The Role of Instability Indices in Forecasting Thunderstorm and Non-Thunderstorm Days across Six Cities in India
Round 1
Reviewer 1 Report
Review on manuscript “The role of instability indices in forecasting thunderstorm and non-thunderstorm days across six cities in India”.
The manuscript focuses on the study of thunderstorms (TS) in 6 cities in India and the evaluation of instability indices for their use in forecasting TS. The manuscript is generally well structured, written with a clear scientific intent.
The investigation uses several TS indices and methods for assessing their suitability for detecting and predicting TS. Methods seem to be more acceptable, and the originality of the research is unquestionable. A sufficiently detailed description of the results obtained is given. However, the study as a whole looks like a case study due to the short duration of the time series under study. However, I have minor comments and I am happy to recommend the paper for publication in Climate, MDPI.
Minor comments:
1. Some references are not displayed in the text of the article. For example, the line 90,
2. Line 88 , 104 The abbreviation “STORM project”“SAARC project” are missing
Comments for author File: 
Comments.pdf
Author Response
Many thanks for your comments on our article, which helped us improve the article. We hope the work provides instructive points for practical applications. Special thanks to you for your constructive comments.
Minor comments:
- Some references are not displayed in the text of the article. For example, the line 90,
References are added again for the correct display
- Line 88, 104 The abbreviation “STORM project “SAARC project” are missing
Done, please find these abbreviations on Lines 95-96 and 100
Reviewer 2 Report
Please see attached document for my review of this paper.
Comments for author File: Comments.pdf
Author Response
Many thanks for your comments on our article, which helped us improve the article. We hope the work provides instructive points for practical applications. Special thanks to you for your constructive comments.
Specific comments: 1. The paper fails to state how the various convective predictor indices are verified. What data is used to objectively determine a TS event? Is it a radar composite or perhaps something else?
The thunderstorm events were recorded in the Meteorological Observatories of India Meteorological Department as synoptic observations (recorded every 3 hours)
Also, what is the horizontal resolution of the verification data, and how does that compare with the resolution of the data used to calculate the indices? Is the latter on some kind of regular grid, or were the comparisons done at observing sites?
Both, the training and the test dataset have the same resolution.
Worrisome here is the statement made on line 349: “the observational sites provisioning TS data are sparsely located and could have missed any event occurrence” (incidentally, the word “provisioning” should be replaced by “providing).
Changed to "providing"
- Due to numerous reference errors caught by the technical editor, not a single one of the figures was correctly referenced in the text, making it nearly impossible for this editor to relate figures to text.
Figure/Table referencing in the text is done again
- Lines 220-223: It is not true that CIN is applicable only in barotropic environments. It has been used profusely even by weather forecasters including those at NOAA’s Storm Prediction Center in highly baroclinic environments, which are characterized by cold fronts, drylines, and cold pools.
Re-wrote for clarification, CIN (Convective Inhibition) is mainly applicable in barotropic environments or the warm regions of mid-latitude storms.
Replaced the word, "Only" with "Mainly"
For the practical application of CIN, please refer: http://www.theweatherprediction.com/habyhints/306/
Note that CINE is misspelt- Corrected the typo error, and used CIN in the updated manuscript.
Done
- Lines 228-237: It is untrue that the cross totals index is a measure of the moisture content in the lower levels of the atmosphere. In fact, it considers both low-level moisture values and the coolness of the air aloft. Moreover, why are the authors even considering the CTI separately when it is much more common to combine the CTI with the VT to compute the TTI (Total Totals Index)? This entire paragraph should be removed, as well as the CTI analysis.
Agreed. It is removed
#################################################
Grammar problems:
Line 27-28: The following sentence is rather awkward: “TSs are the convective scale systems, associated with cumulonimbus clouds (CB) which also accompany lightning, squall, hailstorm, dust storm etc. CB cloud develops in the presence of synoptic systems”. Here is a better way of stating this more clearly: “Thunderstorms are produced by cumulonimbus clouds (CB) and are often accompanied by lightning, squalls, hail, and/or blowing dust. They often develop in the presence of synoptic weather systems”.
Done
Line 32: Rather than state “…the Lifting mechanism to cause atmospheric convection”, do not capitalize lifting and state more precisely the role of lifting, thus say instead: “…the lifting mechanism needed to release the potential instability and generate convection.”
Done
Line 41: replace “TSs over these regions is locally called, Kal-Baisakhi” by “Thunderstorms over these regions are called Kal-Baisakhi”.
Done
Line 45: Define SI.
Already defined in the manuscript. Please refer to lines172-187 in the updated manuscript
Line 48: Incorrect preposition use: instead of “data of”, it should read “data from”.
Done
Line 55: What is meant by “dew point above the local normal”? Do you mean to say dew points that exceed the local climatological values?
Yes, seems so, please find the excerpt from the paper below.
Line 57: Another bad use of a preposition: Replace “associated with convection at 1200 UTC sounding” by “associated with convection using the 1200 UTC sounding”.
Done
Line 59: Comma needed here: parameters for instance…
Done
Line 66: Again, a comma is missing (after Delhi): To forecast TSs over Delhi two…
Done
Line 67: And again here: The first method is graphical whereas the second one… It is clearly apparent that the authors are clueless about proper grammatical use of commas in good writing. Rather than me pointing out more such errors, it is the responsibility of the authors to look for more such egregious errors and correct them using the services of an editorial assistant if necessary.
Re-written with commas included wherever required
Line 73: rather than spell out the words “greater than or equal to 0 to less than -9”, or “a meridional component of wind at 850 hPa (greater than 10 knots)”, and so forth, simply use the acceptable characters, i.e., -9 ≤ SI ≤ 0, or meridional component of wind at 850 hPa > 10 kt, etc.
Done
Line 86: Replace “Most of studies have been carried over” by “Most studies have carried out over”.
Done
Line 95: Do you mean “will provide a longer time frame to issue warnings”?
Yes, re-written
Line 102: you need to use a colon here: “There are two types of the dataset used in this study: first,…”
Don't think so, looks correct as it is, shown below.
There are two types of datasets used in this study. First, the observation-based thunderstorm data and second, instability indices over the same locations of the sounding data. The observation-based thunderstorm occurrence and non-occurrence data have been obtained from SAARC STORM project archives and the information about the indices has been taken from the radiosonde sounding database of the University of Wyoming [21].
Line 136: this formula structure is awkward: ??=????|500−???????|500 It would be clearer to use this: ??=Tenv, 500 – Tparcel, 500
Okay, re-written as suggested
Lines 151-152: Replace “The SI is similar to LI except that while LI starts at lowest 1000 hPa layer while SI considers parcel lifting from 850 hPa to 500 hPa” with “The SI is similar to LI except that LI considers just the lowest 1000 hPa layer, whereas SI considers parcel lifting from 850 hPa to 500 hPa”.
Okay, re-written as suggested
Line 166: Remove mention of “George’s index”.
Re-written for clarification:
K-Index also known as George's index is a measure of the convective potential.
Line 167: “lowers” should be “lower”.
Yes, done
Line 180: There seems to be a period missing for this sentence to make sense. This should read “…to determine the severity of TSs. Even when moisture is lacking…”.
Okay, re-written as suggested
Line 212: “For a parcel lifted from the surface over to the level of free convection (LFC) with vertical temperature” needs to be rewritten as: “For a parcel lifted from the surface to the level of free convection (LFC) with virtual temperature”.
Okay, re-written
Line 217: Reword this as “from lifting associated with low-level convergence along storm-generated outflows”.
Okay, done
Line 274: This sentence needs greater clarity to make it readable. Instead of saying, “where 'e' is the Euler number, 'Z' represents the boundary function which is a linear boundary function (a line)” Say instead: “where 'e' is the exponential function, 'Z' represents a linear boundary function (a line)”.
Okay, re-written
Line 286: There is no need to give the address for Microsoft, which has world renown.
Okay, removed
Line 299: Do not say “predicted” but rather, “predictand”.
Okay, re-written
Line 308: Replace “null hypothesis (?0) assumes model with no independent variables fit the data” (which is poor English) with “null hypothesis (?0) assumes a model in which no independent variables fit the data”.
Okay, re-written
Line 312: Reword “For the P-value, less than the significance level,” as “If the P-value is less than the significance value (0.05)…”
Done
Line 325: “Out of all the considered indices, TTI, LI, and SI turn out to be the dominant factor governing TS activity over Bangalore.” What are you trying to say here? These indices are not “governing factors”; rather, they are the best predictors of TS activity.
Reworded: Out of all the considered indices, TTI, LI, and SI turn out to be the dominant factors in predicting thunderstorm activity over Bangalore.
Line 395: “The dependence, however, increases to 15% with only LI into the relation” is meaningless grammatically. Perhaps this is better: The dependence, however, increases to 15% when LI is included in the relation”.
Done
Lines 420-422: Numerous grammatical errors: “Thus in the next step, we further explore the relationship between the dependent and independent variables to determine the variable that's most significantly impacts TS occurrence. Further analysis reveals that KI alone accounts towards the availability in TS occurrence on a given day over Jodhpur and relation comes out to be…” Should be rewritten as follows: “Thus, we further explored the relationship between the dependent and independent variables to determine the variable that most significantly impacted TS occurrence. Further analysis reveals that KI alone accounts for TS occurrence on a given day over Jodhpur and the relation comes out to be…”
Done
Line 457: Replace “provisioning the indices values” by “providing the index values”.
Done
Line 459: “could have lead” is not correct. This should read as “could have led
Done
Reviewer 3 Report
Comments to the Author
1- Flowchart / Pseudocode and algorithm steps need to be added in more details.
2- Explain the experimental results in more details.
3- Discussion section needs to be added.
4- What is the accuracy % of the proposed system?
5- A comparative study with other related systems need to be added.
6- (Error! Reference source not found.). in Lines 90, 354, 359, 366, 382, 384, and 482 need to be fixed.
7- The present study is based on synoptic and upper air observations at 00UTC of these stations for the period 2013-2015 (line 91) for the summer months of April, May and June. Both the datasets, STORM Project and the sounding indices are considered for each (Line128 ) day for a period of 3 years 2013, 2014 and 2015 during the TS prominent months of India, April, May and June.????? . the data is out of date.
8- References are out of date and need to be updated.
Author Response
Many thanks for your comments on our article, which helped us improve the article. We hope the work provides instructive points for practical applications. Special thanks to you for your constructive comments.
- Flowchart/algorithm needs to be added in more detail: A flowchart of the methodology related to data collection is available in the referred sources no.18 & 19
- Explain experimental results in more detail: Taken care of in the updated manuscript
- Discussion section need to be added: Taken care of in the updated manuscript
- Accuracy of the proposed system: Moderate. We plan to include more analysis with a longer dataset in the next paper
- Comparative study with other related systems need to be added. Please refer to the updated references in the introduction
- Reference errors: Fixed
- Data set is 2013-2015 out of date: The considered data was extensively collected as part of the pilot project (SAARC-STORM) through collaborations with various institutes, universities, the airforce, navy etc, thus making it a comprehensive dataset to consider for the TS events across the considered locations. As stated earlier, we plan to use a longer dataset and more analysis in our next paper.
- References are out of date: Added. As mentioned in the paper, TS forecasting using instability indices is less popular these days and NWP-based synoptic information is frequently used for such prediction however some recent works have been referred to.
Round 2
Reviewer 2 Report
The authors have taken considerable effort to address the many remarks made by this reviewer, and for the most part, the revised manuscript is fully satisfactory for publication. However, note these few remaining issues:
1. This appears in several places throughout the manuscript:
Error! Reference source 408 not found.
2. I do not believe Fig. 2 is referenced in the text.
Author Response
1. This appears in several places throughout the manuscript:
Error! Reference source 408 not found.
Added the reference again, could not find this error at our end
2. Fig. 2 is rererenced on line no. 415 & 421 in the revised manuscript, highlighted for
Reviewer 3 Report
-
Pseudocode / Flow Chart and algorithm steps need to be inserted.
-
Conclusion and discussion Sections need to be inserted.
Author Response
1) Pseudocode / Flow Chart and algorithm steps need to be inserted.
Added in the methodology section. Please refer to line number 333 - 346 in the updated manuscript
2) Conclusion and discussion Sections need to be inserted.
Conclusion: Please refer to the highlighted lines 604-606, 609-611, also 347 - 371 (additional method is added in line with the demanded explanations in the conclusion and discussion sections),
Discussion: Added on 557-561, 604-606 in the updated manuscript
