Prediction of Thunderstorms based on Atmospheric Instability Indices over Bangladesh using WRF-ARW Model

In this study an attempt has been made to inspect the forecasting of thunderstorms based on two cases (1st case: 17th May, 2019 and 2nd case: 31st March, 2019) over Dhaka using WRF Model. The model is run for 72 hours with 03 nested domain of 09 km, 03 km and 01 km horizontal resolutions using 0.25º X 0.25º six hourly global data assimilation system. For model simulation, Milbrandt-Yau Double-Moment 7-class scheme (9) has been used as microphysics scheme in this study. The model performance is evaluated by calculating hourly instability indices (VTI, TTI, KI, CTI, MCAPE, MCIN, BRN, LI, SI, SWI) value and have been compared with the threshold value of indices. Different meteorological parameters such as MSLP, temperature, winds at upper (300 hPa) and lower (925 hPa) level, relative humidity along with vertical cross section are also studied by the model and compared with the favorable conditions for forming of thunderstorms. Area rage rainfall (hourly) value has been also calculated and compared with indices value to comprehend the nature of thunderstorms. Observing the indices value it is seen that all indices value increase sharply 5-6 hours before of thunderstorm occurring and MCAPE is giving more reliable result. Moreover, this study shows that inner two domains (3 and 1 km resolution) are giving better results than outer one and which indices are more probable in forecasting of thunderstorm for our country as well as giving less Root Mean square Error. From the simulated and validated results, it can be concluded that the model performance of instability indices can be used as forecasting of thunderstorms over Bangladesh.

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Evaluation of WRF microphysics schemes in the simulation of a squall line over IRAN using radar and reanalysis data

Nexo Revista Científica ◽

10.5377/nexo.v34i02.11552 ◽

2021 ◽

Vol 34 (02) ◽

pp. 682-697

Author(s):

Mahnaz Karimkhani ◽

Majid Azadi ◽

Amir Hussain Meshkatee ◽

Abbas Ranjbar Saadatabadi

Keyword(s):

Model Simulation ◽

Wrf Model ◽

Skill Score ◽

Reanalysis Data ◽

Squall Line ◽

Microphysics Scheme ◽

Vertical Extent ◽

Simulated Precipitation ◽

Storm Cells ◽

Convective Cells

A squall line was recorded in Dayyer port over southwest of Iran, on 19 Mar 2017. In the present paper, we have simulated the characteristic features associated with the squall line by Weather Research and Forecasting (WRF) model using five different microphysics (MP) schemes. For validating the simulated characteristics of the squall line, the latitude-height and longitude-height cross section reflectivity and precipitation value derived from observed reflectivity gathered by Doppler Weather Radar at Bushehr, synoptic weather station data at Dayyer port along with NCEP-NCAR and ERA-INTERIM reanalyzes data were used. To verify the simulated precipitation, the Fractions Skill Score (FSS) curve was calculated. Examining the simulation results for geopotential and sea level pressure show that the model simulations using different MP schemes, agree well with the verifying reanalyzes. Also, the spatial rainfall distribution of simulations and verifying observations did not show big differences. However, there are significant differences in the details of simulations such as the maximum reflectivity of the convective cells, vertical extent of the storm cells, speed and direction of the wind, rainfall values and FSS curves. Though, all of the simulations have shown convective cells over Dayyer port at the time of occurrence of the squall line, but, only the model simulation using Lin MP scheme is consistent with the corresponding radar reflectivity and vertical extent. The FSS chart showed that the skill changes with spatial scale. Results using Lin microphysics scheme crossed the FSSuniform line at lower scales when compared to other MP schemes.

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The Efficacy of the WRF-ARW Model in the Genesis and Intensity Forecast of Tropical Cyclone Fani over the Bay of Bengal

Journal of Engineering Science ◽

10.3329/jes.v12i3.57482 ◽

2022 ◽

Vol 12 (3) ◽

pp. 85-100

Author(s):

Md Shakil Hossain ◽

Md Abdus Samad ◽

SM Arif Hossen ◽

SM Quamrul Hassan ◽

MAK Malliak

Keyword(s):

Tropical Cyclone ◽

Bay Of Bengal ◽

Lead Time ◽

Wrf Model ◽

Horizontal Resolution ◽

Outcome Analysis ◽

Time Model ◽

Cyclonic Storm ◽

Arw Model ◽

Global Data Assimilation System

An attempt has been carried out to assess the efficacy of the Weather Research and Forecasting (WRF) model in predicting the genesis and intensification events of Very Severe Cyclonic Storm (VSCS) Fani (26 April – 04 May 2019) over the Bay of Bengal (BoB). WRF model has been conducted on a single domain of 10 km horizontal resolution using the Global Data Assimilation System (GDAS) FNL (final) data (0.250 × 0.250). According to the model simulated outcome analysis, the model is capable of predicting the Minimum Sea Level Pressure (MSLP) and Maximum Sustainable Wind Speed (MSWS) pattern reasonably well, despite some deviations. The model has forecasted the Lowest Central Pressure (LCP) of 919 hPa and the MSWS of 70 ms-1 based on 0000 UTC of 26 April. Except for the model run based on 0000 UTC of 26 April, the simulated values of LCP are relatively higher than the observations. According to the statistical analysis, MSLP and MSWS at 850 hPa level demonstrate a significantly greater influence on Tropical Cyclone (TC) formation and intensification process than any other parameters. The model can predict the intensity features well enough, despite some uncertainty regarding the proper lead time of the model run. Reduced lead time model run, particularly 24 to 48 hr, can be chosen to forecast the genesis and intensification events of TC with minimum uncertainty. Journal of Engineering Science 12(3), 2021, 85-100

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A Comparative Study of Bin and Bulk Cloud Microphysics Schemes in Simulating a Heavy Precipitation Case

Atmosphere ◽

10.3390/atmos9120475 ◽

2018 ◽

Vol 9 (12) ◽

pp. 475 ◽

Cited By ~ 2

Author(s):

Hyunho Lee ◽

Jong-Jin Baik

Keyword(s):

Heat Release ◽

Latent Heat ◽

Wrf Model ◽

Heavy Precipitation ◽

Cloud Microphysics ◽

Latent Heat Release ◽

Microphysics Scheme ◽

Surface Precipitation ◽

Double Moment ◽

Bin Microphysics

Comparisons between bin and bulk cloud microphysics schemes are conducted by simulating a heavy precipitation case using a bin microphysics scheme and four double-moment bulk microphysics schemes in the Weather Research and Forecasting (WRF) model. For this, we implemented an updated bin microphysics scheme in the WRF model. All of the microphysics schemes underestimate observed strong precipitation, but the bin microphysics scheme yields the result that is closest to observations. The differences among the schemes are more pronounced in terms of hydrometeor number concentration than in terms of hydrometeor mixing ratio. In this case, the bin scheme exhibits remarkably more latent heat release by deposition and riming than the bulk schemes. This causes stronger updrafts and more upward transport of water vapor, which leads to more deposition, and again, increases the latent heat release. An additional simulation using the bin scheme but excluding the riming of cloud droplets on ice crystals, which is not or poorly treated in the examined bulk schemes, shows that surface precipitation is slightly weakened and moved farther downwind compared to that of the control simulation. This implies that the more appropriate representation of microphysical processes in the bin microphysics scheme contributes to the more accurate prediction of precipitation in this case.

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Numerical Investigations of Atmospheric Rivers and the Rain Shadow over the Santa Clara Valley

Atmosphere ◽

10.3390/atmos10030114 ◽

2019 ◽

Vol 10 (3) ◽

pp. 114 ◽

Cited By ~ 2

Author(s):

Dalton Behringer ◽

Sen Chiao

Keyword(s):

San Francisco ◽

Wrf Model ◽

Cloud Microphysics ◽

The Other ◽

Microphysics Scheme ◽

Atmospheric Rivers ◽

Bright Band ◽

Warm Rain ◽

Double Moment ◽

Warm Rain Process

This study investigated precipitation distribution patterns in association with atmospheric rivers (ARs). The Weather Research and Forecasting (WRF) model was employed to simulate two strong atmospheric river events. The precipitation forecasts were highly sensitive to cloud microphysics parameterization schemes. Thus, radar observed and simulated Z H and Z D R were evaluated to provide information about the drop-size distribution (DSD). Four microphysics schemes (WSM-5, WSM-6, Thompson, and WDM-6) with nested simulations (3 km, 1 km, and 1/3 km) were conducted. One of the events mostly contained bright-band (BB) rainfall and lasted less than 24 h, while the other contained both BB and non-bright-band (NBB) rainfall, and lasted about 27 h. For each event, there was no clear improvement in the 1/3 km model, over the 1 km model. Overall, the WDM-6 microphysics scheme best represented the rainfall and the DSD. It appears that this scheme performed well, due to its relative simplicity in ice and mixed-phase microphysics, while providing double-moment predictions of warm rain microphysics (i.e., cloud and rain mixing ratio and number concentration). The other schemes tested either provided single-moment predictions of all classes or double-moment predictions of ice and rain (Thompson). Considering the shallow nature of precipitation in atmospheric rivers and the high-frequency of the orographic effect enhancing the warm rain process, these assumptions appear to be applicable over the southern San Francisco Bay Area.

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SIMULATION OF A THUNDERSTORM EVENT OVER BANGLADESH USING WRF-ARW MODEL

Journal of Mechanical Engineering ◽

10.3329/jme.v44i2.21437 ◽

2015 ◽

Vol 44 (2) ◽

pp. 124-131 ◽

Cited By ~ 3

Author(s):

M. N. Ahasan ◽

D. A. Quadir ◽

K.A. Khan ◽

M. S. Haque

Keyword(s):

Numerical Simulation ◽

Model Performance ◽

Wrf Model ◽

Horizontal Resolution ◽

Arw Model ◽

Advance Research ◽

Weather Research

Numerical simulation of the thunderstorm event occurred over Srimangal, Bangladesh at 1200 UTCon 21 May 2011 have been carried out using Advance Research dynamic core of Weather Research andForecasting Model (WRF-ARW). The WRF model was run in a domain at 9 km horizontal resolution using sixhourly NCEP-FNL datasets from 0000UTC of 21 May to 0000UTC of 22 May 2011 as initial and boundaryconditions. Hourly outputs have been analyzed to asses and/or compare the model performance. The WRFmodel captured the studied thunderstorm event on 21 May 2011 in reasonably well with some spatial andtemporal biases in the results. But the model simulated 24-h rainfall over the country as a whole overestimatedthe rainfall by 46.72% compared to that of Bangladesh Meteorological Department (BMD) observation.

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On the Importance of a Consistent Treatment of Prognostic Moisture Variables between Convective and Microphysical Parameterizations

Monthly Weather Review ◽

10.1175/mwr-d-17-0305.1 ◽

2018 ◽

Vol 146 (5) ◽

pp. 1527-1548 ◽

Cited By ~ 1

Author(s):

Evelyn D. Grell ◽

Jian-Wen Bao ◽

David E. Kingsmill ◽

Sara A. Michelson

Keyword(s):

Wrf Model ◽

Simulation Models ◽

Cumulus Parameterization ◽

Climate Simulation ◽

Microphysics Scheme ◽

Single Moment ◽

Double Moment ◽

Cloud Parameterization ◽

Microphysical Processes ◽

Consistent Treatment

Abstract Analysis of WRF Model output from experiments using two double-moment microphysics schemes is carried out to demonstrate that there can be an inconsistency between the predicted mass and number concentrations when a single-moment convective parameterization is used together with a double-moment microphysics scheme. This inconsistency may arise because the grid-scale and subgrid-scale cloud schemes generally apply different levels of complexity to the parameterized microphysical processes. In particular, when a multimoment formulation is used in the microphysics scheme and other physical parameterizations modify only the mass-related moment while the values of the second (or higher) moment for individual hydrometeors remain unchanged, an unintended modification of the particle size distribution occurs. Simulated radar reflectivity is shown to be a valuable tool in diagnosing this inconsistency. In addition, potential ways to minimize the problem are explored by including number concentration calculations in the cumulus parameterization that are consistent with the assumptions of hydrometeor sizes in the microphysics parameterization. The results of this study indicate that it is physically preferable to unify microphysical assumptions between the grid-resolved and subgrid cloud parameterization schemes in weather and climate simulation models.

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Evaluation of Weather Research and Forecasting (WRF) Microphysics single moment class-3 and class-6 in Precipitation Forecast

MATEC Web of Conferences ◽

10.1051/matecconf/201815003007 ◽

2018 ◽

Vol 150 ◽

pp. 03007 ◽

Cited By ~ 3

Author(s):

Syeda Maria Zaidi ◽

Jacqueline Isabella Anak Gisen

Keyword(s):

Model Performance ◽

Wrf Model ◽

Precipitation Forecast ◽

Weather Research And Forecasting ◽

Microphysics Scheme ◽

Maximum Rainfall ◽

Rainfall Events ◽

Single Moment ◽

Minimum Medium ◽

Weather Research

In this study, the performance of two different Microphysics Scheme options in Weather Research and Forecasting (WRF) model were evaluated for the estimating the precipitation forecast. The schemes WRF single moment class-3 (WSM-3) and single moment class-6 (WSM-6) were employed to produce the minimum, medium and maximum precipitation for the selected events over the Kuantan River Basin (KRB). The obtained simulated results were compared with the observed data from eight different rainfall gauging stations. The results comparison indicate that WRF model provides better forecasting at some rainfall stations for minimum and medium rainfall events but did not produce good result during maximum rainfall overall. The WSM-6 scheme is found to produce better result compared to WSM-3. The study also found that to acquire accurate precipitation results, it is also required to test some other physics scheme parameterization to enhance the model performance.

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Track and Landfall Characteristics of Very Severe Cyclonic Storm Fani over the Bay of Bengal using WRF Model

Dhaka University Journal of Science ◽

10.3329/dujs.v69i2.56490 ◽

2021 ◽

Vol 69 (2) ◽

pp. 101-108

Author(s):

Md Shakil Hossain ◽

Md Abdus Samad ◽

Most Razia Sultana ◽

MAK Mallik ◽

Md Joshem Uddin

Keyword(s):

Bay Of Bengal ◽

Model Simulation ◽

Wrf Model ◽

India Meteorological Department ◽

Horizontal Resolution ◽

Weather Research And Forecasting ◽

Cyclonic Storm ◽

Intensity Forecast ◽

Global Data Assimilation System ◽

Future Events

An attempt has been made to assess the capability of the Weather Research and Forecasting (WRF) model in simulating the track and landfall characteristics of Tropical Cyclone (TC) Fani (25th April – 05th May 2019) over the Bay of Bengal (BoB). WRF model has conducted on a single domain of 10 km horizontal resolution using Global Data Assimilation System (GDAS) data (0.250×0.250). The model predicted outcomes show auspicious agreement with the observed datasets of the Bangladesh Meteorological Department (BMD) and India Meteorological Department (IMD). It is found that the diminished lead time of the model run plays a crucial role in delivering good consistency with the minimum forecast uncertainty. A strong correlation between the track and intensity forecast deviations has also been determined. According to the results, the model simulation which captures the minimum deviation in the intensity forecast also ensures better track prediction of the system. The feasibility of the track and landfall forecast by the model even up to 27 hr advance is reasonably well. Finally, it can be decided that the model is capable to predict the cyclonic storm Fani precisely and it can be chosen confidently for future events over the BoB. Dhaka Univ. J. Sci. 69(2): 101-108, 2021 (July)

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Evaluating the Performance of a Convection-Permitting Model by Using Dual-Polarimetric Radar Parameters: Case Study of SoWMEX IOP8

Remote Sensing ◽

10.3390/rs12183004 ◽

2020 ◽

Vol 12 (18) ◽

pp. 3004 ◽

Cited By ~ 1

Author(s):

Cheng-Rong You ◽

Kao-Shen Chung ◽

Chih-Chien Tsai

Keyword(s):

Model Simulation ◽

Dynamic Structure ◽

Southwest Monsoon ◽

Model Verification ◽

Squall Line ◽

Polarimetric Radar ◽

Subtropical Region ◽

Microphysics Scheme ◽

Double Moment ◽

Reflectivity Data

In this study, a dual-polarimetric radar observation operator is established and modified for the Taiwan area for the purpose of model verification. A severe squall line case during the Southwest Monsoon Experiment Intensive Observing Period 8 (SoWMEX IOP#8) on 14 June 2008, is selected and examined. Because the operator is adopted from the use of the midlatitude region, sensitivity tests are performed to obtain the optimal setting of the operator in the subtropical region. To accurately capture the dynamic structure of the squall lines, the ensemble-based data assimilation system, which assimilates both radial wind and reflectivity data, is used to obtain the optimal analysis field on the mesoscale for evaluating the performance of model simulation. The characteristics of two microphysics schemes are investigated, and the results obtained using the schemes are compared with the S-band dual-polarimetric radar observations. The horizontal and vertical cross-sections show that the analyses resemble the observations. Both schemes can replicate the polarimetric parameter signature such as ZDR and KDP columns. When comparing model simulation with polarimetric parameters through the drawing of contour frequency by altitude diagrams (CFADs), the results reveal that the single moment microphysics scheme performs better than the double moment scheme in this case. However, the reflectivity field in the stratiform area is more accurately captured when using the double moment scheme. Furthermore, validation with polarimetric variables (ZH, ZDR and KDP) histograms shows underestimation of the KDP field in both schemes. Overall, this study indicates the benefit of assimilating radial wind and reflectivity data for the analyses of severe precipitation systems and the necessity of assimilating polarimetric parameters for the accuracy of microphysical processes, especially complex microphysics schemes in subtropical region.

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A New Double-Moment Microphysics Parameterization for Application in Cloud and Climate Models. Part II: Single-Column Modeling of Arctic Clouds

Journal of the Atmospheric Sciences ◽

10.1175/jas3447.1 ◽

2005 ◽

Vol 62 (6) ◽

pp. 1678-1693 ◽

Cited By ~ 72

Author(s):

H. Morrison ◽

J. A. Curry ◽

M. D. Shupe ◽

P. Zuidema

Keyword(s):

Climate Models ◽

Heat Budget ◽

Number Concentration ◽

The Arctic ◽

Liquid Water Path ◽

Microphysics Scheme ◽

Radiative Fluxes ◽

Arctic Clouds ◽

Single Column ◽

Double Moment

Abstract The new double-moment microphysics scheme described in Part I of this paper is implemented into a single-column model to simulate clouds and radiation observed during the period 1 April–15 May 1998 of the Surface Heat Budget of the Arctic (SHEBA) and First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment–Arctic Clouds Experiment (FIRE–ACE) field projects. Mean predicted cloud boundaries and total cloud fraction compare reasonably well with observations. Cloud phase partitioning, which is crucial in determining the surface radiative fluxes, is fairly similar to ground-based retrievals. However, the fraction of time that liquid is present in the column is somewhat underpredicted, leading to small biases in the downwelling shortwave and longwave radiative fluxes at the surface. Results using the new scheme are compared to parallel simulations using other microphysics parameterizations of varying complexity. The predicted liquid water path and cloud phase is significantly improved using the new scheme relative to a single-moment parameterization predicting only the mixing ratio of the water species. Results indicate that a realistic treatment of cloud ice number concentration (prognosing rather than diagnosing) is needed to simulate arctic clouds. Sensitivity tests are also performed by varying the aerosol size, solubility, and number concentration to explore potential cloud–aerosol–radiation interactions in arctic stratus.

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