Vertically integrated moisture flux convergence as a predictor of thunderstorms

Zomeren, Jeroen van; Delden, Aarnout van

doi:10.1016/j.atmosres.2005.08.015

Cited by 52 publications

(37 citation statements)

References 17 publications

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“…Convective initiation with MFC of #210 23 g kg 21 s 21 was observed in previous studies of severe storm cases (Ostby 1975;Negri and Vonder Haar 1980;Koch and McCarthy 1982;Beckman 1990;Rogash and Smith 2000). However, MFC is a highly scale-dependent storm predictor (Petterssen 1956;van Zomeren and van Delden 2007). In a special observational network with a horizontal resolution of 2.5 km 3 2.5 km and a time resolution of 5 min, Ulanski and Garstang (1978) measured the magnitude of horizontal divergence to be as high as 22.7 3 10 23 s 21 near the developing convective updrafts.…”

Section: ) Organization and Kinematics Of Cellsmentioning

confidence: 53%

Numerical Simulation of Cyclone Sidr Using a Cloud-Resolving Model: Characteristics and Formation Process of an Outer Rainband

Akter

Tsuboki

2012

Monthly Weather Review

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Cyclone Sidr, one of the most devastating tropical cyclones that resulted in several thousand deaths and substantial damages, developed in the north Indian Ocean and made landfall over the Bangladesh coast on 15 November 2007. Observation and simulation results show that Sidr was embedded in a nonuniform environment and contained an intense outer rainband to the east of its center and a significant frontal band to the northwest. A detailed study of the outer rainband is performed by numerical simulation.The eastern band was a long, quasi-straight shape in the meridional direction that remained stationary relative to the cyclone center. This band was composed of convective cells that developed southeast of the center within a synoptic-scale convergence zone and propagated along the band toward the northeast quadrant. The speed of the downwind-propagating cells was greater than that of the cyclone, which resulted in a convective cluster northeast of the center. Only the downwind portion of the band consisted of convection with stratiform rain, whereas the upwind and middle portions contained active convective cells without stratiform rain.The band was located between the synoptic-scale flows of a weakly sheared, gradient-balanced westerly and a strongly sheared, nongradient-balanced prevailing southerly caused by the complex terrain of the Bay of Bengal's southeast region. Low-level convergence along the band was dominated by cross-band flow from both sides of the band and was confined below 3 km. As the cyclone moved northward, the convergence zone resulted in the extension of band length up to ;800 km. The southerly at the eastern side of the center gradually accelerated and was directed toward the center by a strong pressure gradient force. The flow accumulated a substantial amount of water vapor from the sea in addition to the increased moisture in the lower troposphere, resulting in further intensification of the convective cells.

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Section: ) Organization and Kinematics Of Cellsmentioning

confidence: 53%

Numerical Simulation of Cyclone Sidr Using a Cloud-Resolving Model: Characteristics and Formation Process of an Outer Rainband

Akter

Tsuboki

2012

Monthly Weather Review

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“…The second tool is the vertically integrated moisture flux convergence, also calculated for the layer bounded by 700 and 300 hPa (herein VIMFC 700–300 ). This measure, developed by van Zomeren and van Delden (), combines the convergence of the horizontal wind vector with moisture advection. Thus, it is indicative of the dynamic potential of the available water vapour to turn to precipitation.…”

Section: Methodsmentioning

confidence: 75%

Moisture transport by tropical plumes over the Middle East: a 30‐year climatology

Tubi

Dayan

Lensky

2017

Quart J Royal Meteoro Soc

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This study conducts a 30‐year climatological analysis of tropical plumes (TPs) observed over the Middle East (ME). These moisture bursts, conveying water vapour from tropical Africa to the arid ME at mid‐ to upper tropospheric levels, were identified and analysed using multiple data sources and empirical tools, including satellite images, reanalysis data, backward trajectories, and calculation of moisture profiles, water vapour transport and moisture flux convergence. The analysis of the 140 days in which TPs were identified focused on three main elements: (i) TP seasonal distribution and contribution to rainfall regime, (ii) TP moisture pathways, and (iii) the mechanisms leading to TP‐induced precipitation. TPs over the ME are found to be most frequent in the winter season, with the second highest frequency observed during the spring. The estimation of TPs' contribution to the rainfall regime over the ME, the first of its kind, shows that such contribution is limited. However, extreme events may have a significant effect on the overall annual precipitation amount. Two moisture pathways are identified, exhibiting very limited mixing, if any, with the dry air mass at shallow tropospheric levels. The first, originating in tropical West Africa, is associated with the penetration of an intensified subtropical jet stream towards lower latitudes. The second, emanating from East to Central African sources, is closely associated with an anomalous anticyclonic flow over southern Arabia. Moisture conveyed by the latter pathway is supplied from sources that are closer to the target area, transported at lower atmospheric levels, and exhibits more pronounced vertical dispersion. Compared to TPs that did not lead to precipitation, precipitative TPs feature enhanced moisture transport and stronger convergence of moisture flux. Similarly, the belt of moisture flux convergence stretching from the Tropics to the ME is interrupted when non‐precipitative TPs occur but uninterrupted during precipitative events.

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“…where q is the specific humidity (kg H2O kg 21 ), p is the pressure (Pa), u and y are the zonal and meridional component of wind speed (m s 21 ), and g is the gravitational acceleration (m s 22 ) (Zomeren and Delden 2007).…”

Section: A Datamentioning

confidence: 99%

Climate Variability and Trends in Bolivia

Seiler

Hutjes

Kabat

2013

Journal of Applied Meteorology and Climatology

102

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Climate-related disasters in Bolivia are frequent, severe, and manifold and affect large parts of the population, economy, and ecosystems. Potentially amplified through climate change, natural hazards are of growing concern. To better understand these events, homogenized daily observations of temperature (29 stations) and precipitation (68 stations) from 1960 to 2009 were analyzed in this study. The impact of the positive (1) and negative (2) phases of the three climate modes (i) Pacific decadal oscillation (PDO), (ii) El Niñ o-Southern Oscillation (ENSO) with El Niñ o (EN) and La Niñ a (LN) events, and (iii) Antarctic Oscillation (AAO) were assessed. Temperatures were found to be higher during PDO(1), EN, and AAO(1) in the Andes. Total amounts of rainfall, as well as the number of extreme events, were higher during PDO(1), EN, and LN in the lowlands. During austral summer [December-February (DJF)], EN led to drier conditions in the Andes with more variable precipitation. Temperatures increased at a rate of 0.18C per decade, with stronger increases in the Andes and in the dry season. Rainfall totals increased from 1965 to 1984 [12% in DJF and 18% in June-August (JJA)] and decreased afterward (24% in DJF and 210% in JJA), following roughly the pattern of PDO. Trends of climate extremes generally corresponded to trends of climate means. Findings suggest that Bolivia's climate will be warmer and drier than average in the near-term future. Having entered PDO(2) in 2007, droughts and LN-related floods can be expected in the lowlands, while increasing temperatures suggest higher risks of drought in the Andes.

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Vertically integrated moisture flux convergence as a predictor of thunderstorms

Cited by 52 publications

References 17 publications

Numerical Simulation of Cyclone Sidr Using a Cloud-Resolving Model: Characteristics and Formation Process of an Outer Rainband

Numerical Simulation of Cyclone Sidr Using a Cloud-Resolving Model: Characteristics and Formation Process of an Outer Rainband

Moisture transport by tropical plumes over the Middle East: a 30‐year climatology

Climate Variability and Trends in Bolivia

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