Persistent temperature inversions allowed areas of dense fog to develop in the Grand Valley and Grand Flat areas.
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.
Persistent temperature inversions allowed areas of dense fog to develop in the Grand Valley and Grand Flat areas.
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 15, 2:30 PM MST, 12 hours earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 230 PM MST MON FEB 15 2010 .SHORT TERM...TONIGHT THROUGH WEDNESDAY... SHEARED SHORT WAVE DROPS SOUTH SOUTHEAST TONIGHT ALONG THE UTAH AND COLORADO BORDER. THIS DISTURBANCE IS NOT PARTICULARLY STRONG BUT HITS THE WESTERN SLOPE JUST RIGHT FOR LIGHT SNOW ACCUMULATIONS FOR THE MOUNTAINS AND POSSIBLY SOME VALLEYS. LEFT FRONT EXIT REGION OF THE 80 KNOT JET GENERATES THE UPWARD MOTION FOR SNOW. ASIDE FROM THE NEARBY JET CORE...GRADIENT FLOW IS WEAK WITH MOUNTAIN TOP WINDS ON THE ORDER OF 10 KNOTS AND CONFIRMED BY REMOTE SENSORS. SNOWFALL WILL BE MORE DRIVEN BY THE UPPER LEVEL DIVERGENCE AND RELATIVELY LOW STATIC STABILITY RATHER THAN OROGRAPHICS...WHICH JUSTIFIES THE MODERATELY HIGH CHANCE POPS FOR THE VALLEYS. ONLY SOUTHEAST UTAH IS EXPECTED TO BE PCPN FREE AS THIS AREA WILL BE ON THE SUBSIDENT SIDE OF THE JET. SHORT WAVE WILL BE MOVING INTO NRN NEW MEXICO AFTER MIDNIGHT AND EXPECT SNOW TO DECREASE NORTH TO SOUTH. GIVEN THE SHORT DURATION OF UPWARDS FORCING...SNOWFALL IS EXPECTED TO BE SUBADVISORY. MONDAY AND MONDAY NIGHT...THE FLOW BECOMES ANTICYCLONIC AS UTAH AND COLORADO WILL BE IN BETWEEN SHORT WAVES. THE 15Z SREF SHOWS NO QPF FOR MONDAY...BUT SHALLOW MOISTURE THAT REMAINS OVER NW COLORADO COMBINED WITH FAVORABLE BUT LIGHT NORTHWEST FLOW MAY INDUCE A FEW FLURRIES. OTHERWISE MOSTLY TO PARTLY SUNNY CONDITIONS CAN BE EXPECTED FOR ERN UTAH AND SW COLORADO. TUESDAY...A COLD FRONT APPROACHES FROM THE NRN ROCKIES THAT WILL INCREASE THE CHANCE OF SNOW ACROSS THE UINTAS AND NW COLORADO. THE SOUTH WILL REMAIN DRY BUT EXPECT AN INCREASE OF CLOUDS SOUTH OF I70. .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... THE FLOW ALOFT BACKS A BIT TOWARD THE WEST WED NIGHT AS A STRONG SHRT WV ROTATES AROUND A PARENT LOW OVER SRN SASKATCHEWAN AND DROPS INTO SW MONTANA. THIS BRINGS AN INCREASE IN BOTH MSTR AND DYNAMICS ESPECIALLY ALONG AND NEAR THE WY BORDER. THIS FEATURE DROPS INTO WY THURSDAY AND APPEARS SLOWER AND WEAKER THAN PREVIOUS RUNS WITH GENERAL LACK OF WELL DEFINED SFC FRONT. STILL BELIEVE THE NRN AND CNTRL MTNS NEAR THE DIVIDE LIKELY TO RECEIVE LIGHT SNOW. TROF PASSAGE IS EXPECTED THUR NIGHT ACCOMPANIED BY MID LEVEL COLD ADVECTION WHICH WILL INCREASE PCPN POTENTIAL AS LAPSE RATES STEEPEN. HOWEVER BY EARLY FRI MORNING PCPN WILL BEGIN TO DECREASE FROM THE WEST WITH THE EXCEPTION OF THE NRN AND CNTRL MTNS WHERE SHOWERS WILL LINGER. INTERESTING PATTERN EVOLVES BY FRI SHOWING STRONG CLOSED LOW OFF CA COAST WHILE A SECONDARY SHRT WV OVER ERN OR/WA HELPS TO PRODUCE A MORE WESTERLY FLOW WITH MODERATE MSTR AND WARM ADVECTION RESULTING IN SCATTERED MTN SHOWERS. FOR THE REMAINDER OF THIS EXTENDED PERIOD MEDIUM RANGE MDLS TREND OUT OF PHASE...BUT IT APPEARS A WSWRLY FLOW BECOMES ESTABLISHED WITH EMBEDDED WEAK VORT CENTERS ROTATING OUT OF PARENT LOWS OVER THE NRN ROCKIES AND WEST COAST. THIS PRODUCES UNSETTLED CONDITIONS WITH SHWRS OVR THE MTNS...WHICH APPEAR TO FAVOR THE NORTHERN PORTIONS OF THE CWA. TEMPERATURES WILL BE RUNNING NEAR TO SLIGHTLY BELOW SEASONAL NORMS THROUGH THE PERIOD. && .AVIATION... CONDITIONS WILL DETERIORATE THIS AFTERNOON WITH LOWER CIGS AND VIS. VFR WILL GIVE WAY TO WIDESPREAD MVFR WITH LOCAL IFR AS LIGHT SNOW INCREASES AFTER 20Z AND CONTINUES THROUGH 05Z WITH MOUNTAIN OBSCURATIONS. SLOW IMPROVEMENT FROM NORTH TO SOUTH IS EXPECTED BETWEEN 05Z-15Z TONIGHT WITH WIDESPREAD VFR RETURNING AFTER 15Z TUESDAY. SOUTHEAST UTAH AND EXTREME SOUTHWEST COLORADO WILL STAY VFR DURING THE NEXT 24 HOURS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && SHORT TERM...PF LONG TERM....MC AVIATION.....PF
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 545 AM MST MON FEB 15 2010 COZ001>014-017>023-UTZ022>025-027>029-161245- 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 MST MON FEB 15 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT PATCHY FOG WILL DISSIPATE THIS MORNING OVER THE LOWER VALLEYS OF EASTERN UTAH AND WESTERN COLORADO. AREAS OF SNOW MOVE BACK INTO THE NORTHERN AND CENTRAL MOUNTAINS THIS AFTERNOON AND WILL CONTINUE THROUGH TONIGHT. MOUNTAIN LOCATIONS FROM VAIL PASS NORTH TO STEAMBOAT SPRINGS CAN EXPECT NEW SNOWFALL AMOUNTS FROM 3 TO 6 INCHES BY TUESDAY MORNING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SATURDAY NORTHWEST FLOW ALOFT WILL BRING MORE SNOWFALL TO THE NORTH WEDNESDAY NIGHT THROUGH THURSDAY AND AGAIN OVER THE WEEKEND. SPOTTER INFORMATION STATEMENT SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT. TGJT
The national radar mosaic for the moment the first event began.
1 dense fog. Local standard time, as filed.
Areas of dense fog reduced visibilities to 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: 210582.