National Overview — Monday, September 15, 2025
A generally quiet day for widespread rain and snow nationally. No organized excessive rainfall or heavy snow areas are highlighted today. Heat is building and expanding from the West toward the Midwest and the Ohio/Tennessee Valleys. Tropical moisture is beginning to focus over Florida and the Southeast and will ramp up impacts through late week.
Hotspot: Northern/Central California and Western Nevada — Heat, Offshore Winds, and Smoke
Above-normal heat and periods of dry/offshore flow continue. Lingering wildfire smoke is reducing visibility in the Sierra and western Nevada, with elevated fire-weather concerns and heat stress risk for drivers. Dense smoke has recently produced hazardous driving at times along US-395 in eastern CA/NV—use headlights, slow down, and be ready for sudden visibility drops.
- Primary routes: San Francisco Bay Area inland valleys and Delta; Sierra/eastside corridors including I-80 over Donner Pass and US-395 through Mono/Inyo counties; Central Valley routes (I-5/CA-99).
- Impacts: Reduced visibility from smoke, intermittent gusty offshore winds, and heat strain for drivers and equipment.
- Driver tips: Start early where possible, monitor engine temperatures, hydrate frequently, and increase following distance in smoky stretches.
Hotspot: Florida Peninsula and Coastal Southeast — Tropical Downpours and Gusty Squalls Developing
Tropical moisture pooling along a stalled boundary brings increasing risk for heavy rain bands and periods of strong, gusty onshore winds. Localized flooding is possible in poor-drainage and urban areas. Impacts begin to ramp up today and persist through late week.
- Primary routes: I-95 from Miami to Jacksonville, I-4 Tampa–Orlando, and I-75 including Alligator Alley northward.
- Impacts: Ponding on roadways, brief hydroplaning risk, and sharply reduced visibility in downpours.
- Driver tips: Slow down in heavy rain, avoid flooded lanes, use headlights in squalls, and anticipate strong crosswinds near the coast.
Hotspot: Interior West (Great Basin/Rockies) — Pockets of Strong Winds and Crosswind Hazards
Periods of higher winds are possible as a Western trough interacts with tight pressure gradients. High-profile vehicles should anticipate crosswinds, especially through gaps and passes.
- Wind-prone stretches: I-80 across NV/WY (including Arlington–Elk Mountain and Summit areas in WY), I-25 WY–CO, and I-15 UT–NV.
- Impacts: Blow-over risk for light or empty trailers; challenging handling in exposed corridors.
- Driver tips: Secure light loads, reduce speed in open terrain, and consider timing runs to avoid peak winds where feasible.
Additional Notes for Drivers
- Heat safety: Central U.S. heat builds through midweek—monitor cab and engine temperatures and hydrate.
- Precipitation/snow: No significant snow threats and no organized excessive-rain zones nationally today, but localized Florida downpours can still cause delays.
Driver Safety Tip of the Day
Plan for mixed hazards. In heat, check coolant and tires before departure and schedule breaks. In crosswinds, keep both hands on the wheel and reduce speed through exposed gaps and passes. In tropical downpours, slow down early, increase following distance, and avoid standing water.
Sources: National Weather Service, Weather Prediction Center, Climate Prediction Center, local forecast offices, state DOTs, and regional reporting from SFGATE and the San Francisco Chronicle.
This weather briefing was prepared exclusively for truckstopinsider.com.
