Marine Weather and Tide Forecast for Winamac, IN

DISCUSSION
Issued at 245 PM EDT Mon Oct 12 2026

A warm, moist advective regime is underway this afternoon as a low level ridge axis continues to shift east of the area. The more impressive low level theta-e ridging is expected to develop this evening from NE KS into SW WI just downstream of a progressive weak short wave trough ejecting northeast out of the northern Rockies. Precip prospects with an initial strong 310K isentropic forcing surge early this evening appear to be on the low side as better elevated moisture profiles more capable of realizing some weak elevated instability will remain displaced to the west. By late evening and overnight, isolated showers and thunderstorms prospects increase as upstream flattening upper ridge allows some steeper mid level lapse rates to advect eastward to the Mid MS River Valley and southern Great Lakes.
This later timing will also coincide with the northeast progression of the primary low level theta-e ridge and a potential of some 500-750 J/kg MUCAPES. Previous forecast mention of slight chance PoPs north of US Route 6 still seems appropriate as better isentropic forcing and stronger flow on 310K sfc remain across the north. Cannot completely discount an isolated shower south of US Route 6 however, given broad nature of advective forcing.

In terms of temperatures, broad warm advective pattern will allow for unseasonably mild min temperatures tonight. Modest low level dew points and boundary layer decoupling should allow mins to drop into the mid 60s and extent of lows will depend on extent of decoupling and the presence of any mid level warm advection-induced clouds.

Pre-frontal forcing will begin to shift eastward Tuesday morning setting up another warm today for mid-October. The aforementioned western Great Lakes short wave will depart to the east, reaching the eastern Great Lakes by Tuesday evening. This evolution and southeast sinking cut-off upper Low across southwest CONUS will allow associated cold frontal boundary to stall across the area Tuesday night. Much above normal temperatures will continue Tuesday with some uncertainty as to extent of high temperatures. Mixing heights may not be particularly deep given very warm low level thermal profiles, but even mixing to 900 mb would support high temperatures in the low-mid 80s most locations (possibly upper 80s to around 90 far south). These high temperatures would approach or break records for the date of October 13 (84 at FWA set in 1975 and 1899 and 86 at SBN set in 1975). Once again, the extent of lingering mid level cloud will likely play a factor in extent of max temps.

By Tuesday night, a plume of higher level theta-e air will advect northward into the Mid MS Rvr Valley and eventually the southern Great Lakes, while another northern stream trough eventually allows for some frontal forcing to interact with this deeper moisture.
Likely PoPs have been maintained late Tuesday night into early Wednesday afternoon with a potential of a few thunderstorms given likely presence of elevated instability. Frontal zone once again should stall and become less distinct locally later in the day Wednesday, setting up a lull in rain chances Wed night into early Thu.

Attention will then turn to a stronger short wave amplifying across southwest Canada, and potentially phasing with the cut- off negative upper height anomaly across the Central Plains towards the end of the work week. GFS deterministic may be a bit aggressive in phasing these features when considering bulk of GEFS and EC deterministic/ensemble guidance. Nonetheless, this northern stream wave will have some good upper level dynamics to work with and a stronger eastern Pacific jet to help induce cyclogenesis across eastern Great Lakes late Thu/Fri.

Another round of widespread rain is expected Thu/Thu evening as another frontal wave develops along the baroclinic zone, eventually drying out for Friday outside of some likely lake effect rain shower response. Windy conditions are also expected Friday, and will depend on extent of low level cyclogenesis and low level height gradient. However, gusts into the 30 to 40 mph range look possible during the day Friday given what should be fairly deep CAA-induced mixing. Some frost/freeze concerns may develop for Friday night/Saturday AM but will depend on progression of this pattern and how quickly low level anticyclone settles into the area and cloud cover. Greater chances of these frost/freeze concerns may hold off until later in the weekend. After a transition to below normal temps for the weekend, temps should moderate back to, or just above normal levels early next week with dry weather expected Sat to Mon.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
Issued at 1208 PM EDT Mon Oct 12 2026

VFR with southwest winds generally hovering around 10 knots through the period. Low level jet does ramp up a bit tonight as a frontal wave tracks east through the central Great Lakes.
This could bring some marginal LLWS to mainly KSBN tonight.

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