Issue Date: 8/21/2015
Issue Time: 9:45AM

— NO Flood Threat Today
— Elevated Fire Threat West of the Continental Divide

The last several days have been some of the driest days since the start of the Flood Threat Bulletin season. Today, this streak will continue. As the chart shows, below, Precipitable Water (PW) values are in the 0.3 to 0.6 range across the state. These values are expected to stay in this range today, squashing chances of heavy rainfall. Overall, we expect sunny to partly cloudy skies and seasonable temperatures today. The very southeast corner of Colorado, namely Baca and Prowers counties, may see a stray weak thunderstorm this afternoon and early evening. However, the odds for a storm a quiet low, less than 10%. No flooding is expected today.

There is an elevated fire threat today across and west of the Continental Divide. One of the best predictors of wildfire activity is consecutive dry days. And we have seen a string of such days over western Colorado now. A combination of moderate wind speeds, very low relative humidity and decreasing soil moisture will raise the chances of wildfires.

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

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

Mostly sunny and much warmer today with highs in the 60s in the higher terrain to the mid 90s in the lower elevations of the Arkansas River valley. A stray thunderstorm cannot be ruled out in Baca and Prowers County during the late afternoon and early evening. However, rainfall will be limited to 0.4 inches or less due to fast storm motion. Flooding is not expected today.

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

Mostly sunny and much warmer today with highs ranging from the mid 60s in the highest terrain to the mid 90s in the lower valleys. Relative humidity values are expected to drop into the 10-20% range today, which will cause an elevated wildfire threat. Moderate wind speeds and decreasing soil moisture will also contribute to the risk. Please check your local National Weather Forecasts for more detailed fire risk information.

Issue Date: 8/20/2015
Issue Time: 9:45AM

— NO Flood Threat Today

We hope you enjoyed the brief cool-down on Wednesday. Because it will quickly give way to summer again. As shown in the water vapor image, below, Colorado will remain under the influence of a post-frontal airmass. This is marked by very dry conditions, with precipitable water values only ranging between 0.40 to 0.65 inches across the state. Temperatures are expected to be 15-25 degrees higher today, compared than yesterday. While most of the state will be under sunny to partly cloudy skies, a bit of instability will develop over the Southeast Plains. This may lead to a stray weak thunderstorm or two. But fast storm motion and a dry atmosphere will preclude heavy rainfall. Thus, we do not expect any flooding today.

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

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

Mostly sunny and much warmer today with highs in the 60s in the higher terrain to the mid 90s in the lower elevations of the Arkansas River valley. A stray thunderstorm or two cannot be ruled out south and east of Colorado Springs during the late afternoon and early evening. However, rainfall will be limited to 0.4 inches or less due to fast storm motion. If a storm does develop, it could produce gusty winds up to 45 mph.

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

Mostly sunny and much warmer today with highs ranging from the low 60s in the highest terrain to the upper 80s in the lower valleys. Relative humidity values are expected to drop into the 10-20% range today, which will slightly raise the wildfire threat. However, low wind speeds and relatively high soil moisture will not be favorable for wildfire propagation.

Issue Date: 8/19/2015
Issue Time: 7:52 AM

NO FLOOD THREAT IS FORECAST.

Today’s forecast discussion will be short and sweet. After the passage of the cool front yesterday, and the upper-level disturbance overnight/this morning, dry and stable air will take up residence across Colorado today. After the line of weak showers over the Southeast Plains dissipates/exits the state, there will not be any more precipitation today. High temperatures will be cooler than average. Tomorrow morning’s low temperatures will be cool, once again, with clear skies and light winds expected overnight.

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

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

Mostly sunny skies and dry, with highs in the 60s and 70s for lower elevations, 40s and 50s in the mountains. Clear skies and light winds overnight will bring temperatures to a chilly feeling tomorrow morning; a few record lows will be threatened.

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

Mostly sunny and dry, with temperatures similar to yesterday’s highs. Winds will be breezy during the afternoon, calming overnight.

Issue Date: 8/18/2015
Issue Time: 8:25 AM

NO FLOOD THREAT IS FORECAST.

The air mass over Colorado has dried out considerably behind a cool front that passed through the state, with precipitable water values diving below 0.7 inches at all four normal reporting stations. From the 6 AM Denver and Grand Junction soundings, precipitable water values are in the 25th percentile for the date. Altogether, the moisture decline outlines the no flood threat forecast.

There will be isolated-to-scattered showers and weak thunderstorms this afternoon and into the overnight hours, mainly along the Continental Divide and east to the CO/KS border. Precipitation is expected to be light, so no flooding concerns will arise from this activity. Rain rates and timing will be outlined in the zone-specific discussions below. West of the Continental Divide, a dry and cool day is expected.

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

Front Range, Northern Mountains, Central Mountains, and Southeast Mountains:

Isolated-to-scattered showers/weak thunderstorms expected this afternoon and into the overnight hours. Rain rates will be low at 0.15-0.30 inches/hour. Otherwise, partly sunny skies and cool temperatures will be the main story.

Timing: 2 PM – 4 AM

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

Isolated-to-scattered showers/weak thunderstorms are expected over these regions, as well. Activity will get a later start today as compared to recent days, beginning in the mid-afternoon hours, and continuing into the early morning hours tomorrow. Rain rates will not be impressive, coming in at 0.25-0.5 inches/hour under thunderstorms, 0.05-0.15 inches/hour under stratiform showers. Otherwise, expect a partly sunny and cooler forecast period.

Timing: 3 PM – 6 AM

San Juan Mountains, Grand Valley, San Luis Valley, Northwest Slope, and Southwest Slope:

Cooler and dry, with high temperatures about 8-12 degrees cooler than yesterday across all locations. Windy conditions will bring elevated fire concerns, and a Red Flag Warning has been issued across portions of the Southwest Slope. Stay up-to-date on changing fire weather conditions with your local NWS office.