FTB 06-27-2020: Another Round of Scattered Storms Expected for Southern Colorado

Issue Date: Saturday, June 27th, 2020
Issue Time: 8:55AM MDT

— Flooding is NOT expected today

Taking a look at the visible satellite imagery below it’s a beautiful start to the morning across the state for as much rain and severe weather as we had yesterday. As far as the synoptic set up, not much has changed. The entirety of the shortwave trough (red “L” and orange “X’s”) will push eastward through Colorado today as the next, anomalously strong Low moves inland over the Pacific Northwest. This will allow for another round of widespread, scattered storms this afternoon that should initiate over the mountains by early afternoon. Storm motion will continue to be westerly/southwesterly with flow aloft shifting to the northwest tonight as the trough moves as the trough begins to influence the state. This more westerly/southwesterly flow aloft has scoured out a lot of the low-level moisture that filled in behind the cold front yesterday and will continue to do so throughout the day, so storms are expected to be less widespread and have higher bases. This will limit their rain rate efficiency and cause storms to produce more gusty winds than wetting rainfall. With dew points less than 40F (minus the far eastern border), flooding from thunderstorms is not expected.

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:

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

Storms will favor convective initiation further south today, so that means the Southeast Mountains, Palmer Ridge, and eastern Raton Ridge. Expect less storm coverage over the Front Range/adjacent Urban Corridor. As storms move off the mountains, expect some very strong outflow winds due to the dry boundary layer. If storms are able to stay intact and make it a little further east, they should strengthen a bit in the moister environment. However, quick storm motion and relatively dry low-levels should keep the flood threat away today. Max 1-hour rain rates up to 0.15 inches (west) and 0.75 (east) will be possible. Damaging outflow winds are once again expected along with severe hail under the stronger storms. Best chance for those higher rain rates will be over southern Yuma County, Kit Carson County, northern Cheyenne County, and northern Lincoln County.

Primetime: 1PM to 10PM

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

Best chance for storms to produce rainfall today will be over the high terrains in the southwest corner and near the Continental Divide as the shortwave (slightly higher moisture content) slides across the southern border. Localized max 1-hour rain rates up to 0.20 inches (south) and 0.10 inches (north) will be possible. Dry thunderstorms this afternoon will pose a threat for fire danger as dew points drop off into the 20Fs. This will also allow storms to continue to produce very strong outflow winds. Gusts between 50 and 60 mph should be expected once again after looking at this morning’s sounding (coming from the stronger storms). Additionally, a Red Flag Warning has been issued for the San Luis Valley. Expect westerly winds in the 10 to 20 mph range with gusts up to 35 mph.

Primetime: 1PM to 8PM