715 FXUS63 KGRR 171145 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 645 AM EST Tue Feb 17 2026 .KEY MESSAGES... - Central Michigan Freezing Rain Late Tonight - Chance of a Thunderstorm Wednesday Morning - Mixed precipitation with thunderstorms possible again late week - Low chances for accumulating snow this weekend && .DISCUSSION... Issued at 353 AM EST Tue Feb 17 2026 - Central Michigan Freezing Rain Late Tonight Winter Weather Advisory for freezing rain in Clare and Osceola Counties late tonight hinges on the median of the HREF. This area remains on the southern fringe of where freezing rain is most likely to occur across North-Central Lower MI. FZRA is climatologically favored to dip a little south of what is modeled in these scenarios due to the higher terrain in the interior of Central Michigan. The FRAM mean from both the 12z and 00z HREF favors about 0.1 to locally 0.25 inches of freezing rain over Clare/Osceola. However, there remains considerable spread among the member models, as just slight differences in wet bulb temperature can make a big difference in the freezing efficiency of the half-inch of precip that will fall by daybreak Wednesday. There is about a 25 percent chance that virtually no freezing rain will occur in Clare/Osceola, and also a 25 percent chance that portions of adjacent counties just west and south of the advisory could be affected. - Chance of a Thunderstorm Wednesday Morning SPC day 1 and 2 thunderstorm outlook covers the threat in our area from about 4 AM to 10 AM Wednesday. Hail and wind threat is generally less than 5 percent but not zero. A couple hundred J/kg of MUCAPE develops on the western extent of the precipitation as it moves through (instability occurring toward the end of the precip event). Midlevel moist parcels may not be very inhibited from realizing this CAPE, and moderately sheared updrafts may briefly climb through a -10 to -20 Celsius layer. Later Wed morning, steeper midlevel lapse rates associated with the elevated mixed layer advecting through will contribute to higher values of surface-based CAPE, however, surface parcels appear to be strongly capped and model QPF is zero as that occurs. The meager chance of severe would plausibly only occur in association with any small scale gravity waves that develop and move in tandem with convective cells. For example, Monday`s 18Z HRRR is an outlier solution depicting locally strong southeast winds, well before daybreak, briefly intensifying within a small wake low that propagates from west to east. (Previous Discussion...) - Mixed precipitation with thunderstorms possible again late week There is significant disparity among the model solutions regarding what to expect with the next wave of low pressure, but the most plausible scenario at this point is precipitation lifting north into the area starting Thursday afternoon. Thunderstorms will also be possible during this time. Minimum temperatures Friday morning drop below freezing up towards US-10, where there could be a mix of rain and snow, and this wintry mix is expected to spread southwards during the day Friday. This is admittedly a rather precise description, but one that is quite subject to change given the relatively poor predictability at this forecast range. - Low chances for accumulating snow this weekend Impacts are expected to be limited this weekend. Snow eventually becomes the most likely precipitation type with little to no accumulations expected. Temperatures at 850mb won`t be particularly cold; medium range ensemble guidance shows only a 40 percent chance of less than -10C, which is marginally favorable for lake effect. Highs should climb into the lower/mid 30s both days. && .AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 645 AM EST Tue Feb 17 2026 Patchy fog in some areas resulting in temporary LIFR (and recently some below minimums at LAN, TEW, FPK, and AMN) will gradually clear out between 13 and 15 Z. Short term guidance is encouraging for VFR in the afternoon, except for portions of Central Michigan near AMN and MOP. Ceiling and visibility deteriorates to IFR tonight especially between 03 and 06 Z, with rain showers moving in. Instability near the top of the cloud layer, at about 7,000 to 10,000 feet, occurring after 09 Z, may result in convective cloud tops to 20,000 feet and a chance of thunderstorms. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory from midnight tonight to 9 AM EST Wednesday for MIZ039-040. MARINE...None. && $$ DISCUSSION...CAS/TJT AVIATION...CAS

NWS GRR Office Area Forecast Discussion