Area Forecast Discussion
Issued by NWS Grand Rapids, MI
Issued by NWS Grand Rapids, MI
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062 FXUS63 KGRR 030015 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 815 PM EDT Tue Jul 2 2024 .KEY MESSAGES... - Showers with scattered thunderstorms tonight into tomorrow - Strong storms remain possible for Friday - Unsettled weather at times next weekend and early next week && .DISCUSSION... Issued at 324 PM EDT Tue Jul 2 2024 - Showers with scattered thunderstorms tonight into tomorrow Scattered showers continue to stream through the region, mainly along and north of I 96. These showers will continue to move to the northeast as the incoming trough pushes any remaining high pressure eastward. A stronger line of showers and storms out ahead of a frontal system will move through tonight into tomorrow morning. None of the storms are expected to become severe, especially given the lack of dynamics and the time of day. Dry air will move in behind the exiting convection with clearing skies mid to late Wednesday. - Strong storms remain possible for Friday Most of the area should stay dry on Thursday, before shower/storm chances move back in for Friday. We will be in between systems for the most part on Thursday. The front that moves through on Wednesday will slip far enough south of the area to take most if not all of the rain chances with it. There is a small chance the I-94 corridor sees a brief shower on the northern edge of any complex riding along the front. There is fairly good agreement that we will have a potential period of stronger storms on Friday. Models are in fairly good agreement in bringing a healthy short wave and associated sfc front through the area on Friday afternoon. The low level jet associated with the system will help to bring a warmer and more humid air mass (implying instability) up over the area ahead of the upper and sfc features. In addition, an upper level jet max with the upper wave will help to provide plenty of deep layer shear for the storms that are looking increasingly likely to form. There are still a lot of details that have to be worked out, (exact timing, low level flow, etc...) but it is something we will continue to keep our eye on. - Unsettled weather at times next weekend and early next week The system moving through Friday looks to be the beginning of a general pattern change that is expected to hold over the Upper Midwest and Great Lakes into next week. We will see general long wave upper troughing settle in over the area as a fairly extensive upper ridge will set up over the western half of the country. The period from Saturday through next Tuesday will see chances for showers and storms at times. These chances will come via short waves that will be rotating around the long wave trough. These types of scenarios are difficult to pin down this far out due to the evolution of the upper low and where and when if it closes off or not, and the timing of the short waves. Generally speaking, temperatures should be kept down slightly with the lower heights expected. It does not look to be too cool, and could still be warm if the sfc flow ends up from the south. Even with multiple chances of rain expected off and on, much of the time will be dry. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 815 PM EDT Tue Jul 2 2024 Scattered showers this evening mainly north of I-96 impacting MKG. A few rumbles of thunder in that batch of showers should clear east over the next hour. A lull in rain activity this evening with some wind shear possible for northern terminals. Additional rain will moves into the area after 06z tonight from the west as a front approaches. All sites should drop towards MVFR and some northern TAF sites may see a few hours of IFR ceilings. Clouds will lift around mid-day Wednesday. && .MARINE... Issued at 324 PM EDT Tue Jul 2 2024 The small craft / beach hazards threat this afternoon into tomorrow has two portions. The main question was to either wait to issue the second until the first has ended or to issue an advisory to encompass both threats. I chose the latter. South-southeast winds over Lake Michigan will continue to strengthen this afternoon as a pressure gradient continues to tighten between the exiting higher pressure and the approaching frontal system. There will be periods of gusts 25 to 30 knots mainly at and north of Whitehall. There will be a lull in the winds, mainly between 8 pm and 2 am Wednesday, then the winds will increase out of the southwest towards sunrise. These winds will coincide with showers and storms moving through overnight. After frontal passage, including the showers and storms, Winds and waves will slowly decrease Wednesday morning into the afternoon. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 8 AM EDT Wednesday for LMZ844>849. && $$ DISCUSSION...NJJ/Ceru AVIATION...Thielke MARINE...Ceru