A late season winter storm brought accumulating snowfall the higher elevations of eastern Utah and western Colorado, including many of the highly traveled mountain passes.
Every event with a place to put it; 4 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 late season winter storm brought accumulating snowfall the higher elevations of eastern Utah and western Colorado, including many of the highly traveled mountain passes.
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 May 18, 2:56 AM MST, 10 hours 4 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 356 AM MDT TUE MAY 18 2010 .SHORT-TERM...TODAY THROUGH WEDNESDAY NIGHT... DEEP SOUTHERLY FLOW NOW IN PLACE AS ANOTHER UPPER LEVEL LOW PRESSURE SYSTEM TAKES UP RESIDENCE OVER THE GREAT BASIN. EXPECT A GRADUAL DEEPENING OF MID AND LOW LEVEL MOISTURE THROUGH THE DAY WITH SCATTERED TO NUMEROUS SHOWERS DEVELOPING BY THIS AFTERNOON. BULK OF PRECIPITATION TODAY WILL BE IN THE FORM OF RAIN AS TEMPS ALOFT REMAIN QUITE WARM. ONLY AREA THAT SHOULD SEE SOME COOLING WILL BE OVER EASTERN UTAH...WITH THE EASTERN UINTAS GETTING INTO THE COLDER AIR BY THIS AFTERNOON. AS A RESULT...EXPECT SNOW LEVELS IN THIS AREA TO SLOWLY DROP THIS AFTERNOON AND TONIGHT WITH A FEW INCHES OF WET SNOW EXPECTED BY WEDNESDAY MORNING. THE WESTERN COLORADO MOUNTAINS WILL BE SLOWER TO COOL OFF AS WE WAIT FOR THE UPPER LEVEL LOW TO LIFT OUT ACROSS THE REGION. THIS HAPPENS LATE TONIGHT...AND AS THE MID LEVEL FLOW BACKS AROUND TO A MORE FAVORABLE WESTERLY COMPONENT...EXPECT TO SEE LOW END ADVISORY SNOWFALL FOR THE NORTHERN AND CENTRAL MOUNTAINS...WITH BULK OF SNOW FALLING ON WEDNESDAY. DUE TO CLOUD COVER AND INCREASED MOISTURE... HIGH TEMPERATURES TODAY WILL BE RUNNING 5 TO 10 DEGREES COOLER...WITH ANOTHER 5 TO 10 DEGREE DROP ON WEDNESDAY BEHIND A PACIFIC FRONT THAT PUSHES THROUGH AS THE UPPER LEVEL LOW KICKS OUT. NO CHANGES TO THE CURRENT HIGHLIGHTS. .LONG TERM...THURSDAY THROUGH MONDAY... MODELS WERE CONSISTENT IN SHOWING A SHORT WAVE RIDGE OVER THE REGION EARLY THURSDAY. THE HIGH PRESSURE RIDGE GIVES WAY TO LIGHT SOUTHWEST FLOW LATER IN THE DAY AS THE TROF OVER THE EASTERN PACIFIC DEEPENS. NAM AND GFS WERE BOTH DRY DURING THIS PERIOD SO BACKED POPS DOWN TO BELOW MENTION OF SHOWERS IN THE AFTERNOON. FLOW INCREASES OVER THE REGION FRIDAY AS A COLD FRONT APPROACHES THE NORTHWEST CORNER OF THE CWFA. HOWEVER...BOTH NAM AND GFS HELD FRONT OFF FARTHER TO THE NORTHWEST THAN EARLIER RUNS AND AS A RESULT... QPF FIELD WAS NORTHWEST OF THE CWFA BOUNDARY. SINCE LATEST ECMWF NOT IN AS OF THIS WRITING...DID NOT REMOVE POPS ENTIRELY BUT DID BACK THEM OFF A BIT. AHEAD OF THE FRONT...EXPECT BREEZY SOUTHWEST WINDS ...ESPECIALLY FOR THE NORTHERNMOST ZONES. THIS WILL HELP DRIVE TEMPERATURES 5 TO 10 DEGREES ABOVE NORMAL. MODELS LIFT CLOSED LOW OVER THE GREAT BASIN NORTHEAST ON SATURDAY INTO EASTERN MONTANA BY MONDAY. MODELS ARE A BIT DIVERGENT WITH TIMING AND TRACK OF THIS SYSTEM. BROAD TROUGH WILL DOMINATE WEATHER WITH INSTABILITY AND WEAK FORCING KEPT A SLIGHT CHANCE MENTION EACH DAY. BELOW NORMAL TEMPERATURES ARE EXPECTED ON SUNDAY AND MONDAY. && .AVIATION... ISOLATED SHOWERS OVER THE MOUNTAIN PEAKS WILL CAUSE LOCAL MVFR CONDITIONS THIS MORNING. OTHERWISE...EXPECT VFR CONDITIONS. CLOUDS WILL CONTINUE TO INCREASE THIS MORNING AND SHOWERS WILL SLOWLY EXPAND IN COVERAGE FROM WEST TO EAST BY THIS AFTERNOON. THIS WILL RESULT IN LOCAL MVFR CONDITIONS IN AND NEAR SHOWERS. EXPECT MORE WIDESPREAD MVFR CONDITIONS AS CEILINGS CONTINUE TO LOWER LATE THIS AFTERNOON AND OVERNIGHT. && .FIRE WEATHER... ISOLATED THUNDERSTORMS TODAY WILL GENERATE GUSTY WINDS AND LITTLE RAINFALL INITIALLY...BUT WILL BECOME MORE EFFICIENT RAIN PRODUCERS BY LATE THIS AFTERNOON. WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE NEAR COLLAPSING SHOWERS AND THUNDERSTORMS. STRONG WINDS ARE POSSIBLE THIS FRIDAY AND SATURDAY AHEAD OF ANOTHER STORM MOVING INTO THE WEST. THE WIND COUPLED WITH ANTICIPATED LOW AFTERNOON HUMIDITIES...MAY RESULT IN A EXTENDED PERIOD OF CRITICAL FIRE WEATHER CONDITIONS FROM FRIDAY AFTERNOON THROUGH SATURDAY. PERSISTENT GRADIENT WINDS COULD ALSO LIMIT RELATIVE HUMIDITY RECOVERY ON MID AND UPPER SLOPES FRIDAY NIGHT. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. SHORT TERM.....JDC LONG TERM......NL AVIATION.......TGJT FIRE WEATHER...JAD/JDC
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 545 AM MDT TUE MAY 18 2010 COZ001>014-017>023-UTZ022>025-027>029-191145- ANIMAS RIVER BASIN-ARCHES/GRAND FLAT-CANYONLANDS/NATURAL BRIDGES- CENTRAL COLORADO RIVER BASIN- CENTRAL GUNNISON AND UNCOMPAHGRE RIVER BASIN- CENTRAL YAMPA RIVER BASIN-DEBEQUE TO SILT CORRIDOR- EASTERN UINTA BASIN-EASTERN UINTA MOUNTAINS- ELKHEAD AND PARK MOUNTAINS-FLAT TOPS- FOUR CORNERS/UPPER DOLORES RIVER- GORE AND ELK MOUNTAINS/CENTRAL MOUNTAINS-GRAND AND BATTLEMENT MESAS- GRAND VALLEY-LA SAL AND ABAJO MOUNTAINS-LOWER YAMPA RIVER BASIN- NORTHWEST SAN JUAN MOUNTAINS-PARADOX VALLEY/LOWER DOLORES RIVER- ROAN AND TAVAPUTS PLATEAUS-SAN JUAN RIVER BASIN-SOUTHEAST UTAH- SOUTHWEST SAN JUAN MOUNTAINS-TAVAPUTS PLATEAU- UNCOMPAHGRE PLATEAU AND DALLAS DIVIDE-UPPER GUNNISON RIVER VALLEY- UPPER YAMPA RIVER BASIN-WEST ELK AND SAWATCH MOUNTAINS- 545 AM MDT TUE MAY 18 2010 ...WINTER WEATHER ADVISORIES ARE IN EFFECT THIS AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR PORTIONS OF WESTERN COLORADO AND NORTHEAST UTAH... THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP OVER EASTERN UTAH AND WESTERN COLORADO TODAY. THE SHOWERS WILL INCREASE IN COVERAGE TONIGHT...WITH SNOW LEVELS DROPPING TO AROUND 8000 FEET BY EARLY WEDNESDAY MORNING. LOCALLY HEAVY SNOW WILL FALL OVER THE MOUNTAINS OF NORTHEAST UTAH AND OVER THE NORTHERN AND CENTRAL MOUNTAINS OF WESTERN COLORADO. PLEASE VISIT THE NATIONAL WEATHER SERVICE GRAND JUNCTION WEBSITE AT WEATHER.GOV/GJT FOR ADDITIONAL INFORMATION. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY SCATTERED RAIN AND SNOW SHOWERS ARE EXPECTED TO REDEVELOP EARLY FRIDAY...CONTINUING PERIODICALLY THROUGH THE WEEKEND. THIS ACTIVITY WILL MAINLY IMPACT THE HIGHER TERRAIN AND LOWER ELEVATIONS OF THE NORTH. .SPOTTER INFORMATION STATEMENT SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT THOUGH WE ASK SPOTTERS TO REPORT ANY SIGNIFICANT WEATHER OR RAIN AND SNOW ACCUMULATIONS. JDC/NL
The national radar mosaic for the moment the first event began.
4 winter weather. Local standard time, as filed.
Snowfall accumulations ranged from 5 to 12 inches with locally higher amounts of up to 15 inches reported at the Rabbit Ears SNOTEL site.
Snowfall amounts across the area ranged from 5 to 9 inches.
Snowfall amounts across the area ranged from 5 to 9 inches.
Snowfall accumulations ranged from 3 to 9 inches above the 9,000 foot level. Wind gusts up to 45 mph produced some areas of blowing snow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2010Every state in 2010This day in weather historyWarnings in Colorado, May 2010
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: 232892, 232894, 232895, 232893.