Colorado, 2005

Hail in Colorado, May 10, 2005

May 10, 2005 · NWS BOU · 20 events in 2 counties and zones

20 hail, as filed by the National Weather Service.

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
20

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.

What forecasters said that day

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, May 10, 12:04 PM MST, 4 hours 26 minutes before
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, May 10, 9:28 AM MST, 7 hours 2 minutes before
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 radar

The Denver radar (KFTG), 75 km away, was scanning. The volume nearest the first event began at 23:31 UTC.

Open the radar archive at this moment

Event by event

20 hail. Local standard time, as filed.

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

Hail, Boulder

When
May 10, 4:34 PM MST
Where
Boulder County, 6 mi W of Longmont
Measured
1.5 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.333, -104.867

Hail, Boulder

When
May 10, 4:40 PM MST
Where
Boulder County, 5 mi W of Longmont
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.367, -104.750

Hail, Boulder

When
May 10, 4:42 PM MST
Where
Boulder County, 2 mi NNW of Longmont
Measured
1.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.417, -104.733

Hail, Boulder

When
May 10, 4:43 PM MST
Where
Boulder County, Longmont
Measured
2 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.383, -104.683

Hail, Boulder

When
May 10, 4:50 PM MST
Where
Boulder County, Longmont
Measured
1.25 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.417, -104.683

Hail, Boulder

When
May 10, 4:51 PM MST
Where
Boulder County, 5 mi N of Longmont
Measured
0.88 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.433, -104.683

Hail, Weld

When
May 10, 5:28 PM MST
Where
Weld County, Johnstown
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.417, -104.683

Hail, Weld

When
May 10, 5:38 PM MST
Where
Weld County, Johnstown
Measured
1.25 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.450, -104.733

Hail, Weld

When
May 10, 5:40 PM MST
Where
Weld County, 4 mi NW of Greeley
Measured
2 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.417, -104.733

Hail, Weld

When
May 10, 5:42 PM MST
Where
Weld County, 1 mi WSW of Johnstown
Measured
1.25 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.417, -104.683

Hail, Weld

When
May 10, 5:43 PM MST
Where
Weld County, 5 mi SW of Greeley
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.167, -105.100

Hail, Weld

When
May 10, 5:52 PM MST
Where
Weld County, 3 mi W of Greeley
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.167, -105.217

Hail, Weld

When
May 10, 6:00 PM MST
Where
Weld County, Evans
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.167, -105.200

Hail, Weld

When
May 10, 6:03 PM MST
Where
Weld County, Greeley
Measured
1 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.200, -105.117

Hail, Weld

When
May 10, 6:05 PM MST
Where
Weld County, 1 mi N of Greeley
Measured
1.25 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.167, -105.100

Hail, Weld

When
May 10, 6:06 PM MST
Where
Weld County, Greeley
Measured
0.75 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.167, -105.100

Hail, Weld

When
May 10, 6:09 PM MST
Where
Weld County, 4 mi NW of Greeley
Measured
1.25 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.233, -105.100

Hail, Weld

When
May 10, 6:15 PM MST
Where
Weld County, Greeley
Measured
1.5 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.333, -104.850

Hail, Weld

When
May 10, 6:15 PM MST
Where
Weld County, 3 mi W of Greeley
Measured
1.5 in hail
Reported by
TRAINED SPOTTER
Coordinates
40.333, -104.850

What these are

Hail
Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Colorado in 2005Every state in 2005This day in weather historyWarnings in Colorado, May 2005

Sources

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.