Ref.: MWR-D Monthly Weather Review Editor Decision. Dear Prof. Monteverdi,

Transcription

1 Ref.: MWR-D Monthly Weather Review Editor Decision Dear Prof. Monteverdi, I have obtained reviews of your manuscript, "AN ANALYSIS OF THE 7 JULY 2004 ROCKWELL PASS, CA TORNADO: HIGHEST ELEVATION TORNADO DOCUMENTED IN THE U.S." This review is provided below, and is also available on the Editorial Manager website (see link at the end of this letter). The reviewer recommends major revisions, and notes that "In some respects, this paper shows substantial improvement." (I note that this reviewer previously recommended rejection.) Based on my reading of the article, I agree with the main points of the reviewer, especially for "Major Item" #2. The discussion in the latter half of the article seems needlessly long, speculative, and sometimes discusses processes that are impossible to assess with the available data. I ask that you follow the reviewer's 4 suggestions to modify this part of the article. The official editorial decision is Return for Minor Revisions. (Note: I do not think that the revisions needed to address the reviewer's concerns would rise to the level of "major" because it seems no new figures and analyses are needed; rather, revisions to existing figures/text should cover things.) However, I may ask this reviewer to take one last look at the revised manuscript to see if his/her concerns have been addressed. Please submit a revised paper by Oct 14, If you anticipate problems meeting this deadline, please contact me as soon as possible at gbryan@ucar.edu to discuss an extended due date. Along with your revision, please upload a point-by-point response that satisfactorily addresses the concerns and suggestions of each reviewer. Should you disagree with any of the proposed revisions, you will have the opportunity to explain your rationale in your response. No separate cover letter to me is needed unless it contains essential information that does not appear in your reply. Before submitting your revision, please carefully review the AMS Guidelines for Revisions found at to be sure you have complied with all instructions for quick processing of your revised manuscript. Please note that figure source files formatted for publication must be uploaded for

2 ALL revisions. Ensure that your figures adhere to the requirements for Journals authors: Please enter the figure number in the description field when uploading your figure files (or on the Attach Files page after upload). This is required even if the figure number is already in the file name. When you are ready to submit your revision, go to and log in as an Author. Click on the menu item labeled "Submissions Needing Revision" and follow the directions for submitting the file. Thank you for submitting your manuscript to MWR. I look forward to receiving your revision. With best regards, Dr. George H. Bryan Editor Monthly Weather Review *********************************************************** REVIEWER COMMENTS Reviewer #1: MWR-D Manuscript Title: An Analysis of the 7 July 2004 Rockwell Pass, CA Tornado: Highest Elevation Tornado Documented in the U.S. Authors: J. P. Monteverdi, R. Edwards, and G. J. Stumpf Recommendation: Accept with Major Revisions This paper presents the case that the 7 July 2004 Rockwell Pass, CA tornado is the highest elevation tornado documented in the U.S. The subject matter and rarity of high elevation events like this would certainly be of interest to many potential MWR readers. Most of the paper is devoted to examining the mesoscale environment around the Rockwell Pass region in hopes of gaining insight into the convective organizational mode during/near the time of the tornado. In some respects, this paper shows substantial improvement over its predecessor, as the authors have corrected numerous problems and added a key supporting figure (Fig. 5) that orientates the reader regarding the relative positions of the key observer, tornado and Rockwell Pass. They have improved

3 their estimated proximity sounding and hodograph and have eliminated more definitive claims about the storm mode that could not be substantiated with the available data. Still, a couple major problems remain. The first major problem has to do with the estimation of the tornado's elevation. The second major problem involves a needlessly long discussion of storm mode around/during the tornado period and speculation of tornado development from non-mesocyclone or mesocyclone processes. The paper comes off seemingly battling with itself with too much speculation. Major Items: 1. The authors have improved their discussion of the background on how the tornado elevation was determined and added a very nice graphic (Fig. 5) to help the reader. Since this paper makes the claim that this is the highest elevation tornado ever documented in the U.S., it is of great importance that the claimed elevation (and elevation range) is supported. Unfortunately, in this case, the tornado location is determined by a single observer with photographs from a single, line-of-sight, observation position. Tornado range estimates are notoriously poor, even from experienced tornado observers, so the 1 km range estimate should be considered very unreliable, especially given that there is a ridge line in between the observer and tornado. The tornado could easily be double or triple the estimated distance from the observer. I would recommend the authors use a realistic potential distance range of the tornado from the observer to figure out the proper range of elevations the tornado could have been at. This potential distance range should be clearly stated in the text (and shown on Fig. 5). 2. Storm organizational mode at time of tornado: The paper comes across like it is in conflict with itself on the question of storm mode, and sometimes wanders into uncertain territory on how tornadoes form in supercells by non-mesocyclone processes. This discussion in sections 3 and 4 is needlessly drawn out for a case where all one can really conclude (based on the available data) is that the storm may have briefly taken on supercell character around/during the time of the tornado. There is not sufficient evidence to conclude that the tornado developed in association with a low-level mesocyclone in a traditional sense, or for that matter, develop from a non-mesocyclone process. In light of this, the authors need to re-examine this discussion and revise the applicable portions to: 1) make this discussion much more concise, 2) remove the more speculative parts, 3) reevaluate assertions that seem to be in conflict with what they just presented, and 3) eliminate arguments related to tornadogenesis/maintenance processes that are beyond the scope of the paper. In terms of trimming/revising, here are a few examples: * Last paragraph of P11 (L234-L241): Highly speculative

4 * First sentence of P14: What parameters indicated the potential development of low-level rotation? The ones stated in the previous paragraph argued just the opposite. * Last sentence of P14 (L ): This sentence is in conflict with itself because on the one hand it is supporting a non-mesocyclone process in tornado development, but on the other, it is addressing the favorable addition of a lowlevel shear source (topographic channeling) that would seemingly be constructive for low-level mesocyclone development, and potentially, associated tornado development. * L : This paragraph seems to be arguing against itself since it presents evidence for supercell structure and potential mesocyclone-associated tornado occurrence, but is quickly followed by evidence for non-mesocyclone associated tornadogenesis. Then on L390, the paper discusses non-mesocyclone tornado development associated with updraft stretching that amplifies the "low-level shear vorticity". What exactly is the "low-level shear vorticity?" Is it pre-existing vertical vorticity or horizontal vorticity that gets tilted and stretched. In most cases of tornadoes occurring outside the mesocyclone proper in a supercell thunderstorm, the tornado occurs as a roll-up of a vertical vortex sheet that undergoes stretching. By addressing tornadogenesis processes, this paper seems to be delving into a subject beyond its scope. I would recommend, eliminating all text after Kern River Canyon on L390 in this particular paragraph. As a side comment, the terminology of non-mesocyclone related tornadogenesis in supercells is really a poor description, because the mesocyclone is organizing the key boundaries for which these tornadoes form along. * Last two paragraphs of section 4: The discussion of the storm's evolution and demise after the tornado time could probably be summarized in just a sentence or two for a "Picture of the Month" type paper. * Last two paragraphs of section 5: Needlessly long concluding discussion of a topic that could be summarized in just a sentence or two. Minor Items: 1. L34: Suggest changing "? no evidence?" to "? insufficient evidence?" 2. Suggest eliminating the last sentence of the abstract. It comes across as placing sole reasoning for exclusion of a mesocyclone tornadogenesis association on the high LCL environment, when in fact, the vertical shear profile

5 is also poor. Additionally, the authors undermine their own position by stating later in the paper that they do not have confidence in the LCL from their sounding due to the visual cloud base appearance. 3. L173: Eliminate second "location" in this sentence. 4. L198: Could eliminate "above". 5. L272: Suggest deleting "unimpressive and". 6. L339: 2.4º tilt should be 2.5º tilt. 7. L354: "By 2330 UTC, the storm had an overshooting top and had grown to over five times the area of the original development?" Recommend the addition of "the anvil" to this sentence (i.e., "By 2330 UTC, the storm had an overshooting top and the anvil had grown to over five times the area of the original development?". 8. L : "The radar evidence does suggest a possibility that the Rockwell Pass storm was a supercell during the UTC time period?" Due to the prior discussion that included most environmental parameters not being favorable for supercells, how about "The radar evidence does suggest a possibility that the Rockwell Pass storm had some supercell characteristics during the UTC time period?" 9. L : "These were used to modify the objectively obtained estimated sounding and hodograph to an estimated proximity sounding and hodograph, as explained in Section 3." Readers may not quite remember the difference between your estimated sounding and your estimated proximity sounding. May want to reword to clarify. 10. L : "The evidence for low level mesocyclogenesis based upon the proximity sounding and hodograph was not robust." The "was not robust" part of this sentence is misleading (someone that did not read the convective environmental parameters section very closely (or not at all) could gather that perhaps the evidence was moderately favorable (but not robust). Suggest changing the wording to accurately convey that the evidence for low-level mesocyclone formation was quite weak....

6 If reviewer comments have been added in the form of attachments they are found attached to this . They can also be accessed by logging into the Editorial Manager as an Author, or by clicking the following link: