201 FXUS63 KGRR 161108 AFDGRRArea Forecast Discussion National Weather Service Grand Rapids MI 708 AM EDT Tue Sep 16 2025
.KEY MESSAGES...
- Dry and Warm Through Friday
- Showers Possible This Weekend Into Next Week
&&
.DISCUSSION... Issued at 237 AM EDT Tue Sep 16 2025
- Dry and Warm Through Friday
With high pressure in place and light winds we will have the potential for fog the next few nights and early mornings. We`re already seeing some visibility drops toward Alma and lower ceilings in Mount Pleasant. This is seen on the nighttime microphysics satellite imagery expanding from Saginaw Bay. It is in this area we are expecting the lowest visibilities to be present with some locally dense fog possible. Reduced visibilities could expand across the US-127 corridor with any fog burning off within a few hours of sunrise. Similar conditions are expected Tuesday night into Wednesday morning and could expand farther west. Make sure to slow down, give yourself extra time, and use your low-beam headlights in fog.
Light easterly winds and warm temperatures with highs in the 80s continue through the week. A lake breeze is likely each day bringing some cooler temperatures along the lakeshore during the afternoon. A front Thursday night into Friday will bring slightly lower temperatures for Friday with highs in the mid 70s to mid 80s. The 10 to 20 percent PoPs along this front have decreased with the latest trends. This is likely due to the dry air in place, but some increased cloud cover remains possible.
- Showers Possible This Weekend Into Next Week
As the upper level ridge weakens, a weak shortwave trough approaches for the weekend. This may be enough for some showers to develop Saturday and continue into Sunday. Ensembles pick up on this more heading into Sunday night and then are in even more agreement heading into Monday and Tuesday. The higher confidence toward the beginning of next week is due to a stronger/deeper trough bringing with it better moisture. Amounts overall look light in the ensembles with only a 5 percent probability of an inch or more during any 24 hour period.
&&
.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 707 AM EDT Tue Sep 16 2025
Fog this morning is focused mainly north of the TAF sites, but could see visibilities drop into the IFR/MVFR category briefly this morning around 12Z. VFR conditions are expected through the day with a lake breeze along the lakeshore this afternoon. Another round of fog is expected tonight and is expected to be more widespread tomorrow morning dropping visibilities to IFR values and potentially down to LIFR especially toward JXN and LAN.
&&
.MARINE... Issued at 237 AM EDT Tue Sep 16 2025
Fair conditions continue through the week with a chance (20 to 30 percent) for showers over the weekend. Winds will be easterly initially during the day before the lake breeze develops and moves more onshore during the afternoon today and Wednesday. Waves of a foot or less are expected through most of the forecast.
&&
.GRR WATCHES/WARNINGS/ADVISORIES... MI...Dense Fog Advisory until 10 AM EDT this morning for MIZ045-046- 051. MARINE...None.
&&
$$
DISCUSSION...RAH AVIATION...RAH MARINE...RAH
NWS GRR Office Area Forecast Discussion