Marine Weather and Tide Forecast for North Manchester, IN

DISCUSSION
Issued at 242 PM EST Sat Nov 8 2025

A very active weather pattern commences tonight through Monday with the first snow of the season expected across much of the forecast area, including a significant lake effect snow setup Sunday evening into Monday. A surface low pressure system currently centered over South Dakota will move southeast tonight over the Ohio River Valley.
The center of the low is expected to be over central or southern Indiana by tonight (most hi res models have shifted south to favor southern Indiana). Rain overspreads the area after 00Z Sunday, changing over to wet snow as early as 06Z-09Z from north to south as temperatures hover right around freezing. North of the center of the low, 925-850 mb frontogenesis increases overnight along and north of the US 30 corridor as the low deepens. A quick 1-2" of synoptic (system) snow is possible on grassy/elevated surfaces, especially in areas where heavy snow rates can overcome the above-freezing surface temperatures. Minimal, if any, travel impacts due to road/pavement temperatures being above freezing.

As the low exits eastward into the Ohio River Valley, breezy north winds on the backside of the low will allow for lake effect snow to develop as early as 12Z-15Z. A single, dominant, N-S oriented lake effect snow band is expected to develop across Lake Michigan due to the elongated northerly fetch extending all the way up to Lake Superior. The lake effect snow band should initially start off over far NW Indiana (near Gary and Chesterton, IN) before pivoting up into Michigan City, IN and even up to St Joseph, MI as low level converging winds take on a more north-northwest component. During the day Sunday, lake effect snow is expected to persist across the typical lake effect snowbelts in NW Indiana and far SW Lower Michigan. With daytime highs in the upper 30s to near 40 degrees, accumulations will likely be limited. Depending on how far inland the lake effect snow band gets, snow is possible as far east as IN- 15 and as far south as the US 24 corridor. Can't rule out 1-2" of snow on grassy/elevated surfaces but impacts during the day should be limited. Visibilities will likely be low within the band and if any heavier snow rates do materialize, there could be some minor accumulations on roads, especially within the snowbelts.

Lake effect snow continues late Sunday overnight into Monday morning and the environment will become incredibly favorable. Surface low temperatures Sunday night will be in the 20s, which will limit melting. Models vary widely on the positioning of the lake effect snow band Sunday night and into early Monday due to the development of a mesolow. How long the band stays over one area is highly uncertain. A mesolow will likely form over Lake Michigan and drop due south over the lake, which will pull the axis of the lake effect snow to the west over the Chicago metro and potentially even as far west as Waukegan, IL around 06Z-09Z Monday. For locations between Michigan City to St Joseph, MI, there will likely be a lull in snow from this timeframe until about 12Z-15Z Monday when the lake effect snow band pivots back over our forecast area. Increasing inversion heights to around 15,000 ft and impressively steep low level lapse rates of 8.5-9 C/km will create a phenomenal thermodynamic setup, and with a Lake Superior to Lake Michigan connection, the band will be capable of producing snowfall rates of up to 2-3"/hour with thundersnow possible (especially over NW Indiana). Depending on when and where the lake effect snow band sets up, there may be impacts to the Monday morning and evening commutes, especially along the I-94 and I-80/I-90 corridors. Be prepared for slick, snow covered roads! Negative theta-e lapse rates may allow for the band to extend further inland during the day Monday (likely similar to Sunday in that the eastern extent will be IN-15 and the southern extent will be US 24). If this happens, travel impacts may also occur on parts of US 30 in north central and NW Indiana.

Few changes have been made to headlines and forecast snow amounts due to the lingering uncertainty. Cass County, MI has been added to the Winter Storm Watch, which will be in effect from 1 PM EST Sunday to 7 PM EST Monday. If the lake effect snow band stays over our area for longer Sunday night into Monday morning, snowfall amounts could be highly variable at a county level due to the unpredictability of mesovortices within the band. Current forecast snow amounts between Sunday afternoon through Monday evening are 6-12" in La Porte, Berrien, and St Joseph [IN] counties, although I would not be surprised if locally higher amounts of 1.5 to 2 feet are realized somewhere near southern Lake Michigan. Some blowing and drifting may occur in areas that see the highest snow amounts.

Breezy northwest winds and strong CAA will keep temperatures around 20 degrees below normal for this time of year on Monday. High temperatures will be in the low to mid 30s, with some locations struggling to get above freezing. When factoring in the winds, wind chills will only be in the teens and 20s all day Monday. Winds shift to the west by Monday evening, cutting off any remaining lake effect snow.

Through the rest of the week, temperatures gradually warm and return to near normal by Friday and Saturday. A cold front brings slight chances for lake effect rain and snow showers Wednesday, but quiet and dry weather resumes Thursday through the weekend.


AVIATION /00Z TAFS THROUGH 00Z MONDAY/
Issued at 552 PM EST Sat Nov 8 2025

Short wave will continue to move into the area tonight and will provide decent lifting in the low and mid levels which is seen on the latest radar trends with rain showers and drizzle moving into the western portions of the area. The expectation is that with the increase in cold air advection will bring a changeover to a mix of rain showers and wet snow overnight especially for KSBN but will eventually push eastward into the KFWA site. With the wet nature of the snow coupled with warmer ground temperatures most of the falling snow will melt on contact. East winds will also be on the increase with better gradients as the main low circulation arrives. Backing of the winds to more northwest on Sunday as the system pushes eastward. Conditions will drop to IFR or LIFR tonight with lowered cigs and vsbys in precipitation and perhaps some improvement to lower end MVFR Sunday morning as winds back to the northwest. Sunday afternoon and evening much colder airmass will increase lake effect snow and showers which will mainly affect KSBN being in closer proximity to the lake but some snow showers would not be out of the question to make it further southeast to KFWA but less likely. Unfortunately, with the mesoscale nature of the lake effect, wherever the band anchors will determine where the heaviest precipitation will set up but also any meandering of the bands and the further backing of the winds could change quickly the intensity and location of the snowfall.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/
Issued at 1248 AM EST Sun Nov 9 2025

Predominantly IFR/LIFR to start the TAF period at both terminals, then shifting towards MVFR through the afternoon, with periods of IFR possible (especially at KSBN). A low pressure system drifting eastward through KY/IN/OH has brought us periods of rain and/or snow this evening, and this will persist overnight. KFWA has thus far remained all rain with temps around 37-39 deg, but temperatures are expected to fall towards 33-35 degrees around 9-12z. IFR ceilings developed within the last hour, and much of the guidance suggests a drop to LIFR around 500-600ft through late morning. Surrounding observations as of this writing are in the 400-600ft range, so opted to have the LIFR as a tempo until around 9z where it becomes more predominant. Rain/snow (if temps fall) will be fairly showery until closer to 9z, then we expect more persistent snow showers through the early morning before we see yet another mix.
Accumulations should be limited or minor given marginal temps and mixing with rain. Once the broader system moves out, we'll see a lull in precipitation before possibly seeing impacts from a lake effect band in the evening...but it may stay further west. Potential for IFR again after the TAF period.

KSBN will see a diminishing trend in precipitation as the system exits as well, with improvement to MVFR likely (maybe even VFR 16z) before the lake effect band pivots back into the area between 19z and 6z (timing uncertain). Rates within this band could approach 1" per hour at times, so have MVFR ceilings with IFR visibility for now. LIFR conditions will begin to improve towards morning.

IWX WATCHES/WARNINGS/ADVISORIES
IN...Winter Storm Watch from this afternoon through Monday evening for INZ012-014-103-104-203-204.
OH...None.
MI...Winter Storm Watch from this afternoon through Monday evening for MIZ078-177-277.
MARINE...Small Craft Advisory until 7 PM EST Monday for LMZ043-046.