Marine Weather and Tide Forecast for North Manchester, IN

DISCUSSION
Issued at 230 PM EDT Tue Apr 22 2025

Challenge through Wednesday morning lies with a low level baroclinic zone/theta-e gradient that currently extends from southern IA east to N IL and somewhat into NW Indiana. KILX and KDTX 12Z soundings show lots of dry air in place. A small area of showers and storms moved across N IL but has weakened considerably as it encounters the drier airmass. Upstream satellite and radar data shows additional small areas of showers and storms that will take a general west to east track with each subsequent one likely making progress further east. Models have been consistent on advection of low to maybe mid 50 dewpoints into far N/NW areas by early evening and then expanding east and somewhat south as each small area of precip messes with the gradient location. LLJ is barely anything overnight (20 kts at best)
and is parallel to the theta-e gradient. CAMs continue to redevelop clusters of storms in SE IA/NW IL and track them east with the most pronounced possibly taking shape after 6Z and moving east. Elevated instability will be in place with steepening lapse rates to potentially support continuation of the precip east. Even though this moves in, models still show an overall weakening trend so can't justify more than chc pops for now. Effects of the overnight precip, resting location of the theta-e gradient, impacts of any lingering cloud cover and other mesoscale details will dictate whether the same areas that may see precip overnight could see additional showers/storms develop upstream and move in Wed afternoon and evening. Majority of CAMs showing the most activity that develops may remain W or N of the area. While I suspect even the slgt chc pops Wed afternoon may be overdone across the north I will leave them in place until we see the final outcome of tonight's precip.

Wed and Thursday will be much warmer with highs into the 70s Wednesday and some 80s Thursday before the arrival of increasing clouds with a weak southern stream wave. The best dynamics and energy will remain well to the west of the area, but arrival of a cold front still enough forcing and moisture to bring a period of showers/storms possibly as early as Friday morning in the west, with the best chances Fri afternoon into early evening. Have kept likely to cat pops going. Overall environment supports at most some pulsy thunderstorms that produce locally gusty wind and heavy rain with overall severe threat pretty low.

A brief cooldown occurs Sat into Sun behind the front before upper level heights rapidly increase again as deeper longwave trough over the western states edges slowly east into next week. Some additional waves move through the flow that could bring periodic chances for showers/storms but not enough confidence to mess with timing/pops at this point.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
Issued at 122 PM EDT Tue Apr 22 2025

Will continue with prevailing VFR conditions, especially for FWA.
SBN has a potential for rain to creep in especially after midnight tonight when the dew point depressions finally creep low enough.
Will continue to go with prevailing VFR there though with low confidence of flight condition-impactful low level moisture that far out. Otherwise, winds are generally south-southwest through the period with gusts kept at a minimum of occurrences.

IWX WATCHES/WARNINGS/ADVISORIES
IN...None.
OH...None.
MI...None.
MARINE...None.