Issue Date: Tuesday, July 2, 2019
Issue Time: 11:00 AM MDT
– A LOW flood threat is issued for the Front Range, Southeast Mountains, Urban Corridor, Raton Ridge, Palmer Ridge, and portions of the Central Mountains, Northeast Plains, and Southeast Plains. Included in the threat are the Spring Creek and Junkins burn areas.
– A LOW flood threat is issued for the Eagle River near Gypsum, Arkansas River between Avondale and La Junta and the Crystal River near Redstone
Rainfall returns today after two active days with a Low flood threat issued. Upper level flow has shifted to the west southwest with the breakdown of the ridge. Thus, flow will continue to be more zonal today. A shortwave and surface low pressure system over southern Wyoming will move east with the flow, and will help advect moisture north throughout the day. Storm generation will be due to diurnal heating and upslope flow, with most storms peak intensity midafternoon over the southern Front Range.
Surface moisture remains high statewide, which will allow for some heavy rainfall once again. While there is a slight decrease in moisture, fairly slow steering winds and antecedent moisture from the last two days should increase runoff. This is especially true near the Spring Creek burn area and over the lower Arkansas River between Avondale and La Junta, which is already running high due to dam release. Thus, there is a Low flood threat issued over these areas. Storm motion will be to the east southeast at 15-20 mph, which could allow for decent accumulation under a couple storm cores, although storm coverage will decrease from yesterday. Dew points over the eastern plains this morning measured in the 60°Fs and mid to upper 50°Fs, with PW values up to 1.3 inches over the southeast corner (green lines below). Morning and early afternoon cloud cover will limit temperatures from increasing above 90°Fs over the plains and help keep the area capped when it comes to strong convection. West of the Continental Divide, dew points measure in the mid to upper 40°Fs. With slightly lower dew points, and high pressure overhead, rainfall will be limited to weak afternoon thunderstorms.
Remnants of the low pressure system that effected the plains yesterday remains over the far eastern edge of the state, with a stationary front spanning to the east along the Palmer Ridge. Storms are forecast to initiate along this boundary early in the afternoon. A low pressure system over the CO/WY border is providing lift along a dry line (orange line) with precipitation currently over the Grand Valley and Central Mountains.
Flood threats today from rainfall include flooding of small streams (especially at higher elevations where they are already running high), roads and low lying areas. Over the high country, mud flows and debris slides may be possible over the Spring Creek and Junkins burn scars if storms track into the area. Elevated flows continue at high elevations along the Eagle River at Gypsum, the Crystal River near Redstone, as well as the Boulder Creek at Nederland and Orodell. Due to saturated soils, streams and creeks in the high country may rise rapidly if a storm tracks into the area. This may cause some minor flooding issues and destabilize banks, so please use extreme caution. Be sure to follow your local NWS office for the latest flood warnings and advisories as they will be updated throughout the day.
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, Urban Corridor, Southeast Mountains, Raton Ridge
Early afternoon thunderstorms are anticipated due to upslope flow and high moisture over the area. Max 1-hour rainfall rates of up to 1 inch will be possible over the southern Front Range, with rates approaching 0.75 inches over the Southeast Mountains. This may cause flooding issues for the Spring Creek and Junkins burn areas. Moderate rain rates from more general storms could lead to flooding due to the saturated surface. Easterly and Southeasterly winds will push storms over the adjacent plains midafternoon. A Low flood threat has been issued over the area.
Primetime: 1PM to 12AM
Northeast Plains, Palmer Ridge, Southeast Plains
High levels of surface moisture this morning combining with upslope flow will cause thunderstorms that track into the area to produce some decent accumulations. . Storms are expected to move off of the mountains over the plains midafternoon. Additionally, lift will be enhanced over the Cheyenne Ridge due to the surface low passing to the north, so some storms may drift into the Northeast Plains along the northern border. Max 1-hour rain rates of 1.5 inches may be realized over the Low threat area, but rain rates over the far eastern border should remain below flood threat criteria with the cloud cover taking a while to burn off. Flows remain high along the Arkansas River from Avondale to La Junta from releases and rainfall yesterday, which may cause flooding of low lying areas. Storms should come to an end by 2AM, thus ending the flood threat.
Primetime: 3PM to 2AM
Northern Mountains, Central Mountains, San Luis Valley, San Juan Mountains, Southwest Slope, Grand Valley, Northwest Slope
While low level moisture is decreasing over the area, there should be enough antecedent moisture present for afternoon storms over the high country. Upslope flow is forecast to trigger isolated thunderstorms this afternoon favoring the San Juan Mountains and Central Mountains. Max 1-hour rain rates up to 0.4 inches may be possible over the San Juan Mountains and Central Mountains with 1-hour rain rates decreasing over the Northern Mountains to 0.25 inches. A little faster storm motion should keep the flood threat at bay over the 416 burn area, but use caution if storms track over the burn scar. High flows along the Eagle River near Gypsum and Crystal River near Redstone has prompted a Low flood threat for the area as storms that track over these areas may cause some minor flooding issues.
Primetime: 2PM to 8PM
