1 lightning, 1 thunderstorm wind, as filed by the National Weather Service.
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 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 Denver/Boulder, CO wrote its last area forecast discussion before the first event at May 31, 1:28 PM MST, 2 hours 32 minutes earlier.
NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 228 PM MDT SAT MAY 31 2003 SHORT TERM DISCUSSION: TAIL END OF WEAK SHORT WAVE CURRENTLY PASSING ACROSS COLORADO HELPING TO INITIATE CONVECTION ACROSS MOUNTAINS AND FOOTHILLS. SOME SHOWERS AND STORMS HAD MOVED ACROSS THE HAYMAN BURN AREA...SO FAR NO SIGNIFICANT PROBLEMS. PROFILER DATA AND RADAR OBS SUGGEST STORM MOVEMENT AROUND 10-15 KTS. THREAT OF MAJOR FLOODING LOW AT THIS POINT...THOUGH THERE IS A SMALL CHANCE FOR TRAIN ECHOES. STILL POTENTIAL FOR LOCALIZED FLOODING DUE TO STREAMS AT OR NEAR BANKFULL. ACTIVITY ACROSS MOUNTAINS AND FOOTHILLS SHOULD END DURING EVENING ONCE WAVE HEADS EAST AND SUBSIDENCE BEGINS. ACROSS THE PLAINS...AIRMASS STILL A BIT CAPPED...AS THERE IS STILL SOME CIN AROUND. CAPES REACHING 1500 J/KG ACROSS THE FRONT RANGE. SOUNDINGS SUGGEST TEMPERATURES NEED TO REACH 85 DEGREES BEFORE CAP IS BROKEN. MAY END UP HAVING TO WAIT FOR BOUNDARY INTERACTIONS. STILL...THE WAVE SHOULD BE ENOUGH TO BREAK THE CAP. ONCE STORMS DEVELOP...THERE IS POTENTIAL FOR A FEW STORMS TO BECOME SEVERE AS SHEAR PROFILE LOOKS SUFFICIENT. WILL KEEP THE CURRENT POPS AS IS. STORMS NOT EXPECTED TO LAST MUCH PAST MIDNIGHT DUE TO SUBSIDENCE BEHIND WAVE. BOUNDARY LAYER WINDS AND HUMIDITIES SUGGEST SOME FOG TO DEVELOP OVER PORTIONS OF EAST... ESPECIALLY IF DECENT RAINS OCCUR. WILL MENTION PATCHY FOG FOR NOW. ON SUNDAY...AIRMASS LOOKS TO DRY OUT A BIT IN THE MID LEVELS AS NORTHWEST FLOW ALOFT INCREASES SLIGHTLY. STILL QUITE A BIT OF LOW LEVEL MOISTURE PRESENT FOR SCATTERED SHOWERS AND STORMS IN AFTERNOON. CROSS SECTIONS AND FORECAST SOUNDINGS INDICATE A BIT BETTER SHEAR PROFILE...WITH LITTLE OR NO CIN AFTER 18Z. CAPES PROGGED TO BE IN THE 1500 J/KG AREA. MODELS SUGGEST FRONT TO BE DELAYED TILL LATER PERIOD. THUS SEVERE POTENTIAL A BIT BETTER DURING AFTERNOON...WITH HAIL MAIN THREAT. STILL THE POSSIBILITY FOR SOME HEAVY RAIN...DESPITE THE FORECAST OF DECREASING PRECIPITABLE WATER VALUES ACROSS MOUNTAINS AND ALONG FRONT RANGE. D-L LONG TERM DISCUSSION: PERSISTENT PATTERN OF NORTHWESTERLY FLOW ALF...WEAK COOL FRONTS AND A CONTINUED CHC OF THUNDERSTORMS IS PROGGED TO CONTINUE THRU THE WEEK. MDLS BRING NEXT COOL FRONT INTO NERN CO SUNDAY NIGHT. THIS SHUD SET THE TABLE FOR MORE SHOWERS AND THUNDERSTORMS ON MONDAY. AT THIS TIME...THE MESOETA PARKS THE MSTR RIGHT ALONG THE FRONT RANGE AND PALMER DIVIDE...WITH SELY SFC WINDS DVLPG OVER THE PLAINS BY THE AFTN. AS A RESULT...WL KEEP A CHC OF THUNDERSTORM MENTIONED FOR MONDAY AFTN/EVNG. IN FACT...CONVECTION ON MONDAY NIGHT MAY CONTINUE OVERNIGHT AS BOTH THE GFS AND ETA SLIP AN EMBEDDED SHORT WAVE ACRS NRN CO MONDAY NIGHT. SFC HIGH PRESSURE WL MOVE INTO THE NRN GREAT PLAINS TUESDAY AFTN BRINGING ANOTHER ELY SURGE INTO THE CWA. THIS MAY ACT AS A FOCUS FOR THUNDERSTORM ALONG THE FRONT RANGE TUESDAY AFTN/EVNG. ACRS THE NERN PLAINS...AMS MAY BE TOO STABLE FOR THUNDERSTORMS...SO MAY OPT FOR JUST A SLGT CHC THERE. FOR WEDNESDAY THRU SATURDAY...NWLY FLOW WL CONTINUE. GFS NOW SHOWS TO DISTINCT SHORT WAVES MOVING FM THE NRN GREAT PLAINS AND BRUSHING COLO. THE FIRST IS WEDNESDAY NIGHT...WITH ANOTHER THURSDAY NIGHT. ALTHOUGH THE OVERALL PATTERN ADVERTISED BY THE MODELS HAD BEEN CONSISTENT...THE DETAILS RMN WISHY WASHY FROM RUN TO RUN. FOR NOW WL JUST MAINTAIN A CHC OR SLGT CHC OF THUNDERSTORMS THRU THE EXTENDED PERIOD AND LOWER EXPECTED MAX TEMPERATURES SLIGHTLY. COOPER .DEN...NONE.
COZ030>051-011200- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO 1040 AM MDT SAT MAY 31 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL COLORADO. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE AFTERNOON AND EVENING HOURS TODAY...MAINLY OVER THE FRONT RANGE FOOTHILLS AND ADJACENT PLAINS. A FEW OF THE STORMS COULD BECOME SEVERE...WITH LARGE HAIL AND HEAVY RAINS THE MAIN THREAT. WINDS ALOFT WILL BE A BIT STRONGER TODAY...SO THE THREAT OF FLOODING WILL BE LOWER THAN YESTERDAY. MOUNTAIN AND FOOTHILL STREAMS ARE STILL RUNNING NEAR BANKFULL...SO IF THERE IS SUBSTANTIAL RAIN OVER THE FOOTHILLS THESE STREAMS COULD FLOOD. WARMER AND DRIER AIR ALOFT WILL SPREAD OVER THE AREA TODAY...WHICH WILL DELAY THE ONSET OF THUNDERSTORMS. SLIGHTLY COOLER LOW LEVEL AIR IS ALSO EXPECTED TO LIMIT THE PROGRESS OF THUNDERSTORMS ONTO THE PLAINS THIS EVENING. HOWEVER...THERE SHOULD BE ENOUGH HEATING OF THE MOIST AIR TO GENERATE THUNDERSTORMS IN AND NEAR THE FOOTHILLS BY MID TO LATE AFTERNOON. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP EACH DAY. A FEW STORMS MAY BE SEVERE SUNDAY. A PERSISTENT NORTHWESTERLY FLOW ALOFT WILL CONTINUE OVER THE STATE. A SERIES OF COOL FRONTS WILL ALSO MOVE INTO THE AREA THIS WEEK AS SOME WEATHER DISTURBANCES BRUSH THE STATE FROM THE NORTHEAST. AS A RESULT...ENOUGH LOW LEVEL MOISTURE WILL EXIST FOR A CONTINUED CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS THROUGH THE UPCOMING WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED LATE THIS AFTERNOON AND EVENING. D-L/FMC
The Cheyenne radar (KCYS), 77 km away, was scanning. The volume nearest the first event began at 02:10 UTC.
1 lightning, 1 thunderstorm wind. Local standard time, as filed.
Lightning struck and killed one man, and injured another, while they were fishing along the shore of Boyd Lake.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Lightning, Larimer | 2003-05-31 | 31 | Male | Outside/Open Areas | Direct |
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, May 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: 5362011, 5362012.