Issue Date: Thursday, June 30th, 2022
Issue Time: 10AM MDT

— A MODERATE flood threat has been issued portions of the San Juan Mountains, Central Mountains, Front Range, Urban Corridor and Palmer Ridge
— A LOW flood threat has been issued for the Northern Mountains and portions of the Grand Valley and Northwest Slope
— Fire-Burn Forecast Summary: 5 burn areas under MODERATE threat, 4 burn areas under LOW threat; click HERE for more info

This morning there are some ongoing, moderate intensity showers over northwestern Colorado and the northern Front Range. The water vapor imagery below shows the moisture source for these weak storms coming up from the south. With westerly flow aloft around the High continuing today, moisture across the state should be on the rise. PW this morning at Grand Junction and Denver illustrates this point with nearly saturated profiles from about 3km upwards. Their respective values were measured at 1.03 inches and 0.81 inches, which are both above average for this time of year. This indicates that rain rate intensities should be higher today with the scattered storms forecast over the mountains and higher terrains, which will have some spill over into the adjacent, eastern plains.

A jet streak to our north should help keep storms moving relatively quickly from west to east across the northern tier of the state, but local, heavy downpours will still be possible and multiple rounds of rainfall may increase local totals. This is especially true by later this evening as steering flows should begin to decrease with the jet streak lifting north. For this reason, a LOW flood threat has been issued. Further south, storm motion should be a bit slower, and some training storms will be possible. Both of these factors should increase rainfall totals and up the potential for flooding issues. Thus, a MODERATE flood threat has been issued for this region. As storms spill into the adjacent plains with westerly steering flows aloft, there is a better likelihood for decent accumulations with the upturn in moisture and mid-level energy today. Stronger thunderstorms may still produce brief, strong winds and severe hail. Extra moisture convergence is likely over the elevated Palmer Ridge area, so the MODERATE threat has been extended into the area. Flood threats today include ponding in low-lying areas/intersections, increased runoff and mud flows/debris slides over the steeper terrains. The flood threat continues until a couple of hours after the sun sets and instability drops off.

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, Urban Corridor & Palmer Ridge:

Max 1-hour rain rates up to 1.5 inches will be possible today with slow moving and training storms that develop. Local totals just under 2 inches will be possible if a storm lingers for over an hour, so a MODERATE/LOW flood threat has been issued. Stronger storms may also produce some severe hail and outflow winds. These stronger severe storms will be most likely over the adjacent plains though smaller hail will be possible with the mountain storms. Flood threats include road/low-lying intersection flooding, field ponding and mud flows/debris slides over steeper terrains.

Primetime: Ongoing to 12PM

Northern Mountains, Northwest Slope & Grand Valley:

Storms should have quicker movement this morning and afternoon with slower steering flows forecast by this evening. Although rainfall is occurring now, a second set of rainfall is forecast to develop late this afternoon and into the evening hours. Max 30-min rate rates up to 1 inch with local totals up to 1.6 inches will be possible today. This could cause mud flows/debris slides and increased runoff over steeper terrains. A LOW flood threat has been issued.

Primetime: Ongoing to 11PM

Southwest Slope, San Luis Valley, Southeast Mountains, Raton Ridge, Northeast Plains & Southeast Plains:

Isolated rainfall is forecast for the Southwest Slope over the elevated terrains as well as for the Southeast Mountains and Raton Ridge. Max 1-hour rain rates up to 0.75 inches (west) and 0.5 inches (east) will be possible. Some storms may spill into the San Luis Valley with isolated totals up to 0.2 inches possible. More isolated storms will be possible over the Northeast and Southeast Plains with the best accumulation over central and northern Colorado near the Ridges. Max 1-hour rain rates up to 1.25 inches will be possible over these areas. Flooding is NOT expected for these areas today.

Primetime: 12PM to 10PM

Issue Date: Wednesday, June 29th, 2022
Issue Time: 9:05AM MDT  

— Flooding is NOT expected today
— Fire-Burn Forecast Summary: 4 burn areas under LOW threat; click HERE for more info

A hot, but otherwise mild summer day is ahead with storms returning the high terrains this afternoon and evening. A weak ridging pattern remains in place this morning, which will be replaced by more westerly flow aloft by this evening as a trough (red dashed line) moves east to our north. There’s a little moisture and lift marked over northern Utah this morning (orange “X”), which as it moves east with the westerly flow, should help provide a little better storm coverage over the northern and central high terrains today. One lacking ingredient for heavy rainfall today will be moisture. PW at Grand Junction and Denver were measured at 0.78 and 0.60 inches, respectively, but most of this moisture was located in the mid and upper levels of the soundings. This means that weak storms and showers that develop should be widely scattered (north) to isolated (south) in nature and pose more of a wind than heavy rainfall threat. As mentioned above, best coverage of rainfall should be north of I-70, although some isolated, weak storms are also likely to fire with the diurnal flow and residual moisture along and near the Continental Divide over the San Juan Mountains. As anticipated, flooding is NOT forecast 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:

Northern Mountains, Front Range, Northwest Slope, Central Mountains, Grand Valley, Urban Corridor, Palmer Ridge & Northeast Plains:

Max 1-hour rain rates up to 0.5 inches and a couple rounds of rainfall providing local totals up to 0.8 inches will be possible. Best coverage of rainfall should be west of the Continental Divide over the elevated plateaus and mountains and across the southern Front Range. With steering flow becoming more westerly, a few storms may spill into the Urban Corridor, but totals should remain around 0.4 inches or less. With the dry surface layer, strong storms that develop may produce some brief outflow winds, which is especially true as they spill into the adjacent plains. Flooding is NOT expected today.

A Red Flag Warning has been issued for the Northeast Plains as southwest winds gusts could reach up to 35 mph and relatively humidity potentially drops to 10 percent. Tune into your local NWS office for more information.

Primetime: 11AM to 11PM

San Juan Mountains, Southwest Slope, San Luis Valley, Southeast Mountains, Raton Ridge & Southeast Plains:

Best chance for storms will be over the San Juan Mountains today, and max 1-hour rain rates up to 0.4 inches will be possible. Isolated totals could reach up to 0.6 inches by later this evening. A weak storm or two may develop over the Southeast Mountains, but totals should remain under 0.2 inches. Flooding is NOT forecast today.

Primetime: 12PM to 9PM

Issue Date: Tuesday, June 28th, 2022
Issue Time: 10:25 AM MDT

— Flooding is NOT expected today

This morning skies are mostly clear as a high-pressure ridge continues to build in from the west over Utah and Nevada. Subsidence associated with the approaching ridge is expected to contribute to a warming and drying trend statewide. A subtle impulse in the flow, marked by the “X” in the visible satellite image below, is expected to transition southeastward across western Colorado today. Instability is forecast to increase to between 800-1000 J/kg of CAPE in southwestern Colorado this afternoon, which, in conjunction with the approaching upper-level energy and topography, should initiate isolated to widely scattered storm development across western Colorado by early afternoon with storms moving fairly slowly south to southeast.

PW this morning in Grand Junction was measured at 0.71 inches, which is a lesser value than yesterday and is expected to decrease throughout the day with drying. Still, dew points may remain in the upper 40s°F to low 50s°F across southwestern Colorado until evening. With less moisture forecast today, storms are likely to be high based and strong storms may pose a wind and small hail threat. Quick downpours could be possible with the more intense storms over the Southwest Slope and far western San Juan Mountains, but outside of nuisance ponding, flooding is NOT expected 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:

Southwest Slope, San Juan Mountains, San Luis Valley, Southeast Mountains, Grand Valley, Central Mountains, Northwest Slope, Northern Mountains & Front Range:

This morning, skies are mostly clear aside from a few stray high clouds. Isolated storms are expected to develop across the Central Mountains by early afternoon, with more widely-scattered storm development expected further south. The highest precipitation chances appear likely over the Southwest Slope and eastern San Juan Mountains, where moisture and instability are maximized. Maximum 1-hour rain rates of 0.75 inches are possible here, along with strong downdrafts and potentially a small hail threat. Isolated 1-hour rain rates around or just under 0.5 inches will also be possible over the Central Mountains and Southeast Mountains with most storms producing under 0.3 inches of rainfall. Flooding is NOT expected today.

Primetime: Noon to 9PM

Urban Corridor, Northeast Plains, Palmer Ridge, Southeast Plains & Raton Ridge:

Clear skies and warmer temperatures are forecast for eastern Colorado today. Due to the increased warming and drying expected and only meager instability that is forecast across the region, little if any precipitation is expected for the eastern half of the state, aside from perhaps a stray light shower over the Urban Corridor and Palmer Ridge. NO flooding is expected today.

Issue Date: Monday, June 27th, 2022
Issue Time: 10:10AM MDT

— A LOW flood threat has been issued for portions of the San Juan Mountains and Southwest Slope
— Fire-Burn Forecast Summary: 2 burn areas under LOW threat; click HERE for more info

A change in the synoptic pattern will begin today as High pressure begins to build in over the state from the west. More northerly flow aloft will begin to dry out the atmosphere and suppress the subtropical moisture south and eastward by this evening. The beginning of this drying trend can be seen in the water vapor imagery below over northwest and northern Colorado (increase in yellow shades). PW at Denver was measured at 0.71 inches, so it’s already dropping from yesterday. However, for today, the southern tier of the state will continue to be influenced by the High pressure center over Texas with easterly and southeasterly flow aloft forecast. With subtropical moisture, a vorticity maximum and the right entrance of an upper-level jet over southeast Colorado, moderate showers are already occurring this morning. This batch of widespread, light to moderate rainfall is forecast to continue through the mid-afternoon providing more beneficial rainfall to the area as well as cooler temperatures.

A second set of diurnally driven storms is forecast to develop over the mountains this afternoon. As mentioned above, steering flow has changed, so while storms will still be slower moving, expect more SSE storm movement. With drying occurring over north and central Colorado, storms should be more isolated with best coverage over the Front Range. More widely scattered storms and higher local accumulations are forecast over the San Juan Mountains where better moisture will be present. PW over the southwest corner is estimated to be between 0.8 and 0.9 inches this morning with dew points in the 50Fs. While rainfall is not forecast to be as widespread as yesterday, isolated stronger storms may produce heavy, local rainfall over saturated soils. This has the potential to cause mud flows, debris slides as well as excessive runoff over steeper terrains under the stronger storm cores. For these reasons, a LOW flood threat has been issued.

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:

Northern Mountains, Northwest Slope, Central Mountains, Grand Valley, San Juan Mountains, Southwest Slope, Front Range & San Luis Valley:

Storms will be more isolated north and widely scattered south this afternoon and evening. Isolated max 1-hour rain rates up to 0.3 inches (north), 0.5 inches (central) and 0.9 inches (south) will be possible. Gusty winds will also be possible with storms that develop, especially over north and central Colorado. With slower storm motion, isolated local totals may reach up to 1.2 inches over the San Juan Mountains. Over already saturated soils, mud flows, debris slides and excessive runoff may occur under stronger storm cores that develop today. A LOW flood threat has been issued. The flood threat should end as cooler temperatures take over with the setting sun.

Primetime: 1PM to 9:30PM 

Southeast Mountains, Raton Ridge, Southeast Plains, Urban Corridor, Palmer Ridge & Northeast Plains:

Ongoing showers over the Southeast Mountains, Raton Ridge and Southeast Plains will continue through this afternoon. While embedded convection may cause some moderate rainfall rates, flooding is NOT expected. Isolated totals up to 1.5 inches will be possible (east). Additional storms will likely develop over the Southeast Mountains later this afternoon and produce isolated max 1-hour rain rates up to 0.5 inches. Lastly, storms have better potential of spilling into the Urban Corridor today with most rainfall being confined to over or near the elevated ridges. Max 1-hour rain rates up to 0.3 inches (north, Cheyenne Ridge) and 0.5 inches (south, Palmer Ridge) are possible. Flooding is NOT expected.

Primetime: Ongoing to 11PM