Su Aifang, Sun Jinglan, Gu Xiujie, et al. Characteristics and conceptual models of convective rainstorm clouds in Henan Province. J Appl Meteor Sci, 2013, 24(2): 219-229.
Citation:
Su Aifang, Sun Jinglan, Gu Xiujie, et al. Characteristics and conceptual models of convective rainstorm clouds in Henan Province. J Appl Meteor Sci, 2013, 24(2): 219-229.
Su Aifang, Sun Jinglan, Gu Xiujie, et al. Characteristics and conceptual models of convective rainstorm clouds in Henan Province. J Appl Meteor Sci, 2013, 24(2): 219-229.
Citation:
Su Aifang, Sun Jinglan, Gu Xiujie, et al. Characteristics and conceptual models of convective rainstorm clouds in Henan Province. J Appl Meteor Sci, 2013, 24(2): 219-229.
Study on severe weather's conceptual models is important for improving forecasting and early warning capabilities of severe weather. Using FY-2C/E and MODIS satellite data, A0 data, precipitation data of automatic weather stations and conventional observations, meso-scale convective systems criteria of convective rainstorm is revised, and their activity rhythm, as well as rainfall characteristics, are analyzed during convective rainstorm processes. In addition, convective rain storm conceptual models in Henan Province are studied based on analysis of cloud systems and synoptic situations. MCSs of convective rainstorm in Henan Province include newborn convective cloud clusters, MαCS, MβCS and banded MCSs. MCSs with different shape and scale have different characteristics of precipitation. Newborn convective clusters are easy to produce 20—29.9 mm·h-1 rain intensity. The probability of exceeding 30.0—49.9 mm·h-1 rain intensity brought by MβCS is obviously greater. The rain intensity exceeding 30.0 mm·h-1 is most likely caused by MαCS, but banded convective systems have higher probability of exceeding 50.0 mm·h-1 rain intensity than MαCS. However, each type of MCS can form strong intensity of rainfall over 80 mm·h-1 and the strongest intensity of rainfall is made by MβCS. The spatial and temporal variations and morphological characteristics of MCSs can give important information for forecasting thunder-rainstorm, and thunder-rainstorm is easy to occur during the formation and development of MCSs, and in the regions with big gradient of TBB in the back and the center of MCSs. Regions with high cloud optical thickness are potential areas of thunder-rainstorm. Dry and cold air masses in the processes of trough (vortex)-shear and trough's style play an important triggering role of MCSs. In the processes of high pressure's rear, MCSs are closely related to increasing temperature by radiation in boundary layer. Furthermore, energy front and convergence lines in boundary are the trigging systems. Dry lines in the shear line's processes are very important. Formation and development information of MCSs may be dependent on optical thickness. What's more, in the processes of high pressure's rear, the north of dark area on vapor images is easy to bring about MCSs. There are five potential regions of convective rainstorm in Henan Province, and four regions of them are near mountains. The routes of MCSs include eastward, northeastward and southeastward paths. Cloud track wind on high level can provide forecasting information of MCSs.
Fig.
2
Weather system and cloud features during the thunder-rainstorm process on 25 June 2005
(a) weather system and FY-2C IR image at 2000 BT 25 June 2005, (b) FY-2C IR image and rain intensity (unit:mm·h-1) at 1400 BT 25 June 2005, (c) FY-2C IR images and rain intensity (unit: mm·h-1),
(d) FY-2C IR image and rain intensity (unit: mm·h-1) at 0200 BT 26 June 2005, (e) water vapor product of MODIS at 1320 BT 25 June 2005, (f) cloud optical thickness product of MODIS at 1145 BT 25 June 2005
Fig.
3
Weather system, IR image of FY-2C and cloud optical thickness product of MODIS during the convective-rainstorm process on 31 July 2006
(a) weather system and IR image, (b) IR image and rain intensity (unit:mm·h-1), (c) cloud optical thickness product of MODIS (area surrounded by white circle represents potential region of developing MCS)
Fig.
4
Weather systems, FY-2C IR image and water vapor product of MODIS during the convective rainstorm process on 25 August 2007
(a) weather system and IR image (IR image at 1500 BT; red contours are CAPE, unit: J/kg), (b) water vapor product of MODIS (area surrounded by white circle represents potential region of developing MCS)
Fig.
5
Weather system, IR image and cloud optical thickness during the convective-rainstorm process on 4 July 2006 (a) weather system and IR image (IR image at 1400 BT; area surrounded by dotted line: K≥32℃), (b) cloud optical thickness of MODIS
Fig.
7
Typical high-level cloud track wind field and IR image of FY-2C for developing MCS during convective rainstorm process
(black contours represent TBB no more than 220 K; blue and purple arrows indicate moving direction of MCSs and significant airflow direction of high-level cloud track wind, respectively) (a) airflow diversion area, (b) southwest wind divergence area, (c) anticyclonic circulation at the top
Fig.
8
Development regions and movement paths of MCS during convective rainstorms in Henan Province
(bottom picture shows the topography and warm colors on behalf of the mountains; development regions of MCS are gray shaded; path frequency no less than 30% and less than 10% are represented by thick and thin arrows)
Figure 1. Distribution of 119 meteorological ground stations in Henan Province
Figure 2. Weather system and cloud features during the thunder-rainstorm process on 25 June 2005
Figure 3. Weather system, IR image of FY-2C and cloud optical thickness product of MODIS during the convective-rainstorm process on 31 July 2006
Figure 4. Weather systems, FY-2C IR image and water vapor product of MODIS during the convective rainstorm process on 25 August 2007
Figure 5. Weather system, IR image and cloud optical thickness during the convective-rainstorm process on 4 July 2006 (a) weather system and IR image (IR image at 1400 BT; area surrounded by dotted line: K≥32℃), (b) cloud optical thickness of MODIS
Figure 6. The typical conceptual model of the convective rainstorm in Henan Province
Figure 7. Typical high-level cloud track wind field and IR image of FY-2C for developing MCS during convective rainstorm process
Figure 8. Development regions and movement paths of MCS during convective rainstorms in Henan Province