A warm moist flow from the subtroics brought widespread non-severe thunderstorms to the state. Small hail was reported in numerous locations in the Salt Lake and Tooele Valleys in addition to heavy rain fall.
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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 episode as NWS SLC wrote it up.
A warm moist flow from the subtroics brought widespread non-severe thunderstorms to the state. Small hail was reported in numerous locations in the Salt Lake and Tooele Valleys in addition to heavy rain fall. Rainfall amounts (in inches) were: Zion NP - 2.00, Laketown - 1.54, Randolph - 1.36, St. George - 1.24, Kanab - 1.27, Monticello - 1.03, Blanding - 1.02, Duchesne - 0.85, Cedar City - 0.63, Nephi - 0.51, Green River - 0.49, and Bullfrog - 0.37.
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 Apr 23, 2:30 PM MST, 3 hours 30 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 330 PM MDT SAT APR 23 2005 .SYNOPSIS...A LARGE BUT SOMEWHAT DISORGANIZED UPPER LEVEL LOW NEAR THE CALIFORNIA COAST WILL EJECT A STORM IMPULSE INTO THE SOUTHERN GREAT BASIN TONIGHT. THAT DISTURBANCE WILL CONTINUE NORTH THROUGH THE AREA SUNDAY. A MOIST AND UNSTABLE AIRMASS WILL REMAIN OVER THE AREA MONDAY THEN GRADUALLY DRY FROM THE SOUTH THROUGH MIDWEEK. && .DISCUSSION...WELL DEFINED LINE OF SHOWERS/THUNDERSTORMS DEVELOPED UNDER THE JET IMPULSE THAT IS EXITING THE GREAT BASIN. IT WILL KEEP SOME ACTIVITY GOING OVER THE NORTHWEST PORTION OF UT INTO THE EVENING. ASSOCIATED LIFT IN THE RIGHT ENTRANCE REGION OF THE JET IMPULSE MAY HELP THE WEAKER CONVECTION OVER SOME OF THE NORTHERN MOUNTAINS DEVELOP ENOUGH FOR ISOLATED LIGHTNING. THAT WILL ALL TEND TO DECREASE BY AROUND SUNSET. A FEW THUNDERSTORMS ARE ALSO SPREADING INTO SOUTHWEST UT. THESE WILL ALSO WEAKEN BUT MAY NOT COMPLETELY GO AWAY AS THE DYNAMIC LIFT FROM THE SHORTWAVE NEAR THE CA COAST STARTS IMPACTING THE AREA. THEN ITS JUST A MATTER OF WAITING FOR THE SHORTWAVE TO EJECT NORTHEAST ACROSS THE AREA LATER TONIGHT AND SUNDAY BRINGING MORE WIDESPREAD RAIN AND HIGH ELEVATION SNOW AHEAD OF IT. THE SHORTWAVE AXIS IS FORECAST TO BE OVER SOUTHERN NV AT 12Z SUNDAY WITH A CLOSED CIRCULATION THEN DEVELOPING AS IT MOVES NORTH TO NEAR THE GREAT SALT LAKE BY LATE SUNDAY AFTERNOON. STILL SOMEWHAT CONCERNED THAT THE MOISTURE TAP CURRENTLY ALONG THE WEST COAST OF BAJA TO THE SOUTHERN TIP OF NV MAY ADD A LITTLE MORE JUICE TO THE SYSTEM THAN HAS BEEN INDICATED. THE 18Z NAM INCREASED THE TOTAL WATER AMOUNTS OVER MUCH OF WESTERN UT BY ABOUT A THIRD FROM THE 12Z RUN AND THIS IS PROBABLY A GOOD IDEA. THE SHORTWAVE SHEARS EAST AWAY FROM THE PACIFIC LOW SUNDAY NIGHT LEAVING THE NORTHERN HALF OF THE AREA UNDER A DEFORMATION ZONE THAT GRADUALLY SAGS SOUTHWARD INTO TUESDAY. THEN A SHORTWAVE RIDGE STARTS TO DEVELOP AS THE EASTERN PACIFIC LOW WOBBLES BACK TOWARD THE CA COAST. IT SPITS SHORTWAVES ACROSS THE AREA THURSDAY THEN IS KICKED EAST AND CROSSES OUR AREA FRIDAY LEAVING A COOL MOIST WESTERLY FLOW IN ITS WAKE SATURDAY. && .HYDRO...TONIGHTS STORM SYSTEM HAS TAPPED A LITTLE EXTRA MOISTURE WHICH WILL RESULT IN A LITTLE HEAVIER RAINFALL AMOUNTS. OVER SOUTHWEST UT TOTAL WATER AMOUNTS THROUGH SUNDAY ARE NOW EXPECTED TO RANGE FROM ABOUT TWO-THIRDS OF AN INCH IN MOST VALLEYS TO ABOUT ONE AND A QUARTER INCHES OVER THE HIGHER MOUNTAINS. SNOW LEVEL STILL LOOKS LIKE ABOUT 9000 FEET TONIGHT LOWERING TO ABOUT 8000 FEET BY EARLY SUNDAY. FLOWS IN THE MAJOR WATERWAYS SHOULD INCREASE RAPIDLY LATE TONIGHT INTO SUNDAY...BUT ARE EXPECTED TO STAY BELOW FLOOD LEVELS. THE AREAS OF GREATEST CONCERN ARE THE UPPER SECTIONS OF THE SANTA CLARA AND VIRGIN RIVER DRAINAGES. && .AVIATION...SEE SLCTAFSLC && .SLC WATCHES/WARNINGS/ADVISORIES... UT...NONE. WY...NONE. ID...NONE. SANDERS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SALT LAKE CITY UT 550 AM MDT SAT APR 23 2005 UTZ012>021-241300- CASTLE COUNTRY-CENTRAL AND SOUTHWEST MOUNTAINS- GLEN CANYON RECREATION AREA/LAKE POWELL-HENRY MOUNTAINS- SAN RAFAEL SWELL-SANPETE/SEVIER VALLEYS-SOUTH CENTRAL UTAH- SOUTHWEST UTAH-UTAHS DIXIE AND ZION NATIONAL PARK-WEST CENTRAL UTAH- 550 AM MDT SAT APR 23 2005 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MOUNTAINS AND VALLEYS OF THE SOUTHERN HALF OF UTAH .DAY ONE... TODAY LOCALLY HEAVY RAINFALL ACROSS SOUTHWESTERN UTAH TONIGHT COMBINED WITH SNOW MELT RUNOFF WILL BRING SIGNIFICANT RISES TO AREA RIVERS AND STREAMS. .DAYS TWO THROUGH SEVEN... SUNDAY THROUGH FRIDAY RIVERS AND STREAMS IN SOUTHWESTERN UTAH WILL REMAIN AT ELEVATED LEVELS THROUGH SUNDAY...THEN GRADUALLY FALL.
The national radar mosaic for the moment the first event began.
7 heavy rain, 2 heavy snow. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2005Every state in 2005This day in weather historyWarnings in Utah, April 2005
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: 5446499, 5446500, 5446501, 5446502, 5446503, 5446504, 5446505, 5446784, 5446785.