250 FXUS63 KGRR 141815 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 215 PM EDT Thu May 14 2026 .KEY MESSAGES... - Notable Warmup Into Next Week - Several Chances of Showers and Storms Friday Night into Next Week, Some May Be Strong to Severe && .DISCUSSION... Issued at 213 PM EDT Thu May 14 2026 - Notable Warmup Into Next Week A substantial warmup is underway with 850 mb temps climbing well into the teens by Monday. Some uncertainty exists in Saturday`s temperature given the likely presence of an MCV driving shower/thunderstorm potential Saturday and more extensive resulting cloud cover. However, increasing south/southwest flow will support highs well into the 80s, perhaps approaching 90 in some places. Combined with dewpoints in the 70s, early next week will feel downright summer-like. Even once the cold front moves through next week, warm conditions continue with highs in the 70s. The one caveat to this however is that we may see frost develop overnight, especially across our traditional cold spots across our northeastern CWA, depending on how fast clouds move in. If clouds are slow to move in and temperatures fall faster, overnight lows could fall into the mid 30s. Confidence is not high enough to go with a Frost Advisory, but this will be monitored. - Several Chances of Showers and Storms Friday Night into Next Week, Some May Be Strong to Severe Several chances for showers and thunderstorms exist between Friday Night and mid-next week, with some questions as to the exact evolution of this pattern. Starting with Friday Night/Saturday, a mid-level MCV looks to support the potential for showers and thunderstorms across the area, with a second chance possible later Saturday near I-94 as a warm front noses north, with greater precipitation coverage south of the area. Attention then turns to early next week as a low pressure system strengthens across the Plains with a warm front surging north across the area. With MUCAPE aoa 1000 J/kg and PWATs climbing north of 1.5 inches increasing chances for showers and thunderstorms. Cannot completely rule out a stronger storm, but wind fields are weak, with deep layer shear around 30 knots, keeping the risk low. The greatest concern at this time is Monday where we currently sit in a Day 5 Slight Risk from the Storm Prediction Center. Dewpoints surging to near 70 with a 40-50 knot LLJ by Monday evening is synoptically supportive of the potential for strong to severe thunderstorms. However, timing of forcing remains uncertain, with the better threat expected off to our west. This matches what ML guidance from the GEFS/EPS suites has been indicating for several days. Thus, what time the storms arrive and by extension what environment exists for them when they do is uncertain and will become clearer over the next few days. The other concern is the fact that mid-level flow appears to be particularally weak, with the mid- level jet displaced west. This will limit the magnitude of deep layer shear available for these storms. Then, the pattern becomes more uncertain Monday Night into early next week. There is a trend in guidance that the strong ridging in place struggles to dislodge, preventing a cold front from crossing the area until later Tuesday. If this happens, strong to severe thunderstorms would be possible once again as diurnal heating builds instability ahead of the front. This reflects the ECMWF/AI-GFS/AI- ECMWF consensus. On the other hand, the GFS leads the pack of guidance that drives the cold front through Monday Night, putting us in a post frontal environment with little risk for severe thunderstorms Tuesday. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 129 PM EDT Thu May 14 2026 VFR conditions will dominate the pattern over the next few days. There will some partly cloudy skies but nothing substantial. Winds will go calm this evening and then mix out out of the south after sunrise. Gusty winds out of the south to southwest are expected at all TAF sites tomorrow after 15Z. && .MARINE... Issued at 213 PM EDT Thu May 14 2026 Conditions become hazardous to Small Craft starting mid morning on Friday as southerly flow strengthens. North of Holland,sustained winds to 20 knots, with gusts as high as 30 knots possible near Big and Little Sable Points, will drive 3-6 foot waves across the nearshore waters. A Small Craft Advisory will be issued from mid Friday morning through early Saturday morning. South of Holland, the wind field is weaker, so combined with the warm air advection regime limiting gust potential, confidence in more than isolated gusts reaching advisory criteria is low. In coordination with neighbors, will not issue a advisory south of Holland at this time. Winds are then lighter for the weekend, with the potential for fog over the waters as higher dewpoints surge into the region. && .FIRE WEATHER... Issued at 213 PM EDT Thu May 14 2026 Elevated fire danger is likely Friday, particularally along and north of M46 east of US131. Gusty southwest winds to 25-30 mph along with MinRHs falling in the low to mid 30s will drive elevated fire weather conditions.Land management partners report that fuels are drying quickly given little rain over the last day adding to the concerns. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory from 9 AM Friday to 5 AM EDT Saturday for LMZ846>849. && $$ DISCUSSION...Thomas AVIATION...Ceru MARINE...Thomas FIRE WEATHER...Thomas

NWS GRR Office Area Forecast Discussion