Issue Date: Wednesday, June 10th, 2020
Issue Time: 8:50AM MDT

— Flooding is NOT expected today

The vigorous system that brought high winds, rain, and snowfall to the state is now well to our east as seen in the image below. That means there will finally be a break in severe surface winds, which have caused so much damage the last couple of days. Behind the Low, northwesterly flow has taken over, which has pulled in a drier air mass to the state. PW at Denver and Grand Junction was measured at 0.36 inches, which is a significant drop off from the last few days. Today, the ridge is forecast to build northward to our west, which means the rebound in high temperatures will begin. Expecting afternoon highs to be 10-15F warmer than yesterday. As for rainfall, there might be a couple high-based showers that develop along the Continental Divide and over the Front Range near the Palmer Ridge with the upslope flow. However, limited low-level moisture will mean that virga and broken cloud cover will be more likely that measurable rainfall.

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:

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

Highs this afternoon over the valleys will be in the 70Fs with a few places further south nearing that 80F mark. Surface winds look to increase to about 15 – 20 mph this afternoon over the Central and San Juan Mountain valleys, but other than that, a pleasant day is in store. A couple weak showers may develop over the mountains near the Divide further south, but only a few sprinkles are forecast.

Front Range, Southeast Mountains, San Luis Valley, Raton Ridge, Palmer Ridge, Urban Corridor, Southeast Plains, & Northeast Plains:

Severe winds over the eastern plains are not forecast today with the relaxing pressure gradient. However, surface winds over the San Luis Valley and Northeast Plains may still increase to around 15-20 mph this afternoon. This may bring spotty critical fire weather, but a Red Flag Warning will likely not be issued. Highs are forecast to rebound around 10F with some lower elevations seeing as much as a 15F increase. As far as rainfall, the best chance will be along the Divide and southern Front Range/Palmer Ridge intersect, but only a sprinkle or two are forecast. So overall, a pleasant day is in store.

Issue Date: Tuesday, June 9th, 2020
Issue Time: 9:10AM MDT

— Flooding is NOT expected today

Much cooler temperatures are forecast across the state today behind the powerful cold front that brought rainfall and snow to the higher elevations. The system, and associated ongoing rainfall/snow, can be seen over Colorado in the visible satellite imagery below. Further to our east, you can see the remnants of Cristobal. Excepting the precipitation to track eastward throughout the day as the Low tracks into Kansas. Behind the low, it will start to clear as seen by the cloudless conditions over the western border, and stable conditions are forecast.

Lack of instability will keep rain rates below flood threat criteria over the plains, although some isolated 24-hour accumulations up to 1.20 inches will be possible over the Northeast Plains due to favorable upper dynamic support and plenty of low-level moisture. This will also be a nice wetting rainfall for the drought area over the Southeast Plains, and totals by morning are forecast to (generally) be in the 0.50 to 0.75 inches range. As anticipated, flooding is not expected today. Additionally, a High Wind Warning has been issued for the eastern plains with northerly surface winds forecast in the 30 to 40 mph range and gusts between 60 and 70 mph due to the strengthening system. Over the San Luis Valley, drying paired with northwest winds will cause Red Flag Warning criteria from noon to 8PM this evening. Tune into NWS Pueblo for the latest on the fire weather conditions.

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 Plains & Northeast Plains:

It’ll be windy and wet. A High Wind Warning is in effect until 6PM this evening with northwest winds forecast between 30 and 45 mph and gusts up to 65 mph. Overall, this will be a nice, wetting even for the eastern plains and drought region in the Southeast Plains. Totals will be greatest over the Northeast Plains with 24-hour totals up to 1.20 inches possible. Generally, totals will be around 0.75. Over the Southeast Plains, the moderate rainfall will won’t be as widespread, but still, 24-hour totals between 0.50 and 0.75 inches can be expected. Flooding is not forecast.

Primetime: ongoing to 6PM

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

Continued clearing is expected today with cooler high temperatures forecast behind the trough. Lows overnight dropped to below freezing over the mountains and valleys, which was too be expected with such a strong system. Expecting overnight low temperatures to drop to around freezing for the Northwest Slope and high-mountain valleys again, so prepare accordingly. Stability behind the front will keep rainfall out of the forecast, and clear skies are expected by this afternoon.

Front Range, Southeast Mountains, San Luis Valley, Raton Ridge, Palmer Ridge, & Urban Corridor:

Precipitation is starting to come to an end over these regions as the system moves east and subsidence fills in. By later this afternoon, expect skies to clear with highs reaching the mid-60Fs over the lower elevations and 50Fs for the mountain valleys. Enjoy the break from the heat as temperatures rebound quickly by Thursday and Friday afternoon. Also forecast today are some gusty, northerly winds. Winds will pick up by noon and are expected to bring critical fire conditions to the southern portion of the San Luis Valley.

Primetime: ongoing to 11AM

Issue Date: Monday, June 8th, 2020
Issue Time: 10:15AM MDT

— Flooding is NOT expected today

It’s going to be a windy day across the state with the jet overhead and a lee cyclone developing over eastern Colorado. This will mean critical fire weather for southern and eastern Colorado as relative humidity also drops into the teens and single digits. Please visit your local NWS office for Red Flag Warning details.

As far as rainfall, it has really dried out since Saturday with southwesterly flow aloft. PW was measured at 0.45 and 0.30 inches at Denver and Grand Junction, respectively. There is some moisture that is expected to move into northwest Colorado and spread eastward across northern Colorado today with the trough. This will help spark some scattered, high-based storms along a cold front that moves into northwest and central Colorado. Expecting severe winds to be the main threat this afternoon with rain rates becoming more efficient this evening.

That increase in efficiency is due to a second surge of northerly air (colder front) moving south overnight and helping return low level moisture. With the jet/lift overhead tonight, maximized dynamics will create widespread snow and showers for the mountains and I-25 corridor. Storms are expected to continue through tomorrow morning as the trough moves east into the plains. Rainfall is forecast to be gradual enough that flash flooding should be avoided. Additionally, a High Wind Warning has been issued for eastern Colorado from 6PM this evening to 3AM as winds in the 30 to 40 mph range with gusts up to 60 mph are expected to accompany the frontal passage (winds from the north). Behind the front, very cold temperatures are forecast for the higher elevations, so the snowline could drop to around 7,000 feet tonight. This will cause snow accumulation on roads starting around 8,500 feet. Hazardous overnight driving conditions are expected over mountain passes (especially near the Continental Divide), so please use extra caution with the icy conditions. If you are backpacking or camping, be prepared for very cold overnight temperatures.

Lastly, some heavier rainfall will be possible over the northeast corner of the state tonight due to an MCS feature that forms in conjunction with upper dynamics behind the cold front. At this time, the heaviest rainfall looks to be over Nebraska, but isolated totals up to 1.50 inches will be possible by morning. These totals will likely be over a small enough area (Sedgwick and Phillips Counties) that no flood threat is needed.

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:

Northwest Slope, Grand Valley, San Luis Valley, & Southwest Slope:

Going to put the zone-specific forecasts in order of rainfall timing with the Northwest Slope and Grand Valley first. Storms are expected to form along a weak cold front with the main threat being severe winds from storms. Max 1-hour rain rates around 0.15 to 0.20 inches will be possible over the higher elevations. Storms should move into the mountains later this evening. Flooding is not expected. Over the Southwest Slope and San Luis Valley a Red Flag Warning has been issued for westerly surface winds in the 15 to 25 mph range with gusts up to 45 mph possible.

Primetime: 12PM to 10PM

Central Mountains, San Juan Mountains, Northern Mountains, Front Range, & Southeast Mountains:

Storms will start to develop over the Northern Mountains and northern Front Range around 5PM this evening. Accumulation is expected to continue overnight and increase south along and near the Continental Divide. With the passage of the cold front, snowfall is expected over the higher mountain passes and areas greater than 8,500 feet in elevation. Guidance indicates that several inches of snow are possible favoring western facing slopes by tomorrow morning along the Divide (pockets of 7-10+ inches), but most areas will only receive between 2-5 inches. Flooding is not expected due to most areas turning to snow with the frontal passage.

Primetime: 5PM to 4AM

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

Moderate overnight rainfall is possible over the Urban Corridor, Palmer Ridge and Northeast Plains behind the cold front overnight. Totals by tomorrow morning should range from 0.50 to 0.75 inches with isolated areas over the northeast corner possibly reaching 1.50 inches. Further south along the I-25 corridor, totals up to 0.50 inches will be possible. Flooding is not forecast due to gradual rain rates, although some local field ponding may be possible over the northeast corner of the state if storms back build into the area. The area isn’t large enough and confidence isn’t high enough to warrant a threat at this time.

Primetime: 9PM to ongoing

Issue Date: 6/7/2020
Issue Time: 8:35 AM

— A NWS Flood Advisory is in effected for the Los Pinos River near Bayfield affecting La Plata County due to reservoir releases. Minor flooding of lowlands adjacent to the river is expected downstream from the dam.
— Otherwise, Flooding is NOT expected today

Strong southwesterly flow aloft will help to dry out Colorado today, all-but-eliminating rain chances and increasing fire danger. Expansive Red Flag Warnings have been issued as the dry conditions will be concurrent with strong winds. As far as rain chances for today are concerned, only a couple isolated showers/thunderstorms are expected over the Northwest Slope, western portions of the Northern Mountains, and far northern portions of the Grand Valley regions.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. 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

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

Hot and dry conditions will rule the day, with strong winds elevating fire danger to critical levels. Red Flag Warnings have been issued for much of the area. Please visit your local National Weather Service office website for more details.

Northwest Slope, Northern Mountains, and Grand Valley:

Available moisture from previous days’ showers/thunderstorms will combine with *just enough* support from the low pressure system over the Pacific Northwest and result in the development of a few showers/thunderstorms this afternoon and evening. Gusty winds, lightning, and brief periods of moderate rainfall will attend the strongest storms, relatively speaking. Rain rates are expected to generally be less than 0.2 inches/hour, up to 0.25 inches/hour underneath thunderstorms.

Otherwise, portions of Grand Valley are included in the Red Flag warning area.

Timing: 11 AM – 8 PM

Front Range, Southeast Mountains, Central Mountains, Southwest Slope, San Juan Mountains, and San Luis Valley:

Unseasonably hot and dry conditions, combined with gusty winds, will result in elevated fire danger for much of the area. Red Flag Warnings are currently in effect for portions of the Front Range, Southeast Mountains, Central Mountains, Southwest Slope, and San Luis Valley regions. Please visit your local National Weather Service office website for more details.