FTB 06-03-2020: Drying Trend Continues with High-Based, Afternoon Thunderstorms Forecast

Issue Date: Wednesday, June 3rd, 2020
Issue Time: 9:45AM MDT

— Flooding is NOT expected today

Below is the low-level water vapor imagery, and it’s noteworthy that not much moisture looks be trapped under the ridge over the state. This is indicated by more yellow than blue/white. Westerly flow aloft continues over the majority of the state today as the ridge builds northward, which will help further mix out low-level moisture and help set up a dryline (area of convergence) over the far eastern plains. There is also some mid-level energy noted in the image below (orange “X”). One is to our north, and the other further south. The one to our north may help spark some additional thunderstorms over the Cheyenne Ridge that will likely spill into the Northeast Plains with the clockwise steering winds around the High, and it will help set up the dryline over the Northeast Plains. The other shortwave further south may help spark better thunderstorm coverage over the eastern San Juan Mountains and Southeast Mountains/Raton Ridge than there would otherwise be with the diurnal flow pattern. Storms that form over the mountains and Palmer/Raton ridges will move westward with the steering flow.

Coverage of storms will decrease this afternoon due to the increased dryness, and storms that do form are expected to be high-based with the lower dew points. The large difference in temperature and dew points (dew point depression) means gusty outflow winds will be the main threat from storms. Slightly faster steering flows will also limit the amount of rainfall over an area. Higher accumulations are expected further west along the dryline that sets up, but only moderate rainfall is anticipated. Therefore, flooding is not expected today.

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, Southeast Mountains, San Juan Mountains, Raton Ridge, Palmer Ridge, Southeast Plains, Urban Corridor, & Northeast Plains:

Over the mountains, storms will favor areas south and east of the Continental Divide. Additionally, storms are anticipated to form over the southern Front Range Mountains, Palmer Ridge and Raton Ridge. Activity will likely spill into the adjacent plains with the westward motion. Max 1-hour rain rates up to 0.25 inches will be possible under the stronger storms with gusty outflow winds being the main threat from storms this afternoon and evening.

There will likely be a couple areas of rainfall over the Northeast Plains as storms this afternoon initially form along a moisture boundary. Max 1-hour rain rates up to 0.75 inches will be possible over Phillips, Yuma, and Kit Carson County along with severe hail. Then, additional storms may be possible in the region as storms that form north rotate south around the high. Max 1-hour rain rates for those storms will drop to 0.50 inches. Mid-level energy may bring some lighter rainfall to the Southeast Plains this evening, and totals should remain under 0.25 inches.

Primetime: 1PM to 11PM

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

A bit too dry for widespread coverage of afternoon storms, but the passing shortwave to the north may provide a little extra moisture to the northern border. Inverted-V sounds indicated strong outflow winds will be possible with storms that do fire over the Northern Mountains, northern Central Mountains, and Northwest Slope this afternoon. Elsewhere it’s going remain dry and hot with high temperatures similar to yesterday.

Primetime: 1PM to 9PM