Marine Weather and Tide Forecast for Hettick, IL

SHORT TERM
(Through Thursday Night)
Issued at 223 AM CDT Wed Jun 10 2026

Water vapor imagery shows an upper-level trough broadening across the Northern and Central Plains this morning. This trough will mute the upper-level ridge over the Middle Mississippi Valley today, with guidance consensus showing 850 mb temperatures cooling by a degree or two compared to yesterday. While this favors slightly cooler temperatures at the surface, southwesterly surface flow will provide a boost to temperatures via downsloping and adiabatic warming off the Ozarks. This will produce air temperatures a degree or two warmer than yesterday; however, the same process will also lower dew points. In the end, this will result in heat index values similar to if not a few degrees below what was experienced yesterday and below Heat Advisory criteria.

Another heat-mitigating factor is the potential for convection prior to and during peak heating. As the trough draws closer to the CWA, a subtle disturbance within the southwesterly flow aloft will move northeastward across Missouri into northern Illinois from mid morning into the afternoon. Despite this being prior to peak heating and when instability will be maximized, there will be at least 2,500 J/kg of SBCAPE per guidance consensus. Deep layer shear is expected to be around 30 kts, but updrafts may be slightly elevated with lower effective shear. The instability will be sufficient for at least small hail production in the strongest cores, and if the degree of forecasted shear is realized, there will be a threat for isolated large hail and damaging wind gusts across northeastern Missouri and west-central Illinois. Convective debris and/or outflow from this convection will reduce temperatures across this part of the area.

The main concern for strong to severe storms will come later this evening as a cold front sinks south-southeastward into the region.
There is some concern that the early-day convection may reduce instability and the atmosphere not be able to fully recover prior to late afternoon/early evening CI; however, there is a strong consensus among guidance that recovery will not be an issue and the environment will be plenty unstable. Around 4pm when CI is expected roughly across north-central Missouri and southern Iowa, 3,000-4,000 J/kg of SBCAPE is forecast within the warm sector among 30-35 kts of deep-layer shear. The shear vectors will be nearly parallel to the front, leading to quick upscale growth as storms move into the CWA this evening. Clusters of multi-cells with embedded supercells will pose mainly a damaging wind and large hail threat. Low-level shear will be sufficient for tornadoes, though storm interactions and any supercells being short-lived limit this threat to bowing segments that can develop mesovortices. The area most favorable for these threats is northeastern Missouri and west-central Illinois along and north of Highway 36 and I-72. Convection is expected to drift east of the CWA by around midnight as the low-level jet veers, with a relative lull in activity then expected through Thursday morning.

The aforementioned cold front will not make much progress south until a shortwave induces cyclogenesis along the boundary over the Central Plains during the day Thursday; swinging it through the Middle Mississippi Valley during the late afternoon and evening. With that frontal timing, there is a low to medium chance for dangerous heat across portions of the CWA, with potential cloud cover and uncertainty in FROPA specifics leading these confidence levels.
Nevertheless, upwards of 3,000 J/kg of SBCAPE is expected ahead of the front with deep-layer shear once again being around 30kts. An inversion/capping around 700mb within the warm sector is expected to keep convection tied to the front, with the deep-layer shear vectors becoming increasingly parallel to the boundary as proximity to it increases. Both factors will favor clusters and/or a linear storm mode, with steep low-level lapse rates and DCAPE over 1,000 J/kg supporting primarily a damaging wind threat. Low-level shear of 20- 30 kts is favorable for a tornado threat, but a limiting factor may be slightly elevated LCLs. Convection will gradually weaken with southeastward extent as instability and shear decrease through the evening, with the front clearing the CWA as early as late evening to just after midnight.

Elmore

LONG TERM
(Friday through Tuesday)
Issued at 223 AM CDT Wed Jun 10 2026

The consensus among guidance continues to be that zonal flow will persist over the Middle Mississippi Valley in the wake of Thursday's front. This flow and a weekend FROPA will keep temperatures at or below climatological normals through this portion of the period.
This cold front will drift southward through the region Saturday into Sunday and serve as the focus for periodic rounds of rain through the weekend. Guidance diverges on how far south it makes it relative to the CWA before a shortwave enhances rain chances along it early next week. If the front is further south from the CWA, little to no rain can be expected. If it stalls just south of the CWA, rain chances will continue into early next week.

Elmore

AVIATION
(For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1212 PM CDT Wed Jun 10 2026

The primary concern during the 18Z TAF period will be multiple opportunities for thunderstorms, particularly at UIN, and to a lesser extent along I-70 corridor terminals. UIN is likely to see multiple rounds of storms, first early this afternoon and the second again this evening, and these storms may feature bursts of heavy rain and strong, erratic winds. The latter round of storms are more likely to feature higher wind speeds.

Overnight, decaying storms may drift as far south as I-70, potentially impacting the remainder of our local terminals as well. Confidence is relatively low that this will occur.

Otherwise, breezy ambient southwesterly winds can be expected even outside of thunderstorm activity this afternoon.

BRC

LSX WATCHES/WARNINGS/ADVISORIES
MO...Flood Watch through Thursday morning for Knox MO-Lewis MO-Marion MO-Shelby MO.

IL...Flood Watch through Thursday morning for Adams IL-Brown IL-Pike IL.