FTB 09-14-2018: Persistent Ridge Equals another Day of Summer-like Conditions for Colorado

Issue Date: Friday, September 14th, 2018
Issue Time: 08:45AM MDT

 — Flooding is NOT expected today

Another crystal clear start to the day with little change in the dry and warm air mass over the state. Not much movement in the trough pattern over the west coast either, though the upper-level jet will start to pull northward throughout the day. This should reduce areal coverage of higher surface winds across western CO and decrease fire weather over most areas from critical levels to enhanced levels. With such dry fuels and low relative humidity values, extreme caution should still be observed with any activity that could produce a spark. Surface winds over the Northwest Slope are forecast to be in the 15-25 mph range. Gusts up to 40 mph will also be possible over this area. These winds paired with the dry fuels and low relativity humidity values mentioned above will produce Day 4 of a Red Flag Warning. Precipitable Water values were measured around 0.2 inches at both Denver and Grand Junction this morning, so not expecting much, if any, cloud cover again this afternoon. With severe clear skies, flooding is not expected 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:

Southeast Plains, Palmer Ridge, Urban Corridor, Northeast Plains, Raton Ridge, Southeast Mountains, Front Range, San Juan Mountains, San Luis Valley:

Above average temperatures expected again this afternoon with blue skies. Some higher wind speeds are expected over the eastern plains, but higher dew points should keep the area from reaching critical fire weather thresholds. Similar to yesterday, not expecting much, if any, cloud cover this afternoon and evening. Still a lot of enhanced fire weather for these regions, so caution should continue to be used with any activity that could produce a spark.

Grand Valley, Central Mountains, Northern Mountains, Southwest Slope, Northwest Slope:

With the upper-level jet pulling back northwards a bit, the stronger surface winds should be confined to the Northwest Slope. Synced with another day of low relativity humidity and dry fuels, this will produce Day 4 of a Red Flag Warning. Surface winds today will likely be between 15 and 25 mph with gust up to 40mph possible. Please use extreme caution with any activity that can produce a spark. The Red Flag Warning is in effect from 10AM to 9PM. Though still not great conditions for fighting the Silver Creek Fire, the reduced surface winds should be a slight improvement from yesterday.

 

FTB 09-13-2018: Severe Clear with Day 3 of Critical Fire Weather

Issue Date: Thursday, September 13th, 2018
Issue Time: 08:35AM MDT

— Flooding is NOT expected today

The broad ridge over the eastern half of the US will continue to influence its effects over the state again this afternoon, which will bring another day of warm and dry weather. High temperatures will be similar to Wednesday, so 10-15F above average values will be realized once again. Southwest flow will continue to entrain an arid and hot air mass into the state as seen in the water vapor imagery the past couple of days. That means severe clear skies are forecast across the state/area as seen in the visible satellite imagery below. The upper-level jet will sag a bit further south and east today, which means stronger winds aloft will mix down to the surface over a greater area. Expecting surface winds to be a bit stronger over the northwest corner of the state when compared to further south. Gusts up to 45 mph are possible across the lower elevations again north of I-70, whereas surface winds in the 20-30 mph range (north) and 15-25 mph range (south) are anticipated this afternoon. This will return critical fire weather to western and north-central Colorado this afternoon due to relative humidity values in the low-teens and single digits. A Red Flag Warning is in place for the third day (11AM-9PM) over the shaded area below. Across the mountains, including the San Luis Valley, and eastern plains elevated fire danger is expected this afternoon. With severe clear skies today, there is no Colorado flood threat.

 

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:

Grand Valley, Central Mountains, Northern Mountains, Southwest Slope, Northwest Slope:

With the upper-level jet sagging south and east, stronger winds will mix down to the surface over a larger area today. Paired with high temperatures and relative humidity values in the teens to single digits, critical fire weather is forecast once again. Surface winds today will likely be between 20 and 30 mph with gust up to 40mph (north) and 15-25 mph further south. Please use extreme caution with any activity that can produce a spark. A Red Flag Warning is in effect for day 3 from 11AM to 9PM.

Southeast Plains, Palmer Ridge, Urban Corridor, Northeast Plains, Raton Ridge, Southeast Mountains, Front Range, San Juan Mountains, San Luis Valley:

Blue skies and 10-15F above average temperatures will bring another day that feels more like mid-August rather than mid-September. High temperatures over the lower elevations are forecast to be 90F+ with higher elevations reaching high temperatures similar to yesterday. Not expecting much, if any cloud cover this afternoon. Winds between 15-20 mph are possible over the far eastern plains and mountain areas, which is expected to lead to enhanced fire weather. At this time, Red Flag Warning criteria will not be met though caution should be used with any activity that could produce a spark.

 

FTB 09-12-2018: Increased Surface Winds and Low Relative Humidity Combine to Produce another Day of Critical Fire Weather

Issue Date: Wednesday, September 12th, 2018
Issue Time: 09:05AM MDT

— Flooding is NOT expected today

Southwest flow aloft will continue today, which will produce another day of near-record high temperatures. The warm, arid air mass from the southwest has scoured out a lot of the remaining moisture the last few days, so skies are forecast to be mostly clear this afternoon. This will also nearly zero out the chances for rainfall today though some isolated, light cloud cover may be possible. As expected, above average temperatures and low relative humidity values increase fire danger. With stronger winds aloft mixing down to the surface, critical fire weather is forecast for northwest and west-central Colorado. A Red Flag Warning is in place from 11AM this morning to 8PM this evening with surface winds forecast to be between 20 and 30 mph. Gusts up to 40 mph are also possible. As anticipated, there is no flood threat 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:

Southeast Plains, Palmer Ridge, Urban Corridor, Northeast Plains, Raton Ridge, Southeast Mountains, Front Range, San Juan Mountains, San Luis Valley:

Clear skies and above average temperatures will put us near (or above) records again today. High temperatures over the lower elevations are forecast to be 90F+ with higher elevations also increasing a tick or two from yesterday. Isolated, light cloud cover is possible over the higher terrains this afternoon as well as over the Palmer and Raton Ridges though rainfall is not anticipated. Winds between 15-20 mph are possible over the far eastern plains, which should lead to enhanced fire weather over this region. At this time, Red Flag Warning criteria will not be met. There should be plentiful sunshine statewide, so be sure to get out and enjoy the weather.

Grand Valley, Central Mountains, Northern Mountains, Southwest Slope, Northwest Slope:

Stronger winds will mix down to the surface again today. Paired with high temperatures and relative humidity values in the teens to single digits, critical fire weather is forecast once again. Surface winds today will likely be between 20 and 30 mph with gust up to 40mph. Please use extreme caution with any activity that can produce a spark. A Red Flag Warning is in effect from 11AM to 8PM.

FTB 09-11-2018: Critical Fire Weather for Northwest Colorado

Issue Date: Tuesday, September 11th, 2018
Issue Time: 09:15AM MDT

 — Flooding is NOT expected today

The drying and warming trend will continue today. Expecting high temperatures in the lower elevations to reach the 90F mark, which is very impressive for mid-September. Southwesterly and westerly flow aloft will continue to pull in the arid air mass seen in the water vapor imagery below (yellow and orange). Precipitable Water values were measured a little above 0.5 inches at Denver and Grand Junction with both soundings showing an inverted-V profile. Together these indicate most of the low and mid-level moisture has been mixed out, which should limit measurable rainfall chances this afternoon. The water vapor imagery below also shows a shortwave, so increased cloud cover will be likely as the feature moves eastward. While measureable rainfall chances are lower today, there is still a chance for an isolated light shower or two along the Continental Divide this afternoon. Expect some gusty outflow winds rather than wetting rains with storms that are able to form. If the shortwave is able to help maintain a weak storm into the adjacent plains, strong outflow winds are likely as the storm evaporates (similar to yesterday). Lastly, warm temperatures and low relative humidity will be paired with some stronger surface winds over northwest Colorado today, which is expected to produce critical fire weather. A Red Flag Warning is in place from 11AM this morning to 8PM this evening with surface winds forecast to be between 15 and 25 mph.

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:

Southeast Plains, Palmer Ridge, Urban Corridor, Northeast Plains, Raton Ridge, Southeast Mountains, Front Range, San Juan Mountains, San Luis Valley, Southwest Slope:

The drying and warming trend continues, which should produce 90F temperatures in the lower elevations with highs in the 70Fs over the higher elevations. A few light showers are possible along and near the Continental Divide this afternoon, but gusty winds and increased cloud cover are more likely than measureable rainfall. Max 1-hr totals up to 0.1 inches are possible though most storms will likely produce sprinkles. There is a chance that a storm or two survives into the adjacent plains with help from the shortwave. Although rainfall totals would increase slightly, these storms could produce strong outflow winds as they evaporate.

Primetime: 1PM to 8PM

Grand Valley, Central Mountains, Northern Mountains, Northwest Slope:

Warmer temperature this afternoon with some strong winds mixing down to the surface. Paired with high temperatures and low relative humidity, critical fire weather is anticipated for the rest of this week. Surface winds today will likely be between 20 and 25 mph with gust around 30mph, so please use extra caution with any activity that can produce a spark. A Red Flag Warning is in effect from 11AM to 8PM.