Issue Date: Friday, June 10th, 2022
Issue Time: 10:10 AM MDT

— Flooding is NOT expected today

This morning, some high clouds are noted across northern Colorado, but skies are otherwise clear across the state. Pleasant morning temperatures are expected to quickly rise to 10 to 15°F above average statewide by this afternoon. A broad ridge is continuing to build across western Colorado, as shown in the water vapor image below. However, the upper-level energy in Colorado is forecast to remain relatively weak throughout the day. Subsidence associated with the ridge is expected to suppress storm development and keep precipitation chances limited statewide today.

That said, daytime heating and orographic forcing may help to generate subtle terrain-enhanced circulations in the mountains by late afternoon. These features may produce enough lift to trigger some low intensity virga showers over the San Juan and Southeast Mountains, as well as the Front Range, Palmer Ridge, and adjacent foothills this afternoon. Due to the relatively dry boundary layer and DCAPE values forecast to reach between 1400-1700 J/kg this afternoon, gusty outflow winds up to 45mph will be possible with any virga showers that do develop. Given the forecasted low rain rates, NO 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:

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

There are clear skies and warm temperatures this morning across much of southern Colorado. Aside from a few high clouds and brief, isolated virga showers this afternoon, precipitation is expected to remain limited in these zones. Gusty outflow winds and the potential for lightning-related fire hazards are the primary concerns with any storms that do develop in mountains and higher terrain. Max 1-hour rain rates are not forecast to exceed 0.5 inches over the San Juan and Southeast Mountains, with a lower 1-hour maximum of 0.25 inches possible over the Palmer Ridge. Otherwise, primarily hot and dry conditions are forecast for these zones today, and flooding is NOT expected.

Primetime: 4PM – 10PM

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

Aside from some high clouds, skies are mostly clear and temperatures warm and pleasant this morning. Later this afternoon into the evening, a few very isolated virga showers may develop over the Front Range. Gusty winds will likely accompany any brief virga showers that do develop in the mountains, and associated lightning-related fire hazards may exist there as well. Max 1-hour rain rates are forecast to be very minimal at 0.10 inch. Otherwise, mostly hot and dry conditions are expected for these zones. A heat advisory has been issued for Grand Valley for temperatures forecast to reach 100°F! NO flooding is expected today.

Primetime: 6PM – 10PM

Issue Date: Thursday, June 9th, 2022
Issue Time: 10:05AM MDT

— Flooding is NOT expected today

As the last of the trough to our north (orange dashed) moves east today, zonal flow aloft will be replaced by northwesterly flow as a new ridge begins to build to our west. As for mid-level energy, a shortwave back over Utah (orange “X”) and some added ripples in the flow over Wyoming are forecast to move into eastern Colorado this afternoon and evening, which will help produce some lift for storms to develop over the Southeast Mountains, elevated ridges and eastern plains.

PW at Grand Junction was measured at 0.50 inches with the higher moisture located in the mid and upper levels of the atmosphere. This is helping to produce cloud cover this morning, and isolated showers over this area today should be limited to the high terrains near the Continental Divide. Over Denver, PW was still around average, but it has dropped slightly to 0.54 inches. There is still a strong (and expected) gradient to the east with PW around 1 inch over the far eastern plains. A couple surface Lows are expected to set up over the adjacent plains today, and their associated flow should help set up a dry line out east. It is likely that the southerly winds, marking the moisture gradient, will set up over the far eastern border or just to our east. So, storms that develop back to the west should again be high-based, limiting the flood potential over the area. However, out east, if this deeper moisture and associated instability is able to hang on over the border counties, another round of severe storms may be possible. That means that local heavy rainfall may be still be possible in the stronger storm cores, but rain rates are unlikely to exceed flood threat criteria. Therefore, NO flood threat will be 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:

Southeast Mountains, San Juan Mountains, San Luis Valley, Palmer Ridge, Raton Ridge, Northeast Plains & Southeast Plains:

Widely scattered storms are forecast to develop over the eastern San Juan Mountains and Southeast Mountains today with some spillover possible into the northern San Luis Valley. Over the mountains, max 1-hour rain rates up to 0.25 inches are forecast, and if a couple storms track over the same area, localized totals up to 0.50 inches will be possible. Over the edges of northern San Luis Valley, accumulations up to 0.20 inches will be possible. The main threat from storms today will be lightning, which pose a potential fire hazard with plenty of storms producing low rain rates and virga.

As additional should storms develop over the ridges (favoring central/south Colorado), and max 1-hour rain rates up to 0.75 inches will be possible over the adjacent plains. As storms move east, expect upscale growth and strengthening of storms. If moisture can hang on with southerly flow, max 1-hour rain rates up to 1.50 inches will be possible over the eastern border counties. No flood threat has been issued. The main threat from the severe storms that do develop today will be strong outflow winds and hail.

Primetime: 12:30PM to 8PM (west); 1:30PM to 9:30PM (east)

Front Range, Central Mountains, Urban Corridor, Northern Mountains, Northwest Slope, Southwest Slope & Grand Valley:

High-based, isolated afternoon storms will be possible along and near the Continental Divide and over the Front Range. Max 1-hour rain rates up to 0.20 inches are forecast with most storms producing virga and/or brief windy conditions. Therefore, flooding is NOT expected. Afternoon highs should reach into the upper 90Fs over the Grand Valley, and 90Fs are forecast for other lower elevation areas.

Primetime: 2PM to 6PM

Issue Date: Wednesday, June 8th, 2022
Issue Time: 10:30AM MDT

— A LOW flood threat has been posted for parts of the Raton Ridge and Southeast Plains

A complex of storms helped drive a cool front southward across eastern Colorado overnight with temperatures this morning measuring 5-10 F lower compared to yesterday morning. Moisture content has also dropped essentially statewide with morning PW at Denver measuring in at 0.57 inches (right in line with the seasonal normal), but a paltry 0.37 inches at Grand Junction. Most of the state will experience mostly sunny and pleasant weather today with temperatures running a bit below normal over eastern areas and slightly above normal over the western slope.

The only area of concern for heavy rainfall today will be over the Raton Ridge and surrounding areas. A strong moisture gradient was noted this morning, as shown in the PW analysis below. Although Denver’s PW is near normal, the PW at Amarillo, TX was an impressive 1.60 inches, a near record level for early June. With a building ridge overhead, steering flow will weaken considerably today compared to yesterday. In turn, this will allow for our normal topographically-driven circulation to take over. Over southeast Colorado, weak northerly flow seen at lower levels this morning will be replaced by upslope east/southeasterly flow this afternoon, allowing the maintenance of dewpoints in the 48F+ range (along with PW of 0.8-0.9 inches). With CAPE instability up to 1,500 J/kg, slow moving storms will be capable of heavy rainfall, albeit with relatively limited duration. Nonetheless, 30-60 minute accumulation potential of 1.2-1.5 inches, respectively, exceeds our flash flood guidance for the region. Thus, a LOW flood threat has been posted for isolated flash flooding, along with debris slides and mud flows over steeper terrain. Storms should dissipate by late evening.

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, Southeast Plains & Southeast Mountains:

Becoming mostly sunny later this morning, then partly cloudy with scattered showers and thunderstorms expected this afternoon mainly over the Raton Ridge. Max 30-minute rainfall up to 1.2 inches with max 1-hour rainfall up to 1.5 inches possible. Isolated flash flooding, debris slides and mud flows will be possible especially over the steeper terrain. A LOW flood threat has been issued for parts of the area. Hail up to 1 inch will also be possible with the stronger storms.

Primetime: 4PM through 10PM

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

Mostly sunny and pleasant with high temperatures 4-8F below normal east of the Continental Divide and 3-5F above normal west of the Continental Divide. An isolated shower or storm cannot be ruled out over the higher terrain and foothills of the San Juan Mountains, Palmer Ridge and Front Range. However, max 1-hour rainfall only up to 0.3 inches expected. Thus, flooding is NOT expected today.

Issue Date: Tuesday, June 7th, 2022
Issue Time: 9:30AM MDT

— A LOW flood threat has been issued for portions of the Raton Ridge, Palmer Ridge, Northeast Plains & Southeast Plains

A cold front dropped through the state overnight, which is helping to produce some pockets of cooler morning temperatures and higher surface moisture. This morning, there are some light showers just over the border in Nebraska that are moving east. In their wake, they have left cloud cover and fog over the Northeast Plains, but this should begin to burn off after a few hours of heating. Although today should be a quieter rainfall day in terms of coverage when compared to yesterday, heavy downpours and widely scattered severe thunderstorms are forecast again over the eastern plains this afternoon into the evening hours.

PW at Grand Junction was measured at 0.61 inches, so a slight decrease from yesterday. Over Denver, PW has actually increased to 0.73 inches, which can be witnessed by the cloud deck in visible satellite imagery above from earlier this morning. However, the drier westerly flow and daytime heating is expected to mix out the shallow surface moisture over these areas, which will limit the chances of precipitation out west and over the mountains today. Outside of some weak, isolated showers over the Front Range and Southeast Mountains, it should remain dry with plenty of fair-weather cumulus clouds present this afternoon.  

Additional storms are forecast to initiate over the elevated ridges this afternoon and move east where some higher moisture will be present as southeast surface flow resumes. The upper-level jet will continue to sit across the northern border, and it is forecast to dip into the eastern plains this evening. This means a couple things. One is that faster steering flows will be present over northern Colorado again, limiting the flood potential, but also that a stronger thunderstorm could clip the far Northeast Plains later this afternoon. With slower steering flows south and severe thunderstorms ingredients present, heavy rainfall will be likely in the storm cores once again. Therefore, a LOW flood threat has been issued for the area. Similar to yesterday, there is some confidence that a thunderstorm or two may develop over the eastern CO/KS border overnight, so this flood threat continues into the early morning hours.

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:

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

Storms should initiate over the elevated ridges by early afternoon. As they track east, they may become severe with the main threats being large hail (up to 1.75 inches) and strong outflow winds (up to 65 mph), but an isolated tornado cannot be ruled out. In the higher moisture environment, especially with the slower steering flows south, max 1-hour rain rates up to 2 inches could occur. A couple areas (central/south) may see a couple storms track overhead, so isolated storm totals up to 3.5 inches will be possible. A LOW flood threat has been issued for road, low-lying area and local stream/creek flooding possible under the stronger storm cores. A thunderstorm or two could linger into the overnight hours near the KS/CO border, so the threat continues overnight.

Primetime: 2:30PM to 3AM

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

High-based, isolated storms will be possible for the Southeast Mountains and Front Range. Gusty winds will be more of a threat than rainfall, but max 30-min rain rates up to 0.15 inches will be possible. Otherwise, it should remain dry and warm with broken afternoon cloud cover. Flooding is NOT expected.

Primetime: 1PM to 8PM