Bittersweet Ski Area snow report

692 FXUS63 KGRR 170602 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 202 AM EDT Sun May 17 2026 .KEY MESSAGES... - Thunderstorm potential returns Sunday and lasts through Tuesday - Mostly dry and cooler Wednesday and beyond && .DISCUSSION... Issued at 239 PM EDT Sat May 16 2026 - Thunderstorm potential returns Sunday and lasts through Tuesday After an early morning round of locally strong convection, conditions have cleared out nicely across the area this afternoon. We are now likely in a lull of thunderstorm activity until no earlier than very late tonight, and more likely tomorrow morning. This is because we have a front dropping through the region. It is almost to the Lake Michigan shoreline of Wisconsin as of 2 pm this afternoon. This front is mainly a dew point boundary, and will not encounter any instability before dark since a lot of it was cleared out by the convection earlier. In addition, there is really no forcing mechanism aloft to help the front. The front will drop to Southern Lower Michigan by later tonight before stalling out. The HRRR was a bit overzealous with redeveloping additional convection overnight earlier compared to other sets of model data. Latest versions are trending down, and coming into better agreement with other model consensus. We believe this is the right trend as tonight will be different than last night/this morning with no low level jet to lift up over the front to develop convection. We do believe that we will see storm activity pick up Sunday morning and afternoon. We will see the upper flow back a bit to the SW as an upper trough is carved out over the Rockies. This will help the stalled out front lift northward across the area, with increased moisture inflow riding over the front. In addition, a weak short wave/MCV looks to approach the area. MU CAPEs will increase to potentially 2,000 J/kg, with the instability elevated north of the front. Effective shear values are highest at the edge of the instability, and taper off further south. Mid level lapse rates will be on the increase providing a hail threat. Areas with a shallow stable layer could see some wind mixed down to the sfc. A tornado can not be ruled out with good good low level shear near the warm front confirmed by a decently curved hodograph, and SRH`s 150-300 m2/s2 at 0-1 and 0-3km respectively. We should see a break then Sunday night and early Monday as the warm front lifts north of the entire area, putting us in the warm sector. Thunderstorm chances will increase then Monday afternoon and evening as we see the better flow with short wave activity settle into the area, along with the theta e axis. The very warm and increasingly humid air mass will supply the fuel. Potential short waves could fire storms over the area. The one limitation at this time looks to be limited deep layer effective shear only around 20 knots at the synoptic scale. Still plenty of other parameters to compensate for the lack of shear to produce a severe threat. steep mid level lapse rates and DCAPEs over 1,000 J/kg will provide a hail and wind threat. We lose the potential a bit Monday night and Tuesday morning as we lose the heating of the day. That will ramp back up Tuesday afternoon with additional heating. The more favored area Tuesday afternoon looks further SE as the front will be moving through, and those areas have a better chance to maximize heating before the frontal passage. Deep layer shear becomes much better with the better mid-level winds. That combined with potentially strong instability would supply a decent severe threat with all hazards in play. That is quite a bit of time out yet, with things likely to change a bit with regards to timing. - Mostly dry and cooler Wednesday and beyond The front will exit the entire area Tuesday evening, bringing an end to the severe threat. We may keep some low level moisture in early on Wednesday, but a fairly strong area of high pressure will build over the area. This high will remain in control of the weather potentially into next weekend as we get trapped between the northern and southern streams. This will bring seasonable temperatures with mostly dry conditions. Temperatures will gradually increase a bit later in the week as return flow sets up, after the coolest weather with temps in the 60s on Wednesday. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 202 AM EDT Sun May 17 2026 A warm front will lift north through Southwest Lower Michigan tonight, including through all of the TAF sites. The front may touch off a few showers and storms this morning between 11z and 16z at KMKG and KGRR and then for all the TAF sites this afternoon between 17z and 22z. For the most part VFR weather is expected to prevail outside of some scattered showers and storms. The time frame that this activity would impact any one of the TAF sites will be limited. There is a chance for some MVFR ceilings at KMKG for a couple of hours around 18z, but left this small chance out of the TAF at this point. The front should be north of the TAF sites this evening and expect quieter/VFR conditions after 01z. Winds will generally be out of the south today with sustained speeds of 08-12 knots with some gusts to around 20 knots. && .MARINE... Issued at 239 PM EDT Sat May 16 2026 We look to remain headline free for the marine waters for just about all of the daylight hours on Sunday, before needing one beginning Sunday evening. It is at that point that we get into the warm sector solidly, and the gusty winds that come with it. Once the winds pick up Sunday evening, we will likely need a headline through Tuesday when the cold front moves through. Right now it looks like this will be a solid SCA event, with just a small chance it may increase enough to flirt with Gales. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...NJJ AVIATION...Duke MARINE...NJJ