Issue Date: Monday, July 4th, 2022
Issue Time: 9:40AM MDT
— Flooding is NOT expected today
— Fire-Burn Forecast Summary: 2 burn areas under LOW threat; click HERE for more info
A happy 4th of July to everyone! A classic Colorado summer day is on tap with above average temperatures forecast out east and near normal to slightly below average temperatures forecast over western Colorado. Afternoon storms are expected to fire over the mountains in a similar manner to yesterday; however, the incoming trough off the west coast has helped produce a drier southwesterly flow over the western and northern portions of the state. That boundary is marked in green in the water vapor imagery below, which for the forecast, translates to slightly less coverage of storms when compared to yesterday. PW was still measured at 0.91 inches at Grand Junction this morning, which is quite moist, but a lot of dry air was noted above ~600mb. This, paired with the faster steering flows over the area again, should help to temper rainfall activity and the flood threat today. The isolated, but stronger storms that develop will again be capable of producing small hail, strong outflow winds and plenty of lightning over the area.
Switching over to eastern Colorado, PW at Denver was measured at 0.69 inches, so right around average. Dew points were also noted around 50°F across the lower elevations, but increasing westerly flow aloft will likely mix out some of this shallow moisture as the day progresses. At the surface, a trough axis was noted over the plains this morning, oriented from southwest to northeast. This should help keep upslope rather weak this afternoon and prevent strong moisture advection back to the west. Thus, the scattered storms that develop should pose less of a flood risk today even though steering flow remains rather weak over this area. As storms move off the mountains into the I-25 Corridor, gusty outflow winds and dangerous lightning will continue to be the main threats. Moderate rainfall will be possible under the more stationary storms, which will be most likely along and near the elevated ridges, but rain rates are expected to stay under flood threat criteria. Thus, there is NO flood threat issued today.
Today’s Flood Threat Map
For more information on today’s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.
Zone-Specific Forecasts:
Front Range, Central Mountains, San Juan Mountains, Northern Mountains & Southeast Mountains:
Widely scattered to scattered storms are forecast today with the best coverage of thunderstorms over the northern San Juan Mountains, Central Mountains and southern Front Range. Max 1-hour rain rates up to 0.85 inches will be possible along with isolated storm totals up to 1.25 inches, which will be most likely to occur over the northern San Juan Mountains and near the Continental Divide. In addition to dangerous lightning, strong thunderstorms will also be capable of producing small hail and brief, gusty wind. Most activity will end in the late evening hours, but some lingering rainfall will again be possible tonight (south). Flooding is NOT expected today.
Primetime: 1PM to 10:30PM
Raton Ridge, Palmer Ridge, Urban Corridor, Northeast Plains & Southeast Plains:
Steering flows will likely push the scattered storms into these forecast zones by mid-afternoon favoring the Palmer Ridge and northwards for lasting rainfall activity. Max 1-hour rainfall rates up to 0.75 inches will be possible along with isolated storms totals up to 1.1 inches, but most storms will produce storm totals under 0.40 inches. The stronger storms also have the potential to produce brief, outflow winds up to 40 mph.
Primetime: 1:30PM to 11PM
Northwest Slope, Southwest Slope, Grand Valley & San Luis Valley:
More isolated storms are forecast to develop over the elevated ridges and mesas this afternoon. Storms may produce some windy conditions as well as dangerous lightning. Max 30-minute rain rates up to 0.5 inches will be possible, so flooding is NOT expected.
Primetime: Noon to 9PM
