Issue Date: Tuesday, June 13th, 2017
Issue Time: 9:45AM MDT
Summary:
Impressive amounts of low-level moisture were noted on Monday morning across Colorado. Morning dew point temperatures were above 60F across wide areas of the northeast part of the state, with precipitable water exceeding 1.0 inch in a few locations. With a strong approaching disturbance, this could have led to quiet the setup for heavy rainfall. However, two factors mitigated this. First, moisture was quite shallow, which was put on clear display in the early afternoon hours as foothill locations in the Palmer Divide and Front Range experienced a 25F or more drop in the dew point temperature as the boundary layer grew in height and mixed down drier air aloft. Second, the storm steering winds increased in speed to over 40mph. Thus, for the storms that did develop, they were not in one location for very long.
Instead of heavy rain, there were two stories that dominated the weather headlines on Monday. First, several supercell thunderstorms developed in the northern Urban Corridor and Front Range. These storms had access to high amounts of instability, speed and directional shear, creating the perfect setup for strong, rotating updrafts. The result was numerous reports of large hail, as large as 4.25 inches in Weld County. In addition, tornado reports were received in Weld and Larimer counties. Max rainfall with these storms was up to 0.75 inches, with most of that falling in 30 minutes or less.
The second main story was the very windy conditions across western Colorado, as shown in the map below. A report is only recorded if it exceeds 45 mph, and many of the reports below were in excess of 60 mph. With low relative humidity, two more “large incident” fires appeared on Monday: the Dead Dog and Hunter fires, both in Rio Blanco county. Stay tuned to the Grand Junction National Weather Service for updates on these, and fire forecasts.
Flooding was not reported on Monday. For precipitation estimates in your area, check out the State Precipitation Map below.
