A moist southwest flow aloft with an embedded trough was followed by an upper low which moved across the region. This situation resulted in a prolonged snowfall event for western Colorado.
Every event with a place to put it; 21 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.
A moist southwest flow aloft with an embedded trough was followed by an upper low which moved across the region. This situation resulted in a prolonged snowfall event for western Colorado. However, in some areas there was a significant cessation of snowfall between the two systems, which resulted in two separate events.
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 14, 8:33 PM MST, 2 hours 27 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
933 PM MDT SUN APR 14 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 316 PM MDT SUN APR 14 2013
SHRTWV THAT PASSED THROUGH THE REGION LAST NIGHT DROPPED A FAST 6 TO
12 INCHES ACROSS THE NORTHERN AND CENTRAL MOUNTAINS...WITH A FEW
OUTLIERS OVER A FOOT. THIS SYSTEM CLEARED OUT A LITTLE FASTER
THEN EXPECTED AS IT ROAD THE NOSE OF THE 120+ KT JET. STRONG
SUBSIDENCE IN THE WAKE OF THIS EXITING WAVE IN PLACE THIS
AFTERNOON...WITH ONLY A FEW OROGRAPHICALLY DRIVEN SHOWERS
LINGERING NEAR THE DIVIDE. THE BREAK WILL LAST THROUGH THIS
EVENING...BEFORE THE NEXT PERIOD OF WET AND SNOWY CONDITIONS
ARRIVES AFTER MIDNIGHT.
FORECAST FOR THE NEXT 3 DAYS OFFERS MANY CHALLENGES...ESPECIALLY
WITH TIMING OF SNOWFALL...ALONG WITH AMOUNTS AND VARYING SNOW
LEVELS. FIRST WAVE OF ENERGY ARRIVES LATE TONIGHT AND WILL PERSIST
THROUGH EARLY TUESDAY MORNING. STRONG WSW FLOW...DEEP PACIFIC
MOISTURE AND COLD AIR IN PLACE WILL RESULT IN EFFICIENT SNOWFALL FOR
OUR NORTHERN AND CENTRAL MOUNTAINS. ATTM...AMOUNTS THROUGH THIS
FIRST 24 HOUR WINDOW APPEAR TO BE IN THE HIGH END ADVISORY WINDOW.
BECOMING MORE CONVINCED THAT WE WILL SEE A SIGNIFICANT
BREAK...OR DRY SLOT...DEVELOP OVER THE FORECAST AREA ON TUESDAY.
THIS WOULD RESULT AND AT LEAST A 12 HOUR WINDOW WHERE SNOWFALL
PRODUCTION WILL BE GREATLY REDUCED AS DEEP SOUTHERLY FLOW SETS UP
AHEAD OF A DIGGING GREAT BASIN TROUGH. WAA BEHIND RETREATING FRONT
WILL DRIVE SNOW LEVELS UPWARD AS WELL...MINIMIZING IMPACT ON
MAJOR PASSES. SO WE END UP WITH A PERIOD WHERE LITTLE ADDITIONAL
ACCUMULATION WOULD BE EXPECTED OVER OUR AREA. NEXT SURGE ARRIVES
LATE TUESDAY AFTERNOON AND EVENING...ALTHOUGH POSITIONING OF THE
UPPER LOW WOULD RESULT IN ENE FLOW ACROSS THE NORTHERN
MOUNTAINS. THIS IS NOT A FAVORED PATTERN FOR SIGNIFICANT SNOWFALL
IN WESTERN COLORADO...BUT IS A FAVORED DIRECTION FOR OUR NORTHEAST
UTAH MOUNTAINS. SO A VERY COMPLICATED STORM ONCE AGAIN.
AFTER MUCH DEBATE AND DISCUSSION...WE WILL BE SPLITTING THIS STORM
INTO TWO SEPARATE EVENTS FOR WESTERN COLORADO...WITH HIGH END ADVISORIES
LATE TONIGHT THROUGH TUESDAY MORNING...WITH ANTICIPATED SECOND EVENT
TUESDAY NIGHT AND WEDNESDAY. THE TWO EVENTS WILL STILL RESULT IN
ACCUMULATIONS SIMILAR TO OUR ADVERTISED WATCH...BUT REALLY LACK
CONFIDENCE IN RUNNING WITH A 3 DAY WARNING IN MID APRIL AS MOST
EFFICIENT SNOWFALL ACCUMULATIONS WILL BE CONFINED TO THE OVERNIGHT
HOURS...WITH DAYTIME ACCUMULATIONS RESTRICTED TO THE HEAVIEST
SHOWERS. DIFFERENT SITUATION OVER THE EASTERN UINTA MOUNTAINS WHICH
CAN DO WELL IN BOTH SOUTHERLY AND NORTHEAST FLOW PATTERNS...WHICH WE
WILL TRANSITION THROUGH OVER THE NEXT FEW DAYS AS ANOTHER SURGE OF
COLDER AIR SNEAKS BACK INTO THIS AREA. AS A RESULT...WILL GO WITH A
HIGH END...PROLONGED ADVISORY IN THIS AREA. LATER SHIFTS WILL NEED
TO MONITOR THE POSSIBILITY OF UPGRADING THIS AREA TO A WARNING ONCE
THE COLDER AIR PUSHES IN TUESDAY AFTERNOON.
SNOW LEVELS WILL INITIALLY START OFF NEAR THE VALLEY FLOORS LATE
TONIGHT...BUT LIFT THROUGH THE DAY ON MONDAY AS CONDITIONS WARM.
AS A RESULT...WILL NOT EXPAND HIGHLIGHTS INTO THE NORTHERN
VALLEYS...ALTHOUGH A FEW INCHES OF SLUSHY SNOW WILL BE
POSSIBLE. ANY IMPACT WILL BE SHORT-LIVED WITH SNOW FLIPPING BACK
TO RAIN BY MIDDAY. LEVELS DROP AGAIN MONDAY NIGHT...AND THEN LIFT
AGAIN TUESDAY TO NEAR 8K WITH SHOT OF WAA AS THE FRONT RETREATS
IN DEEP SOUTHERLY FLOW AS THE LONG WAVE TROUGH DEEPENS TO OUR WEST.
THE COLDER AIR DOES FINALLY RELEASE TUESDAY EVENING...WITH THE
FRONT DRIVING SOUTH THROUGH THE FORECAST AREA BY EARLY WEDNESDAY
MORNING. THIS WILL BE THE TIME PERIOD FOR THE SECOND SURGE OF
HEAVIER SNOWFALL...WITH MANY VALLEY LOCATIONS ALONG AND NORTH OF
INTERSTATE 70 POSSIBLY IMPACTED. WILL BE KEEPING A CLOSE EYE ON
THIS POTENTIAL OVER THE NEXT FEW SHIFTS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 PM MDT SUN APR 14 2013
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THE AFOREMENTIONED FRONT
WILL LIE NEAR THE I-70 CORRIDOR BY LATE TUESDAY NIGHT. MODELS SHOW
A SURFACE LOW PUSHING EASTWARD ACROSS SOUTHERN COLORADO TUESDAY
NIGHT HELPING TO DRAW THE FRONT SLOWLY SOUTHEASTWARD. THE FRONT
WILL PROVIDE A FOCUS FOR A SECOND ROUND OF MODERATE TO HEAVY
PRECIPITATION. BROAD SCALE LIFT WILL ALSO BE INCREASING AS THE
UPPER LEVEL TROUGH APPROACHES THUS FAIRLY WIDESPREAD RAIN/SNOW IS
ANTICIPATED ACROSS THE NORTHERN 2/3RDS OF THE CWA...WITH ANOTHER
SET OF WINTER WEATHER ADVISORIES LIKELY NEEDED FOR THE
NORTHERN/CENTRAL MOUNTAINS AND POSSIBLY THE NORTHERN VALLEYS. SNOW
LEVELS WILL GENERALLY BE BETWEEN 7000 AND 8000 FT ALONG THE
FRONT...FALLING TO VALLEY FLOORS BEHIND IT. THE MAIN UPPER LEVEL
TROUGH PASSAGE WILL OCCUR THROUGH THE DAY WEDNESDAY WITH
PRECIPITATION SPREADING TO SOUTHERN REACHES AND BEING MORE SHOWERY
IN NATURE AS POTENTIAL INSTABILITY INCREASES SOMEWHAT. THE
PROLONGED PERIOD OF UNSETTLED WEATHER WILL COME TO AN END
WEDNESDAY NIGHT AS THE TROUGH MAKES ITS WAY ONTO THE PLAINS WITH
COLD AIR SETTLING ACROSS THE REGION.
OF INTEREST TO FRUIT GROWERS...BELOW FREEZING TEMPERATURES ARE ONCE
AGAIN EXPECTED THURSDAY AND FRIDAY MORNINGS ACROSS THE CENTRAL VALLEYS.
FOR THURSDAY THROUGH SUNDAY...TEMPERATURES WILL GRADUALLY MODERATE
WITH A COOL NORTHWEST FLOW OVERHEAD. A FEW SNOW SHOWERS WILL LIKELY
CONTINUE ON THURSDAY ACROSS THE HIGHER TERRAIN NEAR THE DIVIDE AS
REMNANT MOISTURE REMAINS. MODELS ARE TRENDING TOWARD A DECENT SHORT
WAVE DROPPING IN FROM THE NORTHWEST NEXT SATURDAY PROVIDING ANOTHER
ROUND OF MOUNTAIN SNOW AND A CHANCE OF VALLEY SHOWERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 932 PM MDT SUN APR 14 2013
MID AND HIGH LEVEL CLOUDS WILL INCREASE OVERNIGHT WITH CIGS GRADUALLY
LOWERING AS THE NEXT SYSTEM MOVES IN FROM THE NW. RAIN AND SNOW
WILL DEVELOP OVER THE NORTHERN HALF OF THE FORECAST AREA WITH LATE
TONIGHT AND CONDITIONS GRADUALLY DETERIORATE. MVFR CIGS AND VSBY
WILL DEVELOP AT KASE AND KEGE...AS WELL AS KHDN...KSBS...AND KASE...
WHERE OCCASIONAL IFR CIGS AND VSBY WILL BE POSSIBLE BY 12Z MONDAY
AND LINGER THROUGH MONDAY NIGHT. GUSTY SOUTHWEST TO WEST WINDS
WILL CONTINUE ACROSS THE REGION THROUGH MONDAY NIGHT...WITH SPEEDS
REACHING 40 KTS...CAUSING AREAS OF MECHANICAL TURBULENCE OVER THE
NEAR RIDGES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 9 AM MDT TUESDAY FOR COZ004-010-
012-013.
WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO 9 AM MDT TUESDAY FOR
COZ009.
UT...WINTER WEATHER ADVISORY UNTIL 6 PM MDT WEDNESDAY FOR UTZ023.
&&
SHORT TERM...JDC
LONG TERM...TB
AVIATION...CCHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 701 AM MDT SUN APR 14 2013 COZ001>014-017>023-UTZ022>025-027>029-151315- 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- 701 AM MDT SUN APR 14 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT SNOWFALL WILL CONTINUE OVER THE COLORADO MOUNTAINS...DIMINISHING BY LATE THIS MORNING. AFTER A BREAK THIS AFTERNOON AND EARLY THIS EVENING...SNOW WILL AGAIN DEVELOP ACROSS THE MOUNTAINS OVERNIGHT. THE HIGHER COLORADO MOUNTAINS FROM VAIL PASS NORTHWARD WILL BE FAVORED. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY PERIODS OF RAIN AND SNOW ARE EXPECTED THROUGH MID WEEK AS A STRONG COLD FRONT REMAINS POSITIONED ACROSS UTAH AND COLORADO. PERIODS OF HEAVY SNOW WILL BE POSSIBLE OVER THE NORTH AND CENTRAL MOUNTAINS WITH THE HIGHEST ACCUMULATIONS EXPECTED OVER THE FLAT TOP MOUNTAINS. SNOW LEVELS WILL RANGE FROM THE VALLEY FLOORS ACROSS NORTHWEST COLORADO...6000 TO 7000 FEET CENTRAL...AND 9000 FEET OVER THE SOUTHERN MOUNTAINS. GUSTY WINDS WILL BE COMMON THROUGH THE PERIOD...ESPECIALLY ON TUESDAY WHEN OCCASIONAL GUSTS TO 45 MPH MAY BE COMMON. .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.
13 winter weather, 5 heavy snow, 3 winter storm. Local standard time, as filed.
Snowfall amounts of 12 to 21 inches were measured across the area. Wind gusts of 25 to 40 mph produced areas of blowing and drifting snow. Locally stronger gusts to 50 mph resulted in blizzard conditions.
Snowfall amounts of 6 to 10 inches were measured across the area.
Snowfall amounts of 10 to 15 inches were measured across the area. Wind gusts of 20 to 35 mph produced areas of blowing and drifting snow.
Snowfall amounts of 3 to 6 inches were measured across the area.
Snowfall amounts of 8 to 20 inches were measured across the area.
Snowfall amounts of 5 to 11 inches were measured across the area. Locally higher amounts included 14 inches at Schofield Pass. Wind gusts of 20 to 30 mph produced some areas of blowing and drifting snow.
Snowfall amounts of 5 to 8 inches were measured across the area. Wind gusts of 20 to 30 mph produced some areas of blowing and drifting snow.
Snowfall amounts of 16 to 30 inches were measured across the area. Wind gusts of 20 to 40 mph produced areas of blowing and drifting snow.
Snowfall amounts of 2 to 6 inches were measured across the area.
Snowfall amounts of 4 to 12 inches were measured across the area. Locally higher amounts included 15 inches near Wolcott.
Snowfall amounts of 7 to 12 inches were measured across the area. Wind gusts of 25 to 40 mph produced areas of blowing and drifting snow. Locally higher wind gusts to 50 mph resulted in a few spots with blizzard conditions.
Snowfall amounts of 5 to 12 inches were measured across the area.
Snowfall amounts of 5 to 10 inches were measured across the area. Wind gusts of 20 to 30 mph produced some areas of blowing and drifting snow.
Snowfall amounts of 4 to 8 inches were measured across the area.
Snowfall amounts of 7 to 12 inches were measured across the area.
Snowfall amounts of 3 to 7 inches were measured across the area. Numerous vehicle accidents occurred due to the slick and snowpacked roads.
Snowfall amounts of 5 to 10 inches were measured across the area. Locally higher amounts included 14 inches at the Beaver Creek SNOTEL site. Wind gusts of 20 to 30 mph produced some areas of blowing and drifting snow.
Snowfall amounts of 3 to 10 inches were measured across the area. Wind gusts of 20 to 40 mph produced areas of blowing and drifting snow.
Snowfall amounts of 4 to 10 inches were measured across the area. Wind gusts of 30 to 45 mph produced widespread blowing and drifting snow. Even stronger winds at ridgetops included a gust to 86 mph on Kendall Mountain.
Snowfall amounts of 5 to 7 inches were measured across the area. Wind gusts of 20 to 35 mph produced areas of blowing and drifting snow.
Snowfall amounts of 5 to 8 inches were measured across the area. Locally higher amounts included 14 inches at Ouray. Wind gusts of 30 to 45 mph produced widspread blowing and drifting snow. Even stronger winds with blizzard conditions occurred in a few areas, including a gust to 60 mph at Huntsman Mesa and 87 mph on Mount Abrahms.
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: 520240, 520243, 520249, 520250, 520251, 520237, 520246, 520241, 520247, 520244, 520239, 520264, 520252, 520259, 520260, 520262, 520253, 520255, 520258, 520256, 520257.