Issue Date: Thursday, June 20th, 2019
Issue Time: 9:20AM 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 and Conejos Rivers in south central Colorado.

Taking a look at the water vapor imagery below, a relatively dry air mass remains over Colorado as indicated by the shades of yellow. The next system, currently over the Pacific Northwest, will begin to drop south today with the back of the jet sagging into Nevada. This will turn flow aloft from westerly to more southwesterly by this afternoon. As this transition occurs, winds will advect the drier air mass over AZ and NM into the southern half of Colorado, which should limit rainfall chances over this area. A couple light showers may form over the high terrains, but only trace amounts are forecast. Over northwest Colorado, a cold front will move through early this afternoon and help kick off thunderstorm activity. Expect trailing storms over the Northwest Slope and Northern Mountains this afternoon. Overnight rainfall is also anticipated over this area with favorable dynamics remaining over the region, so decent accumulations will be likely by tomorrow morning.

To the east, upslope flow will set off storms over the Front Range around 1PM. Additional convergence along the Palmer Ridge, due to a surface trough, will initiate some weak thunderstorms over this area as well. Expect the high-based storms to move west and then northwest with the flow aloft. Limited low-level moisture and fast steering winds will likely only produce moderate rainfall totals, so flooding is not anticipated. Over the Southeast Mountains, downsloping winds on the southwest side of the surface trough will keep rainfall limited to along and near the Continental Divide.

The 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. Minor flooding continues to be reported by local emergency management over these areas. Elevated flows continue over the upper Arkansas River, but flows are forecast to decrease east of Pueblo Dam. No AHPS gages are not forecast to rise above Action stage today.

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

Thunderstorms are forecast to be high-based this afternoon, which should limit the rainfall reaching the surface. Gusty winds may be possible along with small hail and dangerous cloud to ground lightning under the stronger storms. Highest rainfall accumulations for the day are anticipated over the northwest corner due to trailing storms and over the far Northeast Plains where better moisture remains intact. Storms over eastern Colorado should end by midnight. Flooding is not forecast, and max 1-hr rain rates are as follows:

Northwest Slope/Northern Mountains: 0.3 inches with 24-hour totals up to 0.8 inches over the Northern Mountains
Central Mountains/Front Range/Palmer Ridge: 0.1 inches
Northeast Plains: 0.5 inches

Primetime: 12PM to 9AM

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

Best chance for rainfall today will be over San Juan Mountains and Southeast Mountains near the Divide. With dew points dropping off to below 30°F, more cloud cover is anticipated than rainfall. However, a couple storms may produce a sprinkle or two. Skies will begin to clear overnight as the southwest winds pull in a very dry air mass from Arizona and New Mexico. High temperatures similar to yesterday will continue to melt the snowpack, so rivers will remain elevated again this afternoon. Flows are anticipated to drop off over the Arkansas, so the flood threat has been removed. Please follow your local NWS office for the latest on the riverine flooding threat over your area.

Primetime: 1PM to 7PM

Issue Date: Wednesday, June 19th, 2019
Issue Time: 9:15AM MDT

–A LOW flood threat is issued for the Arkansas River downstream of Pueblo Dam to La Junta, Saguache Creek, the Rio Grande in Mineral and west Rio Grande Counties and for the San Antonio and Conejos Rivers in south central Colorado.

Today, Colorado sits between two systems, which will give us a break from widespread, heavy rainfall. Overnight into this morning, flow aloft has been turning from westerly to northwesterly, which is expected to continue as the trough exits to the east. This has pulled in a drier air mass over the state (yellow below) and will continue to push the higher moisture to the east throughout the day. PW values at DIA were measured at 0.65 inches, which is a decrease of 0.25 inches from yesterday morning. Enough residual moisture will remain present for some afternoon storms over the mountains and eastern plains, but storms are expected to be more scattered in nature. The bulk of the storm activity today is forecast over the northern Urban Corridor and Northeast Plains thanks to a passing shortwave, an upper level jet moving into northern Colorado and initiation of storms along the Cheyenne Ridge and northern Front Range. With storm motion to the southeast at ~25 mph and dew points in the upper 40°Fs, heavy rainfall is not forecast. Lower dew points over the mountains should limit storm activity to the near and along the Continental Divide with a couple weak showers possible over the Southeast Mountains and adjacent plains. Brief gusty winds will be likely with storms today due to the high bases and inverted-V soundings. With the right exit region of the jet moving into northern Colorado by early this evening (sinking motion), storms should come to an end a couple hours after sundown. As anticipated, flooding is not forecast due to rainfall.

Flows continue to remain high over the same portions of river as the previous few days. Elevated flows continue for another day along the downstream of Pueblo Dam due to snowmelt, dam releases and rainfall, so the Arkansas from Pueblo to La Junta is under a Low flood threat for possible minor lowland flooding. The Low threat has also been re-issued for central Saguache County, the headwaters of the Rio Grande and Conejos County in south central Colorado. Minor flooding reports continue to be relayed to the NWS offices from emergency management. Gages are not forecast to rise above Action stage today.

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

High temperatures will also increase with a ridge sliding in from the north overhead. Expect temperatures to increase 7-10°F from yesterday afternoon. With storm motion from the northwest, storms that form over the mountains will likely move into the adjacent plains. Max 1-hr rain rates up to 0.2 inches (south) and 0.1 inches (north) are possible with these storms. Over the eastern plains, higher moisture will increase the efficiency of the rain rates. Max 1-hr totals of 0.4 inches are possible, which means there is no flood threat from rainfall today.

Primetime: 1PM to 9:30PM

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

Best chance for rainfall today will be over the northwest facing slopes of the high terrain. With a much drier air mass in place over western Colorado, expect rainfall totals to drop off drastically from the last two days. Isolated max 1-hr rain rates up to 0.1 inches are possible though most storms will only produce cloud cover and maybe some brief gusty winds. High temperatures will be slightly higher than yesterday, so be sure to get out and enjoy the beautiful weather. The Flood Warning for central Saguache County continues as well as for the headwaters of the Rio Grande and San Antonio/Conejos Rivers. Due to recent reports of minor flooding by emergency management, these areas have been given a Low flood threat. Please follow your local NWS office for the latest on riverine flooding threat over your area.

Primetime: 3PM to 8PM

Issue Date: Tuesday, June 18th, 2019
Issue Time: 9:35AM MDT

–A MODERATE flood threat is issued for the Palmer Ridge, and portions of the Urban Corridor and Southeast Plains. This includes the Arkansas River downstream of Pueblo Dam to La Junta.

–A LOW flood threat is issued for the Front Range, Urban Corridor, Southeast Plains and Northeast Plains. This includes the Junkins burn area. Additional LOW flood threats have been issued for Saguache Creek and the headwaters of the and along the Rio Grande in Mineral and west Rio Grande Counties.

Taking a look at the visible satellite imagery below, there is a lot of fog, cloud cover and some light rain over the Central Mountains to start the day. Some drier air has worked its way in from the west over the southwest corner. The moisture gradient (green lines, called isopleths) shows dew points have decreased to the low 40°Fs in this area, so clear skies over that region. The surface low, which is currently over the Oklahoma Panhandle area, continues to hold a very moist air mass in place over eastern Colorado. Westerly winds aloft will likely mix some of this moisture out and pull in lower dew points from west near the southern Southeast Mountains. This is similar to yesterday and should limit the heavy rainfall activity over the Raton Ridge area and keep the heavy rainfall threat limited to the foothills and eastern adjacent plains.

A vorticity max from the west (purple dashed line below) will help spark storm activity over the higher terrains by midday and help increase the coverage of storm activity. For western Colorado, highest accumulations will again be over the Northern and Central Mountains with lighter totals over the San Juan Mountains. Storms will likely track in from the west into the lower valleys (except the southwest corner), but flooding is not forecast for these storms. Emergency management reported flooding in the headwaters of and along the Rio Grande in Mineral and west Rio Grande Counties as well as along Saguache Creek. A Low flood threat has been issued for these Flood Warned areas.

As storms move west off the eastern high terrains, except another MCS to set up over the plains. Heavy rainfall, hail up to 1.75 inches, strong winds (greater than 60 mph) will be possible with the severe storms. Rainfall totals over the eastern border counties yesterday were quite high (see today’s SPM) and likely saturated soils; therefore, except increased runoff over these areas. Even with storm motion slightly faster than yesterday, heavy rainfall and flooding issues will still be likely with dew points over 50°F. PW values at DIA were measured at 0.91 inches (95^th percentile), which is a good indication heavy rainfall will occur again this afternoon. Flood threats include street, small stream/river and arroyo flooding along with field ponding. A Moderate threat has been issued for the Palmer Ridge, southern Urban Corridor and portions of the Southeast Plains. Gages continue to run high downstream of Pueblo Dam due to snowmelt and dam releases, so the Arkansas from Pueblo to La Junta is included in the Moderate threat due to the possibility of minor lowland flooding. A Low threat has been issued for all of eastern Colorado minus the Southeast Mountains and Raton Ridge. The Junkins burn area is included in the Low threat, so use caution if a storm tracks over this area as mud flows, debris slides and flash flooding will be possible.

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, Palmer Ridge, Urban Corridor, Northeast Plains, Southeast Plains, Northwest Slope:

Max 1-hr rain rates up to 1.3 inches are possible this afternoon in the Moderate threat area. Further north along the Urban Corridor, max 1-hr rain rates up to 1.1 inches are possible. Over the eastern plains, totals up to 1.5 inches are possible. While this normally wouldn’t be a threat, saturated soils from yesterday’s ran will increase runoff and the flood risk. Flooding risks today include urban flooding, street flooding, arroyo flooding and field ponding. Storms that track over the Junkins burn area should also be monitored closely as rain rates up to 0.9 inches are possible, which have been known to cause flash flooding and debris slides. A second set of storms is possible over the eastern mountains and Front Range later tonight, but flooding is not anticipated with these storms. Lastly, included in the Moderate flood threat is the area immediately downstream of Pueblo Dam (to La Junta) due to the AHPS gage remaining high throughout the day.

Primetime: 11AM to 3AM

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

Similar set up to yesterday with storms firing over the high terrains this afternoon. Once again, storms will also track into the lower valleys from the west due to increased mid-level energy in the area. Max 1-hr rain rates up to 0.7 inches (mountains) and 0.5 inches (valleys/west) are possible. Storms may linger over the Northern and Central Mountains tonight, with isolated morning totals up to 1.2 inches. Totals up to 0.15 inches is also possible over the northern portion of the San Luis Valley. The Flood Warning for central Saguache County continues as well as for the headwaters of the Rio Grande. Due to recent reports of minor flooding by emergency management, they have been given a Low flood threat. Please follow your local NWS office for the latest.

Primetime: 11AM to 3AM

Issue Date: Monday, June 17th, 2019
Issue Time: 10:25AM MDT

–A MODERATE flood threat is issued for the Northeast Plains and portions of the Urban Corridor, Palmer Ridge and Southeast Plains. An additional MODERATE flood threat has been issued for the Junkins burn area.

–A LOW flood threat is issued for the Front Range, Urban Corridor, Palmer Ridge, Southeast Mountains and Southeast Plains. An additional LOW flood threat has been issued for the Hayden Pass and Spring Creek burn areas.

—Riverine: A MODERATE flood threat is issued for the Arkansas River downstream of Pueblo Dam to Nepesta. A LOW flood threat continues through this afternoon for Saguache Creek just west of Saguache.

Busy water vapor imagery below to start the work week. Today, a trough will sit to our west once again with a surface low over eastern Colorado. The multiple shortwaves associated with the trough (marked in green) and surface low pulling in low level moisture over eastern Colorado has caused a cloudy, wet and foggy start to the morning. High moisture will remain intact over eastern Colorado thanks to the surface low pulling in high dew points from the south and east throughout the day. Expecting areas east of the white line below to have dew points in the low 50°Fs (west) and upper 50°Fs to 60°F (east) by this afternoon. Large PW values over the Northeast Plains and eastern Las Animas/Baca today will return the heavy rainfall threat for storms that track into this area. As storms form over the mountains early this afternoon, faster storm motion should limit the rainfall threat, thus there is only a Low flood threat to the west. Westerly winds over the south half of eastern Colorado will push the best moisture into the eastern portion of the Southeast Plains. However, enough moisture remains in place to cause issues for storms that track over recent burn areas. Thus, a Low flood threat has been issued for the Spring Creek and Hayden Pass burn areas. A Moderate threat has been issued for the Junkins burn areas as storms are expected increase their rain rates over this area.

As storms move east, slow steering winds, higher moisture and increased instability will create a favorable severe thunderstorm environment and storms will be capable of producing heavy rainfall. Initially, expect severe thunderstorms to produce large hail (up to 2 inches), strong winds and a tornado or two (northeast corner). By 6PM an MCS looks to form and hangs over the eastern plains through midnight along a convergence boundary. Therefore, high 2-3 hour rainfall totals will likely cause road and small river flooding over the Moderate threat area.

To the west, PW will also continue to increase with southwesterly flow aloft. Mixed with upper level disturbances passing through the area, rainfall should be widespread over this region as well. By early afternoon, forecasting numerous storms to form over the mountains with incoming storms from the west to bring precipitation to the lower valleys. Highest moisture remains over the north, but faster steering winds should prevent flooding. A few storms may linger through midnight over the northwest corner and Central Mountains, so isolated totals up to 1 inch are possible by tomorrow morning.

Riverine flooding continues for another day, although the flood threat is temporarily retreating. A Flood Warning continues for central Saguache County through 2PM this afternoon, so a Low flood threat has been issued for this area. With other Flood Warnings expiring over southeast corner of the state this morning and river levels dropping, increased flooding activity is not expected to be an issue. However, please continue to use caution as flows will remain elevated. A Moderate flood threat has been issued downstream of Pueblo reservoir to Nepesta where increased flows from releases and snow melt have kept the Avondale gage at Minor flooding.

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, Palmer Ridge, Urban Corridor, Northeast Plains, Southeast Plains, Northwest Slope:

Increased moisture and instability this afternoon will create a heavy rainfall threat for the majority of eastern Colorado. Westerly winds over the Southeast Mountains, should push higher moisture into the eastern portion of the Southeast Plains, but the threat remains for the burn areas. A Low threat has been issued for Hayden Pass and the Spring Creek burn areas with max 1-hr rain rates up to 0.5 inches possible. A Moderate threat has been issued for the Junkins burn area due to rain rates up to 1 inch possible.

Over the northern Urban Corridor and Palmer Ridge, max 1-hr rain rates up to 1.2 inches are possible, so a Low flood threat has been issued. Increasing rain rates over the Northeast Plains and eastern portion of the Palmer Ridge are likely due to increased moisture and slow storm motion. Storms may also produce large hail, gusty winds and a possible tornado. Max 1-hr rain rates up to 1.75 inches are possible. Expecting storms to form an MCS overnight, which may produce isolated totals up to 2.5 inches by morning. Threats today include field ponding, street flooding and small river flooding. 24-hr totals up to 1.75 inches over portions of the Northeast Plains yesterday, will likely increase runoff over these regions.

Lastly, a Moderate flood threat is issued for the area immediately downstream of Pueblo Dam (to Nepesta due to the AHPS gage remaining in the Minor flooding stage throughout the day.

Primetime: 12PM to 1AM

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

Increased cloud cover this morning with some light showers thanks to a passing upper level shortwave. Moisture will continue to be on the increase over the area with southeast flow aloft. Expecting storms to form over the mountains this afternoon with showers also tracking into the lower valleys from the west. Max 1-hr rain rates up to 0.75 inches (north) and 0.5 inches (south) are possible. Storms may linger over the northwest corner and Central Mountains tonight, with isolated 24-hour totals up to 1 inch by morning.

As of 9AM: The Flood Warning for central Saguache County continues through this afternoon. With decreasing flows forecast today, not thinking anything but a Low flood threat is needed at this time. Please follow your local NWS office for the latest.

Primetime: 12PM to 9AM