Issue Date: 7/15/2016
Issue Time: 9:20 AM
A LOW FLOOD THREAT IS FORECAST FOR PORTIONS OF THE FRONT RANGE, URBAN CORRIDOR, PALMER RIDGE, NORTHEAST PLAINS, SOUTHEAST PLAINS, AND RATON RIDGE.
It will be another active day across eastern Colorado, with the threat of strong/severe storms the main story. Dewpoints remain in the 50s and 60s across much of the Urban Corridor, Palmer Ridge, Northeast Plains, Southeast Plains, and Raton Ridge regions, which will leave plenty of fuel for this period’s thunderstorm activity. A reinforcing shot of moisture will come from the east/northeast this morning/early afternoon in the form of an outflow boundary from storms over Nebraska and Kansas. This moisture, combined with strong daytime heating, ample wind shear, steep mid-level lapse rates, and a mid-level disturbance will provide the support for strong/severe thunderstorms capable of producing large hail, damaging winds, periods of heavy rain, and an isolated tornado or two.
There will be a few more thunderstorms over the higher terrain, and further westward than previous days. The Front Range and Southeast Mountains will experience a similar day to yesterday, albeit with slightly more coverage expected. The San Juan Mountains, Northern Mountains, and Central Mountains will get in on isolated high-based showers/thunderstorms, but will receive very little rainfall. In general, any storm activity over these regions will produce mainly gusty winds and lightning, and perhaps a sprinkle or two. Further west, the fire danger is elevated, once again, as dry air, dry fuels, and gusty winds combine forces. 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.
Zone-Specific Forecasts
Urban Corridor, Palmer Ridge, Raton Ridge, Northeast Plains, and Southeast Plains:
Isolated-to-scattered showers/thunderstorms expected, and a few will be strong/severe. The main threats from any strong/severe thunderstorms will be large hail (up to 2.0 inches in diameter), strong winds (up to 60 mph), periods of heavy rain, and an isolated tornado or two. The most likely location for the stronger storms to develop will be over the Northeast Plains, Palmer Ridge, and Southeast Plains regions. If outflow boundaries can push far enough westward into the Urban Corridor, reinforcing deep moisture and easterly low-level flow, the threat for strong/severe storms will increase along the I-25 corridor. Maximum rain rates are as follows:
Urban Corridor: 0.8-1.5 inches/hour
Palmer Ridge and Raton Ridge: 1.0-2.0 inches/hour
Northeast Plains: 1.5-2.5 inches/hour
Southeast Plains: 2.0-3.0 inches/hour
Timing: Noon – 1 AM, with storms ending from west to east
Front Range and Southeast Mountains:
Isolated-to-scattered showers/thunderstorms expected. Most will be garden variety, but one or two will be strong. The main threats from storms will be gusty winds and lightning, with brief periods of moderate-to-heavy rainfall. Maximum rain rates will be 0.7-1.1 inches/hour.
Timing: 11 AM – 8 PM
Northern Mountains, San Juan Mountains, Northwest Slope, Grand Valley, Central Mountains, and Southwest Slope:
Isolated high-based showers/thunderstorms are expected over the higher terrain of the Northern Mountains, Central Mountains, and San Juan Mountains. Very little rainfall, if any, will result. Elsewhere, it will be hot and dry like previous days, with temperatures 4-6 degrees above normal. Fire danger is elevated, once again, so please be extra cautious.
Timing: 11 AM – 8 PM
