Alert archive / Colorado / Special Weather Statements in 2021
Special Weather Statement, NWS Grand Junction, CO
NWS Grand Junction, CO issued this special weather statement at Sep 29, 2021, 12:07 AM MDT. It was in force for 23 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Sep 29, 2021, 12:07 AM MDT (06:07 UTC)
- Expired
- Sep 29, 2021, 12:30 AM MDT
- In force
- 23 min
- Issued by
- NWS Grand Junction, CO
- Hail
- 0.50 in
- Wind
- 40
The radar
The Grand Junction radar (KGJX), 81 km from the middle of the area, began a volume at 06:11 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 00:00Z, 6.1 hours before the alert went out and 57 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
- 107 J/kg
- Mixed-layer CIN
- -39 J/kg
- Mixed-layer LCL
- 1741 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- -6 m²/s²
- 0-3 km storm-relative helicity
- 210 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted.
992
WWUS85 KGJT 290607
SPSGJT
Special Weather Statement
National Weather Service Grand Junction CO
1207 AM MDT Wed Sep 29 2021
COZ001-003-006-UTZ025-027-290630-
Roan and Tavaputs Plateaus CO-Grand Valley CO-
Lower Yampa River Basin CO-Arches/Grand Flat UT-Tavaputs Plateau UT-
1207 AM MDT Wed Sep 29 2021
...Strong thunderstorms will impact portions of northwestern Mesa,
southwestern Garfield, southwestern Rio Blanco, southeastern Uintah
and northeastern Grand Counties through 1230 AM MDT...
At 1206 AM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 35 miles southwest of Rangely to 34 miles
northwest of Grand Junction to 17 miles west of Fruita. Movement was
east at 30 mph.
HAZARD...Winds in excess of 40 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Mack.
This includes the following highways...
Interstate 70 in Colorado between mile markers 1 and 12.
Interstate 70 in Utah between mile markers 227 and 231.
Colorado 139 between mile markers 2 and 37.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Moderate to heavy rainfall is also occurring with these storms and
may lead to localized flooding. Do not drive your vehicle through
flooded roadways.
Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3978 10887 3949 10872 3921 10874 3917 10913
3943 10911 3969 10923
TIME...MOT...LOC 0606Z 257DEG 25KT 3964 10911 3945 10902 3923 10904
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
$$
MDAThe office that day
Everything else NWS Grand Junction, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 29, 12:32 AM MDT | Special Weather Statement | GJT | Mesa | 28 min |
| Sep 29, 1:03 AM MDT | Special Weather Statement | GJT | Garfield | 27 min |
| Sep 29, 5:58 AM MDT | Special Weather Statement | GJT | 32 min | |
| Sep 29, 8:10 AM MDT | Flash Flood Watch | GJT | Eagle, Garfield, Moffat, Pitkin, Rio Blanco, Routt | 31 min |
| Sep 29, 8:41 AM MDT | Flash Flood Warning | GJT | Eagle, Garfield | 3 hr |
| Sep 29, 11:55 AM MDT | Flash Flood Watch | GJT | Eagle, Garfield, Moffat, Pitkin, Rio Blanco, Routt | 11 hr |
| Sep 29, 12:24 PM MDT | Areal Flood Advisory | GJT | Mesa | 4 hr |
| Sep 29, 1:14 PM MDT | Special Weather Statement | GJT | 46 min |
Nearby
Special Weather Statements in Colorado, 2021Every special weather statement 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.