The antecedent atmospheric conditions at midmorning (1200 UTC or 0900 LST) related to subsequent squall-line (SL) initiation in the late afternoon or early evening over the northern coast of Brazil (NCB) were obtained for a specific month (July) when the SL initiation is independent of the strong synoptic forcing related to the intertropical convergence zone. The cases of SL and sparse deep convection in the late afternoon or early evening over the NCB were identified both objectively and subjectively, and grouped into either the SL category (SLC) or the no-convection category (NOC). For the central area of the NCB, the vertical profiles at midmorning for SLC and NOC, computed from radiosonde and ERA-Interim data spanning 9 years (2004–12), were compared. By focusing on the significant differences for both datasets, it was found that two midmorning conditions are favorable to SL initiation in July: a moister layer between 850 and 350 hPa, and a northeasterly flow at 350 hPa. These regional conditions are part of a larger-scale pattern: moister (drier) conditions over the whole NCB (southeastern South America) at 700 hPa and more intense anticyclonic circulation over the Atlantic Ocean close to northeastern Brazil at 350 hPa. The paper’s findings have the potential to aid weather forecasting activities, such as those focused on the prediction of SL-related precipitation 6–12 h ahead.

The daily cycle of atmospheric conditions related to squall‐line (SL) initiation over the northern coast of Brazil (NCB) was obtained for a specific month (March) over the course of a decade (2004–2013). March falls during the NCB's rainy season. A comparison of atmospheric conditions between two categories, the most intense SL events (SLC+) and the weakest coastal convection events (CC–), was carried out. For both categories, the daily cycle of convective cluster properties (i.e. number and area) over the NCB showed that the transition from shallow to deep convection occurred from 1200 to 1500 UTC, and the development of multicell storms occurred from 1500 to 1800 UTC. From 1800 to 2100 UTC for the SLC+ events, the number of clusters decreased sharply, and the area slightly expanded, which indicated upscaling via merging; for the CC– events, merging was a secondary mechanism, and the clusters did not experience upscaling. Atmospheric conditions were computed from the ERA‐Interim reanalysis data. By focusing on the significant differences between the categories, it was found that SL initiation was related to a higher moisture content at approximately 700 hPa for all analysis times (0600, 1200, 1800 and 0000 UTC) and to a stronger low‐level moisture convergence from 0600 to 1800 UTC, mid‐level upward motion from 1200 to 0000 UTC, low‐level convergence at 1200 UTC, and upper‐level divergence from 1800 to 0000 UTC.

Climatological features of convective parameters (K index, IK; 950 hPa K index, IK950; Showalter index, IS; lifted index, ILEV; total totals index, ITT; and convective available potential energy, CAPE) derived from 12 UTC radiosounding data collected at the Alcântara Launch Center (CLA; 2°18'S, 44º22'W) from 1989 to 2008 were computed. The parameters IK, IK950, IS and ITT (ILEV and CAPE) showed a seasonal variation coherent (not coherent) to the annual cycle of precipitation. Interdaily variability was high all year round and was comparable to the monthly average seasonal variation. For IK and IK950, the monthly fraction of days with favorable conditions for precipitation occurrence (FRAC) showed good agreement with the monthly fraction of days with precipitation greater than 0.1 mm (PRP). For ITT and IS, the seasonal variation of FRAC was lower than the seasonal variation of PRP; for ILEV and CAPE, there were marked differences between FRAC and PRP. IK seasonal variation was primarily due to the presence of a deeper (shallower) low-level moist layer in the wet (dry) season. Among the studied convective parameters, the use of IK or IK950 for assessing precipitation occurrence was recommended.

Este trabalho apresenta o jogo Potencializa 3D, desenvolvido à luz da teoria histórico-cultural – thc (VYGOTSKY, 1984), cuja finalidade é servir como instrumento pedagógico ao professor no ensino de conceitos matemáticos básicos a discentes com Deficiência Intelectual (DI). O Potencializa 3D propõe trabalhar relações estabelecidas por meio de formas geométricas básicas, para melhor desenvolver a coordenação motora, percepção e noções de lateralidade. Suas atividades foram desenvolvidas com base nas categorias de mediação, zonas de desenvolvimento e atividade, da thc. O trabalho surge da necessidade de proporcionar aos discentes com DI da cidade de Viana-MA acessibilidade a recursos tecnológicos no cotidiano escolar, de forma pedagógica.

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