FTB 08-12-2020: High Fire Danger Continues with Severe Storms Returning to the Northeast Plains

Issue Date: Wednesday, August 12th, 2020
Issue Time: 10:30AM MDT

— Flooding is NOT expected today

Today will be similar to yesterday’s setup as dry air remains anchored over the western 2/3rds of the state. With the high pressure ridge to the south of Colorado, dry air over southern Utah will continue to flow into western Colorado and spread eastward. Meanwhile, a trough is moving into the Pacific Northwest, which is increasing the height gradients and upper-level winds over the western US. The combination of dry air and gusty surface winds will once again create elevated fire danger for western Colorado today, so a Red Flag Warning has been re-issued for the Grand Valley, Southwest Slope, Northwest Slope, and Central Mountains.

Some surface moisture has banked its way up against the foothills and over the plains of eastern Colorado due to outflow from last night’s storms. This has increased surface dew points into the 50Fs for much of the plains, as indicated on the image below. However, soundings show this moisture is quite shallow, so it should have no problem mixing out from west to east with diurnal heating. Weak showers and a few isolated storms are still expected to fire over the Continental Divide this afternoon, and could produce some gusty winds again as they dissipate across the Urban Corridor. With slightly higher moisture and instability east, storms that can make it into the Northeast Plains should strengthen, and a couple severe thunderstorms could develop with moderate wind shear in place. The severe storms could create strong outflow winds and severe hail as well. Due to moderate upper-level flow, storms should be moving east fairly quickly, and with a little less moisture available than yesterday, flooding is not expected today.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. Hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.

Zone-Specific Forecasts:

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

Strong storms are possible over the northeast corner of the state later this afternoon. Max rain rates up to 1.4 inch are possible under the stronger storm cores, but quick storm motions decrease the chances for flooding. Gusty outflow winds up to 60 mph and severe hail up to 1.5 inch in diameter could accompany the strongest storms.

Little to no chance for storms over the Southeast Plains and Urban Corridor, but as storms move off the higher terrain, they could produce some gusty downbursts. Higher chances of storms and clouds exist farther north.

Primetime: 12PM to 9PM

Grand Valley, Northwest Slope, Northern Mountains, Central Mountains, Southwest Slope, San Juan Mountains, San Luis Valley, Southeast Mountains, & Front Range:

Guidance is showing a higher chance for some storms over the high terrain this afternoon. Unfortunately, without much moisture, they will most likely produce only gusty outflow winds. With the hot and dry conditions continuing, along with wind gusts 30+ mph, a Red Flag Warning has been re-issued along the northwest portion of the state. Keep up to date on wildfire-related road closures (https://cotrip.org/home.htm) and evacuations from their social media pages (linked below). Smoke from the wildfires will also impact air quality for the central and northern mountains and valleys, especially overnight.

Pine Gulch Fire: https://www.facebook.com/PineGulchFireCO
Grizzly Creek Fire: https://www.facebook.com/GrizzlyCreekFireCO