FTB 05-15-2022: Isolated High-Based Storms, But Otherwise Quiet Weather Day

Issue Date: Sunday, May 15th, 2022
Issue Time: 8:45AM MDT

Flooding is NOT expected today

Plenty of sunshine and more heat are forecast to round out this mid-May weekend. Today, the ridge will continue to dominate the weather pattern with the axis sliding east. This will help to produce those warmer temperatures, but also calm the winds. There was a weak cool front that slid through eastern Colorado associated with the departing shortwave from yesterday. Currently, there are some decent northerly wind gusts over the far eastern plains being produced with a second push of this cooler air, but these should begin to settle by late morning. This cool front will help to keep high temperatures only slightly cooler over the northeast portion of the state.

As far as moisture, there was some weak moisture return behind this feature, and PW at Denver and Grand Junction has jumped up to 0.39 inches. This should be just enough moisture help kick off isolated storms over the southern Front Range and Southeast Mountains as well as the elevated Palmer and Raton Ridges as the diurnal upslope flow pattern sets up by this afternoon. Unfortunately, soundings show this moisture in the mid and upper levels. With the dry surface layer remaining intact, there is a better chance for virga and brief outflow winds versus meaningful rainfall accumulation from these storms. So, there is NO flood threat issued. Not all bad news, this slight increase in moisture, paired with less wind, will help to damper the fire danger.

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:

San Juan Mountains, Front Range, Southeast Mountains, San Luis Valley, Raton Ridge & Palmer Ridge:

High-based, isolated storms will be possible today over the southern Front Range, Southeast Mountains, eastern San Juan Mountains as well as the ridges. More virga than meaningful rainfall is forecast due to the dry surface layer. That means that the storms that do develop may produce some brief outflow winds. Max totals up to 0.15 inches may be possible with most storms producing under 0.05 inches. Flooding is NOT expected.

Primetime: 11AM to 6:30PM

Central Mountains, Northern Mountains, Northwest Slope, Grand Valley, Southwest Slope, Northeast Plains, Southeast Plains & Urban Corridor:

Temperatures will be on the rise with slightly cooler temperatures forecast over the northeast corner. Highs are forecast to reach the upper 80Fs over the lower elevations east and west, and 80Fs are forecast for the SLV, Urban Corridor and Northeast Plains. Mountain valleys should reach into the 70Fs. There is an outside chance that some very isolated, high-based storms develop over the Northwest Slope, but they will likely only produce cloud cover and maybe a few sprinkles.

FTB 05-14-2022: Dry + Warm

Issue Date: Saturday, May 14th, 2022
Issue Time: 8:45AM MDT

Flooding is NOT expected today
— Red Flag Warnings continue for south/central Colorado

Zonal flow at the mid and upper levels will gain a slightly more northerly component today as a weak ridge begins to build just to our west. This building ridge will promote subsidence or sinking motion across the state, so another beautiful spring day is on tap. PW at Grand Junction and Denver was measured at 0.30 and 0.24 inches, respectively. So, there is a slight increase in moisture, but it will still be very dry causing the probability of rainfall to remain close to zero. Therefore, there is NO flood threat expected. The good news is that the building ridge should decrease the winds. However, Red Flag Warning criteria will still be met over south-central Colorado, so elevated fire danger continues for this area.

By the afternoon hours, expect cloud cover to increase from north to south as a weak, embedded shortwave moves through the westerly flow to our north (orange “X”). This feature will help to drop a cool front through the state overnight, which is forecast to bring cooler temperatures and cloud cover to eastern Colorado tomorrow morning. This may produce some gusts as it drops south through Sunday morning, which would be most likely to occur over the far eastern plains.

Lastly, the HRRR model indicates near-surface smoke from the High Park Fire (Teller County) will cause air quality and visibility issues to areas to areas east and southeast of the area. The fire had grown to 931 acres as of 6:30AM.

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:

Central Mountains, San Juan Mountains, Front Range, Southeast Mountains, San Luis Valley, Raton Ridge & Southeast Plains:

A Red Flag Warning has been issued for all or portions of these areas from 11AM to 8PM. West to southwest winds in the 10 to 25 mph with gusts up to 35 mph (mountains) and 30 mph (lower elevations) will be possible. Tune into your local NWS for the latest on fire danger over your area. Highs should reach into the upper 70Fs to mid-80Fs across the SLV and adjacent eastern plains with upper 60Fs for the mountain valleys. Rainfall is not forecast.

Northern Mountains, Northwest Slope, Northeast Plains, Urban Corridor, Grand Valley, Southwest Slope & Palmer Ridge:

Above average temperatures and dry conditions will stick around this Saturday. Highs will reach into the 80Fs across the lower elevations with upper 60Fs and low 70Fs forecast for the mountain valleys. No rainfall is forecast today, but expect an increase in cloud cover throughout the afternoon and into the evening.

FTB 05-13-2022: A Pleasant Spring Friday, Though Fire Threat Continues

Issue Date: Friday, May 13th, 2022
Issue Time: 8:45AM MDT

— Flooding is NOT expected today
— Red Flag Warnings remain in effect for parts of the state

After a series of disturbances that raced across Colorado over the past few days fueling mainly a wind threat, things will quiet down in the upper atmosphere today. As shown in the visible satellite image, below, a nonchalant zonal flow is seen from the California coast all the way into Colorado. To the north, relatively higher moisture will support some enhanced cloudiness, along with breezy conditions mainly over northern Colorado. Red Flag Warnings are still in effect mainly over northeast Colorado today. To the south, bone dry conditions will persist though the subsidence of gusty winds will relax the fire threat a bit. This morning’s PW at Denver measured at an incredibly dry 0.17 inches. This would not be too unusual in January, but in mid-May, this sits in the lowest few percentiles, compared to the historical record. Thus, with no precipitation expected anywhere in the state, flooding is also NOT expected today.

Looking ahead to the weekend, an upper-level ridge is expected to develop and push temperatures above seasonal normal statewide. Snowmelt will increase notably over the central and northern high terrains, but precipitation is not expected until perhaps Sunday afternoon.

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, Southeast Mountains, Raton Ridge, Front Range, Urban Corridor, San Luis Valley & Palmer Ridge:

Mostly sunny and seasonably warm today with temperatures 3-6F above normal. Breezy conditions will develop towards the WY border, and Red Flag Warnings are in effect over the Northeast Plains. Flooding is NOT expected today.

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

Partly cloudy and seasonably cool today with temperatures 2-5F below normal. Flooding is NOT expected today.

FTB 05-12-2022: Light Showers Possible Across the Northern Border & Critical Fire Weather East

Issue Date: Thursday, May 12th, 2022
Issue Time: 9:55AM MDT

Flooding is NOT expected today
— Widespread Red Flag Warnings in effect

The trough axis is marked as an orange dashed line in the visible satellite imagery below. Throughout the day, this feature is forecast to move to the northeast bringing with it a little mid-level lift and more widespread, windy conditions. As the Low clips the northwest corner of the state, it will likely bring some modest moisture to the area. PW at Denver was measured at 0.39 inches with moisture located at the surface and near 300mb, and some slightly higher dew points were noted in northeast Utah. This should be just enough moisture for some light precipitation to develop this morning and into the afternoon hours over the Northwest quadrant of the state (just south of the Wyoming border). Generally speaking, it is still quite dry over this region, so only scattered, light precipitation is anticipated, and accumulation is most likely over the higher elevations. A weak storm or two may also fire over the Cheyenne Ridge by midday, but northwest steering flow should keep the measurable precipitation north of the state. Flooding is NOT anticipated today.

Under the influence of the Low, strong winds and critical fire weather are anticipated once again across large portions of the state. The focus area today will be over areas east of the Continental Divide, associated with the location of the jet. The highest fire danger is forecast east of the dotted red line in image above. A very dry air mass will also be advected into the southwest corner of the state, so although winds will be less today, still use caution with any activities that could produce a spark. The good news is that the wind threat should begin to ease up with the northeasterly movement of the jet by this afternoon. However, a secondary peak in wind speed is forecast tonight, which will likely redevelop windy conditions over the Front Range tonight.

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:

Northern Mountains, Northwest Slope & Front Range:

Scattered precipitation will likely develop over these regions, just south of the Wyoming border, by mid-morning. Without much moisture to work with, only scattered, light showers are forecast through the afternoon. Isolated max totals just under 0.20 inches will be possible, and high terrains will be favored for accumulation. Flooding is NOT expected.

Very strong winds are forecast to develop over the next hour or two along the Front Range through mid-afternoon, and a Red Flag Warning has been issued. Windy conditions may redevelop over the high peaks of the Front Range overnight.

Primetime: 10AM to 5PM

Southeast Plains, Northeast Plains, Urban Corridor, San Luis Valley, Palmer Ridge, Raton Ridge, Central Mountains & Southeast Mountains:

Dry and windy day ahead. Critical fire weather is forecast for all or portions of these regions this afternoon. Gusts up to 50 mph are possible over the foothills. Paired with dry conditions (remaining surface moisture mixing out), a Red Flag Warning has been issued until 9PM this evening. High Wind Warnings are also issued through noon for El Paso and Huerfano Counties where gusts up to 55mph were already recorded this morning. Since rainfall is not forecast, there is NO flood threat issued. Tune into your local NWS office today for the latest on the fire danger threat.

Grand Valley, San Juan Mountains & Southwest Slope:

Another dry day on tap, but it should at least be less windy. The exception for this will be over the eastern San Juan Mountains this morning where gusts could reach 50 mph. Despite the lack of windy conditions, there are some very low dew points (dry air) that are expected to work their way into the southwest corner with the SSW wind. So, use caution with activities that could cause a spark. Afternoon high temperatures will be more seasonable today with mid to upper 60Fs forecast for the lower elevations.