Issue Date: Saturday, June 8th, 2019
Issue Time: 9:10AM MDT

–A LOW flood threat has been issued for potions of the Northeast Plains, Palmer Ridge and Southeast Plains.

–A LOW flood threat has been issued for portions of the San Antonio and Conejos Rivers, Rio Grande River near Del Norte and in southern Mineral County along highway 160 between mile markers 160 and 161 near Wolf Creek Pass.

The cold front from the approaching trough has moved into the northwest corner of the state. Temperatures this morning are in the 40°Fs over this area and then rise to 60°Fs over the Grand Valley (further south), which shows you the strength of the front. Today, the front will begin to drop south with a second, more powerful surge occurring overnight. Expect temperatures tomorrow morning statewide, to be similar to what is currently occurring over the Northwest Slope. Western Colorado will be lacking low level moisture once again today, so the best chance for trace amounts of accumulation will be over the Northern Mountains with clear conditions to the south.

This afternoon, expect storms to fire over the eastern mountains once again. With the first front semi-stalling over the northeast corner of the state, more low level moisture will be available over this area. Thus, storms are expected to have the most coverage over the Front Range. Some showers and weak thunderstorms will likely spill into the Urban Corridor late this afternoon. However, the best chance for storms over the Southeast Mountains will occur early tomorrow morning with post frontal upslope flow.

A secondary set of storms is expected to form over the eastern plains this afternoon associated with convergence along the dry line. Severe storms will be possible along the Kansas/Colorado border at the intersect of the Northeast Plains and Palmer Ridge regions. With quick storm motion, they should cross into Kansas relatively quickly and only drop only moderate rainfall accumulations. As the front makes its secondary surge overnight, a second set of severe thunderstorms will be possible over the Northeast Plains. With better low-level moisture and PW values over 1 inch, these storms will likely drop some heavy overnight rainfall. A Low flood threat has been issued for these thunderstorms. As mentioned above, also anticipating some weak showers and thunderstorms over the Urban Corridor, Front Range, Southeast Mountains and Raton Ridge areas late tonight with post frontal upslope flow.

A Low flood threat has also been issued for portions of the San Antonio and Conejos Rivers, Rio Grande River near Del Norte and in southern Mineral County along highway 160 between mile markers 160 and 161 near Wolf Creek Pass, which are currently under a Flood Warning through this weekend for 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:

Afternoon storms are expected to fire over the Front Range foothills early this afternoon with activity spilling into the Urban Corridor. Max 1-hr rain rates up to 0.3 inches (west) and 0.45 inches (east) are possible. Severe storms along a dry line are possible near the Kansas border. Threats include hail up to 1.5 inches, strong winds and moderate rainfall. A second set of storms with the surge of the cold front south will occur overnight. Severe storms will be possible again over the Northeast Plains with max 1-hr rain rates up to 1.75 inches possible. A Low flood threat has been issued with field ponding, road, arroyo and small stream flooding possible. Weak thunderstorms and showers will be likely over the mountains and adjacent plains this evening as well as the front drops south. For the most part, 1-hr rain rates will remain below 0.15 inches.

Primetime: 1PM to 2AM

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

Not much rainfall expected except a sprinkle or two over the Northern Mountains. However, another warm day for the southern portions of these regions mean runoff continues. A Flood Watch is in place for portions of the San Juan Mountains and San Luis Valley citing rapid snowmelt causing creeks, streams and rivers to run high and fast with minor flooding reports. The watch remains in effect through Wednesday morning. There are currently Flood Warnings for the following: portions of the San Antonio and Conejos Rivers, Rio Grande River near Del Norte and in southern Mineral County along highway 160 between mile markers 160 and 161 near Wolf Creek Pass. Areal Flood Advisories are issued for the following: Gunnison River above Grand Junction, Manco River near Mancos and the La Plata River at Hesperus. Several other flood statements can be found at NWS Pueblo. Follow them for the latest updates on the daily runoff and river stages.

 

Issue Date: Friday, June 7th, 2019
Issue Time: 8:45AM MDT

–A LOW flood threat has been issued for portions of the San Antonio and Conejos Rivers

As the next system starts to approach from the west, Colorado’s upper level flow turns more southwesterly this afternoon. This will help eject some mid-level energy seen the water vapor imagery below over the state (orange “X”). Paired with an incoming jet, extra upper dynamics should produce more widespread showers over the mountains this afternoon (when compared to yesterday) with activity transitioning into the adjacent plains by early afternoon. The one catch is moisture. To the west, low relative humidity values should keep the accumulation of rainfall along and near the Continental Divide with broken cloud cover elsewhere. A Red Flag Warning is in place for the Grand Valley and northern Southwest Slope as gusty surface winds from the approaching trough will produce relative humidity less than 15% and winds greater than 25 mph for a period greater than 3 hours.

There is a bit more moisture to the east, so storms will be more numerous over the Front Range and Southeast Mountains. However with high bases, not expecting much rainfall until they transition east of the green line below. A few severe storms are possible over the Northeast Plains and eastern Palmer Ridge area with large hail, strong winds and brief, heavy rainfall being the main threats. Max 1-hr rain rates will remain below flood threat criteria, so there is no flood threat issued. Expect the majority of the storms to end a couple hours after sundown, with a lingering weak thunderstorm possible through midnight due to the right entrance region of the jet moving into the area.

A Low flood threat has been issued for the San Antonio and Conejos Rivers, which are currently under a Flood Warning through Monday morning for 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:

Forecasting storms to begin to fire over the mountains early this afternoon and move into the adjacent plains with northeast movement by mid-afternoon. To the west, limited moisture will keep rain rates below 0.25 inches/hour. However, once the storms are able to reach east of 104°W, most moisture will increase rain rates and instability. Expecting max 1-hr rain rates up to 0.8 inches with isolated 24-hour totals around 1 inch possible over the Palmer Ridge/Northeast Plains intersect. Severe storms are also possible with strong gusts, hail up to 1.5 inches and local heavy rainfall being the main threats.

Primetime: 12PM to Midnight

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

Not a ton of moisture in this area, so rainfall will mostly be confined to near the Continental Divide over the Central Mountains with increasing cloud cover elsewhere this afternoon. Totals up to 0.4 inches will be possible, although 0.25-0.3 inches is a more likely range. A Red Flag Warning is in place through 9PM for the Grand Valley and northern Southwest Slope, so please use caution with any open flames.

The Low flood threat and Flood Warning by the NWS continues through Monday for portions of the San Antonio and Conejos Rivers with minor flooding forecast. Additional Areal Flood Advisories for the Gunnison River above Grand Junction, the La Plata River at Hesperus and for the Mancos River in Montezuma County for minor lowland flooding have been issued. These advisories will continue until further notice by the NWS. Minor flooding has not reported at any of these locations, although rivers remain at or slightly above bankfull, which makes the banks unstable.

Primetime: 1PM to 6PM

Issue Date: Thursday, June 6th, 2019
Issue Time: 9:00AM MDT

–A LOW flood threat has been issued for portions of the San Antonio and Conejos Rivers

With the low to south and east of Colorado, the state will sit between two systems today. This will allow a weak ridge to begin to build back over the state and high temperatures to increase a couple of ticks on the thermometer compared to yesterday. The water vapor imagery below shows drier air over and around the area, which is indicated by the shades of yellow. Expecting most of the current low level moisture to mix out throughout the day, which should limit the coverage of the afternoon storms. Storms will be mostly confined to the mountains this afternoon and evening with steering winds from the north. The main threats will be gusty winds, brief/moderate rainfall and lightning. There is some weak mid-level energy over western Utah, which may help spark a couple additional showers over the northwest corner of the state this afternoon and evening, but flooding is not forecast. A Low flood threat has been issued for the San Antonio and Conejos Rivers, which are currently under a Flood Warning through Monday morning for 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, San Juan Mountains, San Luis Valley, Northern Mountains, Central Mountains:

The bulk of the afternoon, diurnally driven storms will occur over the mountains. With a little better moisture to the east, expecting coverage today to be greatest over the Front Range, Southeast Mountains and eastern San Juan Mountains. Max 1-hr rain rates of 0.35 inches are possible with the stronger storms as well as small hail. Over the Central and Northern Mountains, rainfall will favor the north facing slopes with more limited coverage. Totals are expected to remain under 0.1 inches in these areas. A Low flood threat has been issued for portions of the San Antonio and Conejos Rivers with minor flooding expected over the next several days. The Flood Warning by the NWS has been extended through Monday morning.

Primetime: 2PM to 9PM

Raton Ridge, Palmer Ridge, Urban Corridor, Northeast Plains, Southeast Plains, Northwest Slope, Grand Valley, Southwest Slope:

With northerly storm motion, not forecasting rainfall over these areas this afternoon. The exception is over the Northwest Slope where some mid-level energy may spark some weak showers later this afternoon. With low dew points most storms will produce virga and brief gusty winds. Totals should remain under 0.05 inches. Some wrap around rainfall from the low may be possible over Baca Country this afternoon, but most of the latest model runs are keeping this rainfall east and south of the area. If these occur, expect totals (at most) to reach 0.3 inches.

Primetime: 3PM to 9PM

Issue Date: Wednesday, June 5th, 2019
Issue Time: 9:10AM MDT

–A MODREATE flood threat has been issued for the Spring Creek burn area

–A LOW flood threat has been issued for the Southeast Mountains, Palmer Ridge, Raton Ridge, Southeast Plains, portions of the Front Range and Urban Corridor, and the Junkins and Hayden Pass burn areas

–A LOW flood threat has been issued for San Antonio and Conejos Rivers

The aforementioned cutoff upper low begins to move eastward today, just south of Colorado’s border. Currently, the low can be seen in the water vapor imagery below centered over central Arizona/New Mexico. By late tonight, the low is forecast to be over the Texas panhandle. As the low moves to the east, it will start to pull in the high moisture values to the east of the green line below on its east and north side. This will increase dew points the most over the Southeast Plains, Raton Ridge, Southeast Mountains, Palmer Ridge and San Luis Valley as flow at the surface becomes more easterly early this afternoon. This morning PW was measured at 0.63 inches in the Denver sounding. The increase in upslope flow, low level moisture and slow steering winds will allow heavy rainfall to occur over the Southeast Mountains, Palmer Ridge and Raton Ridge this afternoon and evening with multiple rounds of rain possible. While moisture won’t be quite as deep over the Front Range and Urban Corridor, slow steering winds will allow more rainfall to accumulate and small hail may cause issues over populated areas. A Low flood threat has been issued for this area, and a Moderate flood threat has been issued for the Spring Creek burn area as last year, it only took 1-hour rain rates as low as 0.3 inches to trigger mud flows, debris slides and flash flooding. The Junkins and Hayden Pass burn areas should also be monitored closely for flash flooding/debris slides and fall within the Low flood threat.

Expecting storms to start firing west to east today over the mountains with the diurnal flow and approaching low increasing coverage of storms. The highest concentrations of showers and thunderstorms will be over the higher terrains favoring the peaks east of the Continental Divide and the San Juan Mountains. This also includes the Raton and Palmer Ridges. An isolated severe thunderstorm or two are additionally forecast over the Southeast Plains, which will be supported by the low moving to the east and a stronger convective environment. Even the San Luis Valley will be getting in on the action, which could cause already high rivers to produce minor flooding. A Low flood threat has been issued for the San Antonio and Conejos Rivers, which are currently under a Flood Warning through Thursday morning. Storms this afternoon and evening are expected to end around midnight with atmospheric cooling and subsidence behind the low. For more details, see the Zone-Specific forecasts below.

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

With an increase in low level moisture expected this afternoon along with favorable mid-level dynamics, widespread showers and thunderstorms are expected. Slow steering winds and continuous development will cause a Low flood threat for these regions. The threat has been extended to the Southeast Plains as a couple severe storms will be possible, which would be capable of producing 1.25 inch hail, strong winds and heavy rainfall. A Moderate flood threat has been issued for the Spring Creek burn area with the Junkins and Hayden Pass burn areas falling within the Low threat. Additionally, a Low flood threat has been issued for portions of the San Antonio and Conejos Rivers with rain expected over the San Luis Valley this afternoon and evening. A Flash Flood Watch is effect for the Southeast Mountains through this evening for recent burn areas. Max 1-hr rain rates are the following:

Southern Front Range, Southeast Mountains and Urban Corridor: 0.75 to 1 inch
Southeast Plains, Raton Ridge and Palmer Ridge: 1 inch (west) to 1.4 inches (east) with isolated 24-hr totals up to 2.2 inches over the SE Plains possible
San Luis Valley: 0.5 inches with 24-hour totals up to 0.75 inches

Primetime: 11:30AM to Midnight

Northern Mountains, Central Mountains, Northwest Slope, Grand Valley, Southwest Slope, Northeast Plains:

Not quite as much moisture or upper level dynamics affecting these areas. A few mountain storms could wander into the adjacent lowlands with southwesterly storm movement. Accumulations are forecast to be under 0.1 inches for these storms. Max 1-hr rain rates up to 0.2 inches (north) and 0.4 inches (south) are possible. Main threats will be gusty winds, small hail and lightning. Flooding is not forecast.

Primetime: 12PM to 11PM