claude-sonnet-4-6 Analysis · Sep 13, 2026
A Flash Flood Warning and Flood Watch are in effect through the morning hours, with heavy thunderstorms producing 1–2 inches of rainfall already and additional accumulation expected before noon. Conditions improve significantly by the afternoon, making the morning hours highly hazardous for driving.
- 01 Active Flash Flood Warning effective until 10:00 AM EDT, with flash flooding of highways, streets, underpasses, and low-lying areas reported or imminent in areas including Morristown, Madison, Florham Park, and surrounding communities.
- 02 Active Flood Watch in effect until 12:00 PM EDT covering a wide region including Morris, Somerset, Middlesex, and other NJ counties, as well as parts of Delaware and southeast Pennsylvania.
- 03 Heavy thunderstorms with 85–82% precipitation probability between 7–9 AM and 62–63% through 10 AM, with rainfall totals of 1–2 inches possible today.
- 04 100% relative humidity through 9 AM, reducing visibility and increasing road surface hazards such as standing water and hydroplaning risk.
- 05 Flash flooding is described as ongoing or expected to begin shortly as of 5:54 AM, directly impacting road passability.
- 06 Afternoon conditions clear significantly — partly sunny skies, low precipitation probability (under 10%), and mild 5 mph winds from 1 PM onward — making the second half of the day much safer.
Avoid driving this morning if at all possible. If you must travel in the morning, wait until after 11:00 AM – 12:00 PM EDT when the Flash Flood Warning and Flood Watch expire and storm activity diminishes significantly. Safe morning window (if absolutely necessary): After 11:00 AM EDT, with extra caution for residual standing water and wet roads. Safe evening window: 5:00 PM – 8:00 PM EDT offers the best conditions, with mostly sunny to partly cloudy skies, 0% precipitation probability, light winds around 3–5 mph, and temperatures in the upper 70s to low 80s. Never drive through flooded roads — turn around, don't drown.