An upper level trough moved through the northeast Utah mountains causing some significant snowfall.
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 episode as NWS GJT wrote it up.
An upper level trough moved through the northeast Utah mountains causing some significant snowfall.
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 Grand Junction, CO wrote its last area forecast discussion before the first event at Apr 1, 10:12 AM MST, 3 hours 48 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 1112 AM MDT MON APR 1 2013 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 350 AM MDT MON APR 1 2013 AN UPPER LEVEL LOW CURRENTLY MOVING ONTO THE NORTHERN CA COAST EARLY THIS MORNING WILL PUSH DUE EAST THROUGH THE DAY...REACHING THE NV/UT BORDER BY MID AFTERNOON. INCREASING JET DYNAMICS AND UPWARD QG FORCING ACROSS THE CWA WILL LEAD TO A SCATTERING OF SHOWERS DURING THE MORNING HOURS. CONSIDERABLE THUNDERSTORM ACTIVITY WAS OBSERVED YESTERDAY ACROSS NV IN THE DEFORMATION AHEAD OF THE LOW...STEEP LAPSE RATES AND MARGINAL CAPE WILL ALLOW FOR ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON/EARLY EVENING OVER OUR AREA AS WELL. THE NORTHERN TWO-THIRDS OF THE FORECAST AREA APPEARS TO BE THE MOST FAVORED FOR SHOWER/THUNDERSTORM ACTIVITY TODAY. DRY AIR AND STEEP LAPSE RATES IN THE LOW LEVELS WILL LEAD TO GUSTY AND ERRATIC WINDS AROUND ANY THUNDERSTORMS. CONVECTIVE ACTIVITY WILL SLOWLY DECREASE IN THE EVENING DUE TO THE LOSS OF DAYTIME HEATING. A CONTINUING SW FLOW WILL KEEP TEMPERATURES QUITE WARM TODAY WITH SNOW LEVELS GENERALLY EXPECTED TO RANGE FROM 9K-10K INTO THIS EVENING...WITH HEAVY CONVECTIVE SHOWERS DRIVING LEVELS A BIT LOWER AT TIMES. WITH THIS IN MIND...ACCUMULATING SNOW IS EXPECTED TO REMAIN MAINLY ABOVE 10K TODAY INTO THIS EVENING WITH AMOUNTS RATHER LIGHT. BY TUESDAY MORNING THE UPPER LOW WILL BE NEAR THE UT/CO BORDER AND WILL MOVE SOUTHEASTWARD THROUGH THE DAY EXITING THE CWA BY EARLY EVENING. WEAK MID-LEVEL FRONTOGENESIS IS NOTED ACROSS FAR NE UT AND NW CO TUESDAY MORNING...ALONG WITH SOME WRAP AROUND MOISTURE ON THE TOP SIDE OF THE LOW. THE EASTERN UINTA MOUNTAINS MAY EXPERIENCE A GOOD BURST OF SNOW AS 700 MB WINDS WILL BE FROM A MORE FAVORABLE NORTHERLY DIRECTION AND WILL NEED TO BE WATCHED FOR A POSSIBLE ADVISORY. SNOW LEVELS WILL HAVE LOWERED BY TUESDAY MORNING ALSO...GENERALLY RANGING FROM 7K-8K. ONCE AGAIN DAYTIME HEATING WILL BRING ANOTHER ROUND OF CONVECTIVE PRECIPITATION TUESDAY AFTERNOON UNDER THE COLD UPPER LOW...WITH A WEAK SURFACE COLD FRONT MOVING N-S ALSO ACTING AS A FOCUS. ALTHOUGH SEVERAL INCHES OF SNOW ARE EXPECTED ACROSS MANY MOUNTAIN AREAS ON TUESDAY...DUE TO THE CONVECTIVE NATURE OF THE EVENT IT IS DIFFICULT TO NARROW DOWN WHICH AREAS MAY RECEIVE THE HEAVIER AMOUNTS. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 350 AM MDT MON APR 1 2013 CLOSED UPPER LOW WILL BE MOVING DOWNSTREAM ON TUESDAY NIGHT AND WEDNESDAY...BUT WRAPAROUND MOISTURE WILL AFFECT THE WRN COLORADO HIGH COUNTRY. SHOWERS WILL BE DIMINISHING TUESDAY EVENING...BUT WOULD NOT BE SURPRISED IF COLLAPSING CELLS "SITS" OVER THE SUMMITS AND GENERATES 1-3 INCHES OF SNOW. TOUGH TO FORECAST MESOSCALE FEATURES 36 HOURS IN ADVANCE...BUT KEPT MODERATE POPS TOWARD THE COLORADO SPINE. FOR WEDNESDAY AFTERNOON...RESIDUAL MOISTURE AND AFTERNOON CONDITIONAL INSTABILITY MAY TRIGGER ISOLATED SHOWERS AND THUNDER ONCE AGAIN. BUT FOR THE WRN 2/3RDS OF THE FORECAST AREA WILL BE MOSTLY TO PARTLY SUNNY WITH DRY CONDITIONS. PROGRESSIVE RIDGE AXIS MOVES ACROSS THE FORECAST AREA ON THURSDAY FOR DRY WEATHER...BUT THIS LASTS FOR ONLY ONE DAY AS PACIFIC ENERGY STREAMS ACROSS THE NRN/CENTRAL ROCKIES ON FRIDAY. FAIR AGREEMENT BETWEEN THE ECMWF AND GFS OPERATIONAL MODELS FOR THE UPCOMING WEEKEND. THE MAIN TROUGH STAYS ALONG THE WEST COAST...BUT PIECES OF ENERGY WILL BE TRACKING ACROSS INTERMOUNTAIN WEST. THE PATTERN FAVORS SPOTTY SHOWERS (BEST CHANCE NORTH) WITH THE DESERT VALLEYS GENERALLY DRY EXCEPT FOR BRIEF LIGHT SHOWERS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON TUESDAY) ISSUED AT 1112 AM MDT MON APR 1 2013 VFR CONDITIONS ARE PREVALENT ACROSS THE CWA THIS MORNING WITH SOME AREAS SEEING -TSRA. FOR THE REMAINDER OF TODAY...CHANCES FOR -TSRA WILL BE INCREASING AS INSTABILITY ALSO INCREASES ACROSS MUCH OF THE FORECAST AREA. MAIN CONCERN WITH THESE STORMS WILL BE SOME GUSTY SURFACE WINDS UP TO 35 MPH AND BRIEF...HEAVY SHOWERS. OUTSIDE OF STORMS...VFR CONDITIONS WILL PREVAIL WITH CLOUDS INCREASING OVERNIGHT. AS FAR AS TAF SITES ARE CONCERNED...VCSH SEEMS A SAFE BET WITH CONFIDENCE LOW TO MEDIUM THAT ANY STORMS WILL REACH WITHIN 5NM OF AIRFIELDS. WILL LEAVE OUT VCTS FOR NOW AND WILL ADJUST AS/IF NEEDED. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && SHORT TERM...TB LONG TERM...PF AVIATION...TGR
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 650 AM MDT MON APR 1 2013 COZ001>014-017>023-UTZ022>025-027>029-021300- LOWER YAMPA RIVER BASIN-CENTRAL YAMPA RIVER BASIN- ROAN AND TAVAPUTS PLATEAUS-ELKHEAD AND PARK MOUNTAINS- UPPER YAMPA RIVER BASIN-GRAND VALLEY-DEBEQUE TO SILT CORRIDOR- CENTRAL COLORADO RIVER BASIN-GRAND AND BATTLEMENT MESAS- GORE AND ELK MOUNTAINS/CENTRAL MOUNTAIN VALLEYS- CENTRAL GUNNISON AND UNCOMPAHGRE RIVER BASIN- WEST ELK AND SAWATCH MOUNTAINS-FLATTOPS- UPPER GUNNISON RIVER VALLEY-UNCOMPAHGRE PLATEAU AND DALLAS DIVIDE- NORTHWEST SAN JUAN MOUNTAINS-SOUTHWEST SAN JUAN MOUNTAINS- PARADOX VALLEY/LOWER DOLORES RIVER- FOUR CORNERS/UPPER DOLORES RIVER-ANIMAS RIVER BASIN- SAN JUAN RIVER BASIN-SOUTHEAST UTAH-EASTERN UINTA MOUNTAINS- EASTERN UINTA BASIN-TAVAPUTS PLATEAU-ARCHES/GRAND FLAT- LA SAL AND ABAJO MOUNTAINS-CANYONLANDS/NATURAL BRIDGES- 650 AM MDT MON APR 1 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT A PACIFIC STORM SYSTEM WILL BRING AN INCREASING CHANCE OF VALLEY RAIN SHOWERS AND HIGH MOUNTAIN SNOW SHOWERS TODAY INTO TONIGHT. A FEW THUNDERSTORMS THIS AFTERNOON MAY BRING GUSTY WINDS AND DANGEROUS LIGHTNING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY TUESDAY...VALLEY RAIN SHOWERS...MOUNTAIN SNOW AND ISOLATED THUNDERSTORMS WILL CONTINUE ON TUESDAY AS A PACIFIC STORM SYSTEM MOVES OVERHEAD. LIGHT SNOW ACCUMULATIONS WILL BE POSSIBLE FOR THE MOUNTAINS OF NORTHEAST UTAH AND NORTHWEST COLORADO. THIS STORM WILL MOVE OUT OF THE REGION TUESDAY NIGHT. WEDNESDAY...AFTERNOON THUNDERSTORMS WILL BE POSSIBLE OVER THE HIGH COUNTRY OF WESTERN COLORADO. FRIDAY THROUGH SUNDAY...MORE UNSETTLED WEATHER IS POSSIBLE WITH A CHANCE OF SNOW SHOWERS FOR THE HIGH COUNTRY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1000 AM MDT MON APR 01 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0959 AM SNOW SILVERTON 37.81N 107.66W
04/01/2013 M1.4 INCH SAN JUAN CO TRAINED SPOTTER
1.4 INCHES OF NEW SNOW THIS MORNING.
&&
EVENT NUMBER GJT1300753
RENWICKThe national radar mosaic for the moment the first event began.
1 winter weather. Local standard time, as filed.
Snowfall accumulations of 5 to 11 inches were measured across most of the area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2013Every state in 2013This day in weather historyWarnings in Utah, April 2013
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: 505598.