FTB 09-07-2017: Increased Rainfall Coverage over the Southeast and San Juan Mountains

Issue Date: Thursday, September 7, 2017
Issue Time: 09:55AM MDT

Flooding is NOT expected today

Haze will persist statewide through Friday. The heavier low-level smoke will continue to be over the northwest portion of the state. Most stations in this region are currently reporting haze with visibility around 9 miles. Visibility will continue to decrease throughout the afternoon especially near and southeast of the fires along the WY/CO border. Overnight and early this morning, some moisture has worked its way into the southwest corner of the state with southwest surface winds. This is currently producing light showers and cloud cover.

Northwest flow aloft will continue throughout the day. On the water vapor image below, there is a visible shortwave over WY that will work its way south. This extra upper-level energy is expected to enhance upslope flow along the southern mountains. Thus, shower and thunderstorm potential is more numerous than on Wednesday. Showers will move SE off the higher terrains, but are expected to quickly dissipate over the eastern plains. With Precipitable Water (PW) values up to 0.7 inches over the southern mountains, brief heavy rainfall may be possible with max 1-hr totals up to 0.5 inches. A fair amount of instability is expected to form with daytime heating, so stronger thunderstorms may produce gusty winds. Storms should end shortly 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:

Southeast Mountains, Raton Ridge, Southeast Plains, San Juan Mountains:

Partly cloudy this morning with more clouds burning off after sunrise. Shower and thunderstorm coverage this afternoon is expected to be more numerous with a passing upper-level wave. Max 1-hr rain rates up to 0.5 inches are possible. Flooding is not expected today.

Primetime: 1PM to 9PM

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

Sunny this morning becoming partly cloudy over the mountains this afternoon. Increased coverage of rain expected over the southern portions of the Front Range and Central Mountains. Max 1-hr totals up to 0.25 inches. Flooding is not forecasted today.

Primetime: 2PM to 8PM

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

Sunny and hazy this morning. Decreased visibility in the Northern Mountains and Northwest slope are likely this afternoon. Visibility will be reduced to the 6 mile range and may even be less near the fires along the CO/WY border.  Temperatures are expected to be persistent with highs 5-10F above climatology. Flooding is not expected today.

Primetime: 2PM to 8PM