Monday, 12 August 2002
Meteorological characteristics of a severe wind and dust emission event; southwestern USA, 6–7 April 2001
On 6 April 2001, a strongly forced convective system produced high winds propagating across large portions of the southwestern USA and northern Mexico. These severe winds reached damaging levels over much of eastern New Mexico and the Texas and Oklahoma Panhandles, with wind speeds in excess of 35 m/s being measured at West Texas Mesonet sites in the southern Panhandle. The extensive area of impact coupled with ongoing drought conditions also led an unusually large amount of blowing dust to be lofted into the troposphere from northern Mexico, eastern New Mexico and western Texas, and the rare issuance of a Dust Storm Warning by the Lubbock NWSFO. The synoptic scale conditions causing this severe high wind event included a rapidly deepening surface cyclone (pressure falls of 5 mb in 3 hr) to the north of the region, a dryline across the domain (its passage associated with the majority of the wind damage), a Pacific cold front entering from the west, and tropospheric humidity conditions to support high wind and convective storms resulting in a squall line crossing the Texas Panhandle. During the succeeding day, airborne dust was transported northeastward over east-central North America. Precipitation samples from Pennsylvania and across Ontario, Canada on 7 April were laden with reddish dust that appeared to originate from this event based on air-mass trajectories. The provenance of the dust has been confirmed by tracer analysis of the dust particles.
This paper examines the meteorological conditions that were present during the initiation of the severe windstorms and the occurrence of wind damage across western Texas, and provides an overview of the synoptic scale trajectories that followed the lofting of the dust and the eventual settling/rainout of the aerosols.
Supplementary URL: