Alert archive / Colorado / Flash Flood Watches in 2015

Flash Flood Watch 3, NWS Denver/Boulder, CO

May 18, 20157 counties in Colorado

NWS Denver/Boulder, CO issued this flash flood watch at May 18, 2015, 5:41 PM MDT for 7 counties in Colorado. It took effect at May 18, 2015, 7:00 PM MDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued: May 18, 2015, 5:41 PM MDT (23:41 UTC)
In effect from: May 18, 2015, 7:00 PM MDT
Expired: May 19, 2015, 4:07 AM MDT
In force: 9 hr
Issued by: NWS Denver/Boulder, CO
Flood severity: None

Counties Boulder County, CO, Clear Creek County, CO, Douglas County, CO, Gilpin County, CO, Jefferson County, CO, Larimer County, CO, Park County, CO

The radar

The Denver radar (KFTG), 74 km from the middle of the area, began a volume at 23:41 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, 11.7 hours before the alert went out and 187 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: 685 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 96 m²/s²
0-3 km storm-relative helicity: 131 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 May 18, 3:11 PM MDT, 2 hours 30 minutes earlier.

Area forecast discussion, May 18, 3:11 PM MDT, 2 hours 30 minutes before

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Hazardous weather outlook, May 18, 11:30 AM MDT, 6 hours 11 minutes before

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        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

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

Issued	Product	Office	Counties	Lasted
May 18, 10:34 AM MDT	Winter Storm Warning	BOU	Boulder, Clear Creek, Gilpin, Grand, Jackson, Jefferson and 3 more	31 hr

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.