James LaDue (OSF/OTB)
Brad Grant (OSF/OTB)
Andy Wood (OSF/OTB)
Daphne Zaras (NSSL/CIMMS)
Wendy Abshire (COMET)
Larry Dunn (NWS/WFO-SLC)
Ken Harding (NWS/WFO-ABR)
Greg Jackson (NWS/WFO-SJT)
Kevin Pence (NWS/WFO-BMX)
This session is designed to build onto Session 9.1.1, The Detection of Surface Boundaries which is offered as a teletraining session and is available online. We additionally recommend reviewing the references listed at the bottom of this page.
This is an intermediate course.
While IC9.2.1 covered integrated sensor applications to analyzing surface boundary locations, this session goes one step forward to analyzing the characteristics of surface boundaries that are currently understood to be related to initiating convection. This session will address the questions that are asked below:
- How representative are objective analysis of surface convergence to that of real convergence across boundaries?
- How can a forecaster make estimations on the depth of a boundary ascent zone?
- What boundary-relative flow and shear configurations are favorable (not favorable) for initiating convection?How can boundary-relative flow and shear be easily calculated using AWIPS?
- What impact to boundary intersections and undulations have on the probability of convective initiation?
Note that the scope of this session is limited to surface-based convective initiation on low-level boundaries. This is only a small part of the large number of considerations regarding convective initiation forecasting.
Also remember that the considerations that we present in this session are not hard proven answers that will be the sole basis for anticipating convective initiation. Much research still needs to be done in this area. Some of the theories presented here may change given new observational and theoretical evidence. A major field program called TIMEx is planned in 2002 in the Great Plains in order to understand the nature of convective initiation. In the meantime, each of you also have the capability to validate how effective some of these theories are for your area.
Important
- If you are unfamiliar with Visitview, review the Visitview site.
- There are separate instructor guides or talking points for the web-only and teletraining sessions which provide explanations for each page. To access the guide, follow the link below or click on the 'show URL' button in the visitview lesson and the guide for the corresponding page will appear.
A.) Signup here for the interactive VISITview teletraining session with a VISIT instructor. The session will last 120 minutes. The teletraining sessions utilize the VISITview software, where Windows PC (with 64 MB RAM or greater) with an internet connection is needed.
B.) Web-based training session - a "stand alone" version viewed via a Web browser, with embedded talking points included. This lesson version may be viewed at any time. These slides are ideal for printing from the web browser, just print preview first to choose portrait or landscape mode.
C.) Web-based Visitview session - This version uses the VISITview software within a Web browser, and may be viewed at any time. It retains all the functionality of the VISITview software which you see in a "live" teletraining session. The talking points are not included in this lesson version, but can be viewed in a separate Web browser (or printed out beforehand).
D.) Local Visitview session - This is the same version of the lesson used in a "live" VISITview teletraining session, but no connection is made to an external VISITview server. You may download the file off this page and go through the lesson on your own in "local mode" by starting the "visitlocal.bat" file. Talking points are not included in this lesson version, but can be viewed in a separate Web browser ( or printed out beforehand).
Instructor guide or talking points for the web-only session here. These may be used by local offices to explain important points in the session. Remember that you may also click on the 'show URL' button in Visitview to show each page.
Instructor guide or talking points for the teletraining session here.
Jim LaDue (405) 366-6560 ext. 4281
Brad Grant (405) 366-6560 ext. 4273
Crook, N. A., 1996: Sensitivity of moist convection forced by boundary layer processes to low- level thermodynamic fields. Mon. Wea. Rev., 124, 1767-1785.
Hane, C. E., H. B. Bluestein, T. M. Crawford, M. E. Baldwin, and R. M. Rabin, 1996: Severe thunderstorm development in relation to along-dryline variability: A case study. Mon. Wea. Rev., 125, 231-251.
Kingsmill, D. E., 1995: Convection initiation associated with a sea-breeze, a gust front, and their collision. Mon. Wea. Rev., 123, 2913-2933.
Koch, S. E., and C. A. Ray, 1997: Mesoanalysis of summertime convergence zones in central and eastern North Carolina. Wea. Forecasting, 12, 56-77.
Purdom, J. F. W., 1976: Some uses of high-resolution GOES imagery in the mesoscale forecasting of convection and its behavior. Mon. wea. Rev., 194, 1474-1483.
Rotunno, R., J. B. Klemp, and M. L. Weisman, 1988: A theory for strong, long-lived squall lines. J. Atmos. Sci., 45, 463-485.
Wilson, J. W., G. B. Foote, N. A. Crook, J. C. Fankhauser, C. G. Wade, J. D. Tuttle, C. K. Mueller, and S. K. Krueger, 1992: The role of boundary-layer convergence zones and horizontal rolls in the initiation of thunderstorms: A case study. Mon. Wea. Rev., 120, 1785-1815.
Wilson, J. W., and D. L. Megenhardt, 1996: Thunderstorm initiation, organization, and lifetime associated with Florida boundary layer convergence lines. Mon. Wea. Rev., 125, 1507-1525.
Wilson, J. W., and C. K. Mueller, 1992: Nowcasts of thunderstorm initiation and evolution. Weather and Forecasting, 8, 113-131.
Wilson, J. W., and W. E. Schreiber, 1986: Initiation of convective storms by radar-observed boundary layer convergent lines. Mon. Wea. Rev., 115, 2516-2536.
Ziegler, C. L., and E. N. Rasmussen, 1998: The initiation of moist convection at the dryline: forecasting issues from a case study perspective. Weather and Forecasting, 13, 1106-1131.
Moncrieff, M. W., and C. Liu, 1999: Convection Initiation by Density Currents: Role of Convergence, Shear, and Dynamical Organization. Monthly Weather Review, 127, No. 10, pp. 2455–2464.