Saturday, June 06, 2015

Colorado Tornadoes Intensify

[Examiner] The Colorado Front Range has been under tornado and flood watches today , with a number of tornado warnings being issued for storms near Bennett, Colorado, that produced several confirmed tornadoes. Yesterday, tornadoes touched down between Loveland and Longmont, Colorado, resulting in nearly a dozen destroyed or damaged homes, downed power poles, and debarked trees. The north side of the town of Simla, Colorado, also experienced some significant tornado damage, yesterday, as well.
At night time, the storm that produced tornadoes over northern Longmont in the afternoon, also managed to dump an incredible 6 inches of rain in only a few hours at night creating a number of flash floods in already swollen creeks and river banks.
Tornadic storms resulted from afternoon springtime surface heating with unusually high Colorado surface dew points 82/60, a fairly strong west-to-easterly cold jet flow at 300 mb stronger than 50 knots, augmented by exceptionally high surface based convectively available potential energy (CAPE), high energy helicity (EHI), surface shear, strong backed wind profiles, and surface flows feeding storm inflows from the southeast. A deepening surface low along the warm front boundary in Elizabeth, Colorado contributed to the development of the Simla mega-spercell.
Yesterday morning started out with clear skies and heavy dew points, and the afternoon heated up to mid 80f temperatures. Not long afterwards, jet streaks appeared high over the eastern plains of Colorado, considerably enhancing instability. Storms began to fire in late morning, and intensified sharply as afternoon heating eroded the weak convective inhibition (CAP). Cumulus cloud fields quickly intensified into volcanic updraft towers around the Denver south metro area, and these storms moved eastward into Elizabeth, Colorado, quickly forming into supercell complexes, and evolving into very strong (Texas sized) towering mesocyclone storms, several of which produced tornadic storm structures, and one in particular, a bit north of Simla, Colorado organized into an exceedingly large tornadic storm with tops exceeding 55,000ft at points. The Simla tornadic storm, once anchored to the warm front, slowed easterly progress to around 15 miles per hour, and the storm developed a strong inflow, and right turned to produce a cyclic tornadic storm that created half a dozen strong long lived tornadoes, of various types, including: rope tornadoes, stove pipe tornadoes, and at least one rain wrapped wedge tornado, with a number of these tornadoes occurred simultaneously. On June 4th, the large supercells were slow southeast moving right turning mesocyclones; whereas, today, tornadic storms in Colorado were mostly northeasterly tracking tornado producers. Read More