Swiss Valley Ski Lodge snow report

341 FXUS63 KGRR 180615 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 215 AM EDT Mon May 18 2026 .KEY MESSAGES... - Severe threat with possible tornadoes remains through mid evening - Periodic showers/storms possibly strong to severe through Tuesday - Much quieter and seasonable mid-late week && .DISCUSSION... Issued at 142 PM EDT Sun May 17 2026 - Severe threat with possible tornadoes remains through mid evening All of the ingredients remain in place for a possible severe event late this afternoon and evening for our area north of I-96. As mentioned earlier, we are concerned with an MCV over Wisconsin that looks to interact with a warm front that is draped over the heart of the forecast area. As of 17z/1 pm EDT, the front extended from near the Muskegon/Oceana county border, to Newaygo and Mecosta counties, to just south of Alma. The MCV over Wisconsin is already producing severe weather with Severe Thunderstorm Warnings and Tornado Warning there. Extrapolating this line of storms has it hitting Oceana and Mason Counties near Little and Big Sable Points around 4 pm. This trajectory looks very favorable for interacting with the front. The MCV will help to bump the Effective Deep Layer Shear values up to around 50 knots, right near the front where plenty of low level shear is present. The threat looks to be through about 00-01z/8-9 PM EDT before the MCV moves out. This is likely to give the area a lull in the shower/storm activity for much of tonight. - Periodic showers/storms possibly strong to severe through Tuesday The sequence of events is a bit uncertain then for Monday through Tuesday as multiple rounds of storms will be associated with the main sfc front and waves along it. What we do know is that we should be in the warm sector from Monday through at least early Tuesday. We could see the leftovers of a line of storms come in from our WSW very late tonight and Monday. This then would potentially affect additional development of convection, or subdue it with other convection that would try to form. We are thinking that the main threats Monday would be wind and hail. We do not have good low level shear present on Monday to support any tornado threat. One signal we do have for a better bet of convection will be late Monday night into Tuesday. This would the development of convection to our WSW, and try to bring it in here Tuesday morning. Then, depending on that convection, we will have the potential for frontal convection Tuesday afternoon and evening. The evolution of that will depend on how much early morning convection would affect the area, and limit destabilization ahead of the front. The air mass ahead of the front could be favorable for severe with sufficient destabilization, and 40-50 knots of deep layer shear. Low level shear is also favorable with a 45 knot low level jet core over the area. - Much quieter and seasonable mid-late week All of the rain should be out of the area by midnight Tuesday night/Wednesday morning. High pressure will build in at the sfc. We see a couple of short waves try to clip the area, but they look like they will stay just far enough north to not affect the area. The sfc ridge will funnel dry air in from the NE through Friday. A weak short wave approaches on Saturday, but it will not have much of any moisture to work with. There could be maybe a weak shower on Saturday, but for the most part the area should stay dry. Highs will start out in the 50s on Wednesday, and warm to the 70s by Fri/Sat. with return flow starting to develop. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 214 AM EDT Mon May 18 2026 There are two main aviation concerns today, the first being the chance of thunderstorms and the second being gusty south winds. As for the chance of thunderstorms, a line of weakening showers/storms is located off to the west over Wisconsin and Iowa at 06z. These showers/storms will continue to slowly move our direction and will begin to move into the area after 13z. We expect a weakening line of activity that should mainly be showers at that point. An uptick in activity or a redevelopment will occur between 16z and 18z as the activity move through Southwest Lower Michigan. A period of more substantial showers and some strong storms will be possible between 18z and 23z. After 23z, the activity should wind down and/or move off to the east. Conditions will largely be VFR outside of the short periods that the activity affects any one TAF site. As for the wind, shortly after daybreak or around 13z we expect winds to ramp up out of the SSW from 190-210. Speeds through the bulk of the day will be between 15-30 knots. && .MARINE... Issued at 142 PM EDT Sun May 17 2026 We are going to expand the current Small Craft Advisory further south to our border with IWX at St. Joseph. Plan views of winds indicate that the strongest and most consistent winds will remain north of Holland. However, there is enough wind on and off south of Holland to necessitate the SCA down there. Right now we have it going through Monday evening at 8 pm, but it will likely need to be extended at some point through the Tuesday frontal passage. Once the winds come down after the frontal passage on Tuesday afternoon, headlines will likely not be needed for the rest of the week. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for LMZ846>849. && $$ DISCUSSION...NJJ AVIATION...Duke MARINE...NJJ