FTB 09-15-2017: Cold Front Passage Will Bring Relief from Heat

Issue Date: Friday, September 15, 2017
Issue Time: 10:10 AM MDT

— Flooding is NOT expected today

The system that moved through the state yesterday can currently be seen over WY in the water vapor imagery below. The SW winds associated with the dry slot of the trough will remain over the majority of the state today. This drying will give us a break from the rainfall with the exception of the Northwest Slope and portions of the Northern Mountains. Moisture will remain over this area as it wraps around the low pressure system.

Later this afternoon and evening, a cold front will move through the state and cool temperatures closer to climatology for tonight and tomorrow. The first two weeks of September have been abnormally warm with temperatures over portions of the Central Mountains reaching up to 10F above climatology. More detailed information on the temperature trends can be found in the Flood Threat Outlook. The passing cold front will initiate showers and some snow (at higher elevations) for the Northwest Slope and portions of the Northern Mountains. While the eastern portion of the state is expected to remain dry, the passage of the cold front may slightly increase low-level moisture and produce enough lift for an isolate storm. Storms will produce gusty winds and are not expected to last long in the unfavorable environment. All storms are expected to come to an end a couple hours after sundown.

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:

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

Sunny throughout the day. An isolated shower or thunderstorms may be possible this evening with the passing cold front. Lack of low moisture will cause storms to produce gusty winds and be short-lived in duration. Precipitation amounts are expected to be under 0.1 inches. Flooding is not expected today.

Primetime: 4PM to 10PM

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

Partly cloudy with light showers over the northwest corner this morning as moisture wraps around the trough. Other than the Northwest Slope and Northern Mountains, showers are not expected today. Expect increasing clouds over the higher terrains this afternoon. 24-hour rainfall totals could be up to 0.8 inches (north) with some snow at higher elevations. Flooding is not expected today.

Primetime: 12PM to 11PM