FXUS63 KGRR 200543 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 143 AM EDT Fri Mar 20 2026 .KEY MESSAGES... - Rain Showers North Tonight - Warmup Friday into Saturday, Rain Saturday Night/Sunday - Seasonable Temperatures Early Next Week, Mostly Dry && .DISCUSSION... Issued at 219 PM EDT Thu Mar 19 2026 - Rain Showers North Tonight A mid-level wave drives a surface low north of the area tonight, with the precipitation shield limiting the areal extent of showers to areas north of M-46. The latest probabilistic guidance favors conditions remaining warm enough for precipitation to fall as rain. This is reflective of the latest high resolution model guidance which allows temps to warm into the mid 30s before showers begin. - Warmup Friday into Saturday, Rain Saturday Night/Sunday Southerly flow Friday into Saturday will support a warmup into highs in the 50s north and 60s south. This will be disrupted by a mid- level wave driving a cold front across the area, though guidance varies on when exactly this occurs. Robust moisture doesn't arrive until late Saturday Night/Sunday in the post frontal environment. Latest guidance trends with the slowing of the front suggest precipitation remaining rain for most if not all of Sunday. - Seasonable Temperatures Early Next Week, Mostly Dry As the low/troughing departs, Monday will see the advancement of surface and mid-level ridging into the region. The forecast is generally for dry conditions, however latest guidance suggests that shortwaves (which are difficult to pin down at this forecast range) may drive low precipitation chances. Highs will generally be in the 40s to low 50s, which is near normal for this time of year. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 143 AM EDT Fri Mar 20 2026 Key changes: - extended LLWS through late morning - removed morning mention of MVFR ceilings Confidence for staying out of IFR restrictions through the period is around 90 percent. In fact, through 00Z tonight, we estimate a 80-90 percent chance of remaining VFR. Cloud bases should generally remain well above 10000 ft AGL. This is more optimistic than before, when we advertised ceilings of 2-3 kft AGL developing during the day. Based on model guidance, we decided to keep LLWS until around 16Z. It's unusual to continue LLWS well into the daytime like this, unless there is a strong warm front in the vicinity (which is not the case here). It appears that wind speeds and gustiness will increase as we go through the late morning; however, there appears to be just enough speed and directional (winds veering clockwise with height) shear to keep LLWS going for a while longer. As noted previously, it seems likely that terminals will remain VFR through 00Z. However, there are indications that ceilings around 2000 ft AGL could start affecting terminals not long after that. && .HYDROLOGY... Issued at 219 PM EDT Thu Mar 19 2026 Only one site remains at or above flood stage as of this afternoon. The Grand River at Comstock Park is now cresting at minor flood stage. The Maple River at Maple Rapids went below minor flood stage this morning allowing the warning to be cancelled. With light amounts of precipitation expected over the next few days, additional flooding is not expected. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Thomas AVIATION...TJT HYDROLOGY...Thomas