Issue Date: 6/16/2019
Issue Time: 8:15 AM

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

Arkansas River at Avondale due to snowmelt

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

Arkansas River at Canon City due to snowmelt
Rio Grande in the San Luis Valley due to snowmelt
Portions of the Front Range, Urban Corridor, Palmer Ridge, and Northeast Plains

NOTE: Due to snowmelt, many streams/rivers are running fast/high across the state, especially in the High Country.

In the wake of a departing upper-level disturbance, Colorado finds itself under the influence of an ever-so-slightly cooler air mass that lacks the upper-level support for thunderstorms that was present the last couple of days. That’s not to say that today will be nothing but blue skies: scattered showers/thunderstorms are expected again today thanks to remnant moisture and sunshine that will provide enough instability for their development. Due to the lack of upper-level support, slightly cooler temperatures, and marginal wind shear, nearly all of the activity will be garden variety, producing mainly gusty winds and periods of light-to-moderate rainfall.

There is one area of concern for a couple stronger storms that will be capable of heavy rainfall, and this is outlined by the low flood threat area below. The presence of a weak surface boundary in the area will provide enough wind shear and surface convergence to force the development of a couple stronger thunderstorms over portions of the Front Range, Urban Corridor, and Northeast Plains. Hail up to 1.5 inches in diameter, strong winds up to 60 mph, and periods of heavy rain will attend these stronger storms. Storm motions *should* be quick enough to avoid flash flooding issues; however, the threat of training/backbuilding storms along the boundary is enough to warrant the low flood threat.

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 thunderstorms are expected over the Front Range, Urban Corridor, Palmer Ridge, Southeast Mountains, and Northeast Plains, with more isolated-to-widely scattered coverage over the Raton Ridge and Southeast Plains. Most of the activity will be garden variety, producing periods of light-to-moderate rainfall, gusty winds, and occasional lightning. A few stronger storms are expected in the low flood threat area outlined above, with the potential for hail up to 1.5 inches in diameter, winds up to 60 mph, and periods of heavy rainfall. Maximum rainfall rates are as follows:

Front Range: 0.6-1.0 inches/hour
Urban Corridor and Palmer Ridge: 1.0-1.5 inches/hour
Northeast Plains: 1.5-2.0 inches/hour
Southeast Plains: 0.5-1.0 inches/hour
Southeast Mountains: 0.2-0.4 inches/hour
Raton Ridge: 0.3-0.7 inches/hour

Timing: 11 AM – 11 PM over the Front Range and Southeast Mountains, 1 PM – Midnight over the Urban Corridor and Raton Ridge, and 2 PM – 2 AM over the Northeast Plains and Southeast Plains

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

Scattered showers/thunderstorms are expected today, with the best coverage along/near the Continental Divide. Most valleys will likely remain dry, owing to a relative lack of moisture in the lower levels of the atmosphere. Rain rates will generally be less than 0.2 inches/hour, but a stronger thunderstorm may produce rainfall up to 0.4 inches/hour. Storm motions are expected to be quick enough to the east to avoid any flood threat.

Timing: 11 AM – 10 PM, with a few lingering showers into the early morning hours as the next upper-level disturbance approaches.

Issue Date: 6/15/2019
Issue Time: 9:00 AM

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

Arkansas River at Canon City due to snowmelt
Arkansas River at Avondale due to snowmelt
Rio Grande in the San Luis Valley due to snowmelt
Portions of the Southeast Mountains, Raton Ridge, and Southeast Plains, mainly for the following burn scars: Hayden Pass, Junkins, Buelah Hill, and Spring Creek.
Portions of the Front Range, Urban Corridor, and Palmer Ridge regions.

A weak disturbance aloft will shift east-northeast across the southern and Central Rockies today, providing broad upper-level support for scattered showers and thunderstorms across Colorado. All regions are expected to see some shower/storm coverage, but the greatest amount of activity will be over the Southeast Mountains, Raton Mesa, and Southeast Plains, where the best upper-level support and moisture coincide. Most activity will be garden-variety, producing periods of light-to-moderate rainfall and gusty winds. However, a few strong-to-severe storms will develop over the Southeast Mountains, Raton Ridge, and Southeast Plains, capable of periods of heavy rainfall, gusty winds up to 60 mph, and hail up to 1-1.75 inches in diameter. A special forecast discussion for the Spring Creek, Junkins, and Hayden Pass Burn Areas is below.

Spring Creek, Junkins, and Hayden Pass Burn Areas: Scattered showers and thunderstorms are expected to develop over the Southeast Mountains between 11 AM and Noon, continuing until 9-10 PM. Most rainfall will be light-to-moderate, as instability is fairly limited. However, during peak daytime heat (approx. 2 PM – 6 PM), one or two stronger thunderstorms will develop over the region. Should one of these storms move over a burn scar, flash flooding will be likely with maximum rain rates around 0.8-1.2 inches/hour. These scars should be monitored closely.

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 showers/thunderstorms are expected, beginning during the late morning hours over the Front Range and Southeast Mountains, eventually spreading east over the lower elevations by 2 PM or so. Most of the activity will be garden variety, producing periods of moderate rainfall, gusty winds, and occasional lightning, but a few storms will become strong-to-severe, with attendant periods of heavy rainfall. Maximum rain rates are as follows:

Front Range and Southeast Mountains: 0.8-1.2 inches/hour
Urban Corridor and Palmer Ridge: 1.0-1.5 inches/hour
Northeast Plains and Southeast Plains: 1.25-1.75 inches/hour
Raton Ridge: 0.5-0.9 inches/hour

Most showers/storms will come to an end by 9-10 PM, but a few will linger over the Southeast Plains until Midnight – 1 AM.

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

Scattered showers and garden-variety thunderstorms are expected today, with the best coverage south of I-70. Periods of light-to-moderate rainfall and gusty winds will be the main impacts, with occasional lightning and small hail attending the stronger, relatively speaking, storms. Showers/storms will begin to develop between 10 AM – Noon over the higher terrain, spreading over lower valleys with time, with most activity coming to an end by 9 PM. A couple isolated showers will continue until midnight or so. Rain rates will generally be less than 0.2 inches/hour, with maximum rates of 0.25-0.5 inches/hour possible.

Issue Date: Friday, June 14th, 2019
Issue Time: 9:35AM MDT

–A LOW flood threat is issued for the Arkansas River at Canon City, Saguache Creek just west of Saguache, Southwestern Rio Grande County/Mineral County (particularly Del Norte) and the Dolores River below Rico

Shallow low level moisture will persist over the state today under northwesterly and westerly flow aloft. The axis of a broad, weak trough can be seen in the yellow dashed line below. Expect this feature to slowly move west throughout the day, which should turn the upper level flow more westerly this afternoon. This will likely set up another dry line over the eastern plains and push the best moisture to our east; thus, limiting the flood threat. Better moisture to the north, seen in the image below associated with another shortwave, will provide more rainfall over the northern half of Colorado.

Diurnal flow along with mid-level dynamics will combine once again this afternoon to kick off storms over the Northern Mountains, north Central Mountains and Front Range (near the Divide). Additional storms will be likely over the Northeast Plains/Palmer Ridge and Northwest Slope as storms move in from the west. High bases and limited moisture over the Southeast Mountains and adjacent Southeast Plains should keep accumulations limited to the far eastern counties. A few storms may continue through midnight over the northern high terrains, but flooding is not expected from rainfall today.

High temperatures continue to rise for today, which will begin to push more gages into Minor and Action stages across the San Juan Mountains, San Luis Valley and upper Arkansas River. A Flood Watch remains in place that covers the Dolores River below Rico, San Luis Valley and eastern San Juan Mountains and will last through this weekend. A Low flood threat has been issued for the Arkansas River at Canon City, Saguache Creek just west of Saguache, Rio Grande River near Del Norte and Southwestern Rio Grande County/Mineral County today. An additional Flood Warning and Low flood threat is issued for the Dolores River below Rico as flow reaches bankfull. This should cover current Flood Warnings issued by NWS (as of 9AM). For the latest, tune into NWS Pueblo and Grand Junction.

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:

Northern Mountains, Central Mountains, Front Range, Palmer Ridge, Urban Corridor, Northeast Plains, Southeast Plains, Northwest Slope:

Warmer high temperatures are forecast to increase a couple of degrees again today. Storms will form over the northern mountains early this afternoon favoring development west of the Continental Divide. A secondary set of storms is forecast for the Palmer Ridge/Northeast Plains. Max 1-hr rain rates up to 0.75 inches are possible over both areas. Storminess will also increase over the Northwest Slope again as storms move in from the west. Max 1-hr rain rates up to 0.2 inches are possible. A stronger thunderstorm or two is possible near the Colorado/Kansas border, so severe hail, gusty winds and 0.9 inches of rain may be possible, but flooding is not forecast. Overall, the main threats today will be lightning, moderate rainfall and gusty winds.

Primetime: 1PM to Midnight

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

Main concern this afternoon will be warm temperatures increasing melting rates once again. A couple high-based storms are possible over the mountains, but accumulations are expected to remain under trace amounts. Thus, only forecasting an increase in cloudiness this afternoon.

As of 9AM: The Flood Watch mentioned above continues for the San Juan Mountains and San Luis Valley. A Low flood threat (and NWS Flood Warning) has been issued for the Arkansas River at Canon City, Saguache Creek just west of Saguache, Southwestern Rio Grande County/Mineral County (particularly Del Norte) and the Dolores River below Rico. Current Areal Flood Advisories have been issued for the following rivers: Gore Creek at Vail, Crystal River near Redstone, flows along the Navajo, Little Navajo and Rio Blanco Rivers in Archuleta County, Colorado River near the CO/UT state line, Gunnison River above Grand Junction, Tomichi Creek at Gunnison, East River at Almont, San Juan River at Pagosa Springs, Mancos River near Mancos, Los Pinos River near Bayfield (La Plata County), La Plata River at Hesperus, Eagle River near Gypsum and at Red Cliff, Animas River at Durango and Williams Creek upstream from Lake Cristobal (Hinsdale County).

Issue Date: Thursday, June 13th, 2019
Issue Time: 9:25AM MDT

–A LOW flood threat is issued for the Arkansas River at Canon City, Saguache Creek just west of Saguache, Rio Grande River near Del Norte and Southwestern Rio Grande County/Mineral County

Flow will shift from more northerly to westerly throughout the day with the approaching broad and weak trough. This has started to pull more low level moisture back into the state as seen in the water vapor imagery below. With increased moisture, mid-level energy moving in from the northwest and a weak just over eastern Colorado, expect an increase in shower and thunderstorm coverage this afternoon. By early afternoon storms will kick off over the mountains and quickly spread into the adjacent plains. Storm activity will also increase over northwest Colorado with storms moving into the area from the west. Gusty winds, light rainfall and lightning will be the main threats for western Colorado and the mountains. The westerly flow will set up a dry line over the plains, which would push the heaviest rainfall to our east. However, as storms move into the eastern plains, dew points in the 40°Fs will likely increase the efficiency of the rain rates. A severe storm may be possible over the far southeast corner of the state; however, the latest model runs are pushing the best parameters into the Oklahoma and Texas Panhandles. With support from the jet, weak thunderstorms may continue over the plains and northern high terrains through midnight with activity elsewhere decreasing a couple hours after the sun sets.

High temperatures increase a couple of ticks on the thermometer this afternoon. Thus, the flooding threat for the San Juan Mountains and San Luis Valley continues. The current Flood Watch covers the Dolores River below Rico, San Luis Valley and eastern San Juan Mountains and will likely last through this weekend. A Low flood threat has been issued for the Arkansas River at Canon City, Saguache Creek just west of Saguache, Rio Grande River near Del Norte and Southwestern Rio Grande County/Mineral County today, which covers the Flood Warnings issued by NWS (as of 9AM). For the latest, tune into NWS Pueblo and Grand Junction.

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, Northern Mountains:

Warmer high temperatures are forecast today by a couple of degrees. Storms will form over the mountains early this afternoon and quickly spread into the adjacent plains. Coverage will be more widespread as some mid-level energy and increase in low level moisture combine. Expecting rain rates between 0.1 and 0.2 inches over the mountains and adjacent plains. Over the far eastern plains, 1-hour totals up to 0.6 inches are possible with isolated totals of 0.75 inches over the far Northeast and Southeast corners. Flooding from rainfall is not expected.

Increased flows over the Arkansas west of Pueblo will also be monitored closely over the next couple of days as gages are starting to move into Action stage. The gage at Canon City will likely move into the Minor flooding stage as early as tomorrow morning. The Arkansas gage near Avondale continues to decrease as the releases from the dam have ended for now. Please tune into your local NWS office for the latest on flood warnings, advisories and statements as they can change throughout the day.

Primetime: 2PM to Midnight

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

Slight increase in moisture with the northwest flow will allow for some weak showers and thunderstorms in the forecast today. The air mass is still relatively dry, so storms will be high-based and may produce some gusty winds with lightning. Max 1-hr rain rates up to 0.25 inches are possible over the Northwest Slope, but further south, expect storms to produce between 0.05 and 0.15 inches. Activity should decrease around 9PM with a couple light showers possible over the Northwest Slop through 11PM.

As of 9AM: The Flood Watch mentioned above continues for the San Juan Mountains and San Luis Valley with the addition of the Dolores River below Rico. A Low flood threat (and Flood Warning) has been issued for Saguache Creek west of Saguache, the Rio Grande near Del Norte and for western Rio Grande and Mineral Counties. Current Areal Flood Advisories issued for the following: Eagle River near Gypsum and at Red Cliff, East River at Almont, Colorado River near the CO/UT state line, Mancos River in Montezuma County, San Juan River at Pagosa Springs, Los Pinos River near Bayfield (La Plata County), La Plata River at Hesperus, Animas River at Durango, Gunnison River above Grand Junction, Tomichi Creek at Gunnison and Williams Creek upstream from Lake Cristobal (Hinsdale County).

Primetime: 2PM to 11PM