1 flash flood, as filed by the National Weather Service.
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.
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.
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 Salt Lake City, UT wrote its last area forecast discussion before the first event at Aug 21, 1:40 PM MST, 5 hours 20 minutes earlier.
UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 240 PM MDT THU AUG 21 2003 .SYNOPSIS...A MOIST AND UNSTABLE AIRMASS WILL REMAIN OVER THE AREA THROUGH FRIDAY. THEN A DRIER SOUTHWEST TO WESTERLY FLOW WILL GRADUALLY SET IN ACROSS THE NORTH FOR THE WEEKEND. .DISCUSSION...JET STREAK OVER UTAH TODAY IS HELPING TO IGNITE CONVECTION. THIS INCREASE IN SPEED ALOFT IS KEEPING THE STORMS MOVING SO OUR MAIN THREAT HAS BEEN THE POSSIBILITY OF SEVERE THUNDERSTORMS. THIS JET STREAK WILL MOVE NORTH INTO WYOMING TONIGHT AS WELL AS WEAKEN A LITTLE. HAVE INCREASED THE POPS OVER THE NORTH DUE TO THIS FEATURE. ACTIVITY SHOULD DECREASE IN ALL AREAS AFTER MIDNIGHT. THE TROUGH OFF THE CALIFORNIA COAST WILL OPEN UP FRIDAY AND MOVE NORTHEAST. THE JET ASSOCIATED WITH THIS TROUGH WILL BE MOVING OVER NEVADA BY AFTERNOON PLACING MOST OF WESTERN AND NORTHERN UTAH UNDER A FAVORABLE ENTRANCE REGION OF THE JET FOR LIFT. POPS WERE BOOSTED ACROSS THE WEST AND NORTH IN LIGHT OF THIS FEATURE. MOSTLY CLOUDY SKIES SHOULD RESULT DUE TO THE WIDESPREAD LIFT. DRYING BEGINS TO OCCUR ACROSS THE NORTHWEST ON SATURDAY, BUT PROBABLY NOT AS FAST AS THE ETA MODEL WOULD SUGGESTS. HAVE LEANED TOWARD THE AVN AND KEPT LOW POPS IN FOR THE NORTHWEST THROUGH SATURDAY. THE FLOW BECOMES MORE WESTERLY SUNDAY AND THIS SHOULD CLEAR OUT MUCH OF THE NORTH. HOWEVER, MOISTURE WILL REMAIN OVER THE SOUTH WITH VERY LITTLE CHANCE EXPECTED THERE. A WEAK SURFACE FRONT DROPS ACROSS THE NORTH SUNDAY NIGHT AND DOWN INTO SOUTHERN UTAH MONDAY. THERE PROBABLY WONT BE ENOUGH PUSH TO CLEAR THE SOUTH SO HAVE KEPT POPS IN FOR ALL OF THE SOUTH EXCEPT THE SOUTHWEST WHERE ENOUGH DRYING SHOULD SEEP IN. A WESTERLY FLOW FOR TUESDAY BUT THEN A DEVELOPING TROUGH OFF THE WEST COAST WILL CAUSE THE WINDS TO BACK AND SOME MOISTURE IS EXPECTED TO START MOVING NORTHWARD INTO THE REGION BY WEDNESDAY IN THE SOUTH AND CENTRAL PORTIONS AND POSSIBLY THE NORTH BY THURSDAY. HAVE JUST HINTED TO THIS IN POP FORECAST AND THERE IS A DISPARITY BETWEEN MODELS AS TO WHERE THE TROUGH WILL DEVELOP. SLC 4332 CDC 3433 STRUTHWOLF .SLC...NONE.
IDZ024-025-UTZ001>021-WYZ021-221300- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SALT LAKE CITY UT 730 AM MDT THU AUG 21 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN TWO-THIRDS OF UTAH...EXTREME SOUTHEAST IDAHO AND EXTREME SOUTHWEST WYOMING .DAY ONE... TODAY DEEP MOISTURE AND UNSTABLE AIR MASS WILL LEAD TO SHOWERS AND THUNDERSTORMS TODAY WHICH COULD PRODUCE LOCAL HEAVY RAINFALL OVER MUCH OF SOUTHWESTERN UTAH. .DAYS TWO THROUGH SEVEN... THURSDAY THROUGH TUESDAY A VERY MOIST AND UNSTABLE AIRMASS WILL REMAIN OVER THE THE AREA THROUGH AT LEAST FRIDAY. THUNDERSTORMS DEVELOPING IN THIS AIRMASS WILL BE ABLE TO PRODUCE HEAVY RAIN AND MAY PRODUCE FLASH FLOODING...ESPECIALLY IN DRAINAGES THAT ARE PREDOMINANTLY ROCKY AND IN AREAS WHERE FIRES HAVE REMOVED MOST OF THE VEGETATION. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURE.
The Cedar City radar (KICX), 66 km away, was scanning. The volume nearest the first event began at 01:57 UTC.
1 flash flood. Local standard time, as filed.
Flash flooding was reported on North Creek near the town of Hurricane.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2003Every state in 2003This day in weather historyWarnings in Utah, August 2003
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: 5380006.