Marine Weather and Tide Forecast for Kane, IL

SHORT TERM
(Through Sunday)
Issued at 241 PM CDT Fri May 8 2026

The main focus of this forecast package continues to be in the near term as we watch for the development of scattered thunderstorms later this afternoon and evening. While there remains a limited potential for a stronger core capable of brief strong winds and small hail, the potential for severe thunderstorms remains low.

Driving this potential is a mid/upper level shortwave currently approaching the area from the west, along with a slowly moving and diffuse cold front. Over the course of the morning and early afternoon, a steady stream of mid and high level cloud cover has persisted across the mid-Mississippi River Valley, which has slowed our warming and limited our destabilization locally. While we are finally beginning to see some indications of slowly increasing CAPE, including a few weak elevated cores already producing a few strikes of lightning here and there, the ceiling of instability appears to be rather limited. In addition to the weak heating, mid-level lapse rates are generally modest (6-7C/km) aside from some steepness in the lowest part of that layer. Model forecast and ACARS soundings also support this, and as a result, only about 500-1000 J/kg of ML CAPE can be reasonably expected by roughly 3 to 4 pm, spread out across a long, skinny profile, and this will likely require some advection of steeper lapse rate air from the southwest in order to materialize. Meanwhile, the persistent cloud cover is also expected to limit low level lapse rates, and further limit our severe wind potential.

However, as the shortwave arrives we do expect an increase in mid level winds and likewise will see a boost in effective bulk shear, perhaps to 35-45 kt per most available model guidance. In spite of the rather marginal thermodynamic profiles detailed above, all of these parameters still suggest that organized updrafts remain possible once deep convection can become established. In spite of the slow heating, recent CAMS continue to suggest that more substantial and potentially surface-based convective initiation will begin sometime between 3 and 5 PM along the cold front, extending from Central Missouri eastward into southwest Illinois. Out of this activity we may see a few cores capable of producing mainly small hail and sporadic wind gusts to 40-50 mph, with the highest probabilities of either occurring in central Missouri where instability is projected to be highest. Severe hail appears to be rather unlikely, although we can't rule out a few 1 inch hailstones here and there. While we do note just enough low level shear to support tornadoes, LCLs appear to be prohibitively high, and we do not expect this to be a significant threat.

This line of showers and a few weak thunderstorms is expected to progress slowly southeast through the late afternoon and early evening, and gradually lose strength near and after sunset. The remnants of this activity are expected to clear the area completely after midnight, leaving behind some low clouds and little else.

While technically a cold front will move through our area this afternoon and evening, this front is very weak and does not carry with it a significant push of colder air. In fact this boundary is expected to completely diminish, and warm air advection will resume quickly in its wake. As a result, tomorrow's temperatures are actually expected to be noticeably warmer than today, with highs reaching into the upper 70s to low 80s. However, moisture content will remain rather limited, and this should lead to a mostly dry day.

Later in the evening and overnight, another cold front will sink into the area, and by mid-day is expected to already reach near the MO/AR state line. Along and behind this front, another round of showers is expected to move into the area, although this second round continues to be de-emphasised by model guidance. Considering that these showers are likely to be post-frontal, with only modest MUCAPE to work with overnight, we remain skeptical that thunderstorms will be able to materialize. Instead, expect one or two rounds of showers between Saturday night and Sunday morning, and even then many areas are likely to miss out completely.

Temperatures Sunday are also expected to be much lower, as this second cold front will be driven south by a more expansive area of cooler air. While not exceptionally cold by any means, afternoon temperatures Sunday are expected to be about 10 degrees below seasonal averages, followed by a crisp morning in the low 40s Monday.

BRC

LONG TERM
(Monday through Next Friday)
Issued at 241 PM CDT Fri May 8 2026

For most of the work week, very little in the way of hazards can be expected as we will remain within a persistent pattern of northwest flow aloft and generally dry airmasses. Aside from a few marginal opportunities for showers here and there, dry conditions can be expected, with seasonable temperatures that will warm toward the end of the week.

After a chilly Monday morning, temperatures are expected to rebound nicely into the low 70s during the day, and will be followed up by another slight increase in temperatures Tuesday thanks to the resumption of breezy southwest winds and warm air advection. This will take place ahead of another advancing cold front, which is expected to move through the area sometime between Tuesday night and Wednesday morning. While we can't rule out some showers with this feature, the combination of another nocturnal frontal passage along with rather meager moisture advection (thanks to the previous front cutting off the Gulf) will significantly limit our potential for significant rain and thunderstorms. This will also likely stunt our warming trend, albeit only briefly.

Late in the work week, ensemble guidance continues to suggest that a longwave ridge will slide east into the Central Plains and Mississippi River Valley, and more expansive southerly return flow will resume as well. This will very likely drive another warming trend, although current ensemble mean 850 mb temperature anomalies remain rather subdued through Friday (below the 90th percentile), although we do note increasing spread. This trend does continue beyond the workweek and into the weekend/early next week, though, and there are some early indications that more significant warmth will be possible in the extended period.

BRC

AVIATION
(For the 00z TAFs through 00z Saturday Evening)
Issued at 654 PM CDT Fri May 8 2026

A swath of showers with embedded weak thunderstorms, generally along the I-70 corridor, continues to slide east-southeastward and has cleared KUIN within the last few hours. Both KCOU/KJEF will have the best chance to be impacted by a scattered weak thunderstorm within the next hour or two before the threat ends by 03z. This activity will continue to push eastward into the St. Louis metro terminals at the start of the TAF before pushing out later this evening (04-05z).
With the more intense thunderstorms, which are expected to be very isolated, brief IFR cigs/vis are possible along with small hail and stronger wind gusts. Overnight, some model guidance is hinting that a narrow swath of IFR/MVFR ceilings moves across the central MO and St. Louis metro terminals. Confidence in this is low, but will continue to be monitored throughout the evening. Light and variable surface winds persist this evening and overnight with southwesterly winds increasing in strength after sunrise of Saturday.

Peine

LSX WATCHES/WARNINGS/ADVISORIES
MO...None.
IL...None.