Flash Flood, Mono
- When
- July 18, 1:45 PM PST to 6:00 PM PST
- Where
- Mono County, 10 mi W of Lee Vining
- Property damage
- $1,000
- Reported by
- DEPT OF HIGHWAYS
- Coordinates
- 37.939, -118.887 (the zone’s center; the record gives no point)
Flash Flood in California, July 18, 2002
CALTRANS reports highway 120 closed at Tioga Pass due to brief heavy downpours leading to flash flooding and rock slides as thunderstorms move across the region.
Where it happened
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- $1,000
- Crop damage
- None recorded
- Events
- 1
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
What happened
The episode as NWS REV wrote it up.
CALTRANS reports highway 120 closed at Tioga Pass due to brief heavy downpours leading to flash flooding and rock slides as thunderstorms move across the region.
What forecasters said that day
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Reno, NV wrote its last area forecast discussion before the first event at Jul 18, 8:45 AM PST, 5 hours earlier.
Area forecast discussion, Jul 18, 8:45 AM PST, 5 hours before
WESTERN NEVADA AND EASTERN CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RENO NV 945 AM PDT THU JUL 18 2002 AIRMASS OVER WRN NV AND SIERRA REMAIN MOIST AND UNSTABLE WITH VORT MAX NEAR SAC THIS MORNING. FORECAST LI OF -4 AND CAPE AROUND 1100 J/KG BY AFTN. K INDEX FAIRLY LOW AT 20 MAINLY DUE TO DRY AIR AT 700 MB. SFC DEWPOINTS IN MID 40S TO LOWER 50S AND CONVECTIVE TEMP OF 78 TRIGGERING AT 18Z. STEERING WINDS FAIRLY LIGHT BETWEEN 700 AND 500 MB LESS THAN 15 KTS. WILL ISSUE FF WATCH FOR SRN CWA UNTIL 6 PM DUE TO SLOW MOVEMENT OF STRONG TSTMS. VORT MAX MOVES E OF AREA FRIDAY BUT WITH RESIDUAL MOISTURE AND INSTABILITY WILL KEEP SLGT CHC TSTMS MOST AREAS. ANOTHER VORT MAX MOVES TO CENTRAL CA CST ON SAT FOR MORE TSTMS THIS WEEKEND. CYLKE .REV...FLASH FLOOD WATCH NVZ01..02..03..04...CAZ073 UNTIL 6 PM.
The radar
The San Joaquin Valley radar (KHNX), 192 km away, was scanning. The volume nearest the first event began at 21:45 UTC.
Event by event
1 flash flood. Local standard time, as filed.
What these are
- Flash Flood
- Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Flash Flood in Oregon, July 18, 2002
- Flash Flood in Colorado, July 18, 2002
- Damaging Wind and Lightning Strike in Indiana, July 18, 2002
- Flash Flood in Pennsylvania, July 18, 2002
- Lightning Strike in Florida, July 18, 2002
- Damaging Winds and Lightning Strikes in Michigan, July 18, 2002
- Hail and Damaging Winds in Iowa, July 18, 2002
- Damaging Wind in Florida, July 18, 2002
- Tornado in Minnesota, July 18, 2002
- Hail and Damaging Winds in New York, July 18, 2002
- Damaging Winds in Iowa, July 18, 2002
- Lightning Strike in Florida, July 18, 2002
More
Every storm in California in 2002Every state in 2002This day in weather historyWarnings in California, July 2002
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5314711.