FTB 05-16-2018: High Pressure and Dry Air Aloft Invades the State

Issue Date: 5/16/2018
Issue Time: 9:45 AM


A sharp, upper-level ridge has taken residence over the state today. Along with warm, dry air aloft, this will cap off the atmosphere over Colorado, resulting in a warm and dry day statewide. During the afternoon/evening, a few fair weather cumulus will bubble over the higher terrain as low-level moisture remains plentiful, but aside from a few streaks of virga, it will not be able to muster any precipitation. The only possible exception to the dry rule will be across the eastern plains near the CO/KS border. An axis of instability will set up there as an influx of moisture arrives from the east/southeast, but even so, strong capping aloft and a lack of deep moisture will fight it every step of the way. The chance of isolated thunderstorms development is 20%. For more information regarding rain rates and timing, please see the zone-specific forecast discussions below.

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, jump below the map.

Flood Threat Legend

Zone-Specific Forecasts

Urban Corridor, Palmer Ridge, Northeast Plains, Southeast Plains, and Raton Ridge:

Warm and dry, with plenty of sunshine to go around. A few streaks of virga will paint the afternoon/evening sky as a few cumulus clouds develop near the higher terrain. Near the CO/KS border, an axis of instability will provide a small chance (20%) that an isolated thunderstorm or two can break through the otherwise capped atmosphere aloft. Any storms will quickly move east, and a lack of deep moisture will keep rain rates from reaching flash flood thresholds. Maximum rain rates will be 0.5-1.0 inches/hour.

Timing: 3 PM – 8 PM

Front Range, Northern Mountains, Northwest Slope, Central Mountains, Southeast Mountains, San Juan Mountains, Southwest Slope, Grand Valley, and San Luis Valley:

Scattered cumulus clouds over the higher terrain during peak heating this afternoon/evening will be all the atmosphere can muster on an otherwise warm and dry day. Winds will increase this afternoon as the pressure gradient tightens, so be careful with anything that may cause a spark and result in a fire.