NWS SVR warning – 1.25″ hail, 60 mph, tornado possible – La Salle County, IL

On the evening of August 21, 2026, a severe thunderstorm swept through northwestern La Salle County, Illinois, prompting the National Weather Service in Chicago to issue an urgent Severe Thunderstorm Warning for the region. The storm was detected on radar near Mendota and was moving southeast at 25 miles per hour, carrying hail up to 1.25 inches in diameter — roughly the size of a half dollar — along with wind gusts reaching 60 mph. Communities in the storm’s path included Mendota, Earlville, Leland, Troy Grove, Prairie Center, Triumph, and Harding.

What set this warning apart from a routine severe thunderstorm alert was an additional caution embedded in the NWS bulletin itself: the tornado detection parameter was listed as POSSIBLE, with the National Weather Service instructing residents to remain alert for a potential tornado. The warning was in effect from 6:13 PM CDT to 6:30 PM CDT on August 21. Even within a brief window, a storm carrying 1.25-inch hail and 60 mph winds can leave lasting damage on roofs, siding, and gutters — much of it invisible from the street without a trained inspection.

What the National Weather Service Confirmed

The Severe Thunderstorm Warning for La Salle County was issued by NWS Chicago (Weather Forecast Office LOT) under alert identifier SVSLOT. The following parameters were confirmed by the National Weather Service:

• Warning issued: 6:13 PM CDT, August 21, 2026
• Warning expired: 6:30 PM CDT, August 21, 2026
• Storm detected: Radar-indicated near Mendota, Illinois
• Direction and speed: Moving southeast at 25 mph
• Maximum hail size: 1.25 inches (half dollar size)
• Wind gusts: Up to 60 mph
• Tornado parameter: POSSIBLE — NWS instructed residents to remain alert for a possible tornado
• Primary locations impacted: Mendota, Earlville, Leland, Troy Grove, Prairie Center, Triumph, and Harding in northwestern La Salle County, Illinois

For current and historical weather alerts for your area, visit weather.gov.

To put the hail size in practical terms: a 1.25-inch hailstone carries enough kinetic energy to fracture aged roofing shingles, dent unprotected metal surfaces, and crack vinyl siding — damage that often requires close inspection to identify. Combined with sustained wind gusts at 60 mph, this storm carried the full profile of an event that warrants a careful, systematic post-storm property review.

What Homeowners in Mendota, Earlville, and Surrounding Areas Should Check Now

If your home is in Mendota, Earlville, Leland, Troy Grove, Harding, Prairie Center, or Triumph, a post-storm walk-around is your most important next step. You do not need to climb on your roof — in fact, we recommend against it for safety reasons. Most meaningful damage indicators can be identified safely from the ground. Here is what to look for:

Roof

• Walk the perimeter of your home and check gutters, downspouts, and window wells for an accumulation of granules — the gritty, sand-like coating that protects asphalt shingles. Granule wash-off after a hailstorm is one of the most reliable early indicators of shingle impact.
• Look upward at soft metal components on the roofline — ridge vents, pipe boots, flashing, and gutter aprons. Even small, evenly distributed dents on these surfaces confirm the size and intensity of hailfall with precision.
• Scan visible roofline sections for missing, cracked, curled, or displaced shingles, particularly along ridgelines and eaves where wind damage tends to concentrate.
• If your home has skylights, examine the frames and surrounding flashing from below and at ground level for impact marks or displacement.

Gutters, Siding, and Windows

• Inspect aluminum gutters carefully along their full length — a pattern of round dings is a field-reliable indicator of hail impact and often mirrors what has happened to the roof above.
• Walk each exterior face and look for cracks, fractures, or circular impact marks in vinyl or aluminum siding panels. Given this storm’s southeast track, north- and west-facing walls typically absorb the most direct impact.
• Check window screens, frames, and exterior trim for tears, deformation, or cracked caulking lines that could allow water intrusion over time.

Trees and Outdoor Structures

• Inspect trees for hanging, split, or partially cracked limbs that could fall and cause secondary structural damage.
• Check fences, detached garages, outbuildings, and HVAC equipment for visible wind or impact damage.
• Do not attempt to remove large fallen limbs or trees leaning against the structure on your own — contact a certified arborist or professional removal service.

Interior and Water Intrusion

• Check ceilings and attic spaces for water staining, soft spots, or active dripping, particularly in upper-floor rooms directly below the roofline.
• Look around chimney chases, skylights, and any exterior wall penetrations for interior moisture or discoloration.
• Note any new basement seepage — severe thunderstorms typically produce heavy rainfall that can overwhelm foundation drainage systems.

Document everything you observe with photos and video before disturbing anything. Time-stamped images capturing both wide-angle context and close-up detail are valuable throughout the inspection, claims, and repair process.

If You Find Damage

Discovering storm damage is stressful, but responding in an organized, deliberate way protects your property and keeps the recovery process on track. Here is what experienced restoration professionals recommend:

Photograph before touching anything. Before moving debris, applying temporary coverings, or making any repairs, document every area of concern with clear, time-stamped photos and video. These images form the factual foundation of any insurance claim and protect you throughout the process.

Prevent additional damage when it is safe to do so. If you have a visible breach — an open roof section, broken windows, or compromised siding — temporary protective measures can stop a manageable problem from becoming a significantly larger one. Allied Emergency Services provides emergency tarping and board-up services when conditions call for it.

Report the event to your insurance carrier. Contact your homeowner’s insurance company to file a notice of loss, noting the date, time, and NWS warning that affected your area. Keep your claim number and adjuster contact information organized in a single location.

Work with a licensed Illinois restoration contractor. Allied Emergency Services has 27 years of experience performing storm damage restoration across Illinois and the Greater Midwest. We hold an active Illinois Roofing Contractor license (#104.019029) and are IICRC-certified as a restoration firm. Our team can conduct a thorough property inspection, prepare detailed repair estimates, and be present on-site when your insurance adjuster visits — walking through all documented findings with clarity. As a licensed restoration contractor, Allied documents damage and performs covered repairs; we do not negotiate, settle, or adjust insurance claims on your behalf.

Verify contractor credentials before signing anything. After significant storm events, unlicensed contractors sometimes canvass affected communities quickly. Always request a contractor’s Illinois license number and confirm it with the Illinois Department of Financial and Professional Regulation before entering any agreement.

For broader guidance on disaster preparedness and home recovery, ready.gov offers practical, government-maintained resources for homeowners navigating storm recovery.

Allied Emergency Services Is Ready to Help

If your home in Mendota, Earlville, Leland, Troy Grove, Harding, or anywhere in La Salle County was in the path of last night’s storm, our team is ready to respond. Allied Emergency Services has served Illinois homeowners and property owners for 27 years. We know what these storms can do — and what a properly inspected, fully restored property looks like when the work is done right.

Learn more about our storm damage restoration services, or reach us directly — 24 hours a day, 7 days a week:

• Call 24/7: (800) 792-0212
• Text ESTIMATE to: (844) 907-2546

This article is provided for general informational purposes only and does not constitute legal or insurance advice. Homeowners should consult their individual insurance policy and a licensed professional for guidance specific to their situation.