El Paso County tornado 8/13/08

Overview

Mid-afternoon on August 13th, a supercell spawned a tornado southeast of Ramah. The tornado lasted from 4:16 p.m. to 4:25 p.m. and the path length was approximately 1 1/3 miles. The tornado damage rating was EF1.

Storm Chasers Dann Cianca and Michael Carlson were on the storm and took photographs and video of the developing storm. They also conducted a damage survey of the area. Many thanks to Dann and Michael.

Tornado Track

Photos & Video
Radar
Environment

Photos & Video:


Mesocyclone Captured by Dann Cianca	The Tornado Captured by Dann Cianca	Damage to a Barn Captured by Dann Cianca	Fence Damage Captured by Dann Cianca

Radar:

Radar Base Reflectivity and Base Velocity Volume Scans of the Tornadic Event

Environment

There are three main circulations that can be seen in the SPC upper air maps, two upper level lows, one located over Quebec and the other located over Saskatchewan and Manitoba, and a upper-level ridge located over the majority of the western United States. The ridge built over the western U.S. and the low over Saskatchewan and Manitoba provided northwesterly to west-northwesterly flow over southeastern Colorado. The surface flow, though, was from east-southeast. The surface southeasterly flow did two things for the environment, the first was that it provides a wind sheared environment, conducive for supercell thunderstorms to form, and second, provided low level moisture, with moisture originating from the Gulf of Mexico. The 700-hPa analysis shows a shortwave trough over the region, which formed into a lee trough, underwent lee-cyclogenesis, creating a boundary in which thunderstorms could initiate over. Once the thunderstorm developed over northern El Paso County, a rogue southwesterly propagating outflow boundary originating from a supercell over the eastern Colorado plains, interacted with it, enhancing the low-level shear. The low level shear was strong enough to produce tornadogenesis.
Archived SPC Day 1 Outlook for August 13th, 2008

Archived Day 1 SPC Outlook

August 13th, 2008 at 6:00 AM MDT


Surface Analysis	850-hPa Analysis	700-hPa Analysis


500-hPa Analysis	300-hPa Analysis

August 13th, 2008 at 6:00 PM MDT


Surface Analysis	850-hPa Analysi	Figure 3: Caption


500-hPa Analysis	300-hPa Analysis

Thermodynamic Profiles of the Atmosphere (Skew T Log P Diagram)

August 13th, 2008 at 6:00 AM MDT


KDNR Sounding	KDDC Sounding

August 13th, 2008 at 6:00 PM MDT


KDNR Sounding	KDDC Sounding

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