Marine Weather and Tide Forecast for Pottawattamie Park, IN

DISCUSSION
Issued at 333 AM EDT Sat Jun 14 2025

An upper level trough cut off from the main belt of westerlies across the Northern Plains and Great Lakes region has been attempting to lift northeast but is encountering a confluent flow regime across the southern Great Lakes. As this wave shifts across the Ohio Valley today, it should continue to open and become more sheared in nature due to the influence of this background flow. A downstream reflection of this wave has materialized in the form of an elongated southwest to northeast sfc trough. This trough may make some slight northward advancement through daybreak, but should tend to anchor in vicinity of US Route 24 corridor for a time. Low level level moisture convergence associated with this trough axis and stationary nature to this trough axis could promote some pockets of heavier rainfall (isolated 1 to 2.5" inches) across northeast Indiana and northwest Ohio roughly along US Route 24 corridor. This will likely be in the form of some minor flooding/ponding of water on roadways. Impressive warm cloud depths of around 12k feet, anomalous PWATs of 1.75+ inches. and stationary nature tA stationary front was south of FWA. The front will try to move north as a wave tracks east along the front. Have keep winds ENE north of the front at both TAF sites. Ceilings will fall below 010 into the IFR category and will be slow to lift.
Blended some high res guidance along with currents obs & trends with conditional climatology. o low level trough axis are conducive for isolated heavy rainfall potential. A few negative factors include the dampening nature to the upper wave, stronger dynamic forcing remaining south of the area, and overall weak low level wind fields with a modest 20 knot southerly low level jet supporting only weak to moderate low level moisture convergence. A weak surface wave along this trough axis will eventually shift into west central Ohio this afternoon resulting in a tapering of rain shower potential from northwest to southeast.

Poor mixing today raises the concern that low clouds will be hard to erode across the area. Thus, some lower than normal confidence in max temp forecast today with a possibility that a few areas across northwest Ohio into far northeast Indiana could struggle to reach 70. Some slightly better mixing is possible far northwest areas later in the afternoon that could aid in high reaching into mid 70s.

Quiet conditions are expected tonight, with main item of uncertainty on low cloud evolution across southeast half of the area. Low level northeast flow on western periphery of the dampening mid level trough could allow for some low cloud redevelopment/maintenance across northeast Indiana/northwest Ohio as some slightly better low level moisture advects westward.

Sunday should feature warmer conditions as some short wave upper ridging builds across the southern Great Lakes with better insolation in comparison to today. This should yield highs in the lower 80s most areas, although weak onshore flow could result in some cooler conditions for immediate lakeshore areas across southern Lake Michigan.

For early work week, guidance has been consistent in a slow moving upper wave progressing across the Great Lakes region on Monday, but moisture quality looks questionable for early week which argues for maintenance of just some slight chance PoPs across the west. By Tuesday, indications persist that westerly low level flow will become a bit more pronounced but thunder chances locally may be dependent on convective modification of upstream smaller scale disturbances which has low predictability at this forecast distance.
Thus, will maintain just some mid range chance PoPs Tue-Tue night.

The middle of the week is still shaping up as the potential best chance of greater coverage showers and thunderstorms as a stronger eastern Pacific jet streak induces a stronger upper PV anomaly emerging in the lee of the Rockies. The potential exists for a good moisture transport feed from the southern Plains preceding this wave with a possible pre-frontal forcing focus on Wednesday afternoon/evening. Have made little change to likely shower/storm PoPs for later Wednesday. This still looks to be a period to watch for a potential of strong to severe storms depending on timing of these forcing mechanisms.

Medium range guidance is in general agreement regarding mid level height rises in wake of this upper trough for late work week, but vary significantly in timing of the amplification of the ridge.
Overall pattern does seem to support the potential that a decent instability gradient will be positioned across the region and have broadbrushed latter periods with slight chance shower/storm PoPs. Of somewhat greater confidence is the trend to above normal temperatures toward the end and just beyond this forecast valid period as the upper ridge axis shifts to the eastern Great Lakes.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
Issued at 544 AM EDT Sat Jun 14 2025

A front just south of Frankfort and MIE had drifted north as a weak wave was tracking east along the front. Areas of rain north of the front and ahead of the low had spread into FWA. Will continue to keep winds ENE north of the front at both TAF sites. Ceilings will rise above 010 and will be slow to lift at FWA. Skies should clear near 00Z.

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