CSTAR Update – notes from the quarterly conference call on 09 March

A conference call with the principal investigators, the collaborative investigators, students, and other NWS participants with the ongoing CSTAR project was held on 09 March. Some notes from the call are shown below.

Participants included Dr Lackmann, Dr Aiyyer, Bryce Tyner, Keith Sherburn, Jason Davis, and Jordan Dale (NCSU), Frank Alsheimer (CHS), Justin Lane (GSP), David Roth (HPC), Reid Hawkins (ILM), Gail Hartfield and Jonathan Blaes (RAH), and Jeff Waldstreicher (ERH).

QPF associated with tropical cyclone boundary interaction

  • Project continues to gain momentum and has made a great deal of progress during the past few months.
  • The project will focus on examining the predictability of inland surface boundaries and their impact on tropical cyclone QPF. This project will examine the interaction of tropical cyclones with weak and strong boundaries. The goal is to identify what processes determine if a boundary will form and then determine the resulting distribution of precipitation and wind.
  • A total of 54 tropical cyclones that moved through the CSTAR study domain since 1995 were identified as potential cases.
  • Three criteria were used to trim the dataset and identify a selected number of candidate cases:
    • Must have occurred since the year 2000 to ensure good quality data and somewhat contemporary NWP was used
    • The TC needed to move across the portions of the Carolinas and Virginia
    • A maximum of 6 inches of rain or more was required.
  • An initial list of 7 candidate cases were identified and shared in a spreadsheet in an effort to obtain input from project participants. Input on the event impact, forecast success, availability of archived data such as that for the WES, and general impressions was received. Several project participants provided useful and constructive input which resulted in the addition of 5 cases.
  • Based on the input and the availability of data, Tropical Strom Ernesto from August/September 2006 has been selected as the first case.
  • Tropical Storm Ernesto which can be described as a modest tropical cyclone with a strong boundary; will be compared with Tropical Storm Hanna which can be described as a modest tropical cyclone with a weak boundary.
  • Jordan and Dr Lackmann developed an outline for the TC QPF/Boundary Interaction Case Study methodology which was shared via the CIMMSE blog.
  • Jordan will be visiting RAH the week of 12 March to view archived data for Ernesto via the WES.
  • Conference calls for the TC boundary QPF project were held on 11 January, 1 February, and 7 March.  Notes are available on the CIMMSE blog.
  • Monthly calls have been scheduled for the first Wednesday of the month at 9 AM.

Tropical cyclone inland winds

  • Bryce has largely completed the climatology portion of the project. He has begun working on a manuscript with the intent of publishing the climatology work in a refereed journal. Land reduction and gust factor analysis should be included in the paper.
  • Bryce has begun work on the modeling aspect of the project and has already completed several WRF simulations. Much of the simulation work has focused on 9km and 3km simulations of Hurricane Irene and those are working well. He continues to make adjustments to improve the simulation forecast at 48 hours.
  • Bryce and/or the team will share some of the initial results of the project, likely focused on the climatology, at the WFO CHS tropical weather workshop late this spring.
  • A team led by Reid with help from Frank/Bob (CHS) and Gail (RAH) will create a short set of unified set of training slides that ER WFOs could easily incorporate into their tropical cyclone training.  The materials will be completed by spring and will likely include the items below:
    • Demonstrate the problem, examples of poor collaboration abound
    • Illustrate the inexact nature of the TCM product by noting the limitations the NHC deals with in creating the TCM (Brennan slides)
    • Provide the NDFD verification from this project which notes a consistent high bias in wind forecasts
    • Provide initial guidance on quality land reduction factors and some sort of TCM product correction factor
  • A conference call for the TC wind project was held on 22 February.
  • The group has agreed to establish monthly conference calls, they will be held on the second Wednesday of the month at 11 AM.

High Shear Low CAPE (HSLC) convection

  • Monthly conference calls continue on the 4th Thursday of the month and are well attended.
  • Keith Sherburn will be working on a parameter-based climatology. The desire is to develop composite parameters to better anticipate HSLC events and tornado or no tornado events in particular.
  • SPC analysis data has been converted into Google Earth files (.png + .kml) for the 25 high priority cases and placed online for downloading. The distribution now includes both SPC mesoanalysis parameters as well as a host of useful mandatory level data from the raw RUC grids.
  • Work is underway on a relational database for all 82 of our cases which stretch from 2006-2011. Data is being QC’d with several cases needing attention to remove the cases with CAPE values that exceed our criteria. Statistical analysis is ready to commence.
  • Jason Davis will be working on a radar-based climatology of HSLC events, including an analysis of tornado vs. no tornado cases that examines convective modes and uses radar interrogation strategies such as studying azimuthal shear products.
  • Jason has obtained a database of convection mode associated with a large number of severe weather events from SPC. Details on the database is available in this conference paper. The mode determination is subjective and as can be expected, some of the storms are difficult to categorize. The initial analysis of the data is complete and the database appears to have a large number of supercells. Despite the limitations, the database should be quite useful in a broad view.
  • Relating to the database above, from a 5 March email, Jason is seeking feedback about which convective modes are the most challenging in HSLC warning situations. Some preliminary thoughts from those present on the conference call was that all non-discrete supercells and QLCSs were challenging. He would be interested in seeing what the whole group thinks. The goal in doing this is to determine if   the number of convective modes to focus on can be reduced, and then study tornadic and non-tornadic circulations on days that were dominated by our chosen convective modes.
  • SPC Lead Forecaster Rich Thompson will provide the CSTAR offices a remote presentation on 27 March at 2 PM pm on an analysis of the detailed work he and Bryan Smith have done identifying Convective Modes and Near-Storm Environments associated with all tornadoes and significant severe thunderstorm reports from 2003-2011.
  • On 6 January, NCSU students Jason Davis and Keith Sherburn visited the Greer, SC (GSP) weather forecast office to discuss a variety of topics related to the HSLC portion of the CSTAR project. The students met primarily with Pat Moore, Justin Lane, and Larry Lee from GSP and Hunter Coleman from Columbia, SC (CAE). Additional details are available on the blog.
  • WFO GSP continues to develop a demonstration case study which should provide a sample case study to evaluate, with the eventual goal of agreeing on a standard case study setup/layout. The radar examination portion of the case study is essentially complete.
  • Once a standard case study setup/layout is agreed to, the desire is for participating WFOs to produce nearly a dozen comprehensive cases studies of different events based on the proposed “high priority” case study responsibility table. Initially it was hoped each office could complete two case studies by November, this may be overly optimistic and one case study per office might be more realistic.
  • Justin developed an excellent comprehensive methodology for creating the case studies. The methodology provides excellent references and guidance for a variety of aspects of the case study including obtaining RUC proximity soundings.
  • FFC continues to develop a null database. A tremendous amount of work has gone into this database and it is getting closer to completion.
  • The next HSLC conference call is scheduled for 22 March.

Tropical cyclone initialization

  • Dr Lackmann has agreed to create and present a webinar for an operational audience on how TC initialization is accomplished and how this impacts operational NWP. The date of the training is still to be determined but it will likely be in late May. The goal is to provide a baseline of knowledge (bogusing, vortex relocation, etc) to forecasters and share with them the strengths and limitations of each system in a way that would be helpful for forecasters.

High-Resolution Mid-Atlantic Forecasting Ensemble (HME)

Other items

  • The 6 month CSTAR reporting period ends on 30 April and the 6 month progress report is due on 31 May.
  • The Research and Innovation Transition Team (RITT) Forum was briefly discussed. The RITT is intended to showcase potential transition (to operations) projects. The March RITT Forum will occur on 21 March at 3 PM and feature a presentation by Curtis Marshall titled “The CSTAR Program.” As our projects mature, we would like to share some of our results with the RITT, perhaps 6 to 9 months from now.
  • Participants are encouraged to add blog entries as interesting events or discoveries are made.
  • A fall workshop is still planned in Raleigh on 15-16 November.
  • The next quarterly call is scheduled for 25 May at 3 PM.
This entry was posted in CSTAR, General Information, High Shear Low Cape Severe Wx, TC and Boundary QPF, TC Improved Initial Conditions, TC Inland and Marine Winds. Bookmark the permalink.

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