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.