The purpose of this research was to use observational tools available to the operational forecaster on the SGP of the U.S., such as atmospheric soundings and surface observations, to predict Cl along the dryline. To accomplish this goal dryline cases from the spring months of 2004 and 2005 were compiled. In particular, drylines that stayed within the confines of the WTM array were analyzed. Drylines that were chosen for this research were then categorized as Cl if the dryline initiated deep moist convection, or NCI if convection was not present along the dryline. For this study, Cl was deemed to occur when a precipitation echo was noted on radar along the dryline. From the data collected during the springs of 2004 and 2005, a stepwise logistic regression procedure was executed to generate a forecast equation for Cl along the dryline. It includes the 500 hPa height difference between AMA and MAF, the 700 to 500 h Pa and 850 to 500 h Pa lapse rates, and the SDD. It is hypothesized that the negative correlation between Cl and the 700 to 500 hPa lapse rate (after the variance by dz is explained) is the result of increased entrainment resulting from stronger updrafts present with larger lapse rates. Results from two case studies show the potential usefulness of the Cl probability equation, as the highest probabilities calculated were all on 28 May 2006, when convection initiated along the dryline. Additionally the largest probability was also associated with the strongest convection.
|State||Published - 2007|
|Event||23rd AMS Conference on Severe Local Storms, SLS 2006 - St.Louis, MO, United States|
Duration: Nov 6 2006 → Nov 10 2006
|Conference||23rd AMS Conference on Severe Local Storms, SLS 2006|
|Period||11/6/06 → 11/10/06|