FTB 05-01-2021: Another Warm Day with Isolated Rainfall for the High Terrains

Issue Date: Saturday, May 1st, 2021
Issue Time: 9AM MDT

— Flooding is NOT expected today

The 2021 FTB season is officially under way! Welcome back, and we appreciate the opportunity to serve you this flood season.

The water vapor imagery shows Colorado pinched between two systems this morning (orange X’s). With the ridge still overhead for most of the day, warm temperatures are expected to continue statewide. As the system from the west approaches the state later today into tomorrow, more moisture and slight lift will become available. So, expect an increase in cloud cover from west to east throughout the day across the state. Soundings indicate that most of the moisture today will be located in the mid to upper levels of the atmosphere. This paired with the dry lower layer of the atmosphere indicates gusty outflow winds will be possible with the isolated storms that develop over the mountains this afternoon and evening. Although isolated accumulation will be possible this afternoon and overnight for the central and northern high terrains, the more widespread and measurable rainfall is not expected until tomorrow. Therefore, flooding is not forecast 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:

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

Warm temperatures will continue for another day before a change in the pattern tomorrow. The upper-level lift and moisture from the incoming system looks to be strongest over the Northwest Slope, Central Mountains and Northern Mountains. So, be expecting these areas to have more coverage of isolated storms than further south over the San Juan Mountains. Gusty outflow winds are more of a threat from the storms that develop than measurable rainfall this afternoon. Another round of light showers may move in overnight further north, so isolated totals just under 0.10 inches will be possible by tomorrow morning over the high terrains. A Red Flag Warning has been issued for portions of the western border today and tomorrow, so be sure to tune into NWS Grand Junction for more information about the fire danger.

Primetime: 3PM to 8PM

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

Another day with above average temperatures is expected. As the day continues, cloud cover will increase from the west and move eastward. Some isolated storms are possible over the mountains this afternoon, but accumulation will be unlikely underneath most storms due the dry boundary layer. Brief, gusty outflows winds will be possible with the stronger storms that develop. Light showers are possible over the Front Range overnight, so isolated totals around 0.05 inches are possible over the Front Range by morning. As storms move eastward off the mountains and into the Urban Corridor, they are expected dissipate quickly.  Flooding is not forecast.

Primetime: 3PM to 7PM