Debris Flow in Utah, April 6 to 7, 2004

Name: Debris Flow in Utah, April 6 to 7, 2004
Start: 2004-04-06T16:45
End: 2004-04-07T17:00
Location: Utah

April 6 to 7, 2004 · NWS SLC · 1 event in 1 county or zone

Thunderstorms associated with a relatively mild upper-level Pacific storm system trained from southwest to northeast over the Farmington canyon area Tuesday evening April 6, 2004. 36 inches of rain over the previously burned area and created a landslide/mudslide of about 5,000 cubic yards of earth that rolled in to residential areas of Farmington.

The toll

Deaths: 0
Injuries: 0
Property damage: $40,000
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 SLC wrote it up.

Thunderstorms associated with a relatively mild upper-level Pacific storm system trained from southwest to northeast over the Farmington canyon area Tuesday evening April 6, 2004. The storms dropped 2.36 inches of rain over the previously burned area and created a landslide/mudslide of about 5,000 cubic yards of earth that rolled in to residential areas of Farmington.

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 Salt Lake City, UT wrote its last area forecast discussion before the first event at Apr 6, 2:16 PM MST, 2 hours 29 minutes earlier.

Area forecast discussion, Apr 6, 2:16 PM MST, 2 hours 29 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
316 PM MDT TUE APR 6 2004

.SYNOPSIS...A MILD...MOIST AND UNSTABLE AIRMASS WILL BE OVER THE
AREA THROUGH WEDNESDAY. A WEAK STORM SYSTEM ALOFT WILL TRACK ACROSS
SOUTHERN UTAH TONIGHT AND WEDNESDAY.
&&

.DISCUSSION...CONVECTION DEVELOPING IN MOIST SOUTHERLY FLOW WITH PVA
DYNAMICS INCREASING THIS AFTERNOON OVER WESTERN UTAH. WILL
BROADBRUSH SCATTERED POPS FOR TONIGHT. GENERALLY EXPECTING
CONVECTION TO MOVE TO THE BASINS THIS EVENING AND CONTINUE AT LEAST
ISOLATED COVERAGE THROUGH THE NIGHT. UPPER LOW OVER NEVADA WILL BE
OVER NORTHERN ARIZONA AND SOUTHERN UTAH WEDNESDAY...SO INCREASED
POPS WHOLE SOUTHERN TIER THROUGH WEDNESDAY. AIRMASS BEGINS TO DRY
WESTERN HALF OF THE CWA THURSDAY AS A SHORTWAVE RIDGE PASSES AND A
MORE STABLE NORTHWEST FLOW DEVELOPS. MODELS STILL SHOW A LOW ALOFT
DEVELOPING OVER UTAH BY MIDDAY FRIDAY. SHORTWAVE IS RELATIVELY DRY
AND CONTINENTAL AS IT DEVELOPS OVER THE AREA FROM THE NORTH. HOWEVER
IF THE 500 MB COLD POOL COMES DIRECTLY OVER UTAH WE COULD GET
MOUNTAIN SNOW. FOR NOW INCREASED POPS A BIT IN THE FAR NORTHEAST
ZONES. ALSO COOLED TEMPERATURES FRIDAY THROUGH THE WEEKEND...LEANING
TOWARD THE MODELS COOLER PATTERN.
&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
ID...NONE.
WY...NONE.
&&

GIBSON

Event by event

1 debris flow. Local standard time, as filed.

Debris Flow, Ne Box Elder T X Ne/W Weber/Davis

When: April 6, 4:45 PM MST to April 7, 5:00 PM MST
Where: Ne Box Elder T X Ne/W Weber/Davis forecast zone
Property damage: $40,000
Reported by: EMERGENCY MANAGER

What these are

Debris Flow: A fast-moving slurry of mud, rock and debris, usually on a slope soaked by heavy rain or stripped by a fire.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Utah in 2004 Every state in 2004 This day in weather history Warnings in Utah, April 2004

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: 5420454.