The Synoptic Regulation of Dryline Intensity

Schultz, David M.; Weiss, Christopher C.; Hoffman, Paul M.
May 2007
Monthly Weather Review;May2007, Vol. 135 Issue 5, p1699
Academic Journal
To investigate the role of synoptic-scale processes in regulating the strength of the dryline, a dataset is constructed of all drylines occurring within the West Texas Mesonet (WTM) during April, May, and June of 2004 and 2005. In addition, dewpoint and wind data were collected from stations on the western (Morton; MORT) and eastern (Paducah; PADU) periphery of the WTM domain (230 km across), generally oriented east–west across the typical location of the dryline in west Texas. Drylines were characterized by two variables: the difference in dewpoint between MORT and PADU (hereafter, dryline intensity) and the difference in the eastward component of the wind between MORT and PADU (hereafter, dryline confluence). A high degree of correlation existed between the two variables, consistent with a strong role for dryline confluence in determining dryline intensity. Some cases departing from the strong correlation between these variables represent synoptically quiescent drylines whose strength is likely dominated by boundary layer mixing processes. Composite synoptic analyses were constructed of the upper and lower quartiles of dryline intensity, termed STRONG and WEAK, respectively. STRONG drylines were associated with a short-wave trough in the upper-level westerlies approaching west Texas, an accompanying surface cyclone over eastern New Mexico, and southerly flow over the south-central United States. This synoptic environment was favorable for enhancing the dryline confluence responsible for strengthening the dryline. In contrast, WEAK drylines were associated with an upper-level long-wave ridge over Texas and New Mexico, broad surface cyclogenesis over the southwestern United States, and a weak lee trough—the dryline confluence favorable for dryline intensification was much weaker. A third composite termed NO BOUNDARY was composed of dates with no surface airstream boundary (e.g., front, dryline) in the WTM domain. The NO BOUNDARY composite featured an upper-level long-wave ridge west of Texas and no surface cyclone or lee trough. The results of this study demonstrate the important role that synoptic-scale processes (e.g., surface lee troughs, upper-level short-wave troughs) play in regulating the strength of the dryline. Once such a favorable synoptic pattern occurs, mesoscale and boundary layer processes can lead to further intensification of the dryline.


Related Articles

  • Synoptic Controls on Boundary-Layer Characteristics. Sinclair, Victoria A.; Belcher, Stephen E.; Gray, Suzanne L. // Boundary-Layer Meteorology;Mar2010, Vol. 134 Issue 3, p387 

    We report the characteristics of the three-dimensional, time evolving, atmospheric boundary layer that develops beneath an idealised, dry, baroclinic weather system. The boundary-layer structure is forced by thermal advection associated with the weather system. Large positive heat fluxes behind...

  • Aerosol climatology and planetary boundary influence at the Jungfraujoch analyzed by synoptic weather types. Coen, M. Collaud; Weingartner, E.; Furger, M.; Nyeki, S.; Prévôt, A. S. H.; Steinbacher, M.; Baltensperger, U. // Atmospheric Chemistry & Physics;2011, Vol. 11 Issue 12, p5931 

    Fourteen years of meteorological parameters, aerosol variables (absorption and scattering coefficients, aerosol number concentration) and trace gases (CO, NOx, SO2) measured at the Jungfraujoch (JFJ, 3580m a.s.l.) have been analyzed as a function of different synoptic weather types. The...

  • Tracking the Influence of Irrigation on Land Surface Fluxes and Boundary Layer Climatology. Sridhar, Venkataramana // Journal of Contemporary Water Research & Education;Dec2013, Vol. 152 Issue 1, p79 

    When the land surface is altered as a first order change in the climate system, it affects the latent heat flux and evaporative cooling, thereby altering the surface temperature and boundary layer development. Modeling the processes associated with land surface alteration requires an...

  • Triggering Deep Convection with a Probabilistic Plume Model. D'Andrea, Fabio; Gentine, Pierre; Betts, Alan K.; Lintner, Benjamin R. // Journal of the Atmospheric Sciences;Nov2014, Vol. 71 Issue 11, p3881 

    A model unifying the representation of the planetary boundary layer and dry, shallow, and deep convection, the probabilistic plume model (PPM), is presented. Its capacity to reproduce the triggering of deep convection over land is analyzed in detail. The model accurately reproduces the timing of...

  • Air-mass Origin in the Arctic. Part II: Response to Increases in Greenhouse Gases. Orbe, Clara; Newman, Paul A.; Waugh, Darryn W.; Holzer, Mark; Oman, Luke D.; Li, Feng; Polvani, Lorenzo M. // Journal of Climate;Dec2015, Vol. 28 Issue 23, p9105 

    Future changes in transport from Northern Hemisphere (NH) midlatitudes into the Arctic are examined using rigorously defined air-mass fractions that partition air in the Arctic according to where it last had contact with the planetary boundary layer (PBL). Boreal winter (December-February) and...

  • Hygroscopicity of the submicrometer aerosol at the high-alpine site Jungfraujoch, 3580m a.s.l., Switzerland. Sjogren, S.; Gysel, M.; Weingartner, E.; Alfarra, M. R.; Duplissy, J.; Cozic, J.; Crosier, J.; Coe, H.; Baltensperger, U. // Atmospheric Chemistry & Physics Discussions;2007, Vol. 7 Issue 5, p13699 

    Data from measurements of hygroscopic growth of submicrometer aerosol with a hygroscopicity tandem differential mobility analyzer (HTDMA) during four campaigns at the high alpine research station Jungfraujoch, Switzerland, are presented. The campaigns took place during the years 2000, 2002, 2004...

  • Explicit Numerical Diffusion in the WRF Model. Knievel, Jason C.; Bryan, George H.; Hacker, Joshua P. // Monthly Weather Review;Nov2007, Vol. 135 Issue 11, p3808 

    Diffusion that is implicit in the odd-ordered advection schemes in early versions of the Advanced Research core of the Weather Research and Forecasting (WRF) model is sometimes insufficient to remove noise from kinematical fields. The problem is worst when grid-relative wind speeds are low and...

  • A WRF Ensemble for Improved Wind Speed Forecasts at Turbine Height. Deppe, Adam J.; Gallus, William A.; Takle, Eugene S. // Weather & Forecasting;Feb2013, Vol. 28 Issue 1, p212 

    The Weather Research and Forecasting Model (WRF) with 10-km horizontal grid spacing was used to explore improvements in wind speed forecasts at a typical wind turbine hub height (80 m). An ensemble consisting of WRF model simulations with different planetary boundary layer (PBL) schemes showed...

  • WRF-Fire: Coupled Weather-Wildland Fire Modeling with the Weather Research and Forecasting Model. Coen, Janice L.; Cameron, Marques; Michalakes, John; Patton, Edward G.; Riggan, Philip J.; Yedinak, Kara M. // Journal of Applied Meteorology & Climatology;Jan2013, Vol. 52 Issue 1, p16 

    A wildland fire-behavior module, named WRF-Fire, was integrated into the Weather Research and Forecasting (WRF) public domain numerical weather prediction model. The fire module is a surface fire-behavior model that is two-way coupled with the atmospheric model. Near-surface winds from the...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics