NWS Grand Junction
Winter Warning and Advisory Criteria
Winter Warning and Advisory Criteria
*(Specific Criteria for these winter events vary from place to place across the
U.S., depending on local needs and geography. These definitions apply only to
the
NWS Grand Junction Area of Responsibility
.)
| Type of Snow Event | Valley Locations | Mountain Locations |
|---|---|---|
| Heavy Snow Warning | > 6 inches in 24 hours | < 12 inches in 24 hours |
| Winter Weather Advisory | 3 - 6 inches in 24 hours | 5 -12 inches in 24 hours |
| Blizzard Warning | Snow and/or blowing snow reducing prevaling visibility to < 1/4 mile, and sustained winds > 35 MPH for > 3 hours | |
- Snow Event is defined as lasting < 24 hours; forecaster discretion for when an "event" starts and stops, and when one event ends and another begins.
- Winter Storm Warning is used when heavy snow, or a combination of hazardous winter phenomena, is expected.
- Mountain Locations are defined as areas roughly above 7500 feet. Valley locations imply areas below that elevation.
| Type of Snow Event | Valley Locations | Mountain Locations |
|---|---|---|
| High Wind Warning |
> 40 MPH for > 1 hour > 58 MPH any duration |
> 50 MPH for > 1 hour > 75 MPH any duration |
| Wind Advisory |
> 30 - 39 MPH for >
1 hour > 45 - 57 MPH any duration |
> 40 - 49 MPH for >
1 hour > 58 - 74 MPH any duration |
|
Sustained in black Gusts in red |
||
| Wind Chill Warning | WCT < -25° F | WCT < -35° F |
| Wind Chill Advisory | WCT -18° to -24° F | NA |
WCT - Wind Chill Temperature
| Other Advisories and Warnings | Valid for ALL locations |
|---|---|
| Dense Fog or Smoke Advisory | Visibility reduced to < 1/4 mile over a widespread area |
| Dust Storm Warning | Visibility < 1/4 mile with winds > 25 MPH |
| Blowing Dust Advisory | Visibility < 1 mile and > 1/4 mile with winds > 25 MPH |
| Freeze Warning | Temperature drops to < 32° F for the first time at the beginning or end of the growing season |
