An upper level trough brushed northwest Colorado and produced significant snowfall in the mountains.
Every event with a place to put it; 2 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 brushed northwest Colorado and produced significant snowfall in the mountains.
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 2, 9:32 AM MST, 3 hours 28 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 1032 AM MDT TUE APR 2 2013 .UPDATE... ISSUED AT 1030 AM MDT TUE APR 2 2013 SCALED BACK POPS FOR THE SAN JUANS AND SURROUNDING AREAS AS VISIBILE IMAGERY SHOWS A LARGE DRY SLOT OVER SAID AREA. AS THE LOW DROPS SEWRD TODAY THOUGH AM EXPECTING MORE SHOWERS AND OCCNL TSTORMS TO FIRE UP SO POPS WILL INCREASE THROUGH THE DAY. ASIDE FROM THAT...FORECAST LOOKS ON TRACK. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 356 AM MDT TUE APR 2 2013 THE CLOSED UPPER LEVEL LOW HAS REACHED EAST-CENTRAL UTAH EARLY THIS MORNING AND WILL MOVE SOUTHEASTWARD THROUGH THE DAY REACHING NORTHWEST NM BY THIS EVENING. JET DYNAMICS AND UPWARD QG FORCING WILL SLOWLY DECREASE FROM NW-SE BUT WITH THE UPPER LOW OVERHEAD ...INSTABILITY WILL BE MORE THAN ENOUGH TO BRING FAIRLY WIDESPREAD SHOWER ACTIVITY ESPECIALLY LATE THIS MORNING/AFTERNOON. MODEL CAPE VALUES ARE LESS IMPRESSIVE COMPARED TO YESTERDAY BUT ISOLATED THUNDERSTORMS ARE ONCE AGAIN ANTICIPATED MAINLY THIS AFTERNOON. SHOWER ACTIVITY WILL END QUICKLY THIS EVENING FOR MOST LOCATIONS WITH THE LOSS OF DAYTIME HEATING. SOME WRAP AROUND MOISTURE AND WEAK UPSLOPE MAY KEEP SNOW GOING AROUND THE VAIL PASS AREA INTO EARLY WEDNESDAY. SNOW LEVELS ARE GENERALLY EXPECTED TO RANGE FROM 7K-8K THROUGH THIS EVENING...WITH HEAVY CONVECTIVE SHOWERS DRIVING LEVELS A BIT LOWER AT TIMES. THE EASTERN UINTA MOUNTAINS WILL BE UNDER A FAVORABLE NORTHEASTERLY FLOW AT 700 MB THIS MORNING/AFTERNOON... ALONG WITH ABUNDANT WRAP AROUND MOISTURE AND MODEST INSTABILITY. DUE TO THE POSITIVE FACTORS MENTIONED FELT IT PRUDENT TO ISSUE AN ADVISORY FOR 4-7 INCHES OF SNOWFALL. ANOTHER AREA TO WATCH WILL BE CO ZONE 10 WHERE MODELS HINT AT SNOW AMOUNTS NEAR ADVISORY LEVELS RIGHT ALONG THE DIVIDE. WEDNESDAY WILL BE A TRANSITION DAY AS TUESDAYS UPPER LOW MOVES ONTO THE PLAINS AND A RIDGE OF HIGH PRESSURE BUILDS IN. CONDITIONAL INSTABILITY WILL ACT ON SOME REMNANT MOISTURE TO PRODUCE A FEW HIGHER ELEVATION SHOWERS BUT OTHERWISE PARTLY CLOUDY SKIES AND A WARMING TREND ARE ANTICIPATED. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 356 AM MDT TUE APR 2 2013 DRY NORTHWEST FLOW SETS UP OVER THE AREA WEDNESDAY NIGHT AHEAD OF A RIDGE OVER THE WEST COAST. CONSEQUENTLY...EXPECTING CLEARING SKIES AND DRY WEATHER WEDNESDAY NIGHT INTO THURSDAY AS THE RIDGE AXIS SHIFTS TO THE EAST BECOMING CENTERED OVER THE CWFA LATE THURSDAY AFTERNOON. BENEATH THE RIDGE...7H TEMPERATURES RISE TO BETWEEN 6 DEG C OVER SOUTHEAST UTAH TO NEAR 3 DEG C ACROSS THE NORTH BRINGING ABOVE AFTERNOON HIGHS AROUND 10 DEGS F WARMER THAN NORMAL. THE WARMTH CONTINUES INTO FRIDAY AS A SHORTWAVE TROUGH SWEEPS INLAND THURSDAY NIGHT DRIVING THE RIDGE EAST CAUSING FLOW TO SHIFT TO THE SOUTHWEST. WEAK WARM AIR OVERRUNNING MAY LEAD TO SOME LIGHT SHOWERS OVER THE NORTHERN UTAH MOUNTAINS BY FRIDAY MORNING... HOWEVER CHANCES ARE BETTER FRIDAY AFTERNOON AS THE SHORTWAVE TROUGH MOVES OVER THE AREA. WINDS WILL BECOME BREEZY AHEAD OF A WEAK COOL FRONT WHICH IS EXPECTED TO PUSH ACROSS THE NORTH LATE FRIDAY AFTERNOON...STALLING ALONG THE I-70 CORRIDOR FRIDAY NIGHT. MOISTURE FAVORS THE NORTH AND ARRIVAL OF COLDER AIR ALOFT DURING PEAK HEATING POINTS TO A FEW THUNDERSTORMS FRIDAY AFTERNOON. SHOWERS WILL LARGELY DIMINISH BY SATURDAY MORNING AS THE SHORTWAVE PASSES EAST OF THE DIVIDE. SNOW LEVELS WILL BE FAIRLY HIGH AND ACCUMULATIONS LIGHT. THE PATTERN REMAINS PROGRESSIVE MOVING INTO SATURDAY AS YET ANOTHER SHORTWAVE EJECTS FROM THE EASTERN PACIFIC AND MOVES EASTWARD ACROSS THE AREA GENERATING ANOTHER ROUND OF SHOWERS. ECMWF INDICATED A SHORTWAVE RIDGE AND A SHARP DECREASE IN SHOWER ACTIVITY SATURDAY NIGHT...THE GFS LESS SO. REGARDLESS ...BOTH MODELS INDICATED THE UNSETTLED WEATHER WILL CONTINUE INTO THE LATTER PART OF THE WEEKEND AND INTO EARLY NEXT WEEK AS A TROUGH DEEPENS OVER THE REGION. THE ECMWF WAS DEEPER RELATIVE TO THE GFS AND INDICATED THE POTENTIAL FOR SIGNIFICANT SNOWFALL EVENT FOR THE MOUNTAINS...MAINLY ABOVE 8500 FEET SUNDAY NIGHT INTO THE EARLY PART OF THE COMING WEEK. GIVEN MODEL DIFFERENCES...A BIT EARLY TO START MEASURING UP THE SNOWFALL JUST YET. TEMPERATURES WILL HOVER CLOSER TO NORMAL THIS WEEKEND AND INTO MONDAY AS FLOW WILL BE RELATIVELY ZONAL ON AVERAGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON WEDNESDAY) ISSUED AT 1030 AM MDT TUE APR 2 2013 SHOWERS WILL INCREASE ACROSS NORTHEAST UTAH AND THE NORTHWEST COLORADO PLATEAU THIS MORNING AS A STORM SYSTEM LINGERS OVER EASTERN UTAH. THERE IS A SLIGHT CHANCE FOR SHOWERS TO IMPACT AIRFIELDS NORTH OF THE I-70 CORRIDOR...HOWEVER FLIGHT CONDITIONS ARE UNLIKELY TO DIP BELOW VFR. SHOWERS WILL INCREASE OVER THE AREA WITH A FEW THUNDERSTORMS DEVELOPING. EXPECT SHOWERS TO BE WIDESPREAD OVER THE MOUNTAINS WITH OBSCURATIONS CONTINUING. AIRPORTS EAST OF A KCAG-KRIL-KMTJ LINE HAVE A GOOD CHANCE (40-50 PERCENT) OF RAIN SHOWERS FROM 18Z TO 02Z/WED. THIS MAY BRING BRIEF MVFR VSBY IN HEAVIER SHOWERS AND PERHAPS MVFR CIGS AS WELL. CONDITIONS IMPROVE LATE IN THE EVENING AND OVERNIGHT AS THE STORM CONTINUES TO DRIFT TO THE EAST-SOUTHEAST. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR UTZ023. && UPDATE...TGR SHORT TERM...TB LONG TERM...NL AVIATION...TGJT
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 541 AM MDT TUE APR 2 2013 COZ001>014-017>023-UTZ022>025-027>029-031145- 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- 541 AM MDT TUE APR 2 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT A PACIFIC STORM SYSTEM WILL MOVE OVERHEAD TODAY WITH VALLEY RAIN SHOWERS AND MOUNTAIN SNOW CONTINUING. MODERATE SNOW ACCUMULATIONS WILL BE POSSIBLE FOR THE MOUNTAINS OF NORTHEAST UTAH AND WESTERN COLORADO. A FEW THUNDERSTORMS WILL ALSO BE POSSIBLE TODAY PRODUCING OCCASIONAL LIGHTNING AND BRIEF HEAVY SHOWERS. THIS STORM SYSTEM WILL MOVE OUT OF THE REGION THIS EVENING WITH SHOWERS SLOWLY DIMINISHING TONIGHT. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY WEDNESDAY...A FEW AFTERNOON THUNDERSTORMS WILL BE POSSIBLE OVER THE HIGH COUNTRY OF WESTERN COLORADO. THURSDAY THROUGH MONDAY...MORE UNSETTLED WEATHER IS LIKELY WITH A CHANCE OF SNOW SHOWERS FOR THE HIGH COUNTRY OFF AND ON THROUGH EARLY NEXT WEEK. THUNDERSTORMS ARE POSSIBLE AGAIN THURSDAY AFTERNOON...MAINLY OVER THE HIGHER TERRAIN. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED TODAY OR TONIGHT...HOWEVER SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL AMOUNTS TO THE NATIONAL WEATHER SERVICE IN GRAND JUNCTION.
The national radar mosaic for the moment the first event began.
2 winter weather. Local standard time, as filed.
Snowfall accumulations of 5 to 8 inches were measured across most of the area.
Snowfall accumulations of 4 to 9 inches were measured over half of the area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2013Every state in 2013This day in weather historyWarnings in Colorado, 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: 505596, 505597.