Hail, Boulder
- When
- May 10, 4:30 PM MST
- Where
- Boulder County, Longmont
- Measured
- 2 in hail
- Reported by
- TRAINED SPOTTER
- Coordinates
- 40.450, -104.733
20 hail, as filed by the National Weather Service.
Every event with a place to put it. 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 10, 12:04 PM MST, 4 hours 26 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO ISSUED BY NATIONAL WEATHER SERVICE PUEBLO CO 104 PM MDT TUE MAY 10 2005 .SHORT TERM... TONIGHT AND TOMORROW... CURRENTLY ACROSS NE AND NC CO...BOUNDARY IS LYING FROM DENVER EAST TO JUST N OF LIC AND INTO KS/NE. DWPTS AHVE RECOVERED AND ARE WELL INTO THE 40S OVER FAR NE CO AND 30S ALONG THE I-25 CORRIDOR. SOUTH OF THIS FRONT...SW WINDS OF 10 TO 20 MPH WITH TEMPS APPROACHING 80. ALONG THE CYS RIDGE...LOW CLOUDS REMAIN...AND HAVE NOT MOVED SOUTH MUCH. LATEST SPC CAPE INDICATES 1000+ OVER FAR NE CO. MAIN CONCERN FOR NE CO IS SVR POTENTIAL...I DO NOT BELIEVE FRONT IS GOING TO MIX OUT GIVEN GUSTY NE WINDS OVER THE REGION. ONCE WINDS SHIFT TO E...THEN AN IMPRESSIVE SHEAR PROFILE WILL EXIST OVER THE REGION. MAIN CONCERN IS THE DEPTH OF THE MOISTURE....BUT BELIEVE IF WILL BE DEEP ENOUGH TO SUPPORT SUSTANED CONVECTION...ESPECIALLY N OF A LIC FROM LONGMONT TO WRAY. WITH BOUNDARY IN PLACE AND FORCING COMING OUT OF MTNS...I WOULD NOT BE TOO SURPRISED TO SEE A RED BOX ISSUED THIS AFTERNOON FOR LATER TONIGHT INTO TOMORROW...EXTREMELY DIFFICULT FCST. MODELS WANT TO BE OPTIMISTIC IN KEEPING IT WARM (I.E., FRONT N OF CYS RIDGE...BUT BELIEVE THIS WILL NOT BE THE CASE. THIS IS ESPECIALLY TRUE IF CONVECTION DOES GET GOING THIS EVENING WHICH WILL HELP PUSH THE FRONT SOUTH. FOR NOW HAVE IT MOSTLY CLOUDY FOR TOMORROW MOST OF PLAINS WITH TEMPS ABOUT 10F BELOW GUIDANCE. DEPENDING ON THE EXTENT OF HEATING TOMORROW...SVR THREAT MAY ONCE AGAIN OCCUR OVER NE CO...ESPECIALLY DOWN TOWARDS THE PALMER DVD. /HODANISH .LONG TERM... THURDAY...BOTH THE ETA AND GFS HAVE SOUTHWEST FLOW AT 700MB DEVELOPING AS THE NEXT JET STREAK SWINGS AROUND THE UPPER TROUGH. GFS AND ETA SOUNDINGS SUGGEST THAT UPSLOPE STRATOCUMULUS WILL MIX OUT BY THE AFTERNOON. GFS HAS STRONG WARM AIR ADVECTION AROUND 700MB DURING THE AFTERNOON AND IS LIKELY OVERDOING THE MID LEVEL CLOUDINESS. AT THE MINIMUM...I SUSPECT SOME SUNSHINE DURING THE AFTERNOON EVEN NEAR THE WYOMING BORDER. WITH ANY AMOUNT OF SUNSHINE...HIGHS SHOULD BE WARMER THAN CURRENT FORECASTS NEAR 20F BELOW CLIMO. I WARMED THE MAXES ON THE PLAINS BY 7 DEGREES OR SO ON THURSDAY...WHICH IS STILL AT LEAST 10F BELOW CLIMO AND ABOUT 5 TO 10F BELOW GUIDANCE. IF TREND CONTINUES...LATER SHIFTS MAY WARM MAXES EVEN MORE. ETA PUTS SOME CAPE OVER THE FOOTHILLS AND NORTHERN PORTIONS OF THE CWA THURSDAY...AND I UPPER POPS A LITTLE...WHICH MATCHES CYS BETTER. WITH THE WEST FLOW...EXPECT SHOWERS AND I DID NOT ALTER THE GRIDS MUCH. FRIDAY AND SATURDAY...NEXT SURGE MOVES TROUGH THE PLAINS WITH FRIDAY. ETA IS MORE OPTIMISTIC ABOUT DRYING THE AIR ALOFT ON FRIDAY...WHILE THE GFS WAITS UNTIL FRIDAY EVENING. CURRENT GRIDS LOOK IN GOOD SHAPE AND I DID NOT CHANGE MUCH. GRADUAL WARMING TREND WILL CONTINUE AS AIR ALOFT WARMS AND UPSLOPE GRADIENT WEAKENS. SUNDAY-TUESDAY...THE GFS...ENSEMBLES AND EC INDICATE A SHORTWAVE RIDGE OVER THE REGION ON SUNDAY WITH MILD TEMPERATURES ALOFT. I WARMED THE MAXIMUMS ON SUNDAY TO 5 TO 10F ABOVE NORMAL WITH WEAK LEE TROUGH DEVELOPING OVER THE REGION AND TEMPS AT 700MB WARMING DURING THE AFTERNOON. MAXIMUMS ARE PRETTY CLOSE TO MEX GUIDANCE. ON MONDAY AND TUESDAY...WESTERLY FLOW ALOFT DEVELOPS WITH A LEE TROUGH IN THE REGION. GFS FLIRTS WITH BRINGING SOME +13C 700MB TEMPERATURES INTO THE CWA ON MONDAY AND +10C ON TUESDAY. DRY WITH MAXES IN THE LOWER 80S ON THE PLAINS ON THE PLAINS LOOKS GOOD. --WOLYN-- && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && 99/99
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE DENVER CO ISSUED BY NATIONAL WEATHER SERVICE PUEBLO CO 1028 AM MDT TUE MAY 10 2005 COZ030>051-111630- JACKSON COUNTY BELOW 9000 FEET- WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET- GRAND AND SUMMIT COUNTIES BELOW 9000 FEET- SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/ NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET- SOUTH AND SOUTHEAST GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/ GILPIN/CLEAR CREEK/SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE 9000 FEET-LARIMER AND BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET- JEFFERSON AND WEST DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR CREEK/NORTHEAST PARK COUNTIES BELOW 9000 FEET- CENTRAL AND SOUTHEAST PARK COUNTY- LARIMER COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY- BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY- NORTH DOUGLAS COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE COUNTIES/EAST BROOMFIELD COUNTY- ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES ABOVE 6000 FEET- NORTHEAST WELD COUNTY-CENTRAL AND SOUTH WELD COUNTY-MORGAN COUNTY- CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES- NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN COUNTY- SOUTHEAST ELBERT COUNTY BELOW 6000 FEET/SOUTH LINCOLN COUNTY- LOGAN COUNTY-WASHINGTON COUNTY-SEDGWICK COUNTY-PHILLIPS COUNTY- 1028 AM MDT TUE MAY 10 2005 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST COLORADO...CENTRAL COLORADO...NORTH CENTRAL COLORADO AND EAST CENTRAL COLORADO. ISOLATED THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS AND HIGHER TERRAIN BY EARLY AFTERNOON. THE MAIN THREAT FROM THESE STORMS WILL BE CLOUD GO GROUND LIGHTNING AND HAIL UP TO 1/2 INCH IN DIAMETER. BY LATER THIS AFTERNOON...A FEW SEVERE STORMS ARE EXPECTED TO DEVELOP OVER THE NORTHEAST PLAINS OF COLORADO. THE GREATEST THREAT OF SEVERE THUNDERSTORMS WILL BE NORTH OF A LINE FROM DENVER TO BURLINGTON. THE MAIN THREAT FROM THESE STORMS WILL BE LARGE HAIL AND WIND GUSTS TO 65 MPH. THERE IS ALSO A RISK OF A TORNADO OR TWO ACROSS NORTHEAST COLORADO THIS AFTERNOON AND EARLY EVENING. THIS THUNDERSTORM ACTIVITY MAY DEVELOP AS EARLY AS 3 PM. LATE THIS MORNING A COLD FRONT EXTENDED FROM NEAR DENVER...EAST TO NEAR BURLINGTON. THERE IS SOME UNCERTAINTY ON THE MOVEMENT OF THIS BOUNDARY TODAY...BUT BASED ON LATEST GUIDANCE AND FORECAST EXPERIENCE...THIS FRONT WILL LIKELY NOT MOVE MUCH. IN ADDITION...A STRONG DISTURBANCE ALOFT...COMBINED WITH UPSLOPE FLOW NORTH AND ALONG THE BOUNDARY...WILL SET UP A SHEAR PROFILE FAVORABLE FOR ROTATING SUPERCELL THUNDERSTORMS OVER NORTHEAST COLORADO LATER THIS AFTERNOON AND EVENING. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY ISOLATED SHOWERS AND THUNDERSTORMS WILL AGAIN DEVELOP WEDNESDAY WITH SHOWERS AND STORMS BECOMING MORE NUMEROUS WEDNESDAY EVENING. MOST OF THE STORMS WILL BE UNDER SEVERE LIMITS...BUT AN ISOLATED SEVERE STORM MAY DEVELOP OVER THE PALMER DIVIDE REGION ALONG THE STALLED FRONTAL BOUNDARY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED AFTER 3 PM TODAY NORTH OF A LINE FROM DENVER TO BURLINGTON. HODANISH
The Denver radar (KFTG), 75 km away, was scanning. The volume nearest the first event began at 23:31 UTC.
20 hail. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2005Every state in 2005This day in weather historyWarnings in Colorado, May 2005
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: 5452733, 5452732, 5452731, 5452730, 5452729, 5452728, 5452727, 5452726, 5452725, 5452724, 5452723, 5454631, 5454630, 5454629, 5454628, 5454627, 5454626, 5454625, 5454623, 5454624.