181 FXUS63 KGRR 192327 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 627 PM EST Mon Jan 19 2026 .KEY MESSAGES... - Hazardous Travel Conditions into Early Tuesday Morning - Additional Rounds of Snow Wednesday into Friday - Rare and Potentially Near Record-Setting Cold This Weekend && .DISCUSSION... Issued at 330 PM EST Mon Jan 19 2026 - Hazardous Travel Conditions into Early Tuesday Morning A slow downtrend in the hazardous conditions is expected through tonight, as the worst of the winds and visibility is now past. West wind lake effect snow will continue along with pockets of blowing/drifting snow overnight, good for another 0.5 to 3 inches area-wide, bringing storm totals (not counting drifts) in the warning area to over 6 inches in many areas, and perhaps up to 14 inches between Holland and Grand Rapids where a narrow belt of 6 to 9 inches fell last night. Totals in central and south central Michigan are expected to range around 1 to 4 inches. Overnight, the air near the ground over Central Michigan may cool and decouple, reducing mixing becoming and a little less windy. Still, wind chills -10 to -15 F are likely, and a Cold Weather Advisory continues for interior areas along/north of US-10. Mecosta, Isabella, Montcalm, and Gratiot may also come close to a cold advisory. Lake effect snow will continue overnight, given persisting high instability off the lake surface and inversion heights staying above 5,000 feet, though most snow production should stay above the DGZ, limiting flake size. A weak 500 mb shortwave propagating through the cyclonic synoptic pattern overnight may also throw the lake effect a bit of a lifeline. With central Michigan interior potentially decoupling, low level wind convergence and therefore the main focus for snow will be near and west of US-131, with the exception of a confluence band that could extend farther east toward the Lansing area near or south of I-96. Travel Tue morning will still be slow and slick given the lingering snow and cold temperatures, but conditions slowly improve during the day with light snow showers. - Additional Rounds of Snow Wednesday into Friday The next wave of low pressure along a frontal boundary will roll through Wednesday morning, likely making for another challenging commute. Moisture and lift aloft within the warm air advection (front end) of this system occurring within about a 5,000 ft thick DGZ will contribute to potential half inch per hour snowfall rates leading into the morning commute. A swath of generally 1.5 to 3 inch totals appears favored by mid day Wednesday. 5 inch totals may be possible between Grand Haven and Ludington, where confluent SE/SW flow in the vicinity of the surface low, surface frontogenesis, and a shallow lake effect convective layer could contribute to enhancing snowfall rates near the shoreline. But if the track of the low ends up trending farther south, this scenario would be less of a possibility. Temperatures starting in the teens will rise into the mid 20s, perhaps around 30, during the day, making chemical road treatment more effective. Lake effect snow showers are then likely to continue late Wed through Fri as progressively colder 850 mb air within the broad cyclonic synoptic flow regime. - Rare and Potentially Near Record-Setting Cold This Weekend (Issued at 331 AM EST Mon Jan 19 2026) ECE guidance has been repeatedly indicating a rare bout of truly impressive cold coming our way Friday into the weekend. The Arctic Oscillation (AO) appears to be a major player in the longwave pattern and surface pressure anomalies setting up over the northern United States later this week and weekend. The AO is already negative and is about to drop further into some impressive territory, potentially around an index of -5. As the AO gets increasingly negative, we typically get increasingly colder. ECE probabilities for 850mb temperatures to drop to -30C or colder are now 80-100% across the U.P. and 60-80% near and north of US 10. Various deterministic runs of the ECMWF and GFS have the -30C isotherm (or colder) pushing through the entire Lower Peninsula. The ECMWF and GFS push air temperatures at the surface into subzero territory during the day Friday behind an impressive Arctic front that sweeps through late Thursday night or early Friday morning. Both models are indicating wind chill readings getting down to -25 or colder during the day. By Saturday, ECE mean high temperatures are showing highs around 0F with low temperatures of -10 to -20 across the region. At GRR for example, over 50% of the ECE members show -20 or colder and nearly 20% of the members show -24 or colder, which would tie the coldest reading ever recorded at Grand Rapids. Plenty could change between now and then but given the rarity and strength of the signal it is important to mention, and temperatures this cold can cause some significant issues to cold water pipes. Very cold temperatures are shown by the ECE to continue through the weekend and into the following week with additional subzero nightly readings possible. This will be something to keep an eye on with future forecast updates. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 626 PM EST Mon Jan 19 2026 Improvement will be slow tonight with MKG/AZO/GRR likely to stay IFR through 12z Tuesday as lake effect snow showers continue. BTL/LAN/JXN may bounce between MVFR and IFR as heavier showers track over the terminals. BLSN will diminish over the next few hours as winds continue to diminish. Leaned twoards MOS guidance which seems to be handling visbys well in timing out improvements. Snow showers will continue through late morning/early afternoon Tuesday before ending. MVFR cigs should persist through the rest of the TAF period. There are some signals in guidance that suggest a period of IFR cigs could occur overnight, climatology suggests this is uncommon in lake effect regimes to have left cigs MVFR with this package. Wind gusts to 20-25 knots will persist through the TAF period, highest at MKG. && .MARINE... Issued at 330 PM EST Mon Jan 19 2026 Gales on Lake Michigan are diminishing as expected, and the warning will be transitioned to a small craft advisory no later than 7 PM today. Heavy freezing spray continues through tonight. Winds will be a little less of a factor on Tuesday but still enough for some freezing spray. Hazardous conditions for small craft continue through the rest of the week. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Storm Warning until 7 AM EST Tuesday for MIZ037-038-043- 044-050-056-057-064-065-071-072. Cold Weather Advisory from 11 PM this evening to 8 AM EST Tuesday for MIZ038>040. Winter Weather Advisory until 7 AM EST Tuesday for MIZ039-040- 045-046-051-052-058-059-066-067-073-074. MARINE...Gale Warning until 7 PM EST this evening for LMZ844>849. Heavy Freezing Spray Warning until 7 AM EST Tuesday for LMZ844>849. && $$ DISCUSSION...Hoving/CAS AVIATION...Thomas MARINE...CAS

NWS GRR Office Area Forecast Discussion