Strong winds developed across western Colorado as a dry cold front moved through the area. A 60 foot tall tree with a 4 foot diameter trunk was toppled by the wind in the Grand Valley.
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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.
Strong winds developed across western Colorado as a dry cold front moved through the area. A 60 foot tall tree with a 4 foot diameter trunk was toppled by the wind in the Grand Valley. Minor wind damage also occurred in other 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 Sep 17, 9:15 AM MST, 1 hour 38 minutes earlier.
WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1015 AM MDT WED SEP 17 2003
SHORT TERM DISCUSSION (TODAY THROUGH THURSDAY)...
EVERYTHING POINTS TO WINDS IN MUCH OF LOWER ELEVATIONS OF EAST-
CENTRAL UTAH AND WEST-CENTRAL COLORADO REACHING WIND ADVISORY
CRITERIA THIS AFTERNOON INTO EARLY THIS EVENING. LOCALLY...SOME SPOTS
ALREADY GUSTING TO 30-35 KTS...DYNAMICS OF SYSTEM OVER THE AREA
APPEARS A LITTLE STRONGER THIS MORNING THAN ANTICIPATED...AND MODEL
GUIDANCE SHOWING LOW END ADVISORY CRITERIA WIND SPEEDS FOR ZONES IN
THE ADVISORY. THEREFORE...EXPECT SURFACE PRESSURE GRADIENTS TO BE A
LITTLE STRONGER THAN LATEST MODELS INDICATE...WHILE WINDS ALOFT JUST
ABOVE THE SURFACE LIKELY TO BE A TAD STRONGER THAN INDICATED.
NEXT CONCERN IS THE SLIGHTLY COLDER THAN EXPECTED AIRMASS LIKELY
OVER OUR CWA TONIGHT. APPEARS NOW THAT A FREEZE WARNING MAY BE
NEEDED FOR TONIGHT IN SOME LOWER ELEVATION ZONES. ALSO...MAX TEMPS
TOMORROW MAY NOT BE QUITE AS HIGH AS IN CURRENT FORECAST. WILL
MAKE A DECISION ON THIS BY EARLY THIS AFTERNOON. PRINGLE
AN UPPER LEVEL TROUGH EXTENDS FROM THE NORTHERN ROCKIES SOUTH ACROSS
THE GREAT BASIN. A SHORTWAVE IS MOVING NORTHEAST ACROSS SOUTHWEST
WYOMING WITH ANOTHER, MUCH STRONGER WAVE SITUATED OVER EASTERN
OREGON. AT THE SURFACE...A COLD FRONT EXTENDS FROM SOUTH-CENTRAL WY
TO ABOUT VERNAL, UT THEN INTO CENTRAL NV. STRONG SOUTHWEST FLOW OUT
AHEAD OF THE FRONT WITH KGJX WIND PROFILE SHOWING 35KTS AT THE FIRST
GATE (11K FEET). THE BOUNDARY LAYER HAS STABILIZED ENOUGH TO KEEP
MOST OF THE LOW ELEVATION WINDS DOWN BUT MANY OF THE HIGHER RAWS
SITES ARE BLOWING IN THE 10 TO 20 MPH RANGE WITH GUSTS FROM 20-30
MPH. RELATIVE HUMIDITIES GRADUALLY COMING UP BUT SOME RAWS ARE STILL
SHOWING HUMIDITIES AROUND 20 PERCENT.
FIRE WEATHER THE MAIN CONCERN TODAY. COLD FRONT NOT MOVING TOO FAST
AT THE MOMENT BUT THE UPSTREAM SHORTWAVE WILL KICK IT THROUGH MOST
OF THE FORECAST AREA TODAY. EXACT TIMING WILL BE TRICKY AS
USUAL. MODELS INDICATING LEADING EDGE OF TIGHT THERMAL GRADIENT AT
GJT AROUND NOON, THEN REACHING THE FOUR CORNERS AROUND 6PM. WILL
BASE THE FORECAST ON THIS TIMING. THE PASSAGE OF A STRONG, BASICALLY
DRY COLD FRONT SIGNIFICANTLY RAISES FIRE WEATHER CONCERNS AND
WILL ISSUE A RED FLAG FOR CENTRAL AND SOUTHERN FIRE ZONES BELOW 8K
FEET. NOT AS MUCH CONCERN ACROSS THE NORTH WITH LESS WIND, COOLER
TEMPERATURES, AND HIGHER HUMIDITIES BEHIND THE FRONT.
LOW LEVELS ARE VERY DRY BASED ON LATEST SOUNDINGS. STRONG COLD
ADVECTION BEHIND THE FRONT COMBINED WITH STRONG JET DYNAMICS SHOULD
BE ABLE TO SQUEEZE OUT SOME SHOWERS ACROSS THE NORTH THOUGH. MODELS
MAY BE UNDER DOING THE MOISTURE WITH THIS SYSTEM BASED ON THE
EXTENSIVE MID CLOUD DECK UPSTREAM SO WILL BUMP POPS UP A LITTLE
ACROSS THE NORTH TODAY. NORTHWEST FLOW BEHIND THE FRONT SHOULD
PRODUCE SOME OROGRAPHIC PRECIPITATION ACROSS THE NORTHERN AND
CENTRAL MOUNTAINS OF WESTERN COLORADO TONIGHT. DRYING TREND THURSDAY
WITH MUCH BELOW NORMAL TEMPERATURES. LINDQUIST
LONGER TERM DISCUSSION...
FRIDAY THROUGH SUNDAY...WARMING TREND BEGINS ON FRI AS RIDGE BUILDS
WEST OF THE AREA. HOWEVER LATEST RUNS KEEP THE RIDGE ALONG THE WEST
COAST...KEEPING THE FORECAST AREA IN NORTHWEST FLOW THROUGH THE
PERIOD. ONE SHORTWAVE IS SCHEDULED TO BRUSH THE NORTH LATE SAT/EARLY
SUN. LOOKS LIKE INCREASED WINDS WILL BE THE MAIN RESULT. MAY NEED
TO ADD POPS TO WEST COLORADO MOUNTAINS IF FOLLOWING MODEL CYCLES
SHOW GOOD CONTINUITY.
MONDAY THROUGH WEDNESDAY...DRY NORTHWEST FLOW CONTINUES OVER THE AREA
WITH THE UPPER LEVEL RIDGE POSITIONED ALONG THE COAST AND INTO THE
GREAT BASIN. LITTLE CHANGE TO MOSTLY CLEAR SKIES AND NEAR NORMAL
TEMPS. HEFFERNAN/NL
.GJT...WIND ADVISORY THIS AFTERNOON THROUGH EARLY THIS EVENING
COZ006>008-011-020-UTZ027
RED FLAG WARNING TODAY BELOW 8000 FEET FOR SOUTHEAST UTAH FIRE
ZONES 445/446/447/448/449 AND WEST COLORADO FIRE ZONES
203/205/207.COZ001>014-017>023-UTZ022>025-027>029-181145- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GRAND JUNCTION CO 545 AM MDT WED SEP 17 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN COLORADO AND FOR EASTERN UTAH .DAY ONE...TODAY AND TONIGHT... ...RED FLAG WARNING THROUGH 6 PM TODAY FOR SOUTHEAST UTAH...AND WEST-CENTRAL AND SOUTHWEST COLORADO BELOW 8000 FEET... STRONG SOUTHWEST WINDS FROM 20 TO 30 MPH WITH HIGHER GUSTS WILL DEVELOP THIS AFTERNOON ACROSS SOUTHEAST UTAH AND WEST-CENTRAL AND SOUTHWEST COLORADO. ADDITIONALLY...RELATIVE HUMIDITY WILL REMAIN LOW. COMBINED WITH DRY FUELS...THESE CONDITIONS WILL CREATE A CRITICAL FIRE WEATHER SITUATION LATE THIS MORNING AND THIS AFTERNOON FOR AREAS BELOW 8000 FEET IN SOUTHEAST UTAH...AND IN WEST-CENTRAL AND SOUTHWEST COLORADO. A STRONG COLD FRONT WILL MOVE SOUTH ACROSS THE AREA TODAY. THE PRESSURE GRADIENT WILL TIGHTEN ALONG AND AHEAD OF THE FRONT RESULTING IN STRONG AND GUSTY SOUTHWEST WINDS. THE COLD FRONT WILL MOVE INTO SOUTHEAST UTAH AND WEST-CENTRAL COLORADO THIS AFTERNOON...THEN MOVE INTO SOUTHWEST COLORADO EARLY THIS EVENING. THIS WILL BE A DRY COLD FRONT...EXCEPT FOR A FEW SHOWERS ACROSS THE NORTH. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY... NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY. TAL
The national radar mosaic for the moment the first event began.
7 strong wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2003Every state in 2003This day in weather historyWarnings in Colorado, September 2003
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: 5371946, 5371944, 5371949, 5371947, 5371948, 5371943, 5371945.