Alert archive / Colorado / Flash Flood Watches in 2021
Flash Flood Watch 20, NWS Grand Junction, CO
NWS Grand Junction, CO issued this flash flood watch at Jul 25, 2021, 1:02 PM MDT for 6 counties in Colorado. It was in force for 7 hr.
The area
The counties it named.
The facts
- Issued
- Jul 25, 2021, 1:02 PM MDT (19:02 UTC)
- Expired
- Jul 25, 2021, 7:41 PM MDT
- In force
- 7 hr
- Issued by
- NWS Grand Junction, CO
- Flood severity
- None
Counties Eagle County, CO, Garfield County, CO, Moffat County, CO, Pitkin County, CO, Rio Blanco County, CO, Routt County, CO
The radar
The Grand Junction radar (KGJX), 114 km from the middle of the area, began a volume at 19:06 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
Grand Junction, CO (KGJT), launched 12:00Z, 7.0 hours before the alert went out and 124 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2095 m above ground
- 0-6 km bulk shear
- 3 kt
- 0-1 km storm-relative helicity
- 6 m²/s²
- 0-3 km storm-relative helicity
- 70 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 25, 11:10 AM MDT, 1 hour 52 minutes earlier.
Area forecast discussion, Jul 25, 11:10 AM MDT, 1 hour 52 minutes before
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>Hazardous weather outlook, Jul 25, 5:28 AM MDT, 7 hours 34 minutes before
Hazardous Weather Outlook National Weather Service Grand Junction CO 528 AM MDT Sun Jul 25 2021 COZ001>014-017>023-UTZ022>025-027>029-261130- Lower Yampa River Basin-Central Yampa River Basin- Roan and Tavaputs Plateaus-Elkhead and Park Mountains- Upper Yampa River Basin-Grand Valley-Debeque to Silt Corridor- Central Colorado River Basin-Grand and Battlement Mesas- Gore and Elk Mountains/Central Mountain Valleys- Central Gunnison and Uncompahgre River Basin- West Elk and Sawatch Mountains-Flat Tops- Upper Gunnison River Valley-Uncompahgre Plateau and Dallas Divide- Northwest San Juan Mountains-Southwest San Juan Mountains- Paradox Valley/Lower Dolores River- Four Corners/Upper Dolores River-Animas River Basin- San Juan River Basin-Southeast Utah-Eastern Uinta Mountains- Eastern Uinta Basin-Tavaputs Plateau-Arches/Grand Flat- La Sal and Abajo Mountains-Canyonlands/Natural Bridges- 528 AM MDT Sun Jul 25 2021 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight Thunderstorm development will occur today especially over the mountains by early afternoon. Lightning will be the main threat along with gusty outflow winds. A few storms will be capable of producing locally heavy rainfall which could lead to flooding. Thunderstorms should dissipate by the early morning hours. .DAYS TWO THROUGH SEVEN...Monday through Saturday Daily scattered to numerous showers and thunderstorms can be expected each day with monsoon moisture entrenched across the area. Moderate to heavy rain and gusty winds will be the primary threats with storms along with lightning. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
In the hours before
Local storm report, Jul 25, 8:05 AM MDT, 4 hours 57 minutes before
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>Local storm report, Jul 25, 11:16 AM MDT, 1 hour 46 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1116 AM MDT SUN JUL 25 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0230 PM FLASH FLOOD 1 W COLLBRAN 39.24N 107.98W
07/24/2021 MESA CO TRAINED SPOTTER
EVIDENCE OF ROCKS, MUD AND WATER ALONG MAIN
STREET IN COLLBRAN. SANDBAGS IN FRONT OF
CERTAIN BUSINESSES. SPOTTER ALSO REPORTED 2
TREES BEING UPROOTED DUE TO FLASH FLOODING 2
MILES DOWN ON HIGHWAY 330.
&&The office that day
Everything else NWS Grand Junction, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 25, 1:38 PM MDT | Areal Flood Advisory | GJT | Dolores, San Miguel | 112 min |
| Jul 25, 3:25 PM MDT | Flash Flood Warning | GJT | Gunnison, Pitkin | 3 hr |
| Jul 25, 3:53 PM MDT | Areal Flood Advisory | GJT | Rio Blanco | 2 hr |
| Jul 25, 4:06 PM MDT | Flash Flood Warning | GJT | Eagle | 3 hr |
| Jul 25, 4:45 PM MDT | Areal Flood Advisory | GJT | Montezuma | 3 hr |
| Jul 25, 4:53 PM MDT | Special Weather Statement | GJT | Rio Blanco | 22 min |
| Jul 25, 4:54 PM MDT | Flash Flood Warning | GJT | Montrose | 3 hr |
| Jul 25, 5:20 PM MDT | Special Weather Statement | GJT | Rio Blanco | 40 min |
| Jul 25, 5:46 PM MDT | Areal Flood Advisory | GJT | Rio Blanco | 3 hr |
| Jul 25, 3:30 PM MDT | Flash Flood Warning | GJT | Grand, San Juan | 3 hr |
| Jul 25, 3:33 PM MDT | Areal Flood Advisory | GJT | San Juan | 117 min |
Nearby
Flash Flood Watches in Colorado, 2021Every flash flood watch in 2021
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.