Issue Date: Friday, September 2nd, 2016
Issue Time: 10:30AM MDT
— MODERATE flood threat for Northeast Plains, Palmer Ridge and Southeast Plains
— LOW flood threat for Raton Ridge
A weather pattern change started for Colorado on Thursday as a large-scale upper trough began to impact the western part of the state. As the water vapor image shows, below, a disturbance emanating from this trough is currently positioned along the UT/CO border and will rapidly move through the state today. This disturbance is a bit stronger than even yesterday afternoon’s weather models suggested. Plenty of cloud cover is in place this morning, along with light to moderate showers mainly across the northern and western parts of the state. Cloud-free skies are found in the south and southeast and temperatures will rapidly climb to the 80s to near 90F. Moisture is in abundance today with precipitable water (PW) values at or above 1 inch east of the Continental Divide and in the 0.7 to 0.9 inch range to the west. As the disturbance moves east, moisture return will boost PWs as high as 1.5 inches across eastern Colorado. With plenty of instability available, expect a round or two of strong-to-severe thunderstorms over the eastern Plains. Very heavy rainfall will possible, though the overall threat is mitigated by the fast storm motion. Nonetheless, a Moderate flood threat is warranted for parts of eastern Colorado. Scattered to widespread showers and a weaker storm will occur across the western slope but lower instability and unfavorable dynamics mean that a flood threat is not warranted here.
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, scroll below the map.
Zone-Specific Forecasts:
Northeast Plains, Southeast Plains, Palmer Ridge, Raton Ridge:
Scattered to widespread thunderstorms and showers developing by 1PM. Max 1-hr rain rates up to 2.8 inches, with max 3-hr rates up to 3.8 inches. A Moderate flood threat is in place for parts of the region, with a Low threat surrounding that. Large hail, up to 1.75 inches and winds up to 75 mph will possible with the strongest cells. Storms will move quickly east/southeast, and dissipate within a few hours after sunset.
Primetime: 1PM to 9PM except 11PM in far eastern areas
San Juan Mountains, Southwest Slope, Grand Valley, Central Mountains, San Luis Valley, Northwest Slope, Northern Mountains:
Mostly cloudy with showers and a few thunderstorms increasing in coverage through the late morning and early afternoon. Max 1-hr rainfall up to 0.5 inches with max 24-hour totals up to 1.1 inches possible over the higher terrain of the Northern and Central Mountains. Snow level will be 12,500 feet.
Primetime: Noon to 8PM
Front Range, Urban Corridor, Southeast Mountains:
Mostly cloudy with scattered showers early transition to scattered thunderstorms by early afternoon. Max 1-hr rainfall up to 0.7 inches possible. Hail up to 0.75 inches and winds up to 50 mph are possible with the strongest storms. Flooding is not expected today.
Primetime: 1PM to 7PM
