textproduct: Marquette

KEY MESSAGES

- The threat for flooding continues due to snowmelt. A Flood Watch is in effect for everywhere except the far western UP through Saturday morning.

- Showers and thunderstorms are expected with a cold front Friday evening into Saturday early morning. Widespread totals of 0.25 to 0.75 inches are expected.

- Some stronger storms capable of producing hail and strong wind gusts are possible Friday night.

- Becoming much cooler this weekend, which will slow snowmelt.

DISCUSSION

Issued at 329 PM EDT Thu Apr 16 2026

This afternoon GOES satellite water vapor imagery and model height analysis showed a trough digging into the western U.S with shortwave ridging downstream over the midwest. A shortwave was moving through lower Michigan which brought a few showers into the Menominee area this morning. Otherwise it was dry today and fog had dissipated across most of the area with widespread sunshine. Under those sunny skies it had warmed nicely, pushing into the low 70s in the west. It was a bit cooler, 50s and 60s in the central and east but much cooler 30s and 40s near the lakeshores.

Dry conditions are expected to continue tonight with temperatures staying relatively warm, only cooling into the 40s and low 50s in the west and 30s over the east and Keweenaw. Some fog will likely develop over the eastern U.P. but confidence is much lower as to if the fog will be dense and widespread enough to warrant a dense fog advisory.

A trough will approach the area on Friday bringing southerly flow into the region. This will help bring warmer and gulf moisture north into the U.P. with temperatures into the 70s west and 60s east. It will be cooler, 40s, downwind of Lake Michigan with southerly winds coming up the axis of the lake. As the trough moves east a cold front will approach the area and a low level jet with strengthen. These will provide a mechanism for thunderstorm development late in the afternoon into the evening hours. Some of the storms could be strong to severe over the western half of the U.P, especially near the WI/MI state line where SPC is highlighting a slight risk for severe thunderstorms. The main threat will be damaging winds as the storms are expected to grow into a linear system but marginally severe hail is also possible. Heavy rainfall will also be possible which will contribute to the ongoing flood risk. Will be extending the flood watch through Saturday morning for all but the far western U.P. While snowpack is mostly gone over the south-central U.P. water levels remain high and potential heavy rain with thunderstorms could cause further flooding issues. For the north and east warmer temperatures through Friday and southerly winds will help increase snowmelt, the combination of snowmelt and rainfall will increase the flood risk.

For Saturday light trailing showers behind the cold front will change to the wintery precipitation during the morning. The sfc front will be outrunning the 850-700mb cooling which will provide a brief window for freezing rain and/or sleet though it should be relatively non-impactful, with any light glaze limited to elevated surfaces. Thereafter scattered snow showers are expected into Saturday night but any accumulations should be limited to a dusting. It will feel chilly after a few warm days with highs in the 30s north and 40s south through Sunday. The good news is that this should help slow the snowmelt a bit before we warm up next week.

Expect warmer and drier weather Monday through at least Wednesday with high pressure dominating, bringing highs into the 50s central and east and up into the low 60s west. It will be cooler near the shorelines as the Great Lakes remain fairly frigid.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 747 PM EDT Thu Apr 16 2026

Main aviation concerns are: 1) potential for fog/low clouds tonight at CMX/SAW, 2) low-level wind shear late tonight into Friday morning, 3) southerly winds gusting to near 30 kt Friday, and 4) potential for thunderstorms at IWD after 21Z Friday.

Fog/low cloud potential at CMX/SAW: Less certain than previous nights, as low-level moisture has mixed out today better than previous days, and a light southerly wind has the potential to increase toward sunrise. Removed fog mention from CMX although still consider around a 30% chance of IFR or lower overnight. Bumped back the timing of the TEMPO for LIFR fog at SAW to 04-08Z, with prevailing IFR vsby and LIFR cigs thereafter.

LLWS and gusty winds: Strong low-level jet should bring LLWS conditions to all terminals for a time late tonight into Friday morning before diurnal mixing brings stronger winds to the surface late morning into the afternoon. Expect wind gusts to be near 25-30 kt for much of the day Friday, strongest at IWD.

TS potential at IWD: An approaching cold front will bring a band of showers and embedded thunderstorms to the western UP mainly after 21Z. A stronger storm containing large hail and gusty westerly winds cannot be ruled out at IWD. TS potential at CMX is less than 30% so was not mentioned in this TAF cycle.

MARINE

Issued at 329 PM EDT Thu Apr 16 2026

Southeast winds to 20kt will develop tonight as low pressure takes shape out west and approaches the region. For the western arm of the lake winds will take more of a northeasterly direction. Fog had mainly dissipated except over the far east, where satellite showed some low stratus or fog. Anticipating canceling the dense fog advisory as confidence is low in the coverage and redevelopment of fog overnight. The pressure gradient will strengthen further on Friday morning with southerly winds to 30kt developing over the eastern half of the lake. A few gusts to gale will be possible. Thunderstorms will also be possible late in the day Friday as a cold front pushes across the lake. Winds will shift northwest behind the front late Friday night with gales possible (30-50%) Saturday through Sunday, mainly for the eastern 2/3 of the lake. Winds fall below 20kt Sunday night and shift southerly by Monday morning.

HYDROLOGY

Issued at 329 PM EDT Thu Apr 16 2026

NOHRSC analysis showed snowpack remained over the northern half of the U.P. were several inches to over a foot of SWE remained, greatest in the higher terrain. Snowmelt will continue through the Friday as a warm, moist airmass over the U.P. An area of showers and thunderstorms will move through late Friday with 0.25-0.75 inches expected for most areas, with higher amounts possible in thunderstorms. Colder weather is expected for Saturday night and Sunday which should slow the melt of any remaining snow.

Waters remain high in the southern UP where recent heavy rains and snowmelt contributed to flooding of low-lying areas and some rivers. Rivers will continue to rise in portions of the northern U.P. due to continued snowmelt and additional rainfall. A Flood Watch remains in effect through Thursday night for all but the far western U.P. This flood watch will be extended through Friday night.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Flood Watch through Saturday morning for MIZ001-003>007- 010>014-084-085.

Lake Superior... None. Lake Michigan... None.