Feasibility study of predicting severe storms with a down burst mechanism over Tehran city

Document Type : Research Article

Authors

1 Department of Space Physics, Institute of Geophysics, University of Tehran, Tehran, Iran.

2 Education teacher, Tehran, Iran.

3 Department of Health in Disasters and Emergencies, School of Health Management and Information Sciences, Baqiyatallah University of Medical Sciences, Tehran, Iran.

4 Tehran Disaster Mitigation and Management Organization, Tehran, Iran.

Abstract

In the warm seasons of the year, some storms occur that are difficult and complicated to predict. These strong winds that are usually accompanied by dust are known as Haboob in some countries. In the last decade, some of the storms that have occurred over Tehran area, which have caused numerous damages, have included the mechanism of the Haboob event. In this study, a method is introduced for the feasibility of predicting the potential of storms with a down burst structure, that provides defined warning levels for this phenomenon. In the this method, by using a post-processing on the output of a numerical weather prediction model, according to the dynamics and thermodynamic conditions of the weather, a level of warnings is issued for the potential of storm events with down burst mechanism. In the present work, an ensemble forecasting system developed for the WRF model, is used to provide short term predictions of such storms over Tehran area. Five different thermodynamic indices were calculated for the grid points and the process of calculating the potential of a storm event with a down burst structure was carried out by considering the temperature near the earth's surface, the thermodynamic conditions of the atmosphere, the vertical profile of relative humidity, and also checking the presence of dynamic conditions for air ascent. If the thermodynamic conditions and the instabilities of the atmosphere identified by the relevant indicators are conducive and the temperature of the earth's surface and the vertical profile of the relative humidity are appropriate, then the potential of a storm with a down burst structure can be considered probable. The humidity conditions were considered in such a way that the lower levels of the atmosphere have low relative humidity and the higher levels have more relative humidity so that the probability of evaporation of rain before it reaches the earth's surface is high. By combining these conditions for the output of the numerical model, in all of the time steps, three warning levels of the model output for the potential of a storm with a down burst mechanism were presented in the form of yellow, orange and red color zones. Four cases of strong winds and storm, as well as the famous storm that occurred on June the second, 2014, were investigated for the city of Tehran. Various forecasting maps of the output of model run include the mean sea level pressure, the thickness of the layer between the levels of 500 and 1000 hPa, wind speed, the relative vorticity of the level of 500 hPa, geopotential heights of some levels, thermodynamic indices, relative humidity in some pressure levels and the skew-T diagram was prepared at the grid points to analyze the dynamics, thermodynamic and synoptic conditions of the atmosphere. According to the information of the Meteorological Organization of Iran, winds with speeds between 80 to 120 kilometers per hour have been recorded in the meteorological stations of Tehran on these dates. In all these cases, the recorded wind speeds is significantly higher than the direct prediction of numerical weather forecasting models. In fact, it could not be recognized and predicted only by the output of these models. The maps for forecasting the warning level of the feasibility of a storm with a down burst mechanism in all cases investigated in this work during the calculations related to the probability of the occurrence are presented in this study. It seems that the presented method is able to predict the potential of the occurrence of strong winds and storms with down burst structure for the city and province of Tehran.

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اشرفی، خ.، قادر س.، صداقت‌کردار ع. (1388). اعمال روش پیش‌بینی همادی Breeding‎ به مدل تحقیقاتی-عملیاتی WRF، هشتمین کنفرانس‌ پیش‌بینی‌ عددی‌ وضع‌ هوا، تهران‌، ‎۲‎ دی ‎۱۳۸۸‎.
ترابیان، م. ج.؛ جغتایی، م. و زارع، ی. (1396). آشکارسازی و مسیریابی هبوب تهران، چهارمین همایش ملی فرسایش بادی و توفان‌های گردوغبار، یزد.
سطان‌زاده، ا.؛ بیدختی، ع. ع. و زواررضا، پ.، (1391). بررسی جریان‌های محلی روی تهران با استفاده از یک مدل شهر تک لایه جفت شده با مدل میان ‌مقیاس WRF در حضور شرایط جوی ایده‌ال، مجله فیزیک زمین و فضا، 38 (4)، 207 تا 221.
قادر‏، س.؛ صفر‏، م. و جوان‌نژاد‏، ر.، (1399). ارزیابی عملکرد اعضای یک سامانه همادی توسعه داده شده برای مدل WRF، نوزدهمین کنفرانس ژئوفیزیک ایران، 14 و 15 آبان 1399.
قادر، س.؛ یازجی، د.؛ سلطان­پور، م. و نعمتی، م.، (1394). به کارگیری یک سامانه همادی توسعه داده شده برای مدل WRF جهت پیش‌بینی میدان باد سطحی در محدوده خلیج فارس، فصلنامه هیدروفیزیک، 1(1)، 41 تا54.
Bao, J-W., Michelson, S. A., Persson, P. O. G., Djalalova, I. V., Wilczak, J. M. (2008). Observed and WRF-simulated low-level winds in a high-ozone episode during the central California ozone study. J. Appl. Meteor. Climatol., 47, 2372–2394.
Brier, G. W., & Allen, R. A. (1951). Verification of weather forecasts. In Compendium of Meteorology, Malone, T. F., Ed., American Meteorological Society, Boston, 841–848.
Browning, K.A. (1981). Forward to: Nowcasting: Mesoscale observations and short-range prediction (B. Battrick and J. Mort, eds). Proceedings of an International Symposium, Hamburg, Germany, 25–28 August. European Space Agency SP-16.
Chen, W., & Fryrear, D. W. (2002). Sedimentary characteristics of a haboob dust storm. Atmospheric Research, 61, 1.
Cheng, F., Hsu, Y-C., Lin, P., & Lin, T-H. (2013). Investigation of the effects of different land use and land cover patterns on mesoscale meteorological simulations in the Taiwan area, J. Appl. Meteor. Climatol., 52, 570–587.
Doswell III, C. A. (1996). Verification of forecasts of convection: Uses, abuses, and requirements. Proc. of the 5th Australian Sever Thunderstorm Conference, Avoca Beach, New South Wales, Australia.
DuVivier, A., Cassano, J. (2013). Evaluation of WRF model resolution on simulated mesoscale winds and surface fluxes near Greenland. Mon. Wea. Rev., 141, 941-963.
Farquharson, J. S. (1937). Haboobs and instability in the Sudan. Quarterly Journal of the Royal Meteorological Society, 63(271), 393 – 414.
George, J.J. (1960). Weather Forecasting for Aeronautics, New York City: Academic Press., 673.
Ghader, S.‎, ‎Yazgi, D., Soltanpour, M., & Nemati, ‎‎M.H. (2016). On the use of an ensemble forecasting system for prediction of surface wind over the Persian Gulf, ‎in proceedings ‎of ‎the ‎12th ‎International ‎Conference ‎on ‎Coasts, ‎Ports ‎and ‎Marine ‎Structures ‎(ICOPMAS 2016)‎,‎‎ Tehran, Iran, 31 Oct. 2 Nov. 2016.‎
Hart, K. A., Steenburgh, W. J. , Onton, D. J., & Siffert, A. J. (2004). An evaluation of mesoscale-model-based output statistics (MOS) during the 2002 Olympic and Paralympic games. Wea. Forecasting, 19, 200–218.
Hu, X., Nielsen-Gammon, J., & Zhang, F. (2010). Evaluation of three planetary boundary layer schemes in the wrf model. Journal of Applied Meteorology and Climatology, 49, 1831–1844.
Idso, S. B., Ingram, R. S., & Pritchard, J. M. (1972). An American haboob. Bulletin of the American Meteorological Society, 53(10), 930-935.
Jiménez, P. A., & Dudhia, J. (2013). On the ability of the WRF model to reproduce the surface wind direction over complex terrain. J. Appl. Meteor. Climatol., 52, 1610–1617.
Jolliffe, I. T., & Stephenson, D. B. (2003). Forecast Verification: A Practitioner’s Guide in Atmospheric Science. John Wiley and Sons, 240pp.
Juga I., & Vajda A. (2012). The effect of weather on transportation: Assessing the impact thresholds for adverse weather phenomena, SIRWEC 2012, Helsinki, 23-25 May 2012.
Kok, J. F., Parteli, E. J., Michaels, T. I., & Karam, D. B. (2012). The physics of wind-blown sand and dust. Reports on Progress in Physics, 75(10), 106901.
Lawson, T. J. (1971). Haboob structure at Khartoum. Weather, 26, 105–112.
Means, L. L. (1952). On thunderstorm forecasting in the central United States. Mon. Wea. Rev., 80, 165-189.
Membery, D. (1985). A gravity-wave haboob?. Weather, 40(7), 214–221.
Miller, R. C. (1972). Notes on analysis and severe storm forecasting procedures of the Air Force Global Weather Central. Tech. Rept. 200(R). Headquarters, Air Weather Service, USAF, 190 pp.
Murphy, A. H, & Winkler, R. (1987). A general framework for forecast verification. Mon. Wea. Rev., 115, 1330–1338.
Ruiz, J. J., Saulo, C., & Nogues-paegle, J. (2010). WRF model sensitivity to choice of parameterization over South America: validation against surface variables. Mon. Wea. Rev., 138, 3342–3355.
Salamanca, F., Martilli, A., Tewari, M., & Chen, F. (2011). A Study of the urban boundary layer using different urban parameterizations and high-resolution urban canopy parameters with WRF. J. Appl. Meteor. Climatol., 50, 1107-1128.
Shata, A.S.A. (2008). Theoretical investigation and mathematical modeling of a wind energy system case study for Mediterranean and Red sea. Ph.D. Thesis, Technische Universität Berlin, Berlin, Germany.
Showalter, A.K. (1953). A stability indices for thunderstorm forecasting. Bulletin of the American Meteorological Society, 34, 250-252.
Simpson, J. E. (1997). Gravity currents: In the environment and the laboratory. Cambridge University press.
Stefano, M., & Casaioli, M. (2008). Forecast verifi cation: A summary of common pproaches and examples of application. FORALPS Technical Report, 5. Università degli Studi di Trento, Dipartimento di Ingegneria Civile e Ambientale, Trento, Italy, 60 pp.
Vitousek Peter, M. (1997). Human alteration of the global nitrogen cycle: sources and consequences, Ecological applications 7.3.
Zhang, H., Pu., Z., & Zhang, X. (2013). Examination of errors in near-surface temperature and wind from WRF numerical simulations in regions of complex terrain. Wea. Forecasting, 28, 893–914.
WMO. (2019). 4th African Ministerial Conference On Meteorology (AMCOMET-4): Integrated African Strategy on Weather and Climate Services. WMO: Geneva, Switerland. https://amcomet.wmo.int/sites/default/ files/field/doc/events/draft_africanstrategy-on-weather_climate_services_ver_5_clean_0.pdf [accessed 9 February 2021].