FTB 09-27-2020: Scattered Showers Possible (East) as Another Cold Front Pushes South

Issue Date: Sunday, September 27th, 2020
Issue Time: 9:10AM MDT

— Flooding is NOT expected today

In the water vapor imagery below, the cold front that moved through last night can be seen in blue. The northerly wind shift during the evening hours made for some hazy conditions across the Urban Corridor/Front Range, but cleared out the near surface smoke over northwest Colorado and the eastern plains. Behind that front and with another incoming front, cooler high temperatures are expected today. Except over the southwest corner, where highs will be similar to yesterday.

Precipitation chances will increase slightly today as a strong shortwave (orange “X”) and associated front digs southward. This will increase north/northwesterly flow, and the tightening temperature gradient will produce a narrow band of light, scattered showers beginning by midday (north). As this band of scattered showers moves southward, expect most of the precipitation to fall over the lower elevations of eastern Colorado. Some isolated, light rain may occur over the foothills with a brief rain/snow mix possible over the northern Front Range. With PW measured at 0.65 inches in Denver this morning, relatively low dew points, and limited instability, the highest totals are forecast to be under 0.20 inches. So, flooding is not forecast.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. If there is a threat, 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:

Front Range, Palmer Ridge, Urban Corridor, Southeast Mountains, Raton Ridge, Southeast Plains, & Northeast Plains:

Much cooler high temperatures are expected today, and the Northeast Plains/Palmer Ridge/Urban Corridor will likely only reach into the mid 60Fs. 70Fs are forecast over the lower elevations south of the Palmer Ridge. Over the mountain valleys, highs will only reach into the 50F. Windy conditions are forecast over the mountains and plains as the front moves through and strengthens. Gusts up to 40 mph will be possible, but cooler temperatures and higher relative humidity values means there is no Red Flag Warning issued.

Best chance for measurable rainfall will be over the lower elevations as scattered showers move across the northern border. As this feature moves south and the front tightens, a narrower band of scattered showers is expected (Palmer Ridge). Generally, totals will be between 0.10 and 0.15 inches. A brief light rain/snow mix will be possible over the northern Front Range, and it looks like the Southeast Mountains may get some light rainfall accumulations this evening. Flooding is not forecast.

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

Windy conditions continue for these zones this afternoon, and the mountain zones could see gusts from the north up to 50 mph. The decreasing temperatures and slightly higher relative humidity values will limit the fire danger, so there is No Red Flag Warning issued. No precipitation is forecast west of the Continental Divide due to PW under 0.50 inches and a very dry surface layer. Scattered clouds will be likely today with overcast conditions forecast by tomorrow morning. Highs will be in the 50Fs and 60Fs, expect over the Grand Valley and Southwest Slope where highs will reach into the 70Fs.