FTB 06-30-2017: Severe Storms for Southern Colorado

Issue Date: Friday, June 30, 2017
Issue Time: 11:00AM MDT

Low Threat for Southeast Plains and Raton Ridge

An upper level trough moved into CO from the north last night helping decrease temperatures across the state and increase moisture east of the Continental Divide. Over the western slope, temperatures will be about 5F cooler than climatology. Winds will also decrease lowering the fire threat for today.

East of the Continental Divide, overnight scattered showers accompanied the upper level trough over the Northeast Plains, leaving a moist, stable layer near the surface this morning. For example, the current temperature and dew point readings over Akron are 55F/52F. The ongoing scattered showers and cooler temperatures will limit the amount of instability for severe storms over the Front Range, Urban Corridor, Palmer Ridge and Northeast Plains. As pockets of clouds burn off midday, it will be possible for some instability to form. Therefore, scattered showers over the over higher terrain and the Palmer Divide are forecasted in this cloud-free environment. Rain rates up to 1” will be possible for the isolated thunderstorms that form.

Further south, adequate low-level moisture combined with upslope winds continue to support cloudy conditions this morning. However, warmer morning temperatures and strong June sun will cause this moisture to mix out earlier in the day. The clearer skies will allow for a band of instability this afternoon along the Southeast Mountains and Raton Ridge. High moisture paired with backing winds will create a favorable environment for strong to severe storms. The slow motion movement of the storms (15 kts) will cause rain rates up to 2 inches per hour. The severe storms that form could have hail up to 2 inches in diameter and 60 mph gusts. Storms are expected to diminish by midnight.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below (hover over threat areas for more details). For Zone-Specific forecasts, scroll below the map.

Flood Threat Legend

Zone-Specific Forecasts :

Southeast Plains and Raton Ridge:

 Partly cloudy this morning with sunny skies this afternoon. Daytime heating, low-level moisture and backing winds will provide an environment favorable for strong, slow-moving severe thunderstorms this afternoon. Rain rates up to 2 inches are possible as well as hail as large as 2 inches in diameter and 60 mph gusts. A Low flood threat has been posted for isolated flash flooding, debris slides and mud flows.

Primetime: 2PM to 1AM

Front Range, Urban Corridor, Palmer Ridge, Northern Mountains, Northeast Plains, Southeast Mountains, Central Mountains, San Luis Valley:

 Partly cloudy and cool for today with some light showers this morning. A few storms could develop where clouds dissipate early over the high country and Palmer Ridge. Max 1-hour rainfall up to 1 inch. Storms will begin to dissipate within a few hours of sunset.

Primetime: 3PM to 12AM 

Northwest Slope, Grand Valley, Southwest Slope and San Juan Mountains:

Sunny today with cooler temperatures. Decreasing winds will limit the fire danger for today. Temperatures will be 5F cooler than climatology.