gpt-5.4-nano Analysis · Jul 21, 2026
Unsafe
HIGH RISK
gpt-5.4-nano
78% confidence
Summary
Today (2026-07-21) is characterized by frequent showers and thunderstorms, with storm periods that could bring heavy/torrential downpours. A Flood Watch is in effect early morning into late tonight, increasing the risk of flash flooding and flooded/impassable roads.
Hourly Forecast
7 AM 19%
5 mph
8 AM 58%
8 mph
9 AM 60%
9 mph
10 AM 60%
10 mph
11 AM 75%
12 mph
12 PM 62%
10 mph
1 PM 75%
10 mph
2 PM 53%
9 mph
3 PM 50%
9 mph
4 PM 54%
9 mph
5 PM 76%
9 mph
6 PM 84%
8 mph
7 PM 98%
8 mph
8 PM 89%
8 mph
9 PM 90%
8 mph
10 PM 68%
8 mph
11 PM 60%
8 mph
Key Factors
- 01 Flood Watch (effective through late tonight): flash flooding from excessive rainfall remains possible (issued July 21 at 3:07AM EDT; window extends until July 22 at 2:00AM EDT per alert).
- 02 Rain/storm risk is very high during the day: hourly periods show thunderstorms likely from about 8am–5pm and with a peak risk around 11am–4pm (probability of precipitation ~75–54% with “likely/showers and thunderstorms”).
- 03 Evening/night storms intensify: precipitation probability rises to 84–98% from 6pm–11pm with “showers and thunderstorms” and “likely,” which can quickly reduce visibility and cause standing-water conditions.
- 04 Daily guidance notes some storms could produce heavy rain, and new rainfall amounts of 1–2 inches are possible (and the Flood Watch text mentions 2–3 inches per hour possible in torrential downpours).
- 05 Wind is moderate (about 5–12 mph south/southeast), so crosswind is not the main hazard; the main driving hazard is heavy rain/flash flooding.
Confidence
78%
Recommendation
Avoid driving during the worst heavy-rain windows. If you must travel, consider going in the morning around 7:00–8:00 AM (lower storm likelihood than later hours, starting slightly before storms intensify) and drive in the evening only around 6:00–7:00 PM if conditions are actively improving—otherwise delay due to rapidly increasing thunderstorm/flash-flood risk.