity
given weak flow (generally 25 knots or less of wind from the
surface through the mid levels).
- Drying out towards the end of the week and into the weekend
We look to dry out as we get out into Friday and into the weekend
as the flow transitions to zonal and then ridging into Sunday.
Given drier air in the low levels we have a mainly dry forecast
from Friday through Sunday.
- Temperatures near to above normal
850mb temperatures are about where we would expect for this time
of year between +10C to +15C. This should equate to high
temperatures in the 70s most days. By next weekend climo values
are trending into the upper 60s as we close in on October.
Pleasant weather for sure with mainly dry conditions and warmer
than normal temperatures.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 157 PM EDT Mon Sep 22 2025
Ceilings have recovered above IFR but a broken MVFR cloud deck is
still prevalent across some of the terminals. Scattered showers
and thunderstorms have been moving over Lake Michigan and a few
pop up showers and isolated storms have been occurring over land.
PROB30 groups are currently the best way to handle this threat
into the afternoon and evening given the weak nature of the
convection and overall coverage expected. Lowering visibilities
are likely later tonight (especially after 06z) and additional
showers with a few thunderstorms are possible as well, though
location is difficult to determine at this point.
&&
.MARINE...
Issued at 403 AM EDT Mon Sep 22 2025
Winds and waves are expected to remain below advisory levels
through much of if not all of the work week. A lax pressure
gradient is in place this morning across the region and that will
remain the case into Tuesday. There will be an increase in north
and northeast flow Tuesday evening into Wednesday as the gradient
tightens for a time between low pressure to our south and a high
off to the north. We are not expecting conditions to become
elevated enough though to warrant a Small Craft Advisory or a
Beach Hazards Statement. Waves should be 2 feet or less through
the week. For what September can bring to the waters of the Great
Lakes this will be a tame week on the big lake.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Duke
AVIATION...Hoving
MARINE...Duke

NWS GRR Office Area Forecast Discussion