Alert archive / Colorado / Flash Flood Watches in 2018

Flash Flood Watch 13, NWS Grand Junction, CO

July 26, 20187 counties in Colorado

NWS Grand Junction, CO issued this flash flood watch at Jul 26, 2018, 2:28 PM MDT for 7 counties in Colorado. It took effect at Jul 27, 2018, 11:00 AM MDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued: Jul 26, 2018, 2:28 PM MDT (20:28 UTC)
In effect from: Jul 27, 2018, 11:00 AM MDT
Expired: Jul 27, 2018, 8:00 PM MDT
In force: 9 hr
Issued by: NWS Grand Junction, CO
Flood severity: None

Counties Archuleta County, CO, Dolores County, CO, Hinsdale County, CO, La Plata County, CO, Montezuma County, CO, San Juan County, CO, San Miguel County, CO

The radar

The Grand Junction radar (KGJX), 165 km from the middle of the area, began a volume at 20:27 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

Albuquerq/Krtlnd, NM (KABQ), launched 12:00Z, 8.5 hours before the alert went out and 306 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: 111 J/kg
Mixed-layer CIN: -211 J/kg
Mixed-layer LCL: 2131 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 236 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

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 Grand Junction, CO wrote its last area forecast discussion before this flash flood watch went out at Jul 26, 11:27 AM MDT, 3 hours 1 minute earlier.

Area forecast discussion, Jul 26, 11:27 AM MDT, 3 hours 1 minute before

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Hazardous weather outlook, Jul 26, 5:13 AM MDT, 9 hours 15 minutes before

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In the hours before

Special weather statement, Jul 26, 1:54 PM MDT, 34 minutes before

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The office that day

Everything else NWS Grand Junction, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 26, 1:54 PM MDT	Special Weather Statement	GJT	Mesa	51 min

Nearby

Flash Flood Watches in Colorado, 2018 Every flash flood watch in 2018

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.