textproduct: Grand Rapids

KEY MESSAGES

- Freezing Rain through north early Sunday

- Potential Winter Storm and Windy Monday

- Clipper New Year's Eve

DISCUSSION

Issued at 330 PM EST Sat Dec 27 2025

- Freezing Rain through north early Sunday

Bottom Line Upfront: Have issued a Winter Weather Advisory for inland two tier counties, including the US 10 corridor and Big Rapids and Mount Pleasant. Threat will be freezing rain tonight through Sunday morning. Icy roads with ice accumulations up to a tenth of an inch will be possible. A Warm frontal pattern will move in overnight bringing rain showers tonight through the first half of Sunday. An inversion will set up over the north with temperatures in the above locations expected to drop to and below freezing. Model soundings show a large warm nose from around 2KFT to 8KFT with a moist low level around 28F. Give that moist low levels and cold SFC, these are prime conditions for Freezing rain/drizzle. Conditions will warm through the morning with any frozen precipitation becoming rain by the afternoon.

- Potential Winter Storm and Windy Monday

Strong upper level low remains on track to move into the region Sunday evening through Monday. This low will bring strong cold air through Michigan showing a sharp transition from rain to snow Sunday evening. The tight pressure gradient will coincide with the cold front moving through Sunday night. Strong northwest flow behind the front will couple with lake enhancement to bring quite the Porcella nivis. Winds continue to trend potentially upward of 40 to 50 mph along the lakeshore. The main question is whether those winds will coincide with the best snow rates to reduce visibilities. The main concern will be heavy snowfall along the lakeshore, and snow covered roadways along with reduced visibility's which could make travel hazardous. With 3 to 6 inches, along with locally higher amounts possible, along the lakeshore, and slightly lower amounts along the US 131 corridor, have issued a winter storm watch for Sunday night through Monday. The worst conditions will affect the Monday morning commute. Inland the winds are expected to be slightly weaker but potentially upwards of 45 to 55 mph. Due to that, have a high wind watch for Lower Michigan East of the US 131 corridor. Snow east of the US 131 corridor is still possibly 1 to 4 inches and depending on wind amounts, an advisory will probably be needed tomorrow. Strong forcing will continue into Monday evening before subsiding into Tuesday. Lake effect snow could linger into Tuesday.

- Clipper New Year's Eve

Fast northwest flow brings a short wave trough/clipper Wednesday New Years Eve into Thursday with some lake enhancement and the potential for travel impacts Wednesday evening into Thursday morning. There remains some questions on timing but snowfall remains in the, 1 to 3, or, 2 to 4, inch range.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 639 PM EST Sat Dec 27 2025

Key changes: - added a second window of wind shear Monday evening

No major changes this update, but it should be noted that guidance still strongly suggests ceilings below 200 feet could be realized at many of our terminals for at least a brief period overnight, so I am revising my estimated probability of this occurring from 20 percent to 40 percent. Otherwise, LIFR conditions will be persistent and widespread for the valid period of these TAFs.

Wind shear conditions Sunday morning will affect the I-94 terminals (AZO-BTL-JXN) and now appear to extend a bit farther northward to include the GRR terminal. We will see a second episode of LLWS affecting all but our northwesternmost terminals Sunday afternoon/evening as a strong low level jet brushes southeastern Lower MI.

MARINE

Issued at 355 PM EST Sat Dec 27 2025

Model soundings and cross sections of wind/mixing heights from the CAMS continue to show 50 to 55 knots in the mixing layer under a strong cold advection regime so a Storm Warning has been issued for Sunday night into Monday evening.

GRR WATCHES/WARNINGS/ADVISORIES

MI...Winter Storm Watch from late Sunday night through Monday evening for MIZ037-038-043-044-050-056-057-064-065-071-072. Winter Weather Advisory from 1 AM to 1 PM EST Sunday for MIZ038>040-044>046. High Wind Watch from late Sunday night through Monday evening for MIZ039-040-045-046-051-052-058-059-066-067-073-074. MARINE...Storm Warning from midnight Sunday night to 1 AM EST Tuesday for LMZ844>849.