FTB 09-05-2017: Cold Front Passage Brings Relief from the Heat

Issue Date: Tuesday, September 5, 2017
Issue Time: 10:05AM MDT

Flooding is NOT expected today

The passage of a cold front late yesterday afternoon and overnight has helped decrease the low-level haze as well as the temperature this morning for the eastern portion of the state. A thick stratus deck is present east of the Divide due to the moistening of the lower atmosphere with the passage of the cold front. This will provide relief east of the Continental Divide from the heat wave that has impacted the state the last few days. High temperatures today will be 15-20F lower than yesterday with cloudy skies expected most of the day. While smoke is still being advected into the state from the fires up north, it should be mostly confined to the mid- and upper-levels increasing visibility. West of the Continental Divide, haze will continue in the low-levels further north with the high pressure to the west. The shallow cold front was not able to penetrate the Continental Divide, so expect another day of warm temperatures.

In the wake of the cold front, more stable air has established itself in the eastern portion of the state. This should confine showers to the southern high terrain once again. Expecting showers to produce little in the way of rain, but gusty winds could accompany the stronger storms. Storms should quickly end around sundown this evening with low temperatures in the 30s for the higher terrains. There is no flood threat today.

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.

Zone-Specific Forecasts:

Southeast Mountains, Raton Ridge, San Juan Mountains, San Luis Valley, Southwest Slope:

Cloudy east of the Divide this morning becoming partly cloudy this afternoon. Showers and thunderstorms are expected to initiate this afternoon with the diurnal heating pattern and stronger storms will likely produce gusty winds. Max 1-hr rain rates up to 0.6 inches. Flooding is not expected today.

Primetime: 12:30PM to 8PM

Front Range, Urban Corridor, Northeast Plains, Palmer Ridge, Southeast Plains:

Mostly cloudy this morning with temperatures 15-20F cooler than yesterday. Reduction in low-level smoke is expected, but some haze is still likely. An isolated shower may form over the Front Range, but will only produce trace amounts of rain. Flooding is not expected today.

Primetime: 1:30PM to 8PM

Northwest Slope, Grand Valley, Northern Mountains, Central Mountains:

Sunny this morning with temperatures in the 90s over the lower elevations. Low-level smoke will continue to reduce visibility, especially north. An isolated showers may occur over the Central Mountains, but only trace amounts of rainfall are expected.

Primetime: 1PM to 8PM