Issue Date: Friday, May 1st, 2020
Issue Time: 8:25AM MDT

— Flooding is NOT expected today

Welcome back to the FTB! We’re looking forward to a successful 2020 season serving you.  

Another warm day is on tap for the state to kick off the 2020 FTB season, so be sure to get outside and enjoy the sunshine! Seen (to our east) in the mid-level water vapor imagery below is the surface low and upper ridge that controlled yesterday’s weather. The next system is already lined up behind it, which is marked with the orange “X”. There is minimal residual moisture in the wake of yesterday’s system, so as this system moves west to east throughout the day, it will provide some lift for scattered showers over northern Colorado.

Again, not much in the way of moisture, so expect more gusty winds than accumulating rainfall due to the large spread in temperature and dew point. A cold front will drop in from the north this evening, which will usher in cooler temperatures tomorrow and increase thunderstorm chances over the northern Urban Corridor and Northeast Plains late this afternoon and evening. A stray thunderstorm or two may also be possible over the eastern Palmer Ridge as the front dips south and more moisture becomes available. Expect northerly winds to pick up along the front and gusty outflow winds under the storm bases. Flooding is not expected with the storms that develop today.

Different story for areas south of I-70 where a deepening surface low and a very dry atmosphere will combine for pockets of critical fire weather. Once again, a Red Flag Warning has been issued for the Grand Valley and San Luis Valley. Expect winds to pick up from the west/southwest by mid-afternoon through about 8PM tonight.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. 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:

Northwest Slope, Northern Mountains, Front Range, Urban Corridor, Northeast Plains, Palmer Ridge:

Some nice sunshine to start the day with the break between the two systems. Expect storms to pick up this afternoon over the northern Northwest Slope and Northern Mountains as the next shortwave moves into the state. Best chance for accumulation will be over Routt and Moffat Counties, although gusty wind will be likely than rainfall at the lower elevations. Max 1-hour rain rates up to 0.20 inches will be possible with most accumulations under 0.15 inches. Over northeast Colorado, rain rates up to 0.20 inches per hour (west) and 0.40 inches per hour (east) will be possible with the strongest storms that develop along the cold front. Expect only light accumulation for storms that linger into the night over the Northeast Plains. Flooding is not forecast.

Primetime: 2PM to 3AM

Grand Valley, Southwest Slope, San Luis Valley, San Juan Mountains, Central Mountains, Southeast Plains, Raton Ridge, Southeast Mountains:

It’s going to be another hot one! With the cold front dropping south this evening, some relief from the heat is on its way tomorrow. Highs could hit 90F or greater over the southern Urban Corridor and Southeast Plains, which could cause the Colorado Springs daily high temperature record to be broken. Highs will also reach the upper 80Fs over the Grand Valley. Southwest and westerly winds will pick up this afternoon, and they are expected to be in the range of 10 to 20 mph with gusts up to 30 mph. A Red Flag Warning has been issued for the San Luis Valley and Grand Valley area from 2PM to 9PM this evening.

Hey FTB users! Just a friendly reminder that the Flood Threat Bulletin will be returning on Friday, May 1st. We have a couple new features this year that we are excited to share with you! The first is an interactive burn area map on the About the FTB page. This will allow you to find basic information about the past fires that we feature on our maps (name, year, acres burned). For 2020, we will be issuing specific burn area threats (when necessary) for the following burn areas: 416, Decker, Lake Christine and Spring Creek.

Next, you may have already noticed a new page at the top of the site. The Report a Flood form will let you tell us about flooding happening in your area. We’re hoping to feature these reports in our daily State Precipitation Map posts. Be sure to pass this on to your friends and colleagues that also like to track weather!

Lastly, we’re excited to have a more interactive Flood Threat Bulletin map. When hovering over a threat area, more details about rain rates and potential flooding hazards will pop up. Additionally, we are adding a new threat level to the map that will be specifically for NWS Flood Warnings (riverine) that are active at the time of the FTB post.

Looking forward to serving you for another flood season! To sign up and receive a daily notification of the flood threat to your inbox, please navigate to the Subscribe option above (or click here). You can also follow us on Twitter and Facebook for the latest flood updates.

Issue Date: Monday, September 30th, 2019
Issue Time: 9:20AM MDT

— Flooding is NOT expected today

NOTE: This is the last scheduled Flood Threat Bulletin of the 2019 season. It has been a pleasure to serve you! The next Flood Threat Bulletin season begins on May 1, 2020.

Same pattern is in place over the US with a tight surface gradient creating strong, dry southwest flow over the majority of the state again today. Thinking this gradient will slightly weaken throughout the day, but fast winds and low relative humidity will create Red Flag Warning conditions again for the majority of the state. Conditions will be favorable for the rapid ignition, growth and spread of fires, so open burning is strongly discouraged. PW at Denver was measured at 0.40 inches with very dry air above 600 mb. Grand Junction’s sounding was similar, but slightly higher due to some mid-level moisture. This moisture paired with the jet overhead is helping produce some cloud cover and light rainfall over the northwest corner this morning. As the jet streak moves out later this morning and dry air above and below this mid-level layer mixes out the remaining moisture, showers should begin to diminish. Not expecting rainfall this afternoon with the dry air mass in place over the state.

At the surface, a low develops this afternoon over eastern Colorado, which may help pull in slightly higher moisture over the far southeast corner by making winds a little more southerly. If this moisture (marked by the green arrow below) can push slightly northward, overnight rainfall will be possible for Baca/southern Prowers Counties. Guidance is showing the heaviest rainfall to the south and east, but if higher PW values continues to move north tomorrow morning, some heavier rainfall will be possible on Tuesday morning. Overnight, a strong cold front starts to drop through the state, which looks to return some low-level moisture to the northeast quadrant of the state. Therefore, behind the front, some light showers and cloud cover are possible with fog to start Tuesday morning. The cooler, more fall-like temperatures will be a great way to round out the end of the heavy rainfall forecast season. As anticipated, flooding is not forecast today.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. For Zone-Specific forecasts, scroll below the map.

Zone-Specific Forecasts:

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

Red Flag Warning is in place for the following regions minus the northern portions of the Urban Corridor, Front Range and Northeast Plains where moisture is little higher. Still expecting Elevated Fire conditions over those regions. Southwest winds in the 15 to 25 mph range with gusts up to 40 mph are expected from noon to 7PM with relative humidity values in the teens. Rainfall is not forecast this afternoon with the dry air mass overhead, and temperatures should warm quite a bit when compared to yesterday. Overnight and early morning light rain may be possible behind the passage of a strong front over the northeast quadrant of the state. Max 1-hour rain rates will remain below 0.10 inches with the best chance for accumulation over the northeast corner or northern Front Range.

Additional rainfall may be possible over Baca and southern Prowers Counties tonight if the moisture boundary shifts far enough north. If this occurs, totals up to 0.90 inches will be possible by morning (7AM), so flooding is not forecast at this time. Assuming this moisture continues to push northward tomorrow morning, some heavier rainfall may be possible from Tuesday morning (7AM) into the early afternoon (1PM). Since the FTB season is over and this is a lower end threat at best, not thinking there will be a special bulletin FTB issued at this time.

Primetime: 10PM to 7AM

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

High fire danger continues for these regions as well, although the slight increase in moisture over the Northwest Slope (from movement in the west coast low) should keep relative humidity values high enough that no Red Flag Warning will need to be issued for that region today. Ongoing showers from early this morning may produce isolated totals up to 0.30 inches. A Red Flag Warning has been issued for the Grand Valley, northern Southwest Slope and Central Mountains where southwest surface winds in the 15 to 25 mph range and gusts up to 35 mph can be expected from noon to 9PM this evening in a low relative humidity environment. High temperatures will be a couple degrees warmer than yesterday, minus the Northwest Slope and Northern Mountains due to the increase in cloud cover.

Primetime: Ongoing to 11AM

Issue Date: 9/29/2019
Issue Time: 7:35 AM

NO FLOOD THREAT IS FORECAST TODAY.

The upper-level pattern has changed little since yesterday, but additional strengthening of both the low pressure over the western US and the high pressure over the southeastern US will bring an increase in winds over yesterday’s gusts. These winds will contribute to well above-average temperatures and critical fire weather conditions across much of the eastern half of Colorado. Red Flag Warnings have been issued for portions of the Northern Mountains, Central Mountains, and Front Range; nearly all of the Urban Corridor, Northeast Plains, Southeast Plains, and Raton Ridge; and all of the San Luis Valley, Southeast Mountains, and Palmer Ridge. Please check with your local National Weather Service office for more information.

West of the Continental Divide, a bit more moisture will be present, and a few scattered showers/garden-variety thunderstorms are expected, mainly over the higher terrain, with the best coverage over the Northwest Slope. Wind gusts of 20-35 mph are expected in the lower mountain valleys, with gusts as high as 60-70 mph at the highest peaks, and temperature will be near (or just above) average for this time of year.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. For Zone-Specific forecasts, scroll below the map.

Zone-Specific Forecasts

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

Gusty and dry conditions will be the main impacts today, resulting in dangerous fire weather conditions for the area. Wind gusts up to 35-45 mph over the plains, and up to 50-60 mph over higher terrain are expected. Red Flag Warnings have been issued, please check with your local National Weather Service office for more information. There is a small chance (less than 10%) of an isolated thunderstorm across the far Southeast Plains, but most likely this activity will remain just outside of the state border.

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

Gusty winds will be the most noticeable impact today, as well as a bit of increased cloud cover thanks to a bit more moisture being transported into the state by the upper-level low. With the moisture, a few scattered, high-based showers and garden-variety thunderstorms are expected throughout the afternoon and into the nighttime, with one or two continuing into the early morning. Generally speaking, rain rates will be less than 0.1 inches/hour, with maximum rates less than 0.2 inches/hour. Wind gusts will be 20-35 mph in the lower mountains valleys, and up to 60-70 mph at the highest peaks.