Issue Date: Monday, June 24th, 2019
Issue Time: 9:00AM MDT

–A LOW flood threat is issued for Saguache Creek, the headwaters of the and along the Rio Grande in Mineral and west Rio Grande Counties and for the San Antonio, Conejos Rivers in south central Colorado, Arkansas River downstream of Pueblo Dam to Nepesta and rivers/streams in central Jackson County.

The main axis of the trough has passed to the east, which will place the state under northwesterly/westerly flow aloft today as the ridge slides in from the west and begins to build over the state the next couple of days. Rising pressure with only minimal residual moisture remaining under the ridge (PW was measured at 0.43 inches at Denver) will keep the rainfall today limited to high-based showers and weak thunderstorms favoring the Northern Mountains, eastern San Juan Mountains and southern Front Range/Palmer Ridge intersect for development this afternoon. A couple additional weak storms may be possible over the far Northeast Plains late this afternoon, but should not become severe. Storms are anticipated to dissipate as they move off the mountains with the northwest steering flow. All storm activity is forecast to come to an end a couple hours after sundown as instability declines. As anticipated, flooding from rainfall is not forecast.

The riverine Low flood threat continues for various stretches of river across the state and are marked in the flood threat map below. Saguache Creek, the headwaters of the and along the Rio Grande in Mineral and west Rio Grande Counties and the San Antonio/Conejos Rivers in south central Colorado have a Flood Warning issued through this afternoon. Minor flooding has also been reported, with some rural roads being washed out, in central Jackson County due to snowmelt and heavy rainfall the last couple of days. This Flood Warning continues through 1PM this afternoon with river levels expected to decrease over the next day or two. Lastly, a Low flood threat has been issued for the Arkansas downstream of Pueblo Dam to Nepesta. The AHPS gage in Avondale is in the Minor flooding stage and is expected to remain elevated (at the current level) through today. For the most current updates and the latest information, follow your local NWS WFO (Weather Forecast Office).

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. For Zone-Specific forecasts, scroll below the map.

 

Zone-Specific Forecasts:

Front Range, Southeast Mountains, Raton Ridge, Urban Corridor, Northeast Plains, Palmer Ridge, Southeast Plains:

Much warmer temperatures today with the eastern plains reaching the 80°Fs. Most mountainous regions should reach the 60°Fs, so much warmer temperatures overall.  Isolated max 1-hour rain rates up to 0.2 inches will be possible, but the majority of storms will produce under 0.15 inches or only trace amounts. Flooding is not anticipated except over the lower Arkansas from Pueblo Dam to Nepesta.

Primetime: 1PM to 10PM

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

Very low dew points over these regions and building high pressure, should keep the afternoon storm activity limited. Some high-based showers and a weak thunderstorm or two may be possible over the Northern and eastern San Juan Mountains. Max 1-hour rain rates up to 0.3 inches are possible though most storms will produce under 0.15 inches and plentiful virga. See the riverine section above for the latest on flooding, and also visit your local NWS office for the most recent updates.

Primetime: 2PM to 10PM

Issue Date: 6/23/2019
Issue Time: 8:15 AM

A LOW FLOOD THREAT IS FORECAST TODAY FOR THE FOLLOWING AREAS:

Saguache Creek, the headwaters of the and along the Rio Grande in Mineral and west Rio Grande Counties, the San Antonio and Conejos Rivers in south central Colorado, and the North Platte River near Northgate.

NOTE: Elevated snow melt runoff continues across the High Country, with various flood advisories issued. Please visit the website of your local National Weather Service Office for more details.

The upper-level low that has brought unsettled weather to Colorado the past couple of days is finally departing the region and will be centered over South Dakota/Nebraska by tonight. Before it leaves, though, it will bring another day of below average temperatures and isolated-to-scattered showers/thunderstorms. With cooler temperatures in place, storms will not have the same “oomph” they have had the past few days, with the vast majority of them being garden-variety. Near the CO/KS border, an isolated severe storm or two cannot be ruled out, with the potential to produce half-dollar-sized hail and gusty winds up to 65 mph.

The best coverage of storms today will be north of Highway 50, due to proximity to the low-pressure center aloft and good mid-level moisture. South of Highway 50, drier air and less support aloft will keep a fairly tight lid on things with only a few isolated showers over the mountains and a couple isolated showers/storms east of the mountains. Storm motions will be quick enough, and rain rates low enough, to avoid the issuance of any rainfall-induced flood threats. The only flood threats on the map today are due to ongoing snowmelt.

For more details on timing and rain rates, please see the zone-specific forecast discussions below.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. For Zone-Specific forecasts, jump below the map.

Zone-Specific Forecasts

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

Isolated showers are ongoing north of I-70 this morning. By lunchtime, additional isolated-to-scattered showers/thunderstorms will develop, mainly north of Highway 50, and continue into the late-afternoon hours. Shower/storm activity will diminish by 6 PM, with all activity ending by 9 PM or so. One or two storms near the CO/KS border may become strong/severe, with the potential to produce half-dollar-sized hail, strong winds up to 65 mph, and heavy rain at 1.0-1.5 inches/hour. Otherwise, all of the activity is expected to be garden-variety, producing moderate rainfall and gusty winds with rain rates of 0.3-0.6 inches/hour.

Front Range, Northern Mountains, Northwest Slope, Grand Valley, and Central Mountains:

Isolated-to-scattered rain and snow showers are expected, with snowfall above 9,000 feet and rain below. Showers will be brief, moving quickly towards the southeast, with rain rates less than 0.25 inches/hour. Activity will end from west to east this evening, with all activity ending by 8-9 PM.

Southeast Mountains, San Luis Valley, San Juan Mountains, and Southwest Slope:

A couple isolated showers, mainly over the higher terrain, are expected. Otherwise, the rest of the area will remain dry under mostly sunny skies. Rain rates from any showers will be less than 0.2 inches/hour.

Timing: 2 PM – 7 PM

Issue Date: 6/22/2019
Issue Time: 8:20 AM

A LOW FLOOD THREAT IS FORECAST TODAY FOR THE FOLLOWING AREAS:

Portions of the Front Range, Southeast Mountains, Urban Corridor, Northeast Plains, Southeast Plains, and Raton Ridge regions.

Saguache Creek, the headwaters of the and along the Rio Grande in Mineral and west Rio Grande Counties, and for the San Antonio and Conejos Rivers in south central Colorado.

NOTE: Elevated snow melt runoff continues across the High Country, with various flood advisories issued across the Northern Mountains, Northwest slope, Central Mountains, Southwest Slope, and Grand Valley. Please visit the website of your local National Weather Service Office for more details.

No one told Mother Nature that it is the second day of summer, and the image below depicts a weather pattern more reminiscent of late-September/October than late-June. An upper-level low is currently centered over southern Saskatchewan, with the trough axis extending southwest towards the California Baja. Associated with this system is plenty of upper-level support for showers and embedded thunderstorms, which has kept rainfall (and high elevation snow) ongoing this morning across the Front Range, Central Mountains, Urban Corridor, Palmer Ridge, and Northeast Plains. The unsettled weather will expand in coverage and intensity this afternoon and evening as temperatures warm a bit and increase instability. Ample shear will also be in place thanks to strong southwest flow aloft, so there will be a few embedded strong-to-severe thunderstorms. The greatest severe threat will be east of the mountains, where the combination of shear/instability will be best. These stronger storms will also hold the potential for heavy rainfall, thus the issuance of the low flood threat.

Over the High Country and Western Slope, widespread showers and thunderstorms are expected, with the main impacts being light-to-moderate precipitation, gusty winds, and small hail. A couple stronger thunderstorms cannot be ruled out, which may produce hail up to 1 inch in diameter and strong winds up to 65 mph. Accumulating snow is expected above 9,000-10,000 feet in the Grand Valley, Northwest Slope, Northern Mountains, Central Mountains, and Front Range regions, with higher peaks picking up 6-10 inches of snowfall through tomorrow morning.

For more details on timing and rain rates, please see the zone-specific forecast discussions below.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. For Zone-Specific forecasts, jump below the map.

Zone-Specific Forecasts

Front Range, Southeast Mountains, Urban Corridor, Northeast Plains, Southeast Plains, Palmer Ridge, and Raton Ridge:

Scattered-to-widespread showers and thunderstorms expected today/tonight, with lingering showers into the morning hours tomorrow. A few of the storms will be strong/severe, with the potential to produce hail up to 2 inches in diameter, strong winds up to 75 mph, and a brief tornado or two. Rain rates will generally be below flash flood thresholds, but stronger storms could produce the following maximum rain rates:

Front Range and Southeast Mountains: 0.5-1.0 inches/hour
Urban Corridor: 1.0-1.5 inches/hour
Palmer Ridge, Northeast Plains, and Southeast Plains: 2.0-2.5 inches/hour
Raton Ridge: 1.5-2.0 inches/hour

Storm motions will be at a decent clip towards the east, so only a low flood threat is warranted. The Junkins, Beulah Hill, Spring Creek, and Hayden Pass burn scars may need a watchful eye.

Timing: 10 AM – Midnight for the Front Range and Southeast Mountains (a few lingering showers into tomorrow morning), 1 PM – 1 AM for the Urban Corridor, Raton Ridge, and Palmer Ridge, 2 PM – 2 AM for the Northeast Plains and Southeast Plains (a few thunderstorms lingering until sunrise tomorrow)

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

Scattered-to-widespread showers and thunderstorms expected throughout today and tonight. The bulk of the activity will end by 9-10 PM, but a few isolated showers/thunderstorms will continue into the morning hours tomorrow, mainly north of I-70. Snow accumulation is expected above 9,000-10,000 feet. Most rain rates will be less than 0.2 inches/hour, but a stronger thunderstorm may produce rainfall at 0.2-0.4 inches/hour.

Issue Date: Friday, June 21st, 2019
Issue Time: 9:45AM MDT

–A LOW flood threat is issued for Palmer Ridge and portions of the Urban Corridor, Northeast Plains and Southeast Plains.

–A LOW flood threat is issued for Saguache Creek, the headwaters of the and along the Rio Grande in Mineral and west Rio Grande Counties and for the San Antonio and Conejos Rivers in south central Colorado.

It’s officially the first day of summer, but expecting some colder, more spring like temperatures to move into the state with the next system. Marked in the visible satellite imagery below is the cold front in blue. Over western Colorado, it is more stationary at this point in time. This feature is expected to begin its push south early this evening and overnight, so it will be a cool, cloudy and potentially wet start to Saturday morning over eastern Colorado. Less cloud cover and just cooler temperatures are forecast for the western slope tomorrow morning. The jet axis has moved into the northwest corner of the state with a southwest to northeast orientation. Thus, expecting quick, southwest flow over the state again today, especially to the west. The last impressive feature on the surface maps this morning (not shown) is the really strong dew point gradient over southeastern Colorado. Dew points are in the mid to upper 50°Fs over the far Southeast Plains, but back to the west at Trinidad, the dew point drops to 24°F. Southwest winds aloft will advect the drier air mass over New Mexico into the Southeast Plains this afternoon, so expect the dew points to begin to drop by noon. This should really keep the severe weather and rainfall threat limited to along and north of the Palmer Ridge this afternoon over eastern Colorado.

Ongoing showers over the northwest corner associated with the jet are expected to continue throughout the day and follow the jets movement. Therefore, expecting more storm activity early this evening further south over the Grand Valley, Southwest Slope and Central Mountains. As the axis of the trough moves eastward overnight, showers will diminish west to east with the axis shift. Colder temperatures behind the front will bring snow to higher elevations (above 9,000 feet). Continuous precipitation with this feature will promote some high 24-hour totals over the Northern Mountains and northern Front Range. However, rainfall should be gradual enough that flooding will be avoided.

Back to the east, a shortwave will arrive around peak heating this afternoon helping form numerous and widespread thunderstorm activity over the eastern Front Range, Urban Corridor and Northeast Plains. The best parameters for a large severe thunderstorm of two will be along the Palmer Ridge. Golf ball sized hail, wind gusts greater than 60 mph and a couple tornadoes will be possible with these severe thunderstorms. Heaviest rainfall is expected to fall along the west to east oriented front due to westerly steering winds in the area around 10 mph. A Low flood threat has been issued for this area with the main threats being street and small stream flooding along with lowland flooding.

The riverine Low flood threat continues for Saguache Creek, the headwaters of the and along the Rio Grande in Mineral and west Rio Grande Counties and for the San Antonio/Conejos Rivers in south central Colorado through Monday. Minor flooding continues to be reported by local emergency management over these areas. Elevated flows continue over the upper Arkansas River, but flooding is not anticipated unless there are some large releases from Pueblo Dam. Keep up to date with the release by following the NWS office in Pueblo. With cooler temperatures forecast going into this weekend, flow are forecast to begin to decrease. This should start to push gages below Action stage early next week.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. For Zone-Specific forecasts, scroll below the map.

 

Zone-Specific Forecasts:

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

Ongoing rainfall will continue today with the jet overhead and a stationary front in the area. Storms will increase to the south during the early evening hours as the jet begins to sag south. Max 2 to 3-hr rain totals up to 0.7 inches are possible over the Northern Mountains and Front Range with 0.5 inches elsewhere. 1-hour rain rates around 0.25 inches should keep the flooding issues at bay, but there may be increased runoff near the Lake Christine burn area. Isolated 24-hour totals up to 1.5 inches may be possible over the north central mountains with 4 to 10 inches of snow above 10K feet by Sunday morning along and near the Continental Divide.

Primetime: Ongoing to 9AM

Urban Corridor, Northeast Plains, Palmer Ridge:

Heaviest rainfall is expected to occur along the front today, which will rest across the Palmer Ridge. However, with the shortwave moving through, thunderstorm activity will be widespread across these regions. Max 1-hr rain rates up to 1.25 inches will be possible over the western portion of the threat with rates increasing to 1.5 inches over the eastern portion of the threat. Road and small stream flooding along with flooding of low laying areas will be possible. A severe storm or two over the Palmer Ridge will be capable of producing golf ball sized hail, severe wind gusts and a tornado or two. Further north and along the Urban Corridor, max 1-hr rain rates could reach 0.5 inches.

Primetime: 2PM to 10PM

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

Drier air will preside over these regions with southwest flow pulling in a dry air mass from Arizona and New Mexico. Dew points are forecast to be 20°F and lower. This will keep these regions mostly cloud free with a slight increase in cloud cover this afternoon over the San Juan Mountains. Temperatures over the eastern plains will be in the 90°Fs with 80°Fs in the mountain valleys. The cold front will move through overnight, so expect overnight temperatures to reach 50°F over the plains and 40°Fs in the valleys.