Issue Date: Monday, July 11th, 2022
Issue Time: 9:45AM MDT
— A MODERATE flood threat has been issued for the Raton Ridge and portions of the Southeast Plains
— A LOW flood threat has been issued for the Southeast Mountains and portions of the Front Range, Central Mountains, San Luis Valley, San Juan Mountains and Urban Corridor
— Fire-Burn Forecast Summary: 1 burn area under MODERATE threat, 1 burn area under LOW threat; click HERE for more info
There’s a bit of a change in the weather pattern today as shown in the water vapor imagery below. At the mid-levels, the 500mb High will start to rebuild back to the west, which should help to transition the flow aloft over the state from more westerly to northwesterly over the course of the day. At the surface, a disturbance to our east (orange “X”) is creating a northerly wind surge over the eastern plains this morning. This is helping to produce cooler morning temperatures as well as an increase in cloud cover behind it over northwest Colorado. This stabilizing air mass should help confine rainfall activity to the southern Front Range and south today.
As far as moisture, PW at Grand Junction was measured at 0.92 inches with dew points in the upper 40°Fs and low 50°Fs noted across the lower elevations in southern Colorado. As the front and associated lift push south, scattered storms are forecast to develop over the central and southern high terrains. Moisture over central Colorado and the western valleys should continue to be limited at the surface, which will limit the flood threat over the area. However, higher moisture over portions of the southern San Juan Mountains, Southeast Mountains, San Luis Valley and immediate adjacent eastern plains paired with extra lift from the boundary will return the flood threat to the area. A LOW flood threat has been issued. Longer duration rainfall, expanding thunderstorm coverage and higher dew points over the immediate adjacent plains along the elevated Raton Ridge could cause widespread heavy rainfall through this evening, so a MODERATE flood threat has been issued for this area.
Flood related threats today include the possibility for isolated mud flows and debris slides over steeper terrains along with road flooding, field ponding and rises in local streams and creeks possible (east) under the stronger storm cores that develop. The heavy rainfall looks to wind down after about midnight, but some light rainfall may linger over and near the Raton Ridge through early tomorrow morning.
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:
Raton Ridge, Front Range, Central Mountains, Southeast Mountains, Southeast Plains, San Luis Valley, & San Juan Mountains:
Scattered to numerous thunderstorms are forecast for these zones today. Northwesterly steering flows by later this afternoon should produce some spill over into the adjacent plains favoring the elevated ridges, especially south, for rainfall accumulation. Over the southern San Juan Mountains, scattered storms may produce 1-hour rain rates up to 1.1 inches, and for the Southeast Mountains, 2 to 3-hour totals up to 2.25 inches will be possible. This could cause isolated mud flows and debris slides as well as road flooding. A LOW flood threat has been issued.
Longer duration, heavy rainfall is forecast for the Raton Ridge through about midnight, although some lighter rainfall could linger into the early morning hours. Max 1-hour rain rates up to 1.9 inches and storm totals just under 3 inches will be possible. This could cause road and arroyo flooding, field ponding as well as rises on local streams/creeks. A MODERATE threat has been issued. A couple severe thunderstorms are also possible over the eastern Raton Ridge area along the front late this afternoon into the evening hours, so some hail and strong outflow winds may accompany those if they develop.
Primetime: 12PM to 9PM (west); 12PM to Midnight (east)
Northern Mountains, Northwest Slope, Grand Valley, Southwest Slope, Northeast Plains, Urban Corridor & Palmer Ridge:
It should be relatively quiet on the rainfall front over these zones today with drier and/or stable conditions forecast. Some isolated, light precipitation will be possible over the high terrains west, but rainfall amounts should remain under 0.1 inches. Better rainfall chances will be over the elevated regions of the Southeast Slope where totals up to 0.5 inches will be possible. Flooding is NOT expected. The more northern zones, especially east, should have a nice break from the heat.
Primetime: 12PM to 8PM
