Extended Abstract (412K)P3.12
A Forecaster challenge: Convectively enhanced winds in a strongly forced synoptic environment in complex terrain
M. Meyers, NOAA/NWS, Grand Junction, CO; and J. LaDue, J. Pringle, and C. Cuoco
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.
Poster Session 3, Forecasting, Climate and Air Quality
Thursday, 31 August 2006, 2:30 PM-4:00 PM, Ballroom North
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