Dense fog formed across the area just before sunrise and persisted into the early morning hours.
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.
Dense fog formed across the area just before sunrise and persisted into the early morning hours.
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 4, 4:03 AM MST, 1 hour 27 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 403 AM MST MON FEB 4 2013 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 403 AM MST MON FEB 4 2013 AREAS OF FOG DEVELOPED IN THE EASTERN UINTA BASIN AND SOME WEST-CENTRAL AND SOUTHWEST CO VALLEYS PRIOR TO MIDNIGHT AND BEHIND AN UPPER DISTURBANCE THAT HAS SINCE EXITED TO OUR SOUTHEAST. DENSE FOG WAS EARLIER REPORTED AROUND NUCLA/NATURITA AND VERNAL BUT VISIBILITY HAS SINCE IMPROVED AT THE NUCLA AND VERNAL ASOS SITES. HOWEVER...SATELLITE FOG PRODUCT STILL SHOWED LOW CLOUDS AND/OR FOG IN THESE AREAS SO PLAN TO KEEP THE DENSE FOG ADVISORY IN PLACE FOR THESE LOCATIONS. LOW CLOUDS AND POSSIBLY PATCHY FOG ALSO IN THE DELTA/MONTROSE AND GUNNISON AREAS. DRY CONDITIONS SHOULD BE THE RULE THROUGH TUESDAY. AN UPPER JET WAS PUNCHING INTO B.C. CANADA THIS MORNING WITH WARM ADVECTIVE MID/HIGH CLOUDS SPILLING DOWN ACROSS ID/WRN WY AND WILL EVENTUALLY SPREAD INTO NE UT/NW BY SUNRISE. FORECAST SOUNDINGS SHOW HIGHER HUMIDITY LOWERING INTO THE 700-600 MB LAYER AT HAYDEN LATE TODAY AS A WEAK WAVE DROPS ACROSS THE AREA...BUT MODEL PRECIPITATION IS SCANT TO NONE SO WILL KEEP IT OUT OF THE FORECAST. LOW AMPLITUDE RIDGING SLIDES EAST ACROSS THE FORECAST AREA ON TUESDAY WITH SOME MID/HIGH LEVEL CLOUDS STILL ACROSS THE NORTH. THE FLOW ALOFT SHIFTS FROM NW TODAY TO W-SW BY TUESDAY AFTERNOON FOR A BIT WARMER TEMPS TOMORROW COMPARED TO TODAY. WITH LITTLE TO FLUSH OUT THE EASTERN UINTA BASIN TODAY...EXPECT LOW CLOUDS AND AREAS OF FOG TO REDEVELOP THERE AGAIN TONIGHT. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 403 AM MST MON FEB 4 2013 TUESDAY NIGHT AND WEDNESDAY...GENERALLY DRY CONDITIONS ARE EXPECTED...BUT THE 500 MB RIDGELINE WILL PASS OVERHEAD WED AFTERNOON AND EVENING AS A WEAK 500 MB SHORTWAVE TROUGH MOVES THRU THE GREAT BASIN AND OVER THE FORECAST AREA. THE MODELS HAVE UNDERPLAYED THE LAST FEW OF THESE TROUGHS SO HAVE EDGED THE CLOUD COVER AND CHANCE OF PCPN UP A BIT FOR BOTH PERIODS. WED NIGHT AND THURSDAY SHOULD BE DRY...AS A SHORTWAVE RIDGE PASSES OVERHEAD. THEN THE NEXT STRONG STORM WILL APPROACH AND SW WINDS ALOFT WILL INCREASE AHEAD OF THIS SYSTEM THURSDAY. THURSDAY NIGHT THRU SUNDAY...THE MIDRANGE MODELS SEEM TO SLOW DOWN THE EASTERLY PROGRESSION OF THE NEXT STORM. THE GFS DIGS A STRONG CLOSED LOW INTO THE WESTERN GREAT BASIN THU NIGHT AND STALLS IT OVER NEVADA FRI. THE EC DEVELOPS THE LOW FURTHER WEST AND MOVES IT IN THE WESTERN GREAT BASIN IN THE SAME TIMEFRAME. BOTH MODELS INCREASE THE SW FLOW AND HIGH CLOUDS OVER THE AREA FRI AND FRI NIGHT BUT HOLD OFF LOWER CLOUDS AND PRECIP. THE EC IS FASTER THAN THE GFS AND SPREADS PRECIP ACROSS THE AREA LATE FRI NIGHT AND SAT. THE EC ALSO BRINGS IN A MORE DISTINCT SURFACE FRONT WITH THE PRECIP. THE GFS BRINGS IN THE PRECIP SAT. HAVE INCREASE CLOUD COVER AND CHANCE OF PRECIP ACROSS THE AREA FRI NIGHT AND SAT. BOTH MODELS ARE SLOW TO MOVE THIS SYSTEM OUT OF THE AREA AS IT GETS CUT OFF FROM THE GENERAL FLOW AND REMAIN OVER THE AREA THROUGH THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 403 AM MST MON FEB 4 2013 MVFR CIGS SHOULD STAY AT KMTJ AND KGUC THROUGH MID-MORNING BEFORE IMPROVING TO VFR. KVEL IS CURRENTLY ON THE NORTHERN EDGE OF AN AREA OF MVFR/IFR CIGS AND FOG...WHICH COULD EXPAND BACK OVER THE KVEL AIRFIELD AT TIMES THROUGH THE MORNING HOURS. THE EASTERN UINTA BASIN AND KVEL WILL LIKELY EXPERIENCE SIMILAR LOW CLOUDS/FOG AGAIN TONIGHT. VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THIS AFTERNOON. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...DENSE FOG ADVISORY UNTIL 9 AM MST THIS MORNING FOR COZ020. UT...DENSE FOG ADVISORY UNTIL 9 AM MST THIS MORNING FOR UTZ024. && SHORT TERM...JAD LONG TERM...CC AVIATION...JAD
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 407 AM MST MON FEB 4 2013 COZ001>014-017>023-UTZ022>025-027>029-051115- 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- 407 AM MST MON FEB 4 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT AREAS OF FREEZING FOG WILL LOWER VISIBILITY TO LESS THAN 1 MILE IN THE EASTERN UINTA BASIN AND THE PARADOX VALLEY THIS MORNING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY ANOTHER WEAK WAVE WILL MOVE OVER THE FLATTOPS AND GORE RANGE WEDNESDAY EVENING BRINGING A SLIGHT CHANCE FOR SOME LIGHT SNOWFALL. ANOTHER STRONG WINTER SYSTEM WILL BRING MORE SIGNIFICANT PRECIPITATION TO THE REGION FROM FRIDAY THROUGH THE WEEKEND. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. JAD/CJC
The national radar mosaic for the moment the first event began.
1 dense fog. Local standard time, as filed.
Extensive fog was reported around the area, and especially in the late night hours to mid morning hours when visibilities dropped to a quarter mile or less.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2013Every state in 2013This day in weather historyWarnings in Utah, February 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: 484586.