NOAA/National Severe Storms Laboratory

November 18-19, 1997, Norman OK


Opening Remarks (Schneider)

A. Goals for the meeting
B. Motivation for experiment
C. Philosophy of TIMEx planning
D. Proposed limits of the experiment with brief open discussion

Presentation of Hypotheses (moderated by Rasmussen, Ziegler, and Schneider)

Candidate Experiment Designs (moderated by Rasmussen)

A. Region (where; multiple sites?)
B. Season (when?)
C. Design elements (do what, how many times?)
D. Develop running summary of common design elements across hypotheses (where do the individual designs match?

Observational resource requirements (moderated by Ziegler) Each presenter to define the following:

A. What resources will be needed?
B. Which resources are easily acquired?
C. Which resources might already exist (e.g., old, under-analyzed data)?
D. Which resources require new funds/support?

Discussion of experiment timetable (moderated by Schneider)

A. Competing field projects?
B. What is an appropriate timetable for planning? (when are requests for facilities required, when are deadlines for proposals, etc.?)
C. What is the optimal target date for each/any of the field experiments?
D. Concatenate complimentary activities/field experiments into proposed TIMEx IOPs.


A. Topics and concerns not yet addressed.
B. Next gathering?

Meeting Participants


Roger Wakimoto (UCLA): 1 hypothesis
Andrew Crook (NCAR): 1 hypothesis
Tammy Weckwerth (NCAR): 1 hypothesis, several observing systems.
David Dowell (OU/SOM): 1 hypothesis
Rita Roberts (NCAR): 1 hypothesis
Jim Bresch (NCAR): 1 hypothesis
Dave Blanchard (NSSL): 1 hypothesis
Conrad Ziegler (NSSL): 4 hypotheses
Schneider for Atkins (1), Koch (3), Kingsmill (1)


Josh Wurman (OU/SOM): DOW radars
Andrew Pazmany (UMASS-AMHERST): several observing systems.
Bob Banta (NOAA/ETL): ETL lidar system


Vince Wong (CAPS): ARPS model
Jerry Klazura (ANL): ABLE network
Bob Lee (OSF): NEXRAD network
Randy Peppler (OU/CIMMS): ARM network
Curtis Marshall (OU/SOM): Oklahoma Mesonet


Kathy Kanak (OU/SOM) Doug Lilly (NSSL)
Renee McPherson (OU/OCS) Ken Crawford (OU/OCS)
Fred Carr (OU/SOM) Jerry Straka (OU/SOM)
Howie Bluestein (OU/SOM) Russ Schneider (NWS/SPC)
Steve Weiss (NWS/SPC) William Nichols (NWS/Dodge City)
Larry Ruthi (NWS/Dodge City) Steve Cobb (NWS/Amarillo)
Dave Andra (NWS/Norman) Dave Stensrud (NSSL)
Jeff Trapp (NSSL) Keith Brewster (CAPS)
Steven Peckham (Texas A&M) Rodger Brown (NSSL)
E. DeWayne Mitchell (NSSL)  


Meeting Introduction (by J. Schneider)

Goals for the meeting:

Galvanize the participants and the development of the hypotheses and plans. Walk away with critical seed material to start writing proposals.



1) Experience during VORTEX
2) Matching frustration among Southern Region SOOs
Summary - accurate prediction of convective initiation an unsolved problem.

What has been done? (a number of programs...clues)
What needs to be done? (more we look, more we see)
What can be done? (fiscal realities set in hard)


Philosophy of TIMEX Planning:


- program managers have become extremely reluctant to fund data collection/field programs, for some good reasons (from their point of view)
- remember the notable examples in the last 10 years of failures of established methods in the design, justification, and "sales" of field programs
- exception: VORTEX, which did an awful lot with very little.

We're taking the VORTEX approach a bit further, in a direction we believe will improve our chances of:
a) doing solid science, start to finish; and
b) obtaining the necessary funding.



- clear link between proposed activities and gain in knowledge;
- clear definition of costs of each hypothesis test;
- flexibility in changing fiscal environment;
- maintains individual ownership of scientific ideas (portable with scientist);
- allows plans to evolve with early results.



- requires a lot of thinking up front.


Outline of philosophy:

My own vision continues to evolve with discussion. Instead of a single effort, Iím beginning to think in terms of a continuing series of linked efforts. The collection of hypotheses will grow (see Figure 1) and each will evolve with development of the experiment designs and discussion. Hypotheses with identical or overlapping observational requirements should be fielded simultaneously (for example, Hyp. B, D, and E might be tested together). Lessons learned from early field efforts will generate revised (and better) hypotheses. We plan to use a web page to act as virtual meeting room for discussion and planning, and to provide support during proposal writing.



- just convective initiation
- hypothesis driven organization


Draft Timeline:

Dates Strategies
April - June, 1999 TIMEx Phase I: Test observing strategies, etc.
FY 2000 Analyze '99 results, modify hypotheses and observing strategies.
April - June, 2001 TIMEx Phase II
FY 2002 and on Analyze results.

TIMEx Field Area:



Meeting Notes

Generally, the degree of interest was even higher than we had expected. It is obvious that the general problem of convective initiation is quite complex, and poorly understood. This relative immaturity of understanding makes it difficult to phrase good testable hypotheses. As expected, there was a large variety in development of the presented hypotheses and related experiment plans. Plans from PIs with related field work tended to be focused on one or more specific aspects of candidate initiation processes, and were usually more advanced. Proposed locations to test this first generation of hypotheses tended to be in the Southern Great Plains, west of the tree line. This was primarily the result of the density of observing systems in this region, and challenges of observing surface-based initiation processes. It was broadly acknowledged that similar investigations may be required for regions with different climates and dominant initiation mechanisms, but none are currently expressed as hypotheses.

There was also a fair amount of resistance expressed on the first day relative to our hypothesis-based approach. Not all who are interested in the subject of convective initiation are prepared to tackle the problem within this framework. Participation in TIMEx is completely voluntary, and we welcome all who are willing to collaborate. Otherwise, we expect individual scientists to continue to pursue their goals in the manner they deem best outside of TIMEx.

In the process of discussion, several considerations became clear. First, the hypotheses posted and shared to date break down roughly into two kinds: elevated initiation processes (e.g., related to LLJ dynamics); and surface-based initiation processes (e.g., dry lines, outflow boundaries). The logistical and observational challenges involved in testing hypotheses are quite different for the two groups.

For elevated initiation processes, it appeared that some research could be performed immediately using either archived data, or operational and research network data. Testing of other hypotheses would require directed programs using existing instrument systems. Coordination and logistics would be quite similar to that of previous field programs (i.e., no new paradigms were required). For these hypotheses, the draft timeline for operations was reasonable.

The heavier demands arose relative to hypotheses on surface-based initiation. A number of scientists with related field experience presented strong arguments articulating a need to observe the evolution of the 3-D water vapor field, analagous to our ability to observe the wind field (e.g., portable scanning Doppler radars). Further, observation of moving surface boundaries presents an entirely different set of coordination and logistical challenges, of a higher degree of difficulty than has been previously managed (even in VORTEX). For these hypotheses, field operations will depend on developing:

- the required observational systems;
- techniques for targeting and observing moving surface boundaries; and
- refined experiment plans, based on both of the above.

With these points in mind, it wasnít clear whether the draft timeline was reasonable or not. Presentations on existing and possible observing systems were tantalizing (especially water vapor DIAL and mobile Raman lidar systems), but did not resolve the basic question of whether systems capable of observing the spatially and temporally complex water vapor field near the surface would be available. Interested PIs left the meeting with an agenda to explore and define the observational opportunities and challenges related to surface-based initiation.