Strong and persistent temperature inversions combined with ample low-level moisture to produce dense valley 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 and persistent temperature inversions combined with ample low-level moisture to produce dense valley 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 16, 6:36 PM MST, 2 hours 24 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 636 PM MST TUE FEB 16 2010 .UPDATE...FOG AT GRAND JUNCTION ARPT HAS BEEN BTWN 1/8 MILE TO 1/4 MILE FOR LAST HOUR AND REC'D REPORTS THAT FOG IS DROPPING VIS TO OUR W. LOCAL INVERSIONS AND AMPLE MOISTURE FROM PRECIP YESTERDAY HAS SET UP PERFECT ENVIRONMENT FOR DENSE FOG TONIGHT. THUS...ISSUED DENSE FOG ADVISORY FOR GRAND VALLEY THROUGH 10AM TOMORROW. .PREV DISCUSSION... /ISSUED 230 PM MST TUE FEB 16 2010/ .SHORT TERM...TONIGHT THROUGH THURSDAY... STRATOCUMULUS SHIELD THAT COVERED MOST AREAS ALONG AND NORTH OF I70 THIS MORNING IS RAPIDLY ERODING AWAY THIS AFTERNOON. ANY CLEARING ACROSS THE NRN HALF DURING THE AFTERNOON WILL BE SHORT LIVED AS THE NEXT UPSTREAM PACIFIC WAVE BEGIN TO ADVECT HIGH CLOUDS. STABLE CONDITIONS PERSIST ACROSS THE UINTA BASIN AND EXPECT LOW CLOUDS WITH PATCHY FOG TO CONTINUE. THE FIRST IN A SERIES OF SHORT WAVES FROM THE PACIFIC NORTHWEST DROPS SOUTHEAST AND REACHES NW COLORADO BY WEDNESDAY AFTERNOON. THE INITIAL WAVE IS WEAK AS IT RUNS INTO DIVERGENCE FROM A FLAT RIDGE... BUT GFS AND NAM MODEL DATA SHOW WEAK UPWARDS FORCING. QPF IS LIGHT AND MOSTLY NORTH OF I70 WEDNESDAY AFTERNOON AND EARLY EVENING. LIGHT SNOW TAPERS OFF BRIEFLY WEDNESDAY EVENING BEFORE THE NEXT SHORT WAVE ENTERS NW COLORADO AFTER WEDNESDAY MIDNIGHT. AREAS OF LIGHT SNOW ACROSS THE NORTH WILL GRADUALLY EXPAND AND SPREAD SOUTHWARD AS THE STRONGER THIRD WAVE ARRIVES THURSDAY AFTERNOON. THE NAM AND GFS DIVERGE A BIT ON HOW THE CLOSED UPPER LOW FROM THE NRN INTERMOUNTAIN REGION MOVES TOWARD THE CENTRAL ROCKIES. THE GFS AND NAM DO AGREE THAT THE SURFACE FRONT MOVES INTO NW COLORADO AND REACHES THE ROAN/TAVAPUTS PLATEAU AND THE FLAT TOP MOUNTAINS LATE IN THE DAY. UPWARDS FORCING IS BETTER DEFINED THAN THE PRECEDING SHORT WAVES...SO THE THE TREND OF RISING POPS FOR THE NEXT 48 HOURS IS ACCEPTABLE WITH LIKELY POPS FOR THE NRN AND CENTRAL HIGH COUNTRY BY THURSDAY. .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY... UNSETTLED WEATHER EXPECTED FOR MUCH OF THIS PERIOD AS AN UPPER LOW DEVELOPS OVER SOUTH-CENTRAL CANADA...AND PACIFIC ENERGY EVENTUALLY UNDERCUTS THE PERSISTENT WESTERN RIDGE THIS WEEKEND. SHORTWAVE DROPPING DOWN THE EAST SIDE OF THE RIDGE CROSSES OUR FORECAST AREA THU NIGHT...SHIFTING THE FLOW FROM WESTERLY TO NORTHWESTERLY AFTER MIDNIGHT. SOME SEMBLANCE OF A FRONT/BAROCLINIC ZONE EVIDENT THAT MAY HELP WITH LIFT. DYNAMIC LIFT ON THE WANE AFTER MIDNIGHT BUT SHOULD PICK UP SOMEWHAT ACROSS THE N BY FRI MORNING AS ANOTHER SHORTWAVE FOLLOWS CLOSE BEHIND. W TO NW FLOW WILL FAVOR BEST SNOWFALL ACROSS THE CENTRAL AND NRN MTNS THU NIGHT-FRI WITH POSSIBLE ADVISORY SNOW AMTS THERE. DIFFERENCES BETWEEN THE GFS AND ECWMF GROW THIS WEEKEND AND EARLY NEXT WEEK. THE ECMWF SEEMING TO FAVOR SHORTWAVES IN THE NRN STREAM... WHILE THE GFS FOCUSES MORE ON PACIFIC SHORTWAVES CROSSING THE GREAT BASIN. BOTH...HOWEVER...SO SHOW THE WESTERN RIDGE GETTING PINCHED OFF WITH THE HIGH CENTER OVER THE ALASKAN PANHANDLE. FIRST SUBSTANTIAL PACIFIC SHORTWAVE TRIES TO PHASE WITH A SHORTWAVE DROPPING DOWN THE NRN ROCKIES THIS WEEKEND...SO WILL KEEP A CHANCE OF SNOW IN THE FORECAST THROUGH THE WEEKEND FOR THE MTNS AND NRN VALLEYS. HOW MUCH PAC MOISTURE GETS WRINGED OUT BY THE MTNS TO OUR WEST AND THE STRENGTH OF THE SHORTWAVES ARE STILL UNCERTAIN. IF GFS PANS OUT...SAT POPS WILL NEED TO BE RAISED ESPECIALLY FOR THE S. GENERAL W-NW FLOW MON-TUE WITH EMBEDDED SHORTWAVES. WENT TOWARDS CLIMO POPS FOR MON-TUE WITH CONFIDENCE LOW IN THE DETAILS. && .AVIATION... PATCHY DENSE FOG AT 18Z WILL QUICKLY DISSIPATE BY 20Z WITH WIDESPREAD VFR FOR THE REMAINDER OF TONIGHT. THE EXCEPTION WILL BE PARTS OF THE UINTA BASIN WHERE PERIODS OF MVFR AND LOCAL IFR CONDITIONS WILL CONTINUE THROUGH TONIGHT. TOWARD THE NRN DIVIDE...EXPECT MOUNTAIN OBSCURATIONS OVER THE PASSES. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...DENSE FOG ADVISORY UNTIL 10 AM MST WEDNESDAY FOR ZONE 006. UT...DENSE FOG ADVISORY UNTIL 10 AM MST WEDNESDAY FOR ZONE 027. && UPDATE.......TGR SHORT TERM...PF LONG TERM....JAD AVIATION.....PF
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 545 AM MST TUE FEB 16 2010 COZ001>014-017>023-UTZ022>025-027>029-171245- 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 TUE FEB 16 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN COLORADO. .DAY ONE...TODAY AND TONIGHT LOW CLOUDS AND FOG OVER MUCH OF THE REGION THIS MORNING...WILL DISSIPATE BY THIS AFTERNOON. LIGHT SNOWFALL IS POSSIBLE OVER AREA MOUNTAINS TODAY...FAVORING THE CONTINENTAL DIVIDE. LITTLE TO NO ACCUMULATIONS ARE EXPECTED. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH SUNDAY NORTHWEST FLOW ALOFT WILL BRING MORE SNOWFALL TO THE NORTH BEGINNING WEDNESDAY NIGHT AND INTO THE WEEKEND. SIGNIFICANT SNOWFALL WILL BE POSSIBLE OVER THE NORTHERN AND CENTRAL MOUNTAINS OF WESTERN COLORADO THURSDAY NIGHT AND FRIDAY. SPOTTER INFORMATION STATEMENT SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT. TGJT
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
537 PM MST TUE FEB 16 2010
..TIME.. ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE.. ....MAG.... ..COUNTY LOCATION.. ST.. ...SOURCE....
..REMARKS..
0536 PM DENSE FOG GRAND JUNCTION 39.09N 108.55W
02/16/2010 M0.25 MILE MESA CO NWS OFFICE
FOGBANK ROLLED THROUGH MOVING WEST TO EAST AT THE
AIRPORT. CURRENTLY VIS DOWN TO QUARTER MILE.
&&
EVENT NUMBER GJT1000188
MALEKSAThe national radar mosaic for the moment the first event began.
2 dense fog. Local standard time, as filed.
Dense fog formed near Canyonlands Airport and the town of Moab and extended southward to the San Juan county line. Visibilities were reduced to less than one-quarter mile.
Dense fog reduced visibilities to one-quarter mile in areas.
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: 210595, 210591.