Issue Date: 5/4/2016
Issue Time: 9:35 AM

NO FLOOD THREAT IS FORECAST.

High pressure at the surface and upper-level ridging overhead will leave today beautiful across Colorado. Sun-drenched skies will allow temperatures to climb to values slightly higher than yesterday statewide, offering the perfect excuse to eat lunch outside or perhaps leave the office just a little early to enjoy the conditions. There just simply is not much to dislike about today’s forecast.

It would not be a Colorado spring forecast, however, if we did not discuss at least the isolated risk of showers/weak thunderstorms over the High Country. A narrow ribbon of moisture is expected to shift into southwestern and central Colorado this afternoon. This moisture, combined with sufficient daytime heating, will allow for a couple brief showers/weak thunderstorms to develop. Activity is expected to be elevated, and will result in more wind than rain. For more specifics, see the region-specific 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, Southeast Plains, Palmer Ridge, Raton Ridge, and Northeast Plains:

Sunny and warm, with high temperatures in the 70s for the lower elevations, and in the mid-to-upper 60s for the higher elevations of the Palmer Ridge and Raton Ridge. Overnight, the skies will remain clear with lows in the 40s.

Northern Mountains, Northwest Slope, Front Range, Southeast Mountains, and San Luis Valley:

Mostly sunny and warm will be the main weather story today, with high temperatures in the 50s and 60s for mountain valleys and in the 40s for the higher elevations. An isolated shower/weak thunderstorm or two cannot be ruled out over the higher terrain, mainly south of I-70. Activity will elevated, resulting in more wind than rain. Rain rates will be less than 0.15 inches/hour.

Timing: 1 PM – 9 PM

Grand Valley, Central, Mountains, San Juan Mountains and Southwest Slope:

Plenty of sunshine and warmth are in the forecast today, especially for valley locations. Over the higher peaks, there will be a couple isolated showers/weak thunderstorms this afternoon and evening, but nothing significant. Rain rates will be less than 0.15 inches/hour everywhere except the San Juan Mountains region, where better moisture will push maximum rain rates to 0.25 inches/hour.

Timing: 11 AM – 8 PM

Issue Date: 5/3/2016
Issue Time: 9:27 AM

NO FLOOD THREAT IS FORECAST.

Today will be a beautiful day across Colorado as surface high pressure moves in from the west and upper-level ridging amplifies overhead. Much of the state has started out sunny this morning, minus the area of remnant scattered clouds associated with the weak frontal boundary that moved across the plains last night/this morning. The ample sunshine will allow temperatures to push back up to seasonable values, so try to get outside and enjoy it.

Even with that said, an isolated shower or two will be possible across the higher terrain of the Southwest Slope, Central Mountains, and San Juan Mountains regions. Any rain that falls will be light and brief, with rain rates less than 0.15 inches/hour. That is simply nowhere near flash flood thresholds.

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

Sunny skies and warmer temperatures will be the name of the game today, as highs climb into the 60s below 6,200 feet and upper 50s for the higher elevations of the Raton Ridge and Palmer Ridge. Breezy conditions out of the north/northwest are expected, with winds gusting to 15-30 mph. Skies will remain clear tonight.

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

Warmer and drier today as high pressure builds across the region. High temperatures will vary with elevation, but generally in the upper 50s/low 60s for the valleys and upper 30s/low 40s for the higher elevations. Gusty winds (15-20 mph) out of the west/northwest are expected. Clear skies will be in place for the overnight hours.

Central, Mountains, San Juan Mountains and Southwest Slope:

Mostly sunny and warm, with high temperatures varying with elevation. High temperatures in the valleys will range across the low 60s, with low 40s for the higher elevations. Winds will be gusty out of the west at 10-15 mph.

An isolated shower/weak thunderstorm or two cannot be ruled out across the mountain peaks this afternoon/evening. The best relative chances will be across the higher elevations of the San Juan Mountains and Southwest Slope regions. Even so, rain rates will be meager at less than 0.15 inches/hour. Any activity will diminish by the late evening as the sun goes down. Skies are expected to be mostly clear overnight.

Issue Date: 5/2/2015
Issue Time: 10:00 AM

NO FLOOD THREAT IS FORECAST.

Surface high pressure has settled in (albeit briefly) across Colorado, while an upper-level ridge slowly builds overhead. Clouds have mainly cleared from areas east of the mountains, while still in place across much of the High Country. The clearing skies will allow for a warm up in temperatures to values that haven’t been observed in recent days, although still below average for this time of year. The daytime heating will kick off isolated showers/thunderstorms across the High Country this afternoon/evening, mainly south of I-70. Instability values will remain fairly low, however, and any thunderstorms will be of the garden variety.

Northerly steering flow will keep the thunderstorms over the mountains, and it will be difficult for any to leak over the Urban Corridor or adjacent plains. It cannot be ruled out entirely, but it is unlikely. Rain rates will vary across the regions, but will remain below flood threat thresholds in each. Specifics on rain rates will be given in the zone-specific forecast discussion below.

Unfortunately, the surface high pressure will be short lived as a weak frontal surge will move into northeastern Colorado between 3 and 5 PM, bringing spotty, light precipitation with it. The weak front will race southward across the eastern third of the state, exiting the Southeast Plains region by tomorrow morning. The main area of light precipitation will remain across eastern portions of the Northeast Plains, Palmer Ridge, and Southeast Plains, but an isolated shower or two will work back into the Urban corridor, western portions of the Southeast Plains adjacent to the mountains, and Raton Ridge.

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

Drying and warming today, before a weak frontal surge moves through eastern third of Colorado beginning later this afternoon/early evening. The frontal surge will bring increasing clouds, gusty northerly winds, and isolated light showers before exiting the state tomorrow morning. Rain rates will be low (0.1-0.2 inches/hour), so no flood threat is expected. Temperatures will closer to average, although still on the cool side for the date.

Northern Mountains, Northwest Slope, Grand Valley, and Front Range:

Isolated showers/weak thunderstorms are expected to develop around lunchtime, diminishing between 7 and 9 PM. Light rain (snow for the higher peaks) will be the result, along with cool, gusty winds. Maximum rain rates will be 0.1-0.2 inches/hour. Temperatures will continue to be a little cooler than normal, but will be warmer than yesterday.

Central Mountains, Southeast Mountains, San Juan Mountains, Southwest Slope, and San Luis Valley:

Isolated showers/garden-variety thunderstorms are expected to develop after 11 AM, and then diminish between 7 and 10 PM. Light rain (snow for the higher peaks) will be the main result, along with cool, gusty winds. The favored areas will be the higher terrain of the San Juan Mountains, Southwest Slope, and Central Mountains regions. Maximum rain rates will be slightly higher than other regions, coming in at 0.2-0.5 inches/hour. Just as the other regions, temperatures will be warmer than yesterday, but still below average for this time of year.

Issue Date: 05/01/2016
Issue Time: 10:40 AM

NO FLOOD THREAT IS FORECAST.

First of all, we would like to welcome everyone back to the Flood Threat Bulletin for the 2016 Season. It is truly our pleasure to serve you. With that said, let’s dive right in to the forecast…

Large-scale troughing continues over much of the US, as you can see in the water vapor image below. The main upper-low circulation resides over eastern AZ/western NM at this time (red “L”), and is expected to move east-northeast today, moving across KS/OK by tonight. The path taken by this upper-low will focus the best lift for precipitation to the south across NM, but will provide sufficient lift across Colorado for another day of unsettled weather.

Snow levels will be around 6,000-7,000 feet during the day, and above 5,000 feet tonight. Snow accumulations will vary by region, so that will be broken down in the region-specific forecasts below. As far as QPF goes, the greatest precipitation totals will be confined to the Southwest Slope and San Juan Mountains regions; this is where the best overlap of large-scale lift and moisture will exist. From a statewide perspective, rain rates will remain below flood threat thresholds, and therefore, no flood threat will be issued 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

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

Mix of rain and snow for the lower elevations, with snow showers likely above 7000 feet. Precipitation will be more isolated-to-widely scattered in nature north of I-70, with coverage increasing as latitude decreases. Accumulations of both rain and snow will remain light. Precipitation coverage will peak this afternoon/evening, and diminish late tonight and into tomorrow morning.

Northwest Slope and Grand Valley:

Overall, these three regions will be the driest across Colorado today. The higher terrain will be favored for scattered light snow showers throughout the day and into the evening hours. Isolated, light rain showers are possible in the valleys, but less than 0.1 inches of rain is expected.

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

Scattered snow showers are expected throughout today, gradually clearing from north to south late tonight and into tomorrow morning. Generally speaking 1-2 inches of snow is expected across the Front Range, Central Mountains, and Northern Mountains. The Southeast Mountains will have the best moisture in place, and totals there will be slightly higher at 2-5 inches.

San Juan Mountains and Southwest Slope:

These regions will feature the best overlap of large-scale lift and moisture, and are the favored regions for the highest precipitation totals. As much as 12-18 inches of snow is expected for the higher peaks, with widespread 4-6 inches of snow expected for the higher elevations overall. Valleys below 7,000 feet will see mainly rain, with totals generally ranging from 0.1-0.4 inches.

A thunderstorm or two will be possible this afternoon/evening, with maximum rain rates of 0.15-0.3 inches/hour, which is well below flood threat thresholds.

Precipitation will continue through the nighttime hours, but will diminish in coverage by tomorrow morning.

San Luis Valley:

Isolated-to-scattered light rain showers are expected today, with totals expected to be less than 0.2 inches. A few snowflakes may mix in, but accumulations, if any, will remain light. Isolated light showers will continue through the night, before clearing out early tomorrow morning.