732 FXUS63 KGRR 131855 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 255 PM EDT Fri Mar 13 2026 .KEY MESSAGES... - Strong winds continue into this evening with some additional snow - Strong storm to impact area Saturday night-Monday trending NW - Moderating temps and quiet conditions mid-late next week && .DISCUSSION... Issued at 255 PM EDT Fri Mar 13 2026 - Strong winds continue into this evening with some additional snow We will be leaving all headlines with the current event as is with this afternoon`s forecast package. The biggest impact for most of the area with the current system is the wind. We have seen some of the top winds thus far range from 56 to 62 mph. We continue to see many sites gusting into the 50+ mph range this afternoon. Wind cross sections show 50 knots of wind at 1- 2k ft agl until about 22-00z this evening. The other impact expected through this evening will be additional snow showers affecting most of the area, but additional accumulations expected over the higher elevation of the interior portions of Central Lower. Most sites have gone back to snow after a mix of rain earlier. The U.S.-127 corridor is still seeing some rain, but colder air advecting in there will change it over to snow soon. The Central Interior area is the most favored for additional snow accumulations with the favored area of the upper wave moving across this area. Some of which will be after dark that will help the cause for sticking, and the higher terrain (lower freezing level) will also assist. Thankfully the air does not get too cold before the snow stops later this evening. This will allow many roads to dry before they could potentially freeze. The best chance for ice on the roads will be up north where snow will accumulate and temps will drop below freezing sooner. We will see all snow end no later than around 06z tonight as the entire upper wave finally moves far enough east of our region. High pressure will settle in for Saturday. - Strong storm to impact area Saturday night-Monday trending NW We will be leaving the current Winter Storm Watch as is for this forecast package. The dry period on Saturday will be short lived as precipitation will make a run over the forecast area later Saturday night. This precipitation will be the result of low level moisture transport ramping up ahead of the main storm system that will just diving into the Plains at that time. This precipitation will start largely as snow with sufficiently cold enough air as it develops along and north of I-96. The precipitation will expand southward as a warm front develops at the sfc near the MI/IN line. Some of this precipitation may start out as rain as it will be warmer closer to the front. The snow up north could transition to a mix of sleet and freezing rain for a bit as the elevated warm layer advances northward. By mid-late Sunday afternoon, the latest trends in just about all of the model platforms have the mixed precipitation shifting north of our forecast area border. The trend with the system has been to the NW over the last few runs with the upper system wrapping up better. What looked like heavy snow and some freezing rain a couple of days ago for Ludington, now looks like some snow and freezing rain going to rain as warmer air gets further north. Now with the further north placement of the warmer air, one has to look at the other side of this system, the severe thunderstorm potential. Obviously a LOT of sheer going on with the strong upper jet overhead. However, instability at this time is looking quite weak, with maybe just enough for a chance of thunder. This is the case as the system looks to be starting to occlude as it gets here, and the best sfc based instability rides along the MI and IN/OH border. Still time for this to change, and it could become more of a problem if the trend to the NW continues. Maybe the worst conditions of this whole system will be on the backside of the system on Monday into Monday night. We will see all precipitation change to snow as the cold air moves back in. This cold air will come in via strong winds on the backside. We will likely see the wraparound snow bring some accumulations and blowing snow, and then some lake effect when the air becomes sufficiently cold. - Moderating temps and quiet conditions mid-late next week Once the large low lifts NE and away from the area later Tuesday, we will see conditions settle down for the rest of the week. One more wave moves through Wednesday, but it will not have much moisture associated with it. Temperatures will start out cold on Tuesday with the core of the low level cold air in place. We then see upper heights build from the main ridge axis over the Western portion of the country. The northern jet stream will lift well north of the area, and the upper flow will come from the Pacific. The low level flow will be coming from the SW, helping to advect warmer air over the area for the end of the week. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 200 PM EDT Fri Mar 13 2026 MVFR cigs and vsbys in rain and snow will continue through the afternoon. Plan on MVFR to IFR much of the day for most of the area. Strong low pressure system moving through with rain and snow showers today, gusty winds 30 up to 55 knots. While there could be periods of LLWS the strongest winds will make it to the surface and any winds aloft will be within 30 degrees. There will be another swath of precip this evening between 22Z and 02Z. After that conditions will slowly improve. Winds will drop between 02Z and 05Z, and then below 10kts between 05Z and 10Z. && .MARINE... Issued at 255 PM EDT Fri Mar 13 2026 We will maintain the current set of Storm Warnings and Gale Warnings into this evening, before a period of Gale Warning s will be needed overnight as winds begin to diminish more. Limited lakeshore observations indicate that wind gusts are right up there near Storm Force this afternoon, so there is no reason to downgrade it yet. The 50 knot potential diminishes right toward the end time of the Storm Warning. Gales will then hold on much of the night before dropping enough by daybreak Saturday. We will see a bit of a break on Saturday, before at least Gales, and possibly Storms may be needed with the next system Saturday night through Monday. Especially Monday as the strong winds on the backside of the system are accompanied by strong cold air advection. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...High Wind Warning until 8 PM EDT this evening for MIZ037-043>046- 050>052-056>059-064>067-071>074. Winter Storm Watch from late Saturday night through Monday evening for MIZ037>040-043>045. Winter Weather Advisory until 2 AM EDT Saturday for MIZ038>040- 044>046. MARINE...Storm Warning until 11 PM EDT this evening for LMZ844>848. Gale Warning until 11 PM EDT this evening for LMZ849. && $$ DISCUSSION...NJJ AVIATION...Ceru MARINE...NJJ

NWS GRR Office Area Forecast Discussion