Nearest monitored road: South Gilbert Street (Secondary)
- seasonable temperatures, dry conditions, and hazy skies likely through thursday.
- widespread showers and thunderstorms likely (50-70%) thursday night and friday.
Issued at 219 PM CDT tue jul 28 2026
Light northeasterly low level flow has brought less humid conditions compared to previous days, to much of the forecast area today. Temperatures and dewpoints are 7 to 12 degrees cooler compared to 24 hrs ago. However, it still feels quite humid across southern ia through west central il, where dewpoints are still in the upper 70S. Visible satellite depicted a nice sct-bkn low cloud deck, along with high clouds today that has kept temps cooler. Some smoke aloft was also noted on satellite creating a hazy/milky looking sky.
Decreasing clouds and quiet conditions will be seen this evening/overnight as high pressure drops south out of the great lakes. Temperatures to drop into the 60S area-wide, with some upper 50S not out of the question across northern il. With overnight lows dropping below crossover temperatures and very light wind, can't rule out some fog developing in river valleys and low lying areas primarily across northeast ia and northwest il. Decided to leave out of the public forecast for now, but will pass on to the evening shift for any possible additions.
Wednesday...mostly sunny skies and similar highs in the mid to upper 80S is forecast. The only caveats to that would be the mixing depth and any influence of smoke aloft that could keep US a degree or two cooler. Model near-surface smoke and aqi outputs keep the highest concentrations well to our west and north and thus have left out any smoke mention in the grids because of this. Overnight, some more fog may develop east of the mississippi river in closer proximity to the center of the surface high. Overnight lows to drop into the lower 60S.
Issued at 219 PM CDT tue jul 28 2026
Continued dry and seasonable conditions are expected thursday, as the upper ridge retrogrades west and builds across the southwest conus. At the same time, all ensemble and deterministic solutions have a strong shortwave rounding the top of the ridge over the northern plains. 850mb moisture transport ahead of this wave will initially be pointed to our west, keeping the local area dry during the daylight hours thursday.
Thursday night-friday...as expected at this time range, the latest deterministic model data has varying solutions of the evolution of the aforementioned shortwave. Strong moisture transport evident by pws increasing to 1.6-1.7" range (90th percentile) and large scale forcing to support widespread showers and thunderstorms. A dprog/dt of 24-hr QPF greater than 0.50" from the nbm has shown an increase into the 70-75% range. This is good news and will be much welcomed for the cwa, as most of the region has seen less than 0.05" in the past 7 days. Taking a look at the severe risk, the lref joint probabilities of mucape>500 j/kg & deep layer SHEAR>30KTS and ncar ml severe probs would continue to suggest a very low risk for severe storms. Better support for organized convection will be displaced further to the south over eastern mo. Regarding temperatures, latest nbm has come down for highs on friday into the upper 70S/low 80S. However, some further lowering into the mid 70S will be certainly possible with precip/clouds through much of the day.
Saturday-early next week...lingering precip chances will be seen saturday AM, exiting the area from northwest to southeast by mid-day. Following the passage of the shortwave, the upper level flow will become northerly as an area of high pressure sets up over the northern great lakes. This will result in a rather pleasant start to the month of august. Dry conditions and cooler temperatures are forecast, with highs in the upper 70S to lower 80S.
Issued at 1211 AM CDT wed jul 29 2026
VFR conditions are expected this taf period. Current satellite imagery shows an area of sct to bkn high clouds moving southeast across eastern iowa and western illinois. Once these clear out around 29/12Z, skies will be clear, save a few to sct deck of clouds at 4000 ft making their way into areas near dbq by 29/18Z. Despite the lack of clouds through much of the day, the sky will appear hazy due to smoke aloft. Winds will be light and variable to easterly through the period.