Issue Date: Wednesday, May 25th, 2022
Issue Time: 8:40AM MDT

— Flooding is NOT expected today

To the east of Colorado, the Low pressure system that helped produce our last precipitation event can be viewed in the visible satellite imagery below. This morning, it looks like there is still some lingering cloud cover over the mountains and valley fog as well as plenty of new snowpack (bright white). A dry NNW flow aloft will move over the state today as the ridge begins to migrate eastward (yellow arrow). PW at Denver has dropped about a tenth of an inch since yesterday, nearly matching Grand Junction in this morning’s sounding at 0.38 inches. In combination with subsidence under the building ridge, rainfall is not anticipated today. Therefore, there is NO flood threat issued.

Increased flow is forecast along the Green River today due to releases at Flaming Gorge Reservoir (northwest CO). Flow along the Yampa River is also expected to increase later this week below the confluence with the Green River (west-central Moffat County).

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.

Zone-Specific Forecasts:

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

Near normal temperatures are forecast today over the northern Urban Corridor and Northeast Plains with afternoon highs remaining 8-15F below normal over the mountains and Southeast Plains. Plenty of sunshine for a pleasant spring day with northerly winds in the 15 to 20 mph range this afternoon. Rainfall is not anticipated today, so there is NO flood threat issued. 

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

Near normal temperatures are forecast this afternoon with 70Fs forecast across the lower elevations and 60Fs for the mountain valleys. Very little cloud cover is expected, but anticipate an increase in cloudiness by tomorrow morning. Winds today will be coming out of the NNW and are forecast in the 10 to 20 mph range over the steeper terrains. Rainfall is not forecast today, so flooding is NOT expected.

Issue Date: Tuesday, May 24th, 2022
Issue Time: 10:30AM MDT

— Flooding is NOT expected today
— Red Flag Warnings in effect for parts of Southwest Slope

As we approach June, it becomes less and less likely that we get widespread precipitation events without some kind of flood threat. Fortunately, today is one of those days. As seen in the water vapor image, below, a deep trough is currently centered over Colorado, and supported by strong jet streak dynamics. To the east, a surface low pressure currently sits over western Oklahoma and is expected to move slowly east-northeast through the day. Light precipitation is ongoing over the Southeast Plains and will continue throughout the day, as weak warm air advection from the low circulation will force relatively warm moist air to rise and condense as it is pushed into Colorado. PW this morning was 0.47 and 0.35 inches at Denver and Grand Junction, respectively, and will stay steady or drop especially over central and western Colorado. Without any meaningful instability over eastern areas, only light or perhaps briefly moderate rain intensity is expected. Though all of it will of course be mighty welcome.

Further west over the higher terrain, very cold mid and upper-level temperatures are moving into the state. Combined with at least some solar insolation peeking through the clouds this morning and afternoon, this will destabilize the atmosphere to produce CAPE of up to 500 J/kg. However, with such cold temperatures and swift storm motion, the main form of precipitation will be snow, or more appropriately: thundersnow! Very impressive, though brief, snow rates are expected today with up to 1-2 inches of snow possible over 15-30 minutes this afternoon. However, flooding is NOT expected.

Lastly, subsidence behind this disturbance will bring down drier air from the mid-levels of the atmosphere, which along with gusty winds has prompted Red Flag Warnings for lower-elevation parts of southwest Colorado.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.

Zone-Specific Forecasts:

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

Mostly cloudy with rain showers and weak isolated storms expected to increase in coverage this afternoon. The best coverage will be over the Southeast Plains. Max 1-hour rainfall up to 0.4 inches is possible, but flooding is NOT expected. Up to 1.75 inches of precipitation is expected to fall by late tonight.

Primetime: Ongoing to 11PM

Northern Mountains, Front Range, Central Mountains, San Juan Mountains, San Luis Valley & Southeast Mountains:

Partly cloudy early then mostly cloudy with scattered to numerous snow showers and weak thunderstorms. Max 1-hour liquid equivalent up to 0.4 inches possible, which could lead to a quick 1-2 inches of snow in less than 1 hour. The snow level will vary between 7,000 and 8,500 feet. Flooding is NOT expected today.

Primetime: 12PM through 8PM

Grand Valley, Southwest Slope & Northwest Slope:

Mostly sunny early then partly cloudy, breezy and cool with isolated rain and snow showers possible during the afternoon. An isolated storm cannot be ruled out. Max 1-hour rainfall up to 0.3 inches. Flooding is NOT expected today.

Red Flag Warnings are in effect for parts of the Southwest Slope as gusty winds and lower humidity are expected this afternoon.

Primetime: 12PM through 6PM

Issue Date: Monday, May 23rd, 2022
Issue Time: 10:25AM MDT

— Flooding is NOT expected today

From the perspective of atmospheric dynamics, the next 36-48 hours will excite many meteorologists across Colorado. As shown in the visible satellite image below, a large trough remains in place over the western United States. A new strong jet streak was noted this morning, entering the Great Basin from the northwest. Despite the fact that the jet streak itself has winds exceeding an impressive 180 mph, the trough is actually nearly stationary. Instead, the incoming jet streak will “dive” over the Four Corners and provide synoptic-scale upward motion over the next 48 hours for Colorado. This will favor cool temperatures and relatively widespread precipitation, especially east of the Continental Divide.

PW at Denver and Grand Junction this morning was 0.51 and 0.26 inches, respectively. However, with low-level flow turning more southerly over time, moisture advection will become a factor, and help raise PW to nearly 1 inch over far southeast Colorado. Precipitation coverage will be most widespread over eastern Colorado today. However, the vast majority of the rain (and higher elevation snow) will be non-convective. The highest rain intensity from convective storms will be found along the NM and OK borders where broken clouds will still allow for solar heating to support instability of perhaps 700 J/kg. Yet, due to the expect widespread coverage of showers and storms, this instability will be quite localized and fleeting, only lasting for 1 to, at most, 3 hours. Thus, overall, while we expect some brief moderate to heavy rainfall this afternoon and early evening, flooding is NOT expected. Isolated severe weather will be possible for the far southeast portions of the Southeast Plains.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.

Zone-Specific Forecasts:

Southeast Plains & Raton Ridge:

Becoming overcast with numerous showers and storms developing by mid-afternoon. Max 1-hour rainfall up to 1.1 inches right along OK/NM border (especially Baca County) with max 3-hour rainfall up to 2.0 inches possible. Some ponding of water is possible for low lying areas, but flooding is NOT expected today. An isolated severe storm cannot be ruled out, especially with the early round of storms. Light/moderate rain and snow will continue into the overnight hours.

Primetime:

3PM to 8PM, with lighter rain/snow continuing into overnight hours

Northeast Plains, Northern Mountains, Front Range, Urban Corridor, Central Mountains, Palmer Ridge & Southeast Mountains:

Mostly cloudy and cool today with scattered showers and embedded, isolated storms possible this afternoon. Max 1-hour rainfall 0.7 inches (east) and 0.5 inches (west). The snow level will range from 7,500 – 9,000 feet today. Flooding is NOT expected today.

Primetime: 11AM to 7PM

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

Partly cloudy and cool today with high temperatures of 5-10F below normal. Isolated rain and higher elevation snow showers will be possible, mainly for the higher elevations of the San Juan Mountains and adjacent valley. Max 1-hour rainfall up to 0.2 inches. Flooding is NOT expected today.

Issue Date: Sunday, May 22nd, 2022
Issue Time: 9:55AM MDT

— Flooding is NOT expected today

It will finally start to get warmer today with the ongoing snow and rain across the Palmer Range/southern Front Range beginning to diminish as the jet and mid-level energy move out of the area. Zonal flow from the jet stream, that is currently located over eastern Colorado, is forecast to begin to weaken through the morning, although there will still be a good speed max that remains over the Palmer Ridge and Southeast Plains late this afternoon into the overnight hours. This should provide some extra lift for storms that develop over the area this afternoon and help keep some light precipitation going over the Southeast Plains tonight. Westerly winds aloft are expected to shift to more WSW as the next shortwave digs south into Utah (orange “X” below). This shortwave is expected to produce some mid-level lift across the state, and paired with the diurnal flow, should help develop isolated precipitation over the mountains this afternoon. PW has dropped to 0.26 inches at Grand Junction, so west, expect the precipitation to be confined to the higher elevations. Storms that attempt to develop across the lower elevations are forecast to produce more wind than measurable rainfall.

Over eastern Colorado, PW was measured at 0.36 inches in Denver and is likely close to 0.50 inches over the Southeast Plains, so it has dried out a little bit when compared to the last couple of days. Southerly surface winds will gain an easterly component with the diurnal flow late this afternoon, which typically favors precipitation development over the Palmer Ridge and northern Front Range/Urban Corridor. With only light to moderate rainfall forecast for the afternoon and evening hours, flooding is NOT anticipated. Precipitation is forecast to continue over the Southeast Plains/Palmer Ridge/Southeast Mountains and northern Front Range tonight. With a cold front pushing in from the northwest, it should help to lower the freezing line over Front Range fairly quickly. So, anticipate some more snowfall by morning for the mountain zones east.

One last note, with the warmer temperatures and snow line dropping today, rain on snow may be possible over isolated areas. This could help increase local runoff and cause a spike in streamflow. The only AHPS station currently approaching “Action” stage is the Arkansas River near Avondale. While there have been steady increases to the streamflow up north as well, base flows were fairly low to start, so not anticipating any flood risk today.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.

Zone-Specific Forecasts:

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

High temperatures over the lower elevations should reach into the upper 50Fs (north) and 60Fs (south). Over the mountains, it will still be quite cool with highs reaching into the 40Fs for the foothills and remaining in the 30Fs for the higher elevation valleys.

Isolated precipitation is forecast for the mountains today with precipitation forecast to continue over the northern Front Range and Southeast Mountains tonight. Max liquid equivalent up to 0.85 inches will be possible through tomorrow morning. Over the plains, isolated totals up to 0.60 inches will be possible. Due to the gradual nature of the rainfall and snow at the higher elevations, there is NO flood threat issued.

Primetime: Ongoing

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

It’s going to start heating back up with highs across the lower elevations reaching into the upper 60Fs and 70Fs. Afternoon high temperatures across the mountain valleys should reach into the 40Fs and low 50Fs. Isolated precipitation is forecast for the mountains near the Continental Divide this afternoon/evening with overnight snow forecast for the eastern San Juan Mountains. Isolated liquid totals up to 0.30 inches will be possible by morning. It could get breezy this afternoon with winds from the west forecast to be in the 15 to 20 mph range as the trough apprroaches. A cold front looks to slide in from the northwest this evening, keeping overnight lows chilly for the northwest corner.

Primetime: 11AM to 6AM