A strong thunderstorm produced a funnel cloud near Cahone.
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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 strong thunderstorm produced a funnel cloud near Cahone.
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 Aug 3, 2:59 PM MST, 1 hour 31 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 359 PM MDT MON AUG 3 2015 .SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT) ISSUED AT 359 PM MDT MON AUG 3 2015 THE NATURE OF THE CONVECTION HAS CHANGED THIS AFTERNOON AS WE ADD A BIT OF DRIER AIR AND STRONGER WINDS ALOFT. BRIEF HEAVY RAINFALL CAN NOT BE RULED OUT BUT STORM MOVEMENT AND STRONGER UPDRAFTS SUGGEST THE THREAT OF GUSTY OUTFLOW WINDS AND SMALL HAIL WILL BE MORE OF A CONCERN THROUGH SUNSET. WATER VAPOR IMAGERY SHOWS A CLEAR PICTURE OF WHAT IS HAPPENING THIS AFTERNOON AS A CYCLONE IS LIFTING NORTHEAST OUT OF THE GREAT BASIN. THE MONSOON PLUME HAS BEEN PUSHED EAST OF THE ROCKIES BY THE INFLUX OF STRONGER WESTERLY FLOW WRAPPING INTO THE LOW. RESIDUAL LOW LEVEL MOISTURE AND THE DRY AIR ALOFT IS EFFECTIVELY PRODUCING MODERATELY UNSTABLE CONDITIONS. LOOKING UPSTREAM...THE NOSE OF A PACIFIC JET IS MOVING INTO SOUTHERN NEVADA FORCING CONVECTION TO FIRE OVER EAST CENTRAL PORTIONS OF THAT STATE. WITH THE LOSS OF HEATING THE SHOWERS SHOULD EXHIBIT THE NORMAL DIURNAL DOWNTREND NEAR SUNSET. HOWEVER A PORTION OF THE UPSTREAM JET WILL BE MOVING OVER OUR WESTERN CWA OVERNIGHT AND OVER-RUNNING AN AREA OF RATHER STEEP LAPSE RATES AT THE TOP OF THE EML. HAVE KEPT A MENTION OF ISOLATED STORMS PAST MIDNIGHT IN OUR WEST THOUGH MUCH OF THIS MAY TURN OUT TO BE ACCAS. HEATING WILL INCREASE IN THE DRIER AIRMASS ON TUESDAY AND HIGHS SHOULD PUSH BACK TO NORMAL. EXPECT ANY RESIDUAL MOISTURE TO BE LIFTED BY THE TERRAIN WINDS TO PRODUCE SOME RIDGETOP BUILDUPS. ONLY ISOLATED STORMS ARE EXPECTED FROM THIS ACTIVITY AND FOCUSED OVER OUR EASTERN MOUNTAINS. A QUICK DOWNTURN BY EVENING WILL LEAVE A MAINLY CLEAR NIGHT IN PLACE. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 359 PM MDT MON AUG 3 2015 THE ANOMALOUSLY STRONG LOW DOMINATING THE HUDSON BAY AREA WILL BE EJECTED DOWNSTREAM BY ANOTHER STRONG SYSTEM DROPPING OUT OF THE ARCTIC REGION DURING THE MID TO LATE WEEK PERIOD. THIS WILL ALLOW THE DOWNSTREAM PATTERN OVER THE REMAINING PORTION OF NOAM TO BECOME A BIT MORE PROGRESSIVE. IN THE BIG PICTURE THE SUB-TROPICAL HIGH WILL BECOME RE-ESTABLISHED OVER THE SOUTHERN PLAINS BY WEEK/S END WHERE IT WILL REMAIN THROUGH THIS FORECAST PERIOD. A QUICK MOVING SYSTEM TO OUR NORTH WILL DRAG A BIT OF MOSITURE TO OUR NORTHERN BORDER AND MAY LEAD TO A SLIGHT UPTICK IN THUNDERSTORM ACTIVITY THURSDAY AFTERNOON BUT CONFIDENCE LOW ATTM. MORE CERTAIN IS THE INFLUX OF MONSOON MOISTURE EARLY FRIDAY AS THE RIDGE AXIS ALOFT SHIFTS EAST OF THE ROCKIES. A SIMILAR PATTERN TO WHAT IS CURRENTLY HAPPENING IS THEN FORECAST TO OCCUR LATE SATURDAY WITH A SYSTEM LIFTING NORTHWARD ACROSS THE GREAT BASIN. THIS LEAVES SATURDAY SATURDAY AFTERNOON AS THE PERIOD MOST LIKELY FOR HEAVY RAIN AND THUNDERSTORMS WITH THE ACTIVITY RAMPING UP FRIDAY AFTERNOON AND DECREASING SUNDAY AS DRIER AIR SWEEPS IN. TEMPERATURES LOOK TO COOL BELOW NORMAL WHEN THIS MOISTURE ARRIVES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 359 PM MDT MON AUG 3 2015 KTEX...KASE AND KEGE HAVE THE MOST LIKELY CHANCE TO BE IMPACTED BY PASSING THUNDERSTORMS FROM 03/22Z TO 04/02Z. ERRATIC AND GUSTY OUTFLOW WINDS APPEAR THE BE THE MAIN THREAT TO AVIATION BUT SMALL HAIL AND LIMITED VISIBILITY DUE TO PASSING RAIN SHOWERS CAN NOT BE RULED OUT. AFTER SUNSET IMPROVEMENT SHOULD OCCUR RAPIDLY AS THE STORMS WEAKEN AND DISSIPATE. DO NOT ANTICIPATE LOWER FLIGHT CRITERIA OVERNIGHT BUT HEAVY RAINFALL NEAR THE TERMINALS COMBINED WITH CLEARING SKIES TONIGHT MAY PRODUCE SOME LIGHT FOG BY SUNRISE...HOWEVER CONFIDENCE EXTREMELY LOW. VFR AND MOSTLY SUNNY SKIES DOMINATE THE FORECAST FOR TUESDAY. && SHORT TERM...15 LONG TERM...15 AVIATION...TGJT
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
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GRAND JUNCTION CO 216 PM MDT MON AUG 3 2015 COZ008>010-012-013-032045- GRAND AND BATTLEMENT MESAS CO-CENTRAL COLORADO RIVER BASIN CO- FLATTOPS CO-WEST ELK AND SAWATCH MOUNTAINS CO- GORE AND ELK MOUNTAINS/CENTRAL MOUNTAIN VALLEYS CO- 216 PM MDT MON AUG 3 2015 ...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL EAGLE...NORTHWESTERN PITKIN AND SOUTHEASTERN GARFIELD COUNTIES UNTIL 245 PM MDT... AT 215 PM MDT...DOPPLER RADAR WAS TRACKING AN AREA OF THUNDERSTORMS NEAR GLENWOOD SPRINGS...MOVING NORTHEAST AT 30 MPH. BRIEF HEAVY RAIN AND OCCASIONAL LIGHTNING CAN BE EXPECTED WITH THE PASSAGE OF THESE STORMS. WINDS IN EXCESS OF 40 MPH WILL ALSO BE POSSIBLE WITH THESE STORMS. LOCATIONS IMPACTED INCLUDE... GLENWOOD SPRINGS...CARBONDALE...DOTSERO...CATTLE CREEK...SHOSHONE AND EL JEBEL. LAT...LON 3919 10749 3949 10749 3974 10712 3951 10692 TIME...MOT...LOC 2015Z 235DEG 25KT 3947 10735 TGR
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
430 PM MDT MON AUG 03 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0429 PM HAIL 2 ESE STEAMBOAT SPRINGS 40.47N 106.79W
08/03/2015 M0.25 INCH ROUTT CO COCORAHS
&&
EVENT NUMBER GJT1500952
JDCSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GRAND JUNCTION CO 445 PM MDT MON AUG 3 2015 COZ019>021-UTZ028-032315- PARADOX VALLEY/LITTLE DOLORES RIVER CO- FOUR CORNERS/UPPER DOLORES RIVER CO-SOUTHWEST SAN JUAN MOUNTAINS CO- LA SAL AND ABAJO MOUNTAINS UT- 445 PM MDT MON AUG 3 2015 ...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL SAN MIGUEL AND NORTHWESTERN DOLORES COUNTIES UNTIL 515 PM MDT... AT 445 PM MDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 7 MILES NORTHWEST OF DOVE CREEK...OR 17 MILES EAST OF MONTICELLO... MOVING NORTHEAST AT 10 MPH. WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM. LOCATIONS IMPACTED INCLUDE... DOVE CREEK...UCOLO AND EGNAR. LAT...LON 3770 10904 3786 10914 3801 10891 3777 10875 TIME...MOT...LOC 2245Z 242DEG 8KT 3782 10901 JAM
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
458 PM MDT MON AUG 03 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0456 PM HAIL 1 SE STEAMBOAT SPRINGS 40.47N 106.81W
08/03/2015 E0.25 INCH ROUTT CO TRAINED SPOTTER
1 SE OF SBS .31 IN 20 MIN. PEA SIZED HAIL
&&
EVENT NUMBER GJT1500953
ADLThe Grand Junction radar (KGJX), 166 km away, was scanning. The volume nearest the first event began at 23:30 UTC.
1 funnel cloud. Local standard time, as filed.
A primary funnel cloud with two smaller vortices spinning around it was observed by a farmer near Cahone.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2015Every state in 2015This day in weather historyWarnings in Colorado, August 2015
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: 633014.