Strong valley temperature inversions combined with moisture from snow-covered ground to produce widespread dense fog.
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.
Strong valley temperature inversions combined with moisture from snow-covered ground to produce widespread dense fog.
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 Feb 3, 3:28 PM MST, 4 hours 32 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 328 PM MST WED FEB 3 2010 .SHORT TERM...TONIGHT THROUGH FRIDAY SOUTHERN LOW TRACKING OVER NORTHERN MEX INTO NM THIS AFTERNOON. THE LOW WILL EJECT NORTHEASTWARD LEAVING THE SAN JUANS AND ASSOCIATED SOUTHERN VALLEYS ON THE NORTHERN EDGE OF THE STORM THIS EVENING AND THE WESTERN EDGE AFTER MIDNIGHT. AS THE STORM SHIFTS NORTHEAST AND OVER SOUTHEASTERN CO WINDS ALOFT WILL SHIFT TO THE WEST. MID TO HIGH LEVEL CLOUD COVER IS INCREASING FROM THE SOUTH AND SHOULD CONTINUE TO PUSH NORTH THROUGH THE EVENING. FAIRLY DEFINED GRADIENT ALONG THE WESTERN EDGE OF THE CLOUD BAND ON SATELLITE IS ALSO REPRESENTED IN MODEL DATA. WILL TRIM POPS DOWN ALONG THE WESTERN EDGE OF THE CWA TONIGHT. NEXT TROUGH FROM THE NORTHWEST DIGS SOUTH INTO THE REGION EARLY THURSDAY. THE NORTHERN TROUGH TRACKS OVER THE NORTHERN PORTION OF THE CWA AND EXITS OVER THE DIVIDE LATE THURSDAY AFTERNOON LEAVING NORTHWESTERLY FLOW ALOFT. THE FOCUS FOR SNOW WITH THE SECOND TROUGH IS OVER THE NORTHERN AND CENTRAL MOUNTAINS OF WESTERN CO. ACCORDING TO SATELLITE AND MODELS DATA THIS SECOND PIECE OF THE SYSTEM IS FAIRLY DRY AND SHOULD LIMIT SNOW ACCUMULATIONS TO BELOW ADVISORY CRITERIA. LOCALLY HIGHER AMOUNTS ARE POSSIBLE ON WEST AND NORTHWEST FACING SLOPES OF THE HIGHER PEAKS. MAY HAVE TO WATCH A FEW LOCATIONS FOR ENOUGH SNOW FOR HILITES AS THIS STORM SYSTEM DEVELOPS. ONE EXAMPLE IS THE UNCOMPAHGRE GORGE AREA WITH MODELS GIVING INDICATIONS OF BETTER LOCALIZED SNOW AMOUNTS ON THURSDAY AS THE WINDS TURN NORTHWESTERLY. WILL WAIT FOR ANOTHER MODEL RUN OR TWO BEFORE FOCUSING IN THESE LOCAL AREAS. A RIDGE OF HIGH PRESSURE MOVES OVER THE REGION FRIDAY AND HELPS CLEAR SHOWERS. A FEW WEAK DISTURBANCES MOVE THROUGH THE RIDGE WHICH SHOULD KEEP SOME CLOUD COVER. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY... RIDGING SHIFTS EAST FRI NIGHT AND SAT AS THE NEXT SPLITTING PACIFIC STORM MOVES INLAND. CENTER OF THE SOUTHERN SECTION THEN MOVES JUST SOUTH OF THE FOUR CORNERS SUN-SUN NIGHT. 12Z ECMWF AND GFS IN REASONABLE AGREEMENT WITH THIS. GFS MODEL ESPECIALLY PUTS AN EAST- WEST DEFORMATION ZONE ACROSS SE UT/SW CO SUNDAY FOR A POSSIBLE FOCUS OF HEAVIER SNOW HERE..AND WILL BUMP UP SUNDAY POPS ACROSS THIS AREA. 12Z GFS ACTUALLY STARTS INCREASING THE CHANCE OF PRECIP AS SOON AS SAT EVENING...BUT THIS IS NOT READILY SUPPORTED BY THE 12Z ECWMF AND A SPLITTING SYSTEM MAY SLOW AS IT ENCOUNTERS THE RIDGE. SHORTWAVE ROTATING AROUND A LARGE UPPER LOW OVER ERN CANADA THEN DROPS SOUTH ACROSS THE DAKOTAS SUN NIGHT-MONDAY. TIMING AND THE WESTWARD EXTENT OF THIS WAVE/TROUGH IS UNCERTAIN WITH THE 12Z GFS TAKING IT FARTHEST WEST...CROSSING OUR FORECAST AREA LATE MON-TUE. WILL KEEP A CHANCE OF SNOW FOR THE MTNS MON NIGHT IN W-NW FLOW... GRADUALLY DECREASING TUE AND TUE NIGHT AS THE TROUGH MOVES INTO THE CENTRAL STATES. && .AVIATION... IFR CONDITIONS IN LOW CLOUDS AND FOG WILL FORM IN THE UINTA BASIN IMPACTING KVEL AIRPORT LATER TONIGHT AND EARLY THURSDAY. PATCHY FOG WITH LOCAL MVFR VIS WILL BE POSSIBLE ALONG THE COLORADO RIVER UNTIL MID THURSDAY MORNING...INCLUDING KGJT...KRIL...AND KEGE. MID AND UPPER LEVEL CLOUDS WILL INCREASE NORTHWARD TONIGHT AND CEILINGS WILL DECREASE OVERNIGHT AND INTO THURSDAY WITH AREAS OF IFR CONDITIONS OVER THE MOUNTAINS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && SHORT TERM...AS LONG TERM....JAD AVIATION.....PF/AS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 600 AM MST WED FEB 3 2010 COZ001>014-017>023-UTZ022>025-027>029-041300- 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- 600 AM MST WED FEB 3 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT PATCHY FOG IS POSSIBLE IN SOME OF THE VALLEY AREAS THIS MORNING... ESPECIALLY IN THE UINTA BASIN IN NORTHEAST UTAH...AND ON THE GRAND FLAT IN EAST CENTRAL UTAH. VISIBILITY MAY FALL BELOW ONE MILE AT ISOLATED LOCATIONS. SCATTERED SNOW SHOWERS WILL DEVELOP OVER THE SOUTHERN MOUNTAINS TONIGHT...WITH LITTLE TO NO ACCUMULATION. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THURSDAY...THERE WILL BE AN INCREASING CHANCE OF SNOW OVER THE MOUNTAINS AND VALLEYS ABOVE 6000 FEET...WITH STORM TOTAL AMOUNTS NEAR 6 INCHES OVER THE NORTHERN AND PORTIONS OF THE CENTRAL MOUNTAINS. SNOW WILL DECREASE THURSDAY NIGHT. FRIDAY AND SATURDAY...PACIFIC MOISTURE WILL STREAM ACROSS COLORADO FOR A SLIGHT CHANCE OF SNOW OVER THE MOUNTAIN PASSES. SUNDAY AND MONDAY...A STRONGER PACIFIC STORM WILL BRING A CHANCE OF SNOW ACROSS MUCH OF THE REGION. MODERATE AMOUNTS OF SNOW WILL BE POSSIBLE IN THE MOUNTAINS. .SPOTTER INFORMATION STATEMENT SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT. TGJT
The national radar mosaic for the moment the first event began.
2 dense fog. Local standard time, as filed.
Dense fog frequently reduced visibilities to below one-quarter mile, especially along Interstate 70 west of the Colorado border and Highway 191 from the Interstate southward towards Moab.
Dense fog frequently reduced visibilities to below one-quarter mile.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2010Every state in 2010This day in weather historyWarnings in Utah, February 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: 210569, 210568.