A Preliminary Investigation and Diagnosis of Weak Shear Summertime Convective Initiation for Extreme Southwest Alabama

Medlin, Jeffrey M.; Croft, Paul J.

doi:10.1175/1520-0434(1998)013<0717:apiado>2.0.co;2

Cited by 9 publications

(5 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Maxima of 0.05-0.08 flashes km Ϫ2 (regime day) Ϫ1 are over New Orleans, in coastal Mississippi, and in a north-south line extending northward from Mobile. The Mississippi and Alabama maxima are consistent with Medlin and Croft (1998) who noted that southwesterly low-level flow produced the greatest radar echo frequencies in those areas. The thermal circulation that develops between the warm, shallow water and the land along the sharply defined coastline forms, strengthens, and progresses inland during the morning.…”

Section: E Southwest Flowsupporting

confidence: 82%

“…The convection is enhanced by interactions between the sea breeze and local circulations (i.e., bay breezes) and topography. Medlin and Croft (1998) also showed a maximum of convection on the north and northwest sides of Mobile Bay during southwesterly flow. They stated that convergence in this region is enhanced by interactions between the low-level flow and locally higher elevations.…”

Section: E Southwest Flowmentioning

confidence: 91%

See 1 more Smart Citation

Warm Season Lightning Distributions over the Northern Gulf of Mexico Coast and Their Relation to Synoptic-Scale and Mesoscale Environments

Smith

Fuelberg

Watson

2005

Weather and Forecasting

View full text Add to dashboard Cite

Cloud-to-ground lightning data from the National Lightning Detection Network are used to create a warm season (May-September) lightning climatology for the northern Gulf of Mexico coast for the 14-yr period 1989-2002. Each day is placed into one of five flow regimes based on the orientation of the low-level flow with respect to the coastline. This determination is made using the vector mean 1000-700-hPa wind data at Lake Charles and Slidell, Louisiana. Flash densities are calculated for daily, hourly, and nocturnal periods.Spatial patterns of composite 24-h and nocturnal flash density indicate that lightning decreases in an east-to-west direction over the region. Flash densities for the 24-h period are greatest over land near the coast, with relative maxima located near Houston, Texas; Lake Charles, Baton Rouge, and New Orleans, Louisiana; Biloxi, Mississippi; and Mobile, Alabama. Flash densities during the nocturnal period are greatest over the coastal waters.Lightning across the northern Gulf coast is closely related to the prevailing low-level synoptic flow, which controls the sea breeze, the dominant forcing mechanism during the warm season. Southwest flow, the most unstable and humid of the five regimes, exhibits the most flashes. In this case, sea-breeze-induced convection is located slightly inland from the coast. Northeast flow, the driest and most stable of the regimes, exhibits the least amount of lightning. The large-scale flow restricts the sea breeze to near the coastline.Geographic features and local mesoscale circulations are found to affect lightning across the region. Geographic features include lakes, bays, marshes, swamps, and coastline orientations. Thermal circulations associated with these features interact with the main sea breeze to produce complex lightning patterns over the area.

show abstract

Section: E Southwest Flowsupporting

confidence: 82%

Section: E Southwest Flowmentioning

confidence: 91%

Warm Season Lightning Distributions over the Northern Gulf of Mexico Coast and Their Relation to Synoptic-Scale and Mesoscale Environments

Smith

Fuelberg

Watson

2005

Weather and Forecasting

View full text Add to dashboard Cite

show abstract

“…Many of these definitions are developed and applied by those manually recording convective initiation events. As a result, the rules employed by these studies are geared towards human‐researcher capabilities (Wilson and Schreiber, ; Wilson and Mueller, ; Medlin and Croft, ; Dixon and Mote, ; Roberts and Rutledge, ; Mecikalski and Bedka, ; Frye and Mote, ; Weckwerth et al , ). More recent research has implemented objective approaches such as using existing storm‐tracking algorithms to detect convective initiation occurrences automatically (Lima and Wilson, ; Davini et al , ; Duda and Gallus, ; Kain et al , ; Burghardt et al , ; Clark et al , ; Fabry and Cazenave, ; Lock and Houston, ).…”

Section: Introductionmentioning

confidence: 99%

The effect of urbanisation on the climatology of thunderstorm initiation

Haberlie

Ashley

Pingel

2015

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

This study assesses the impact of urban land use on the climatological distribution of thunderstorm initiation occurrences in the humid subtropical region of the southeast United States, which includes the Atlanta, Georgia metropolitan area. Initially, an automated technique is developed to extract the locations of isolated convective initiation (ICI) events from 17 years (1997-2013) of composite reflectivity radar data for the study area. Nearly 26 000 ICI points were detected during 85 warm-season months, providing the foundation for first long-term, systematic assessment of the influence of urban land use on thunderstorm development. Results reveal that ICI events occur more often over the urban area compared to its surrounding rural counterparts, confirming that anthropogenic-induced changes in land cover in moist tropical environments lead to more initiation events, resulting thunderstorms and affiliated hazards over the developed area. The ICI risk for Atlanta is greatest during the late afternoon and early evening in July and August in synoptically benign conditions. Greater ICI counts downwind of Atlanta suggest that prevailing wind direction also influences the location of these events. Moreover, ICI occurrences over the city were significantly higher on weekdays compared to weekend days -a result that was not apparent in a rural control region located west of the city. This suggests that the weekly commuting cycle and associated aerosol levels of Atlanta may amplify ICI rates. The investigation provides a methodological framework for future studies that examine the effect of land use, land cover, and terrain discontinuities on the spatio-temporal character of ICI events. A. M. Haberlie et al.a geostatistical analysis using an unprecedented sample size of ICI events, while also creating an experimental framework that permits a comparison of ICI activity around Atlanta to a rural control region (Lowry, 1998;Ashley et al, 2012). Here, we present the first objective, long-term climatology of land-use induced ICI events for Atlanta and the surrounding region.

show abstract

“…Convex coastlines were found to create convergent flow and enhance sea breeze development, while concave coastlines created divergent flow and retarded development. The influence of coastline shape on sea breeze-related convection also has been examined using satellite imagery (Gibson and Vonder Haar 1990) and radar imagery (Medlin and Croft 1998).…”

Section: Introductionmentioning

confidence: 99%

Warm Season Lightning Distributions over the Florida Peninsula as Related to Synoptic Patterns

et al. 2002

View full text Add to dashboard Cite

Cloud-to-ground lightning data from the National Lightning Detection Network are examined over the Florida peninsula during the warm seasons of 1989 through 1998. The lightning data are stratified according to the location of the subtropical ridge (i.e., north of Florida, south of Florida, and within Florida) as well as other common flow types. Each day is placed into a flow regime based on radiosonde-derived low-level winds at three stations within the study area. Maps of lightning flash density are generated for each flow regime over hourly, daily (24 h), and nocturnal periods. Results for the 24-h period indicate that complexities in the Florida coastline produce four areas of relatively large flash densities: near Tampa, Fort Myers, West Palm Beach, and Cape Canaveral. Nocturnal lightning is found to occur mostly offshore-related to the Gulf Stream, coastline orientations, the prevailing flow, and land breezes. The location of the subtropical ridge with respect to the Florida peninsula is found to play an important role in the spatial and temporal distribution of lightning. For example, when the large-scale flow is from the southeast, the east coast sea breeze and its associated lightning are relatively weak. However, the west coast sea breeze is strong and remains near the coastline, producing the most lightning near Tampa. Conversely, when the largescale flow is from the southwest, there is relatively little convection along the west coast, but major lightning activity occurs along the east coast.

show abstract

A Preliminary Investigation and Diagnosis of Weak Shear Summertime Convective Initiation for Extreme Southwest Alabama

Cited by 9 publications

References 15 publications

Warm Season Lightning Distributions over the Northern Gulf of Mexico Coast and Their Relation to Synoptic-Scale and Mesoscale Environments

Warm Season Lightning Distributions over the Northern Gulf of Mexico Coast and Their Relation to Synoptic-Scale and Mesoscale Environments

The effect of urbanisation on the climatology of thunderstorm initiation

Warm Season Lightning Distributions over the Florida Peninsula as Related to Synoptic Patterns

Contact Info

Product

Resources

About