Alert archive / Colorado / Flash Flood Watches in 2015

Flash Flood Watch 7, NWS Denver/Boulder, CO

June 10, 201516 counties in Colorado

NWS Denver/Boulder, CO issued this flash flood watch at Jun 10, 2015, 11:41 AM MDT for 16 counties in Colorado. It took effect at Jun 11, 2015, 9:00 AM MDT. It was in force for 18 hr.

The area

The counties it named.

The facts

Issued: Jun 10, 2015, 11:41 AM MDT (17:41 UTC)
In effect from: Jun 11, 2015, 9:00 AM MDT
Expired: Jun 12, 2015, 3:00 AM MDT
In force: 18 hr
Issued by: NWS Denver/Boulder, CO
Flood severity: None

Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Clear Creek County, CO, Denver County, CO, Douglas County, CO, Elbert County, CO, Gilpin County, CO, Jefferson County, CO, Larimer County, CO, Lincoln County, CO, Morgan County, CO, Park County, CO, Washington County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 15 km from the middle of the area, began a volume at 17:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 5.7 hours before the alert went out and 128 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1897 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, 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 this flash flood watch went out at Jun 10, 11:41 AM MDT, 0 minutes earlier.

Area forecast discussion, Jun 10, 11:41 AM MDT, 0 minutes before

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Hazardous weather outlook, Jun 10, 11:09 AM MDT, 32 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1109 AM MDT WED JUN 10 2015

COZ030>051-111715-
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-
1109 AM MDT WED JUN 10 2015

...A VERY WET WEATHER PATTERN STARTING TODAY...FLOODING CONCERNS
INCREASING THURSDAY INTO FRIDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EARLY
EVENING. A FEW STORMS COULD BECOME SEVERE WITH GOLF BALL SIZE HAIL
AND DAMAGING WINDS. A BRIEF TORNADO OR TWO CAN'T BE RULED OUT.
THE BEST CHANCE FOR SEVERE THUNDERSTORMS WILL BE ALONG AND EAST
OF A LINE FROM FORT MORGAN TO LIMON.

HEAVY RAIN WILL ALSO BE POSSIBLE WITH THE THUNDERSTORMS. AN INCH
OF RAIN IN 20 TO 30 MINUTES WILL BE POSSIBLE WITH THE STRONGER
STORMS WHICH COULD CAUSE FLOODING OF LOW LYING AREAS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

ANOTHER ROUND OF WET WEATHER IS EXPECTED THURSDAY AND FRIDAY WITH
A THREAT OF HEAVY RAIN AND FLOODING AGAIN. ABUNDANT MOISTURE WILL
COMBINE WITH UPSLOPE FLOW AND AN UPPER LEVEL LOW PRESSURE SYSTEM
TO BRING THE WET WEATHER TO THE OUTLOOK AREA. THE FOOTHILLS AND
LOCALES CLOSE TO THE FOOTHILLS WILL HAVE THE GREATEST THREAT OF
FLOODING THURSDAY AFTERNOON THROUGH MOST OF FRIDAY. THERE IS ALSO
THE POSSIBILITY OF SOME OF THE THUNDERSTORMS BECOMING SEVERE
THURSDAY AFTERNOON MAINLY OVER THE PALMER DIVIDE.

DRIER AND WARMER CONDITIONS WILL GRADUALLY WORK THEIR WAY INTO
THE OUTLOOK AREA OVER THE WEEKEND AND INTO THE EARLY PART OF NEXT
WEEK. THE POSSIBILITY OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL NOT COMPLETELY VANISH DURING THIS PERIOD BUT
CONDITIONS WILL LIKELY RETURN TO THOSE MORE NORMAL FOR THE MIDDLE
PART OF JUNE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED THIS AFTERNOON...BUT REPORTS
OF LARGE HAIL GREATER THAN ONE INCH IN DIAMETER AND DAMAGING WIND
WILL BE APPRECIATED.

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 10, 10:44 AM MDT	River Flood Warning	BOU	Grand	49 hr
Jun 10, 11:17 AM MDT	River Flood Advisory	BOU	Adams	52 hr
Jun 10, 11:17 AM MDT	River Flood Advisory	BOU	Jefferson	52 hr
Jun 10, 1:19 PM MDT	River Flood Advisory	BOU	Grand	9 days
Jun 10, 1:19 PM MDT	River Flood Advisory	BOU	Summit	50 hr
Jun 10, 4:26 PM MDT	Areal Flood Advisory	BOU	Douglas	94 min
Jun 10, 4:30 PM MDT	River Flood Warning	BOU	Boulder	62 hr
Jun 10, 4:52 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	38 min
Jun 10, 5:25 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	35 min

Nearby

Flash Flood Watches in Colorado, 2015 Every flash flood watch in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.