Issue Date: 6/13/2016
Issue Time: 9:10 AM
A MODERATE FLOOD THREAT HAS BEEN ISSUED FOR PORTIONS OF THE NORTHEAST PLAINS, SOUTHEAST PLAINS, PALMER RIDGE, AND URBAN CORRIDOR.
A LOW FLOOD THREAT SURROUNDS THE MODERATE FLOOD THREAT, INCLUDING PORTIONS OF THE RATON RIDGE, FRONT RANGE, SOUTHEAST MOUNTAINS, CENTRAL MOUNTAINS, AND NORTHERN MOUNTAINS.
A LOW FLOOD THREAT HAS BEEN ISSUED FOR THE GREEN RIVER IN WEST CENTRAL MOFFAT COUNTY, THE CACHE LA POUDRE RIVER AT THE CANYON MOUTH AFFECTING LARIMER COUNTY, AND THE CACHE LA POUDRE RIVER NEAR GREELEY AFFECTING WELD COUNTY.
This period looks to be an active one across the state as a mid-/upper-level disturbance shifts across the region. At the surface, dewpoints continue to sit in the 40s/50s across eastern Colorado, with a few locations reporting dewpoints near 60 F. This moisture shows up well in the IPW chart below: Pueblo (pink line) is above 1 inch, and both Boulder (blue) and Schriever AFB (red) are near 0.8 inches. The Grand Junction station shows that it is a bit drier to the west, but sufficient moisture remains.
For areas along/east of the Continental Divide, ingredients are coming together for another day of scattered strong/severe storms, with an uptick in intensity over yesterday’s storms expected. All hazards are possible with severe storms, including damaging winds, large hail, isolated tornadoes, and heavy rain. Storm motions will mitigate the flood threat somewhat, as storms will move at a decent clip to the east. Even so, owing to the depth of moisture and available instability/upper-level support, a moderate flood threat is warranted.
West of the Continental Divide, moisture/instability will be less than points to the east, and storm motions will be quicker, general speaking. A few stronger storms will be possible this afternoon/early evening, producing small hail, gusty outflow winds, and brief periods of moderate-to-heavy rain. Even so, storm motions preclude the issuance of any flood threat for these areas.
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, Northeast Plains, Palmer Ridge, Raton Ridge, and Southeast Plains:
An active weather day ahead, with scattered thunderstorms expected. The environment is favorable for the development of strong/severe storms, with all severe hazards possible: This includes hail (up to 1.5-2.5 inches in diameter), damaging winds (greater than 50 mph), and isolated tornadoes, along with heavy rain. Maximum rain rates are as follows:
Urban Corridor, Palmer Ridge, and Southeast Plains: 1.8-2.5 inches/hour
Raton Ridge: 1.5-2.0 inches/hour
Northeast Plains: 2.0-3.0 inches/hour
Timing: Noon – Midnight, with a few showers/thunderstorms continuing into the morning hours, mainly along the eastern CO border
Front Range, Northern Mountains, Central Mountains, and Southeast Mountains:
Scattered showers/thunderstorms are expected, and a couple will be on the strong side. The main threats from storms will be gusty winds, hail, and periods of moderate-to-heavy rainfall. Maximum rain rates are follows:
Front Range: 1.5-2.0 inches/hour
Northern Mountains, Central Mountains, and Southeast Mountains: 0.8-1.2 inches/hour
Timing: 10 AM – 10 PM, with a couple isolated showers/thunderstorms lingering until 2 AM.
Northwest Slope, Grand Valley, Southwest Slope, San Juan Mountains, and San Luis Valley:
Scattered showers/thunderstorms are expected. The higher terrain will see the most coverage, but due to storm motions and the nature of the broad-scale lift overspreading the area, valleys will get in on the scattered showers/storms, as well. A few storms will become strong, producing small hail and gusty outflow winds. Brief periods of moderate-to-heavy rainfall are possible, but storm motions preclude the issuance of any flood threat. Even so, be on the lookout for minor street ponding underneath stronger thunderstorms, mainly where drainage is poor.
Maximum rain rates…
Northwest Slope: 0.3-0.6 inches/hour
Grand Valley, Southwest Slope, and San Juan Mountains: 0.4-0.8 inches/hour
San Luis Valley: 0.2-0.4 inches/hour
Timing: Ongoing – 9 PM, with a couple of isolated showers/weak thunderstorms continuing until 11 PM over the higher terrain.
