Poster Session P3.12 A Forecaster challenge: Convectively enhanced winds in a strongly forced synoptic environment in complex terrain

Thursday, 31 August 2006
Ballroom North (La Fonda on the Plaza)
M. Meyers, NOAA/NWS, Grand Junction, CO; and J. LaDue, J. Pringle, and C. Cuoco

Handout (405.7 kB)

On April 05, 2006, a strong cold front moved through the eastern Great Basin region and subsequently, through western Colorado. The front was associated with a deep positively tilted trough aloft. Ahead of the surface front, wind speeds at several mountain locations across eastern Utah and western Colorado exceeded 30 m s-1 (500 hPa wind speeds of 35 to 40 m s-1). At approximately 11:00 AM MDT, a line of Deep, Moist Convection (DMC) developed over the Utah Wasatch Front. Given that the favorable near storm environment existed for severe winds and/or hail, SPC and GJT decided to issue a Severe Thunderstorm Watch at 11:30 AM MDT. The line moved east at 12 m s-1, with individual cell movement at 25 to 30 m s-1. This line of DMC eventually moved into the Grand Junction WFO (GJT) forecast area. However, the thunderstorms weakened considerably shortly thereafter. Though convective cells covered most of the GJT area, a relatively small percentage of them produced lightning. We will examine whether a Severe Thunderstorm Watch was the most appropriate product, or if a High Wind Watch or Warning would better suit the situation.

- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner